Sheet stacking apparatus, image forming system, and information processing apparatus

Abstract

A sheet stacking apparatus (100) includes a transfer unit (512, 513, 514), a discharge unit (515), a stacking unit (751) that stacks sheets being discharged by the discharge unit, and a control unit (636) that stops a stacking operation of the sheets to the stacking unit in accordance with an amount of sheets stacked on the stacking unit. The control unit stops a stacking operation of the sheets on the stacking unit in response to a first amount of sheets being stacked on the stacking unit in a case where the sheets having no perforations provided thereon are stacked on the stacking unit, and in a case where the sheets having the perforations provided thereon are stacked on the stacking unit, stopping a stacking operation of the sheets on the stacking unit in response to stacking an amount of sheets smaller than the first amount on the stacking unit.

Description

Technical Field

[0001] The present invention relates to a sheet stacking device for stacking sheets that have been subjected to a process for forming perforations on the sheets being conveyed, and an image forming system and an information processing apparatus equipped with the sheet stacking device. Background Art

[0002] Hitherto, a sheet processing apparatus is known that forms perforations on a sheet being discharged from an image forming apparatus (refer to, for example, "Patent Document 1"). The sheet processing apparatus disclosed in Patent Document 1 conveys the sheet having perforations formed therein toward the downstream side and conveys it to a finisher. Hitherto, a finisher is known that is equipped with a stacking tray for stacking sheets (refer to, for example, "Patent Document 2"), and also according to the apparatus disclosed in Patent Document 1, sheets having perforations provided thereon are stacked on the stacking tray.

[0003] [Citation list]

[0004] [Patent Document]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-206420

[0006] [Patent Document 2] Japanese Patent No. 5825914 Summary of the invention

[0007] [Technical issues]

[0008] In order to form perforations on a sheet, a plurality of tiny perforation holes or slits are formed approximately in a straight line with intervals therebetween in a direction orthogonal to the sheet conveying direction, but unlike a punching process (so-called perforation), the portion where the perforation holes are formed is not cut off, and a protrusion such as a burr or a flash is formed in the thickness direction of the sheet around each of the holes constituting the perforations.

[0009] If a plurality of sheets that have been subjected to the punching process and have the above-described convex portions formed thereon by the punching are stacked on a stacking tray of a finisher, the region where the convex portions are formed rises, and the stacking state deteriorates.

[0010] [Solution to the problem]

[0011] According to one aspect of the present invention, a sheet stacking device includes: a conveying unit, which is configured to convey sheets in a predetermined conveying direction; a discharge unit, which is configured to discharge sheets conveyed by the conveying unit; a stacking unit, which is configured to stack sheets discharged from the discharge unit; and a control unit, which is configured to stop the stacking operation of sheets on the stacking unit according to the amount of sheets stacked on the stacking unit, wherein the control unit is configured to stop the stacking operation of sheets on the stacking unit in response to a first amount of sheets being stacked on the stacking unit when sheets without perforations provided thereon are stacked on the stacking unit, and to stop the stacking operation of sheets on the stacking unit in response to an amount of sheets less than the first amount being stacked on the stacking unit when sheets with perforations provided thereon are stacked on the stacking unit.

[0012] According to one aspect of the present invention, an information processing device includes: a memory configured to store a control program, the control program configured to control the stacking operation of sheets on a stacking device, sheets that have been subjected to a perforation process by a perforating device and sheets that have been transmitted from an image forming device and have not been subjected to the perforation process by the perforating device are stacked on the stacking device; and a processor configured to execute the control program, wherein, in a state in which the program is executed by the processor, in a case where sheets that have been subjected to a predetermined perforation process are stacked on the stacking device, the processor is configured to stop the stacking of sheets on the stacking device based on the number of stacked sheets that is smaller than an upper limit of the number of stacked sheets in a case in which predetermined sheets that have not yet been subjected to a perforation process are stacked on the stacking device.

[0013] According to one aspect of the present invention, regarding a sheet stacking device, sheets sent from an upstream device in a sheet conveying direction are stacked on the sheet stacking device, and the sheet stacking device includes: a conveying unit, the conveying unit being configured to convey the sheets sent from the upstream device; a discharging unit, the discharging unit being configured to discharge the sheets being conveyed by the conveying unit; a stacking unit, the stacking unit being configured to stack the sheets being discharged from the discharging unit; and a control unit, the control unit being configured to obtain perforation existence information of the sheets stacked on the stacking unit from the upstream device, and control the discharging unit so that the upper limit of the number of stacked sheets of the sheets being stacked on the stacking unit is changed, wherein, in a case where a predetermined sheet identified as having a predetermined perforation provided thereto is stacked on the stacking unit, the control unit is configured to control the discharging unit to stop the stacking of the sheets on the stacking unit based on the number of stacked sheets that is smaller than the upper limit of the number of stacked sheets of the predetermined sheet identified as not having the predetermined perforation provided thereto.

[0014] [Advantageous Effects of the Invention]

[0015] According to the present invention, in a sheet stacking device for stacking sheets in which perforations are formed, alignment characteristics of stacked sheets can be improved.

[0016] Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.In the accompanying drawings, the same or similar configurations are denoted by the same reference numerals. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a cross-sectional view illustrating the configuration of a sheet processing apparatus and an image forming apparatus equipped with a sheet stacking apparatus according to the present invention.

[0018] Figure 2 is a block diagram illustrating a configuration of a control system of a sheet processing apparatus and an image forming apparatus equipped with a sheet stacking apparatus according to the present invention.

[0019] Figure 3 is a cross-sectional view of the configuration of the sheet processing apparatus.

[0020] Figure 4 It is a block diagram showing the configuration of a control system of a sheet processing apparatus.

[0021] Figure 5 This is a side view showing the sheet processing apparatus from the downstream side in the conveying direction.

[0022] Fig. 6A is a perspective view of a sheet which has been provided with a treatment (ie, a perforation) in the vicinity of a central location.

