JP2010269908A - Post-processing device and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically recover from a fully filled condition detected erroneously. <P>SOLUTION: A post-processing device 100 performs prescribed post-processing to a plurality of sheets of paper in which an image is formed in an image forming device 10, and prepares a paper bundle. The paper bundle conveyed by a paper bundle conveying part 250 is stacked on a paper bundle stacking part 240. A paper stack monitoring part 260 detects the fully filled condition of the paper bundle. When the fully filled condition is detected, a control part 200 makes the paper bundle conveying part 250 execute retry processing for reconveying the paper bundle to the paper bundle stacking part 240. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a post-processing apparatus and an image forming system.

  The post-processing device performs various post-processing on the paper on which the image is formed in the image forming apparatus. The post-processed sheet bundle is discharged to a discharge tray of the post-processing apparatus by a discharge conveyance motor. The number of sheet bundles that can be stacked on the discharge tray varies depending on the size of the discharge tray. When the sheet bundle is detected by the sensors provided at the top and bottom of the discharge tray, the post-processing device determines that the sheet stack is full and cannot be stacked any more (hereinafter simply referred to as a full state). . When the full state is detected, the post-processing apparatus transmits an instruction to stop image formation to the image forming apparatus.

Japanese Patent Application Laid-Open No. 2004-228561 describes a technique related to a paper discharge device that automatically detects a paper stacking condition or a paper jam and reduces the monitoring burden on an operator.
Patent Document 2 describes a technology related to a packaging system that prevents collisions between products that are discharged even when the products are full at the discharge destination.

JP-A-8-81109 Japanese Patent Laid-Open No. 11-314621

  Depending on the printing method, paper type, number of sheets, and the like of the bundle of sheets discharged to the discharge tray, the sensor on the discharge tray may erroneously detect a full state. Even if the sheet bundle can still be placed on the discharge tray, the full state is detected when the sheet bundle has turned on the sensor of the discharge tray for a predetermined time for some reason.

  FIG. 7A schematically shows the discharge tray when the full state is not detected. In the example shown in FIG. 7A, the full state is detected by two sensors (discharge upper limit detection sensor SE1 and full state detection sensor SE2) above and below the discharge tray. That is, when the discharge upper limit detection sensor SE1 and the full state detection sensor SE2 detect the sheet bundle, the post-processing device determines that the discharge tray is full. The pressing member P is used to align the sheet bundle. In the example shown in FIG. 7A, the discharge upper limit detection sensor SE1 is ON, but the full state detection sensor SE2 is not ON, and the full state is not detected.

  FIG. 7B schematically shows the discharge tray when the full state is detected. In the example shown in FIG. 7B, the discharge upper limit detection sensor SE1 and the full state detection sensor SE2 are both ON, and the full state is detected. As shown in FIG. 7B, even when the discharge tray is not full, there are cases in which the full state is detected due to the sheet bundle slipping due to the inclination of the discharge tray or the overlapping state of the sheet bundle. That is, although the sheet bundle can still be stacked, the full state is detected and the image formation is stopped.

  FIG. 8A schematically shows a case where the sheet bundle is not sufficiently conveyed and the full state is erroneously detected. As shown in FIG. 8A, even when a sheet bundle is conveyed for a predetermined time by the paper discharge conveyance motor, sufficient conveyance cannot be performed due to the weight of the sheet bundle and the full state detection sensor SE2 cannot be turned off. There is a false detection.

  FIG. 8B schematically illustrates a case where the sheet bundle is weakly stopped and is erroneously detected by being caught by the most recently ejected sheet bundle. As shown in FIG. 8B, when the discharged sheet bundle is caught, the full state detection sensor SE2 cannot be turned off even if it is transported for a predetermined time by the transport motor.

FIG. 9A shows the state of each sensor when the full state detection sensor is turned off after the sheet bundle is conveyed for a predetermined time. The paper discharge sensor detects the discharge of the sheet bundle from the discharge tray. When each sensor is ON, this indicates that the sensor is detecting a sheet bundle. When each sensor is OFF, this indicates that the sensor is not detecting a sheet bundle.
As shown in FIG. 9A, in a normal state (a state that is not full), the full state detection sensor is turned OFF after the paper discharge transport motor transports the sheet bundle for a predetermined time. That is, the sheet bundle is discharged to the discharge tray, passes through the full state detection sensor, and is placed on the discharge tray.