[0023] Figure 6B is a perspective view of a sheet which has been provided with a treatment (ie perforations) in the vicinity of the upstream edge.

[0024] Figure 6C is a perspective view of a sheet that has been provided with treatments (ie, perforations) near a central location and near an upstream edge.

[0025] Figure 7 is a cross-sectional view of the configuration of the finisher.

[0026] Figure 8 is a block diagram of the configuration of the control system of the finisher.

[0027] Fig.9A This is a view for setting the punch type screen.

[0028] Fig. 9B This is a view of the screen used to set the position of a single punch hole.

[0029] Fig. 9C This is a view of the screen for setting the position of the double perforation.

[0030] Fig. 10A is a cross-sectional view of a state in which sheets that have not yet been subjected to a punching process are stacked on a stack tray of a finisher.

[0031] Fig. 10B is a cross-sectional view of a state in which thin paper that has been subjected to a punching process is stacked on a stacking tray of a finisher.

[0032] Fig. 10C is a cross-sectional view of a state in which thick paper that has been subjected to a punching process is stacked on a stack tray of a finisher.

[0033] Fig.11 is an explanatory diagram of the upper limit of the number of stacked sheets according to the perforation pattern.

[0034] Fig.12 This is a flowchart of the flow of printing processing.

[0035] Fig.13 It is a flowchart of the flow of the determination process of the upper limit of the number of stacked sheets. DETAILED DESCRIPTION

[0036] Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0037] like Figure 1 As shown in , the image forming system 1 includes an image forming apparatus 600, a sheet processing apparatus 200 arranged adjacent to a side surface of a main body of the image forming apparatus, and a finisher 100 serving as a sheet stacking apparatus arranged adjacent to an opposite side of the sheet processing apparatus from the image forming apparatus 600.

[0038] The image forming apparatus 600 includes a document feeder 650 and an operation unit 601, in which a document fed by the document feeder 650 is read and an image is formed on photosensitive drums 914a to 914d. The position where the user faces the operation unit 601 to enter various inputs and settings of the image forming apparatus 600 is referred to as the front direction of the front side of the image forming system 1, hereinafter referred to as the "front direction", and the back side of the apparatus is referred to as the rear direction.

[0039] The toner images of four colors, namely yellow, magenta, cyan and black, are transferred to the sheets supplied from the sheet cassettes 909a and 909b in the image forming apparatus 600 by the photosensitive drums 914a to 914d serving as image bearing members. The photosensitive drums 914a to 914d constitute image forming units for forming toner images on sheets, respectively. The toner images are conveyed to the fixing unit 904 where the toner images are fixed, and if the single-sided image forming mode is selected, the sheets are discharged to the outside of the image forming apparatus 600 by the sheet discharge roller 907 in this state. In the double-sided image forming mode, the sheets are conveyed from the fixing unit 904 to the reverse conveying roller 905. Then, when the trailing edge of the sheet in the conveying direction moves beyond the reverse baffle 3, the reverse conveying roller 905 rotates in the reverse direction. Thus, the sheets are conveyed in the direction of the double-sided conveying rollers 906a to 906f, which is the opposite direction to the sheet conveying direction.

[0040] Then, the four color toner images are transferred again from the yellow, magenta, cyan and black photosensitive drums 914a to 914d to the back surface side of the sheet. The sheet with the toner images transferred to its two surfaces is again conveyed to the fixing unit 904 where the toner images are fixed, and then discharged to the outside of the image forming apparatus 600 by the sheet discharge roller 907.

[0041] The sheet processing apparatus 200 conveys the sheet discharged by the sheet discharge roller 907 of the image forming apparatus 600 toward the finisher 100 , and also subjects the sheet to a punch hole forming process described later in the middle of the conveyance.

[0042] The finisher 100 receives sheets discharged from the sheet processing device 200 used as a punching processing device, and discharges the sheets onto the lower stacking tray 750 or the upper stacking tray 751, but based on the user's setting, the sheets can also be discharged onto the lower stacking tray 750 after subjecting the sheets to post-processing (such as binding processing or stack alignment).

[0043] The sheet discharged from the image forming apparatus 600 can be processed by the sheet processing apparatus 200 and the finisher 100 connected in line. In addition, the image forming apparatus 600 can be used alone without connecting the sheet processing apparatus 200 to the sheet discharge port 9. The image forming apparatus 600 can have the sheet processing apparatus 200 and the finisher 100 integrally assembled as a sheet discharge apparatus. In addition, the image forming apparatus 600 is not limited to the image forming apparatus body that performs the color image formation described above, and it can be a monochrome image forming apparatus body.

[0044] Figure 2 1 is a block diagram illustrating the configuration of the control unit 4 that controls the image forming system 1. Figure 2 6, a CPU (Central Processing Unit) circuit unit 630 includes a CPU 629, a ROM (Read Only Memory) 631, and a RAM (Random Access Memory) 655. The CPU circuit unit 630 controls a document feeder control unit 632, an image reader control unit 633, an image signal control unit 634, a printer control unit 635, a finisher control unit 636, a sheet processing control unit 638, and an external interface 637. The CPU circuit unit 630 performs control based on a program stored in the ROM 631 and a setting of the operation unit 601. The document feeder control unit 632 controls the document feeder 650. The image reader control unit 633 controls the image reader 5.

[0045] The printer control unit 635 controls the image forming apparatus 600. The sheet processing control unit 638 controls the Figure 3 The sheet processing apparatus 200 serving as a sheet processing unit performs predetermined processing on a sheet conveyed by a conveying roller pair 211 serving as a sheet conveying unit shown in FIG.

[0046] The finisher control unit 636 controls the finisher 100. In the present embodiment, the configuration in which the sheet processing control unit 638 is disposed in the sheet processing apparatus 200 and the finisher control unit 636 is disposed in the finisher 100 is described.

[0047] The present invention is not limited thereto, and the sheet processing control unit 638 or the finisher control unit 636 may be disposed integrally with the CPU circuit unit 630 in the image forming apparatus 600, and the sheet processing apparatus 200 and the finisher 100 may be controlled from the image forming apparatus 600 side. In addition, the finisher control unit 636 communicates with the image forming apparatus 600 and acquires post-processing information entered by the operator.

[0048] The RAM 655 can be used as an area for temporarily holding control data, or as a work area for arithmetic operations accompanying control. The external interface 637 is an interface with the personal computer (PC) 620, and expands the print data into an image and outputs it to the image signal control unit 634. The image read by the image sensor 5a is output from the image reader control unit 633 to the image signal control unit 634. Then, the image output from the image signal control unit 634 to the printer control unit 635 is recorded in the exposure control unit not shown, which controls the laser scanner 10 used as the image exposure unit.

[0049] The sheet processing control unit 638 is disposed in the sheet processing apparatus 200, and performs overall drive control of the sheet processing apparatus 200 by transmitting information with the CPU circuit unit 630 of the image forming system 1. The finisher control unit 636 is disposed in the finisher 100, and performs overall drive control of the finisher 100 by transmitting information with the CPU circuit unit 630 of the image forming system 1. The sheet processing control unit 638 and the finisher control unit 636 control various motors and sensors provided in the image forming system 1.

[0050] Next, we will refer to Figure 3 and Figure 5 Describe a sheet handling device. Figure 3 As shown in , the sheet processing device 200 includes a housing 271 supported by casters 270, and a sheet processing path 6 extending in the horizontal direction is arranged in the housing 271. A processing unit 8 is arranged midway in the sheet processing path 6, and the processing unit 8 includes a sheet processing unit 220 that performs a perforation forming process for forming perforations, and a transverse direction-skew registration correction unit (hereinafter referred to as a transverse registration skew correction unit) 250 arranged adjacently on the downstream side of the sheet processing unit 220. A plurality of conveying roller pairs 202, 208, 209, 210, and 211 are arranged along the sheet processing path 6 on the upstream side of the sheet processing unit 220, and each conveying roller is configured so that, in the example of the conveying roller pair 211, a driving (i.e., active) roller 211a is arranged on the lower side of the sheet processing path 6, and a driven roller 211b is arranged on the upper side in contact with the driving roller 211a. The driving rollers of these conveying rollers are driven by a motor M25. In addition, the entrance portion of the sheet processing path 6 is deployed in a manner aligned with the sheet discharge port 9 of the image forming device 600, and an entrance sensor 201 is deployed to detect sheets entering the sheet processing path 6 from the sheet discharge port 9, and a sheet edge detection sensor 213 and a unit identification sensor 222 are arranged on the entrance side of the processing unit 8.

[0051] Along the sheet processing path 6 on the downstream side of the lateral registration skew correction unit 250, similarly to the upstream side thereof, a plurality of conveying roller pairs 214, 215, 216, and 206 are arranged, and a sheet discharge sensor 207 is arranged at its sheet discharge port. The sheet discharge port of the sheet processing path 6 is aligned with the sheet path entrance portion of the finisher 100. The driving rollers of the downstream side conveying roller pairs 214, 215, 216, and 206 are driven by a motor M26.

[0052] like Figure 5 As shown in , the sheet processing unit 220 includes a punch plate 225, and shaft guides 228a and 228b are erected at edge portions of the punch plate 225 in the front and rear directions, wherein the punching forming blade 404 is movably supported in the up-down direction on the shaft guides.

[0053] like Figure 3 As shown in , a pressing drive unit 280 is arranged above the sheet processing unit 220. The pressing drive unit 280 includes a cam driving motor M21, and an eccentric cam 282 driven by the cam driving motor M21. The eccentric cam 282 is eccentrically rotated by a cam shaft 281 and presses the perforation forming blade 404. In addition, the perforation forming blade can adopt various shapes, such as a rotary cutter configuration.

[0054] Next, the operation of the sheet processing apparatus 200 described above will be described. The sheet processing apparatus 200 sequentially takes in sheets discharged through the sheet discharge port 9 of the image forming apparatus 600. Sheet processing in the sheet processing apparatus 200 is operated according to the setting performed by the user through the operation unit 601 disposed on the image forming apparatus 600. The sheet discharged through the sheet discharge port 9 of the image forming apparatus 600 is conveyed to the conveying roller pair 202 of the sheet processing apparatus 200. In this state, the conveying timing of the sheet is detected by the entrance sensor 201 at the same time. The sheet is conveyed to the processing unit 8 by the conveying roller pairs 208 to 211. Then, the sheet passes through Figure 3 and Figure 5 The conveying path 232 of the sheet processing unit 220 is shown in FIG.

[0055] The sheet having passed through the conveying path 232 stops when it reaches a predetermined position in the sheet conveying direction, and the sheet is subjected to a perforation forming process in the sheet width direction orthogonal to the sheet conveying direction by the processing unit 8. Perforations according to the present specification refer to a row of slits (formed in plural with intervals therebetween) along a straight line from a first end to a plurality of ends in the sheet width direction, or a series of a plurality of fine punched holes, and perforations formed by a single operation of a perforation processing mechanism described below is defined as a row of perforations.