  FIG. 9B shows a state of each sensor when the full state detection sensor once turned off after the sheet bundle is conveyed for a predetermined time is turned on again. As shown in FIG. 9B, the sheet discharge motor is driven for a predetermined time, and the sheet bundle is discharged to the discharge tray. The full state detection sensor SE2 is once turned off, but the sheet bundle is slipped off and turned on. That is, the full state is erroneously detected as shown in FIG. 7B, FIG. 8A, or FIG. 8B described above.

  As described above, even when the full state is erroneously detected, the image forming apparatus stops image formation, and therefore cannot perform efficient printing. In the technique of Patent Document 1, it is possible to automatically detect a paper stacking state or a paper jam, but there is no description about processing after a full state erroneous detection. Patent Document 2 can prevent a product from colliding even if the product is full at the discharge destination, but there is no description about means for preventing erroneous detection of a full state.

  The present invention has been made in view of the above problems, and an object thereof is to automatically recover from a misdetected full state.

In order to solve the above-mentioned problem, the invention described in claim 1
A post-processing device that creates a sheet bundle by performing predetermined post-processing on a plurality of sheets on which images have been formed,
A sheet bundle stacking unit for loading the sheet bundle;
A sheet bundle conveying unit for conveying the sheet bundle to the sheet bundle stacking unit;
A paper stack monitoring unit for detecting a full state of the paper bundle in the paper stack stacking unit;
Control for causing the sheet bundle conveyance unit to execute a retry process for conveying the sheet bundle in which the full state is detected to the sheet bundle stacking unit again when the full state is detected by the sheet stacking monitoring unit. And
It is characterized by providing.

The invention according to claim 2 is the invention according to claim 1,
The control unit causes the retry process for a predetermined time to be executed a plurality of times.

The invention according to claim 3 is the invention according to claim 2,
The post-processing device further includes a storage unit that stores an operation condition table that stores the predetermined time and the plurality of times in the retry process,
The control unit causes the sheet bundle conveyance unit to execute a retry process based on the operation condition table.

The invention according to claim 4 is the invention according to claim 2 or 3,
The predetermined time is a time based on sheet bundle information including a pattern of post-processing applied to the sheet bundle, the number of sheets included in the sheet bundle, and a paper type of the sheet bundle.

The invention according to claim 5 is the invention according to any one of claims 2 to 4,
The plurality of times is a number based on sheet bundle information including a pattern of post-processing applied to the sheet bundle, the number of sheets included in the sheet bundle, and a paper type of the sheet bundle.

The invention according to claim 6 is the invention according to any one of claims 1 to 5,
The sheet stacking monitoring unit is a sensor provided at an upper end and a lower end of the sheet bundle stacking unit.

The invention according to claim 7 is an image forming apparatus for forming an image on a sheet,
The post-processing device according to any one of claims 1 to 6, wherein a predetermined post-processing is performed on a plurality of sheets of images formed by the image forming device.
An image forming system comprising:

  According to the present invention, it is possible to automatically recover from an erroneously detected full state.

1 is a schematic cross-sectional view of an image forming system in the present embodiment. It is a control block diagram of the post-processing apparatus shown in FIG. It is a flowchart of the full state detection process performed by the control part shown in FIG. It is an example of data storage of the operation condition table memorize | stored in the memory | storage part of FIG. It is a flowchart of the retry process performed by the control part shown in FIG. It is a schematic diagram which shows the state of each sensor of the post-processing apparatus shown in FIG. It is a schematic diagram which shows the conventional discharge tray. It is a schematic diagram which shows the conventional discharge tray. It is a schematic diagram which shows the state of the sensor of the conventional post-processing apparatus.

  The configuration of the post-processing apparatus and the image forming system 1 according to the present invention will be described below with reference to the drawings.

  FIG. 1 shows an overall view of an image forming system 1 according to the present invention. As shown in FIG. 1, the image forming system 1 includes an image forming apparatus 10 and a post-processing apparatus 100.

  The image forming apparatus 10 receives job data from an external device such as a personal computer or a copy function that forms a read image of an original on a sheet as an output image, and forms a corresponding image on a sheet for output. This is a so-called digital multi-function machine including an image forming unit 20 that realizes a printer function and the like for outputting as an image. The image forming unit 20 includes a photoconductor and a charging device, and forms an image on a sheet by an electrophotographic process.