[0056] FIG. 6A to FIG. 6CEach is a perspective view of a sheet that has been processed (ie, punched) by a sheet processing unit. Fig. 6A The diagram illustrates a state in which perforations have been formed according to a pattern in which perforations are formed at an approximate center position (i.e., center portion) of a sheet in the conveying direction (i.e., length direction) of the sheet indicated by arrow A and in a direction orthogonal to the conveying direction of the sheet (i.e., width direction) (hereinafter referred to as "center perforations"). Figure 6B The diagram shows a state where perforations have been formed in a pattern (hereinafter referred to as "single perforation") in which perforations are formed in the vicinity of the upstream edge in the conveying direction (i.e., the length direction) of the sheet indicated by arrow A (i.e., the upstream edge portion, which is 12 mm downstream from the upstream edge of the sheet according to the present embodiment) in a direction orthogonal to the conveying direction (i.e., the width direction) of the sheet. In addition, Figure 6C The diagram illustrates a state in which perforations have been formed according to a pattern in which two perforations are formed along the width direction of the sheet (hereinafter referred to as "double perforations") at two positions (at the approximate center position in the length direction of the sheet along the conveying direction of the sheet indicated by arrow A, and near the upstream edge, which according to this embodiment is a position 12 mm downstream from the upstream edge of the sheet).

[0057] The sheet subjected to the punch hole forming process by the sheet processing unit 220 is again nipped and conveyed by the conveying roller pair 211 , conveyed by the conveying roller pairs 214 to 216 and the conveying roller pair 206 , and is transferred to the finisher 100 disposed downstream.

[0058] A plurality of types of processing units having different perforation patterns are prepared in the sheet processing unit 220, and these processing units are interchangeably disposed. Identification information stored in a storage unit of an IC (Integrated Circuit; Semiconductor Integrated Circuit) chip 221 serving as a storage unit disposed in the sheet processing unit 220 is read by a unit identification sensor 222. Thus, which type of sheet processing unit 220 is disposed in the processing unit 8 is identified.

[0059] like Figure 4As shown in , the sheet processing control unit 638 includes a CPU (Central Processing Unit) 701 composed of a microcomputer. It also includes a RAM (Random Access Memory) 702 and a ROM (Read Only Memory) 703. It also includes an I / O (Input / Output) 705 used as an input / output unit, a communication interface 706, and a network interface 704. In addition, the conveying processing of the sheet is performed in the conveying control unit 707. In addition, in the sheet processing drive control unit 708, the eccentric cam 282 is controlled by the cam drive motor M21 to be rotationally driven. In the sheet processing unit identification unit 709, the type of the sheet processing unit 220 being installed is identified by reading the type information stored in the storage unit of the IC chip 221 used as a storage unit installed in the sheet processing unit 220. In addition, the skew correction of the sheet is performed in the lateral registration skew correction control unit 710.

[0060] Next, we will refer to Figure 7 The configuration of the finisher 100 is described. Figure 7 yes Figure 1 . The finisher 100 sequentially takes in sheets discharged from the sheet processing device 200, and performs various sheet post-processing, such as a process of aligning a plurality of sheets being taken in and stacking the sheets into a single stack, or a process of stapling the trailing edge of the stack of sheets being stacked. The finisher 100 takes in sheets transmitted from the sheet processing device 200 into the conveying path 520 via a conveying roller pair 511. The sheets taken in by the conveying roller pair 511 are conveyed via conveying roller pairs 512, 513, and 514 serving as conveying units. Conveying sensors 570, 571, 572, and 573 are disposed on the conveying path 520, and each of the conveying sensors 570, 571, 572, and 573 detects the passage of sheets. The conveying roller pair 512 is disposed in the shift unit 580 together with the conveying path sensor 571. The shift unit 580 can move the sheet in the sheet width direction orthogonal to the conveying direction by the shift motor M11 described below. By driving the shift motor M11 while the conveying roller pair 512 is clamping the sheet, the sheet can be offset in the sheet width direction while being conveyed. In the shift sorting mode, the position of the sheet stack is shifted per unit in the width direction. The amount of offset can be 15 mm in the front direction relative to the center position in the width direction, that is, front shift, or 15 mm in the rear direction, that is, rear shift. If there is no shift designation, the sheet is discharged at the same position as the front shift. When it is determined by the input of the conveying path sensor 571 that the sheet has passed the shift unit 580, the finisher 100 drives the shift motor M11 and returns the shift unit 580 to the center position.

[0061] A switching flapper 540 for guiding the sheet that has been reversed and conveyed by the conveying roller pair 514 to the buffer path 523 is arranged between the conveying roller pair 513 and the conveying roller pair 514. The switching flapper 540 is driven by a solenoid not shown. A buffer path roller pair 519 is arranged on the buffer path 523. A switching flapper 541 for switching the conveying destination to any one of the upper sheet discharge path 521 and the lower sheet discharge path 522 is arranged between the conveying roller pair 514 and the upper sheet discharge roller pair 515. When the switching flapper 541 is switched to the upper sheet discharge path 521 side, the sheet is guided to the upper sheet discharge path 521 by the conveying roller pair 514 driven by the conveying motor M1. Then, the sheet is discharged onto the upper stacking tray 751 by the upper sheet discharge roller pair 515 serving as a discharge unit driven by the sheet discharge motor M2. An upper tray sheet discharge sensor 574 is disposed on the upper sheet discharge path 521, which detects the passage of the sheet. When the switching flapper 541 is switched toward the lower sheet discharge path 522 side, the sheet is guided to the lower sheet discharge path 522 by the conveying roller pair 514 driven by the conveying motor M1. Then, the sheet is guided to the processing tray 530 by the first lower conveying roller pair 516, the second lower conveying roller pair 517, and the processing tray conveying roller pair 518 driven by the conveying motor M1. A first conveying sensor 575 and a second conveying sensor 576 are disposed on the lower sheet discharge path 522, which detect the passage of the sheet.

[0062] The sheets guided to the processing tray 530 are discharged to the processing tray 530 or the lower stacking tray 750 by the bundle sheet discharge roller pair 590 driven by the bundle sheet discharge motor (not shown) according to the post-processing mode. A lower tray sheet discharge sensor 577 is arranged on the processing tray 530, which detects the passage of the sheets. In addition, a stapler unit 591 is arranged on the processing tray 530, which staples the aligned sheet bundle on the processing tray 530.

[0063] The lower stacking tray 750 and the upper stacking tray 751 can be raised and lowered by the lower tray lifting motor M10 and the upper tray lifting motor M9 described below. The uppermost surface of each stacking tray or the sheet on each stacking tray is detected by the lower tray sheet surface detection sensor 720 and the upper tray sheet surface detection sensor 721. The finisher 100 performs control by driving the lower tray lifting motor M10 and the upper tray lifting motor M9 based on the detection results of the lower tray sheet surface detection sensor 720 and the upper tray sheet surface detection sensor 721 so that the distance between the uppermost surface of the sheet on each of the stacking trays or each of the stacking trays described above and the sheet discharge port of the sheet is maintained at a predetermined distance. In addition, the upper tray sheet presence detection sensor 730 and the lower tray sheet presence detection sensor 731 can detect the presence of sheets on the lower stacking tray 750 and the upper stacking tray 751.

[0064] Next, we will refer to Figure 8 414, ROM 415, input / output I / O 411, and communication interface (SCI) 413. The finisher control unit 636, which functions as a control unit, is composed of a CPU 412, a RAM 414, a ROM 415, an input / output I / O 411, and a communication interface (SCI) 413. The finisher control unit 636 communicates with the CPU circuit unit 630 to send and receive commands or exchange data such as job information and notification of sheet transport, and performs drive control of the finisher 100 by executing various programs stored in the ROM 415. In other words, the finisher control unit 636 can be regarded as an information processing device including the CPU 412 serving as a processor and the RAM 414 and ROM 415 serving as memories, wherein the ROM 415 serving as an example of a non-disposable computer-readable storage medium stores a control program for controlling a sheet stacking operation to the finisher 100 serving as a stacking device on which sheets conveyed from the image forming device 600 and not subjected to a punching process by the sheet processing device 200 serving as a punching device are stacked.

[0065] The finisher control unit 636 is used as a control unit (i.e., a perforation information acquisition unit 4123 and a grammage information acquisition unit 4122) that receives post-processing information (such as information about perforation forming processing or information about grammage) that the image forming device 600 has received from an operator from the CPU circuit unit 630. The RAM 414 is used to temporarily hold control data and is used as a work area for performing arithmetic operations accompanying control. The communication interface (SCI) 413 performs serial communication with the CPU circuit unit 630 of the image forming device 600, and transmits operation instructions and control data. The input / output I / O 411 sends an on-off signal from the CPU 412 to an output device (such as a motor), or sends a signal from an input device (such as a sensor) to the CPU 412. The conveying motor M1 and the sheet discharge motor M2 are connected to the input / output I / O 411. The lower tray alignment motor (front side) M6, the lower tray alignment motor (rear side) M7, the lower tray alignment plate lifting motor M8, the upper tray lifting motor M9, the lower tray lifting motor M10, and the shift motor M11 are also connected to the I / O 411. In addition, the upper tray sheet surface detection sensor 721, the lower tray sheet surface detection sensor 720, the upper tray sheet presence detection sensor 730, the lower tray sheet presence detection sensor 731, the upper tray sheet discharge sensor 574, and the lower tray sheet discharge sensor 577 are also connected to the I / O 411.

[0066] In addition, an upper tray drive encoder 578 and a lower tray drive encoder 579 are connected to the I / O 411. The upper tray drive encoder 578 and the lower tray drive encoder 579 each output a pulse corresponding to the movement of the lower stack tray 750 and the upper stack tray 751 which are raised and lowered accompanying the sheet surface detection operation of the sheet on each of the lower stack tray 750 and the upper stack tray 751. The CPU 412 can detect the movement amount of the lower stack tray 750 and the upper stack tray 751 by counting the pulses output from the upper tray drive encoder 578 and the lower tray drive encoder 579.

[0067] 9A to 9C Each is a view illustrating one example of an operation screen where the user can enter a punching type and position in the operation unit 601. In the image forming system 1, the user can select a plurality of types of punching processes, and the position for forming a punching hole can also be adjusted by the user within a prescribed range.

[0068] Fig.9A 2 is a view showing an example of a screen for setting a punching type. Fig.9AAs shown in FIG. 3 , a center perforation selection combo box 301, a single perforation selection combo box 302, a double perforation selection combo box 303, and a non-perforation processing (bypass) selection combo box 304 are displayed on the perforation processing selection screen 300. The user can select the type of perforation to be performed from these combo boxes.

[0069] In addition, a single punching position adjustment button 305 and a double punching position adjustment button 306 are displayed on the punching process selection screen 300, and by pressing these buttons, the display Fig. 9B The single perforation position adjustment screen 310 shown in FIG. Fig. 9C The double perforation position adjustment screen 320 shown in FIG. 3 is used to adjust the position of each perforation.

[0070] In addition, buttons such as an OK button 307 and a cancel button 308 are also displayed on the punching process selection screen 300, but since such buttons are a common user interface, the explanation thereof is omitted.

[0071] Fig. 9B 2 is a view illustrating an example of a screen for adjusting a position for forming a single perforation. Fig. 9B As shown in FIG. 6 , a single punch hole X position adjustment bar 311, an OK button 307, and a cancel button 308 are displayed on the single punch hole position adjustment screen 310. The user can input a numerical value into the single punch hole X position adjustment bar 311 through a numerical value input button (not shown) of the operation unit 601, thereby adjusting the position for forming a single punch hole within a prescribed range.

[0072] Fig. 9C 2 is a view illustrating an example of a screen for adjusting a position for forming a double perforation. Fig. 9C As shown in FIG. 6 , a double punch hole Y position adjustment bar 321, a double punch hole X position adjustment bar 322, an OK button 307, and a cancel button 308 are displayed on the double punch hole position adjustment screen 320. The user can input values ​​into the double punch hole Y position adjustment bar 321 and the double punch hole X position adjustment bar 322 through the numerical input buttons (not shown) of the operation unit 601, thereby adjusting the positions for forming the double punch holes within a prescribed range.