  The operation unit 30 includes a screen composed of a liquid crystal display disposed on the upper front side of the image forming apparatus 10, a touch panel provided on the screen, various input switches, and the like. The operation unit 30 accepts various input operations from the user, and an operation signal corresponding to the operation is transmitted to the CPU of the image forming apparatus.

  The operation unit 30 also performs various settings related to the job, for example, the size of the paper on which image formation is performed (for example, the total length and the full width ascertained from the paper size standards such as A4 and B5), the print mode (for example, duplex printing) Mode / single-sided printing mode), the type of post-processing to be performed on the paper (for example, stapling or shifting), and the like can be input.

  The post-processing apparatus 100 includes a carry-in unit 101, a paper feed tray SP, discharge trays T1 and T2, a stack unit 140, and the like, and executes various post-processings on the paper discharged from the image forming apparatus 10. Post-processing conditions and the like are determined based on job data transmitted from the image forming apparatus 10. The job data includes the mode that is the content of post-processing (tri-fold, middle fold, etc.), the amount of sheets, the number of sheets included in the sheet bundle, and the like.

  The carry-in unit 101 includes a conveyance roller 102, a sheet passage detection sensor 103, a conveyance path switching plate 104, a staying unit 105, a conveyance roller 106, and the like.

  The transport roller 102 carries the paper discharged from the image forming apparatus 10 into the post-processing device 100 and carries it out toward the paper passage detection sensor 103.

  The sheet passage detection sensor 103 outputs an ON / OFF signal to the control unit 200 described later when the sheet conveyed by the conveyance roller 102 passes. By receiving this signal, the control unit 200 detects that a sheet has been carried into the post-processing apparatus 100.

  The transport path switching plate 104 switches the transport path so that the paper that has passed through the paper passage detection sensor 103 passes through either the staying portion 105 or the transport roller 106.

  The staying unit 105 superimposes the paper in the transport direction by shifting the front and rear positions of the transported paper.

  The conveyance roller 106 conveys the sheet without causing the staying unit 105 to retain the sheet.

  The sheet feed tray SP is a tray for introducing slip sheets such as a cover sheet and an insertion sheet, and is conveyed to the conveyance roller 102 via the conveyance rollers 107 to 109.

  The switching gate 110 selectively drives one of three paper conveyance paths, that is, a conveyance path to the discharge tray T1, a conveyance path to the shift unit 120, and a conveyance path to the stack unit 140 by driving a solenoid (not shown). It is branched to.

  The discharge tray T1 is for stacking sheets not subjected to post-processing. The discharge tray T1 sequentially stacks sheets when simple discharge (indicating that no post-processing is performed) is set in the job data.

  The shift unit 120 performs a shift process for changing the paper discharge direction to a direction orthogonal to the paper transport direction every predetermined number of sheets.

  The discharge tray T <b> 2 is for stacking sheets that have been shifted by the shift unit 120 and sheets that have been bound by the binding unit 130. The discharge tray T2 includes a full state detection sensor 150 and a discharge upper limit detection sensor 160. The full state detection sensor 150 and the discharge upper limit detection sensor 160 are configured by a photodiode or the like, detect whether or not there is a sheet bundle on the sensor, and transmit a corresponding signal to the control unit 200.

  The stack unit 140 includes a carry-in roller 141, a paper carry-in detection sensor 142, a stacker 143, a rewind paddle 144, and the like.

  The carry-in roller 141 is a roller that carries the paper into the stacker 143 when the conveyance path to the stack unit 140 is selected by the switching gate 110.

  The paper carry-in detection sensor 142 is a sensor that outputs an ON / OFF signal to the control unit 200 when the paper conveyed to the carry-in roller 141 passes. By receiving this signal, the control unit 200 detects that a sheet has been carried into the stacker 143.

The stacker 143 includes an inclined portion 143a, a stopper 143b, and the like, and stacks a plurality of sheets carried by the carry-in roller 141 in a state of being bundled and aligned.
The inclined portion 143a has an inclined surface, receives the paper carried from the carry-in roller 141 on the inclined surface, and places the stationary paper on the stopper 143b.
The stopper 143b stops the paper sliding down by the inclined portion 143a, and stacks a plurality of sheets together with the inclined portion 143a.