[0073] FIG. 10A to FIG. 10C 7 is a view illustrating a state in which sheets received by the finisher 100 from the sheet processing apparatus 200 are stacked on the upper stack tray 751. Fig. 10A As shown in , if sheets not subjected to the perforation process are stacked in multiple layers, the sheets are stacked flat so that the sheets stacked on the upper stacking tray 751 are stacked approximately parallel to the angle of the sheet contact surface of the upper stacking tray 751.

[0074] At the same time, if a punching process is performed in the sheet processing device 200, protruding portions such as burrs and flash are generated at the portions where the perforations have been formed, so that if a large number of sheets that have been subjected to the punching process are stacked on the upper stacking tray 751, the protruding portions will protrude and the sheets will not be stacked in approximately parallel on the sheet setting surface of the upper stacking tray 751.

[0075] Regarding the influence of protruding portions such as burrs and flashes caused by the perforation process on the stacked sheets, a sheet having a smaller weight per unit area and a weaker hardness (i.e., a sheet having a weight of 100 g / m 2 or less, hereinafter referred to as "thin paper") than a sheet having a larger weight per unit area and having a stronger hardness (i.e., a sheet having a weight of more than 100 g / m 2 The sheet with a grammage of 200,000 (hereinafter referred to as "thick paper") is more affected. The height of the protruding portion such as burrs and flash is not much different between thick paper and thin paper, so the above-mentioned difference is caused by the thin paper having a higher deformation rate conforming to the shape of the already stacked sheets due to the small thickness of the sheet itself, being unable to flatten the burrs due to the light weight of the sheet, and having a weak sheet hardness (i.e., having a lower rigidity). As a result, even if the number of stacked sheets of thick paper is small, the already stacked sheet bundle will be greatly distorted compared to thick paper. Fig. 10B is a view illustrating the shape of a sheet bundle that has been stacked in a case where 300 sheets of thin paper having a center perforation provided thereon are successively stacked on the upper stack tray 751, and Fig. 10C 751 is a view illustrating the shape of a sheet bundle that has been stacked in the case where 300 sheets of thick paper having a center perforation provided thereon are successively stacked on the upper stack tray 751, wherein Fig. 10B The protrusions in Fig. 10C Large, and the sheets tend to fall off.

[0076] In the finisher 100, usually, the upper limit number of sheets stackable on the lower stacking tray 750 or the upper stacking tray 751 is set to the maximum number of stackable sheets of the tray on which the sheets are to be stacked, that is, the maximum stackable amount, which is 4000 sheets according to the present embodiment. When the number of stacked sheets reaches the upper limit number, the finisher control unit 636 outputs a signal for notifying an overload to the image forming device 600, which refers to a state in which no more sheets can be stacked on the tray of the image forming device 600, hereinafter referred to as a "full load state". When receiving the overload notification from the finisher 100, the image forming device 600 temporarily stops the printing process, and operates to wait for the sheet bundle to be removed from the lower stacking tray 750 or the upper stacking tray 751. Even in the case of stacking sheets that have been perforated, if an upper limit (4000 sheets) of the number of similar stacked sheets is set, the protruding portion may protrude as described above, depending on conditions such as the shape or angle of the tray on which the sheets are stacked, and stacking failure or the falling of the subsequent sheets may occur when the subsequent sheets are stacked. The upper tray sheet surface detection sensor 721 and the lower tray sheet surface detection sensor 720 described above can detect the sheet surface of each tray, and lower the tray by driving the tray lifting motor to maintain a fixed paper surface height, wherein a full load state can be set when the tray lowering limit is reached.

[0077] Therefore, the upper limit of the number of sheets to be stacked in the case of stacking sheets that have been perforated can be changed according to the positions where the perforations have been provided and set to an appropriate number of sheets so that stacking failure of sheets and falling of sheets can be prevented.

[0078] [Setting of upper limit of number of stacked sheets]

[0079] Since the stackability of sheets on a stacking tray varies depending on the perforation pattern and sheet weight described above, reference will be made to Fig.11 The relationship between the perforation pattern and the setting of the upper limit of the number of stacked sheets is described.

[0080] like Fig.11As shown in, in the case where no perforation is performed (i.e., no perforation), the upper limit of the number of stacked sheets is set to 4000 sheets, i.e., the maximum number of stackable sheets. Whereas in the case where the perforation mode is center perforation, due to the influence of burrs and flash, the vicinity of the center position of the sheet will protrude compared with other parts, so that when subsequent sheets are stacked, the sheet will fall downstream in the conveying direction along the shape of the stacked sheet pile. Therefore, in the case where thin paper is greatly affected by burrs and flash, 300 sheets are set as the upper limit of the number of stacked sheets, and in the case of thick paper with less influence of burrs, 1000 sheets are set as the upper limit of the number of stacked sheets. In addition, in the case where the perforation mode is double perforation, the vicinity of the center position of the sheet and the vicinity of the upstream edge will protrude compared with other parts. In that case, not only one part will be extremely distorted, but also the stackable number of sheets can be increased compared with the case of center perforation. In this example, 1500 is set as the upper limit of the number of stacked sheets in the case of thin paper, and 3000 is set as the upper limit of the number of stacked sheets in the case of thick paper. In addition, in the case of a single perforation, the vicinity of the upstream edge of the sheet will protrude compared to the other portions. This embodiment is described based on a system for discharging sheets to a finisher, and the lower stack tray 750 and the upper stack tray 751 are as shown in FIG. Figure 7 and FIG. 10A to FIG. 10C As shown in the figure, the tray will have an inclination angle so that when only the vicinity of the upstream edge of the sheet rises, the sheet will have a lower probability of falling downstream in the conveying direction compared with the center perforation or the double perforation. Therefore, in this example, 2000 is set as the upper limit of the number of stacked sheets in the case of thin paper, and 3000 is set as the upper limit of the number of stacked sheets in the case of thick paper.

[0081] That is, in this embodiment, if predetermined sheets (i.e., sheets of predetermined sheet type, grammage, and size; for example, plain paper, A3 size, with a thickness of 70 g / m 2 grammage), the finisher control unit 636 stops the stacking operation of the sheets on the stacking tray according to the state that the first amount of sheets (i.e., the first upper limit of the number of stacked sheets, such as 4000 sheets described above) has been stacked on the stacking tray. In addition, if predetermined sheets (i.e., sheets of predetermined sheet type, grammage, and size; for example, plain paper, A3 size, with 70 g / m 2 gram weight), the finisher control unit 636 stops the stacking operation of the sheets on the stacking tray according to the state that a predetermined number of sheets less than the first amount (i.e., a number of sheets smaller than the first amount, such as 3000, 2000, 1500, 1000 or 300 as described above) has been stacked on the stacking tray.

[0082] The finisher 100 is a sheet stacking device on which sheets sent from an apparatus on the upstream side in the sheet conveying direction (which is the image forming apparatus 600 and the sheet processing apparatus 200 according to the present embodiment) are stacked, and includes a pair of conveying rollers 512, 513, and 514 serving as a conveying unit for conveying sheets sent from the apparatus disposed upstream, an upper sheet discharging roller pair 515 serving as a discharging unit for discharging sheets conveyed by the conveying unit, a stacking unit for stacking sheets discharged from the discharging unit, and a finisher control unit 636 serving as a control unit for controlling the discharging unit by acquiring perforation presence information of sheets stacked on the stacking unit from the upstream side apparatus and changing an upper limit of the number of stacked sheets stacked on the stacking unit. If predetermined sheets recognized as having predetermined perforations are stacked on the stacking unit, the finisher control unit 636 controls the discharging unit to stop stacking of sheets to the stacking unit based on the number of stacked sheets less than the upper limit of the number of stacked sheets of the predetermined sheets recognized as not having predetermined perforations.

[0083] In addition, predetermined sheets (i.e., sheets of predetermined sheet type, grammage, and size; for example, plain paper, A3 size, having 70 g / m 2 In the case of a sheet having a second amount of sheets smaller than the first amount (i.e., a first upper limit of the number of stacked sheets, such as 3000 in the case of thick paper and 2000 in the case of thin paper), the finisher control unit 636 stops the stacking operation of the sheets on the stacking tray according to the state that a second amount of sheets less than the first amount has been stacked on the stacking tray (i.e., a first upper limit of the number of stacked sheets, such as 3000 in the case of thick paper and 2000 in the case of thin paper). In addition, if a predetermined sheet having perforations provided at a second position (such as a center portion) different from the first position is stacked on the stacking tray (i.e., a sheet of a predetermined sheet type, grammage, and size; for example, plain paper, A3 size, having 70 g / m 2 gram weight), the finisher control unit 636 stops the stacking operation of the sheets on the stacking tray according to the state that a third amount of sheets less than the second amount (i.e., a third upper limit of the number of stacked sheets, such as 1000 in the case of thick paper and 300 in the case of thin paper) has been stacked on the stacking tray.

[0084] That is, in other words, the finisher control unit 636 causes the CPU 412 to acquire position information of punch holes on predetermined sheets to be subjected to punching processing stacked on the stacking device. In a state where the acquired punch hole positions are approximately the center in the sheet conveying direction, the CPU 412 stops stacking of sheets to the stacking unit based on the number of stacked sheets less than the upper limit of the number of stacked sheets where the positions of the punch holes of the predetermined sheets are close to the trailing edge in the sheet conveying direction.

[0085] In addition, if sheets of the first grammage (such as thick paper, A3 size, having a thickness of more than 100 g / m2) having perforations provided at specific positions by the same pattern, the same position, and the same number are stacked on the stacking tray, 2 gram weight), the finisher control unit 636 stops the stacking operation of the sheets on the stacking tray according to the state that a fourth amount of sheets less than the first amount (i.e., a fourth upper limit of the number of stacked sheets, such as 3000 and 1000) has been stacked on the stacking tray. In addition, if sheets having a second gram weight less than the first gram weight (such as thin paper, A3 size, having 100 g / m2) having perforations provided at specific positions are stacked on the stacking tray, 2 or less in grammage), the finisher control unit 636 stops the stacking operation of the sheets on the stacking tray according to the state that a fifth amount of sheets less than the fourth amount (i.e., the fifth upper limit of the number of stacked sheets, such as 2000, 1500, 300) has been stacked on the stacking tray.

[0086] In other words, the finisher control unit 636 causes the CPU 412 to acquire grammage information of the sheets subjected to the punching process stacked on the stacking device by the CPU 412. In a state where the grammage of the sheets of a predetermined size subjected to the punching process being acquired is less than a predetermined value, the CPU 412 stops stacking of the sheets on the stacking device based on the number of stacked sheets that is smaller than the upper limit of the number of stacked sheets (specifically, the upper limit of the number of stacked sheets to the stacking tray) for a case where the grammage of the sheets of the predetermined size is greater than the predetermined value.

[0087] In addition, in a state where sheets subjected to perforation are stacked on the stacking tray, the finisher control unit 636 changes the amount of sheets based on which the stacking operation of the sheets on the stacking tray is stopped according to the number of rows of perforations applied to the sheets being stacked on the stacking tray. For example, when comparing double perforations and center perforations, in the case of double perforations, the upper limit of the number of stacked sheets is 3000 sheets for thick paper and 1500 sheets for thin paper, while in the case of center perforations, the upper limit thereof is 1000 sheets for thick paper and 300 sheets for thin paper.

[0088] That is, in other words, the finisher control unit 636 causes the CPU 412 to acquire the row number information of the perforations of the sheets stacked on the stacking device. In a state where the row number of perforations of the predetermined sheet being acquired is one, the CPU 412 stops the stacking of the sheets on the stacking device based on the number of stacked sheets that is less than the upper limit of the number of stacked sheets in the case where multiple perforations are applied to the predetermined sheet.