  The binding unit 130 performs a stapling process on a plurality of sheets stacked on the stacker 143 by placing a binding needle at one location or two locations in the vicinity of the side edge piece. The plurality of sheets subjected to the stapling process are transported as a sheet bundle by a transport belt 145a operated by the control of the paper discharge transport motor 145, and discharged to the discharge tray T2. The paper discharge sensor 146 is a sensor for detecting discharge of the sheet bundle to the discharge tray T2, and outputs an ON / OFF signal to the control unit 200 when the sheet bundle passes through the sensor.

(Control structure of image forming system)
FIG. 2 shows a control block diagram of the post-processing apparatus 100.

  The control unit 200 is mainly configured by a CPU, and in cooperation with a program stored in the storage unit 270, the control unit 200 includes a sheet transport and various post-processes by the post-processing apparatus 100, and a sheet bundle discharge process. Control the whole.

  The RAM 210 functions as a work area for temporarily developing programs and various data stored in the storage unit 270. The RAM 210 stores the number of retries when a retry process is executed in a full state detection process described later.

  The time measuring unit 220 generates a timer necessary for controlling each unit of the post-processing apparatus 100. This timer serves as a time reference for each sensor and is output to the control unit 200.

  The paper processing unit 230 is a binding unit 130, a stacker 143, or the like, and performs post-processing on the paper discharged from the image forming apparatus 10.

  The sheet bundle stacking unit 240 is a discharge tray T1 and T2, and stacks the sheet bundle discharged after the post-processing.

  The sheet bundle conveyance unit 250 is a sheet discharge conveyance motor 145, a sheet discharge sensor 146, and the like, and conveys a sheet bundle subjected to post-processing.

  The paper stack monitoring unit 260 includes a full state detection sensor 150, a discharge upper limit detection sensor 160, and the like, and detects whether or not a paper bundle stacked on the paper bundle stacking unit 240 is full.

  The storage unit 270 includes a nonvolatile memory such as an HDD, and stores an operation condition table TB1 used in the full state detection process, such as a control program and various data for operating each unit of the post-processing device 100. Further, the sheet bundle information included in the job data transmitted from the image forming apparatus 10 is stored. The sheet bundle information may be stored in the RAM 210.

Next, the operation of the post-processing apparatus 100 will be described.
FIG. 3 shows a flowchart of the full state detection process executed in the post-processing apparatus 100 in the present embodiment. The full state detection process is executed in cooperation with the control unit 200 and a program stored in the storage unit 270.

First, it is determined whether or not the full state detection sensor 150 is OFF (step S1). If it is determined that it is OFF (step S1; YES), the process returns to step S1, and it is determined again whether or not the full state detection sensor 150 is OFF.
When it is not determined to be OFF (step S1; NO), the operation condition table TB1 stored in the storage unit 270 is read (step S2).

  FIG. 4A shows an example of the operation condition table TB1 stored in the storage unit 270. As shown in FIG. 4A, the operation condition table TB1 includes a “mode” field, a “weight” field, a “number in bundle” field, a “first time” field, a “Wait1-2” field, and a “second time”. A field, a “Wait2-3” field, a “third time” field, and the like.

  The “mode” field, the “weight” field, and the “number in bundle” are the mode, the weight, and the number in bundle, respectively, included in the job data. The “first time” field is a condition for the first retry process executed after the full state is detected. “RT1” specifies a time for turning on the paper discharge motor 145, and “Dir” indicates a discharge time. The driving direction of the paper transport motor 145 is designated. The drive direction is the direction of rotation of the paper discharge transport motor 145. The drive direction “CW” indicates that the discharge conveyance motor 145 is driven in the direction of discharging the sheet bundle, and “CCW” in the other operation condition table in FIG. This indicates that the paper discharge transport motor 145 is driven in the direction opposite to the direction in which the bundle is discharged.

  The “Wait1-2” field is a time difference (referred to as t1) between the end of driving of the discharge conveyance motor 145 in the first retry process and the start of driving of the discharge conveyance motor 145 in the second retry process. The “second time” field is a condition for the second retry process executed after the full state is detected. The “Wait2-3” field is a time difference (denoted by t2) between the end of driving of the paper discharge transport motor 145 in the second retry process and the start of driving in the third retry process. The “third time” field is a condition for the third retry process executed after the full state is detected.

  In the data storage example shown in FIG. 4A, when the mode of the job for which post-processing is executed in the post-processing apparatus 100 is “tri-fold”, the wrinkle amount is “70”, and the number of sheets in the bundle is “2”. The first retry indicates that the discharge conveyance motor 145 is driven “800 (ms)” in “CW” (ie, forward direction). The same applies to other data, and retry conditions corresponding to jobs for which post-processing is executed are stored.

  FIG. 4B shows another example of the operation condition table TB1 stored in the storage unit 270. As shown in FIG. 4B, the operating condition table TB1 stores “CCW” in “Dir”. In this case, the sheet discharge motor 145 is driven in the direction opposite to the discharge direction.

  Returning to FIG. 3, the retry number N, which is a counter variable, is created in the RAM 210, and 0 is substituted for the retry number N (step S3). A retry process is executed based on the job data being post-processed and the operation conditions in the operation condition table TB1 read in step S2 (step S4).

FIG. 5 shows a flowchart of the retry process executed in step S4.
First, as shown in FIG. 5, the retry count N stored in the RAM 210 is acquired (step S41). Next, a retry timer RTn is stored (set) in the RAM 210 based on the retry count N (step S42). Specifically, a record in which the contents of the job data match the value stored in the field of the operation condition table TB1 (hereinafter referred to as “match record”) is referred to, and “N + 1” (“N” is the retry count “N”). The retry timer RTn is set by referring to “RTN” in the field.

  Next, the retry count N is incremented by 1 (step S43). Based on the operation condition table TB1, the rotation direction of the paper discharge motor 145 in the N-th retry process is designated, and the paper discharge motor 145 is turned on (step S44). As described above, the rotation direction of the discharge conveyance motor 145 is designated by referring to “Dir” of the “Nth” field in the matching record of the operation condition table TB1.

  Returning to FIG. 3, it is determined whether or not the full state detection sensor 150 is OFF (step S5). If it is determined that it is OFF (step S5; YES), the paper delivery motor 145 is turned OFF (step S6), and the process returns to step S1.

If it is not determined that it is OFF (step S5; NO), it is determined whether or not the retry timer RTn has been counted up (step S7).
If it is not determined that the count has been incremented (step S5; NO), the process returns to step S5, and it is determined again whether or not the full state detection sensor 150 is OFF.

  If it is determined that the count has been incremented (step S7; YES), the paper discharge transport motor 145 is turned off (step S8). It is determined whether or not the upper limit of the number of retries is reached (step S9). Specifically, it is determined whether or not the retry count N stored in the RAM 210 is an upper limit value (3 times in the example shown in FIG. 4) of the retry count corresponding to the operation condition table TB1. The upper limit value may be determined in advance in the storage unit 270 or the like.

When it is determined that the upper limit is reached (step S9; YES), the operation unit 30 is notified that it is full (step S10), and the process ends.
If it is not determined that the upper limit is reached (step S9; NO), the retry start timer tn is stored (set) in the RAM 210 (step S11). Specifically, the matching record tN (“N” of tN matches the retry count N) is set.

  Next, it is determined whether or not the retry start timer tn has been counted up (step S12). When it is not determined that the count has been incremented (step S12; NO), the process returns to step S12 again, and it is determined whether or not the retry start timer tn has been incremented.

  If it is determined that the count is up (step S12; YES), the retry process shown in FIG. 5 is executed again (step S13), the process returns to step S5, and whether or not the full state detection sensor 150 is OFF again. Is judged.

  FIG. 6A schematically shows the state of each sensor when the full state detection process is executed. In FIGS. 6A to 6C, it is assumed that the discharge upper limit detection sensor 160 is ON. As shown in FIG. 6A, when the paper discharge sensor 146 is OFF and the full state detection sensor 150 is ON, the control unit 200 determines that the discharge tray T2 is full. To do. In this case, a retry process is executed in step S4, the paper discharge motor 145 is turned on, and the retry process is started. When the sheet discharge motor 145 is ON for T, the sheet bundle is discharged to the discharge tray T2. When the sheet discharge motor 145 is ON during RT1, RT2, and RT3, it corresponds to the first to third retry processing, respectively.

  FIG. 6B shows a case where the full state detection sensor 150 is not turned OFF even if the retry process is repeated a predetermined number of times. In this case, a full state notification is made in step S9.

  FIG. 6C shows the state of each sensor and the rotation direction of the paper discharge transport motor 145 when the rotation direction of the paper discharge transport motor 145 is designated. As shown in FIG. 6C, the rotation direction of the paper discharge transport motor 145 is controlled so as to coincide with the value specified in the operation condition table TB1.

  As described above, according to the post-processing apparatus in the present embodiment, when the full state of the paper bundle is detected by the full state detection process, the paper delivery motor is rotated and the paper bundle is conveyed again by the retry process. be able to. Since the sheet bundle touching the full state detection sensor is transported, even if the full state is erroneously detected, it is possible to recover from the full state detection state by retry processing. For example, even when a full state is erroneously detected as shown in FIGS. 7B, 8A, and 8B, by rotating the paper discharge conveyance motor by retry processing, It is possible to automatically recover from the misdetected full state.

  Further, by storing the operation conditions of the retry process in the operation condition table, the retry process corresponding to the post-process can be executed, and the recovery efficiency can be improved. For example, the recovery efficiency can be further improved by determining the operation condition based on the post-processing pattern, the number of sheets included in the sheet bundle, and the sheet type.

  Note that the description in this embodiment described above is an example of a suitable post-processing apparatus according to the present invention, and the present invention is not limited to this. For example, the retry operation condition stored in the operation condition table is three times, but may be any number of times, for example, the number of retries may be different depending on the contents of post-processing.

  Further, the full state is detected when both the full state detection sensor and the discharge upper limit detection sensor are ON. However, the detection method is not limited to this as long as it is a predetermined detection method. For example, the full state may be detected by one sensor provided in the discharge tray.

  As other computer-readable media other than the ROM in the present embodiment, non-volatile memory such as a flash memory such as an SD (Secure Digital) card or USB (Universal Serial Bus) memory, a CD-ROM or the like is possible. A portable recording medium can be applied. It is also possible to provide various data such as program data and audio data according to the present invention over a carrier wave via a communication line.

  In addition, the detailed operation of the image forming system can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Image forming system 10 Image forming apparatus 20 Image forming part 30 Operation part 100 Post-processing apparatus 101 Carry-in part 102 Conveyance roller 103 Paper passage detection sensor 104 Conveyance path switching plate 105 Stay part 106 Conveyance roller 107 Conveyance roller 108 Conveyance roller 109 Conveyance roller 110 Switching gate 120 Shift section 130 Binding section 140 Stack section 141 Carry-in roller 142 Paper carry-in detection sensor 143 Stacker 143a Inclined section 143b Stopper 144 Rewind paddle 145 Paper discharge transport motor 145a Transport belt 146 Paper discharge sensor 150 Full state detection sensor 160 Ejection Paper upper limit detection sensor SP Paper feed tray T1 Discharge tray T2 Discharge tray

Claims (7)

A post-processing device that creates a sheet bundle by performing predetermined post-processing on a plurality of sheets on which images have been formed,
A sheet bundle stacking unit for loading the sheet bundle;
A sheet bundle conveying unit for conveying the sheet bundle to the sheet bundle stacking unit;
A paper stack monitoring unit for detecting a full state of the paper bundle in the paper stack stacking unit;
Control for causing the sheet bundle conveyance unit to execute a retry process for conveying the sheet bundle in which the full state is detected to the sheet bundle stacking unit again when the full state is detected by the sheet stacking monitoring unit. And
A post-processing device comprising:   The post-processing apparatus according to claim 1, wherein the control unit causes the retry process for a predetermined time to be executed a plurality of times. The post-processing device further includes a storage unit that stores an operation condition table that stores the predetermined time and the plurality of times in the retry process,
The post-processing apparatus according to claim 2, wherein the control unit causes the sheet bundle conveyance unit to execute a retry process based on the operation condition table.   3. The predetermined time is a time based on sheet bundle information including a pattern of post-processing applied to a sheet bundle, the number of sheets included in the sheet bundle, and a paper type of the sheet bundle. 3. A post-processing apparatus according to 3.   3. The plurality of times is a number based on paper bundle information including a pattern of post-processing applied to the paper bundle, the number of sheets contained in the paper bundle, and a paper type of the paper bundle. The post-processing apparatus according to any one of 4.   The post-processing apparatus according to claim 1, wherein the sheet stacking monitoring unit is a sensor provided at an upper end and a lower end of the sheet bundle stacking unit. An image forming apparatus for forming an image on paper;
The post-processing device according to any one of claims 1 to 6, wherein a predetermined post-processing is performed on a plurality of sheets of images formed by the image forming device.
An image forming system comprising:

Images