[0089] In addition, according to the present embodiment, a stacking setting is provided that enables selection of whether to give priority to the stacking amount of sheets stacked on the lower stacking tray 750 or the upper stacking tray 751 or to give priority to their stacking accuracy. This setting can be set through the operation unit 601. That is, the finisher control unit 636 is configured to be able to execute a stacking amount priority mode and a stacking accuracy priority mode. In the stacking setting, in the case where the stacking amount priority mode (i.e., the second mode) is selected, regardless of the presence or absence of perforations, an upper limit on the number of stacked sheets of 4,000 sheets (i.e., the maximum number of stackable sheets) is set. In the case where the stacking accuracy priority mode (i.e., the first mode) is set, as described above, the upper limit on the number of stacked sheets is set according to the perforation pattern and the grammage of the sheet.

[0090] The upper limit of the number of stacked sheets described here is an upper limit number assumed to be stacked on the lower stacking tray 750 or the upper stacking tray 751 of the finisher 100 according to the present embodiment, and it is preferable to set an appropriate upper limit number according to the execution conditions such as the shape or angle of the stacking tray. The present embodiment has been described based on the shape of the stacking tray having an inclined angle decreasing toward the upstream side in the conveying direction, but even in the case of an approximately horizontal tray shape without an inclined angle, the alignment characteristics of the sheets subjected to perforation can be improved by executing the present invention.

[0091] Now, refer to Fig.12 The flowchart describes the process of printing processing performed in the image forming system 1, from conveying the sheet on which the image has been formed in the image forming device 600 to the sheet processing device 200, providing perforations to the conveyed sheet in the sheet processing device 200, discharging the perforated sheet to the finisher 100, and discharging the sheet to the upper stacking tray 751 or the lower stacking tray 750 by the finisher 100 to completing the stacking.

[0092] The printing process is achieved by the CPU 629 of the CPU circuit unit 630 in the image forming device 600 reading the program stored in the ROM 631 to the RAM 655 as needed and executing the program, the CPU 701 of the sheet processing control unit 638 in the sheet processing device 200 reading the program stored in the ROM 702 to the RAM 703 as needed and executing the program, and the CPU 412 of the finisher control unit 636 in the finisher 100 reading the program stored in the ROM 415 to the RAM 414 as needed and executing the program.

[0093] exist Fig.12 In the state where the print process (job) is started, the CPU 629 of the image forming apparatus 600 receives the registered print job (step S101).

[0094] After receiving the print job, the CPU 629 of the image forming device 600 feeds the sheets corresponding to the received print job information from the sheet boxes 909a and 909b to the image forming unit not shown, forms an image on the sheets through the image forming unit (step S102), and discharges the sheets on which the image has been formed to the sheet processing device 200.

[0095] In a state where a sheet discharged from the image forming apparatus 600 is received by the sheet processing apparatus 200 , the CPU 701 of the sheet processing apparatus 200 recognizes whether the received sheet is a sheet on which a punch hole forming process is to be executed based on the print job information (step S103 ).

[0096] If it is discriminated in step S103 that the received sheet is not a sheet to be subjected to the punch hole forming process (step S103 : NO), the CPU 701 of the sheet processing apparatus 200 discharges the sheet to the finisher 100 without executing the punch hole forming process.

[0097] Meanwhile, if it is recognized in step S103 that the received sheet is a sheet to be subjected to punch hole forming processing (step S103 : YES), the CPU 701 of the sheet processing apparatus 200 executes the punch hole forming processing (step S104 ) and discharges the sheet to the finisher 100 .

[0098] The CPU 412 of the finisher control unit 636 acquires the entered print job information (step S105), and determines the upper limit of the number of stacked sheets that can be stacked on the lower stack tray 750 or the upper stack tray 751 based on the acquired information (step S106). A method for determining the upper limit of the number of stacked sheets will be described in detail below.

[0099] Thereafter, the CPU 412 determines whether the discharge destination tray of the received sheet is the upper stack tray 751 or the lower stack tray 750 (step S107 ).

[0100] If it is determined in step S107 that the discharge destination tray is the upper stack tray 751 (step S107 : YES), the CPU 412 conveys the sheet along the upper sheet discharge path 521 and discharges the sheet onto the upper stack tray 751 (step S108 ).

[0101] Meanwhile, if it is determined in step S107 that the discharge destination tray is the lower stack tray 750 (step S107 : NO), the CPU 412 conveys the sheet along the lower sheet discharge path 522 and discharges the sheet onto the lower stack tray 750 (step S109 ).

[0102] When the discharge of the sheets to the lower stacking tray 750 or the upper stacking tray 751 is completed, the CPU 412 increments the counter of the number of stacked sheets for each tray (step S110). In this state, the stacked sheet number counter being incremented is not limited to the total sheet counter that counts the total number of sheets stacked on the lower stacking tray 750 or the upper stacking tray 751, but may also be a punched sheet counter that counts only the number of sheets subjected to the punching process, or the above two counters may be provided to count the sheets.

[0103] After incrementing the stacked sheet number counter, the CPU 412 determines whether the stacked sheet number counter has reached the upper limit of the number of stacked sheets determined in step S106 (step S111 ).

[0104] If it is determined in step S111 that the number of sheets stacked on the lower stack tray 750 or the upper stack tray 751 has reached the upper limit of the number of stacked sheets (step S111: YES), the CPU 412 notifies the image forming apparatus 600 that the lower stack tray 750 or the upper stack tray 751 is overloaded (step S112).

[0105] The image forming apparatus 600 continues to operate from the time point when the notification of the overload of the number of stacked sheets has been received until the fed sheets have been stacked on the stacking tray, and thereafter temporarily stops the image forming process. When the paper on the lower stacking tray 750 or the upper stacking tray 751 is removed and the CPU 412 recognizes that the sheet presence detection sensor 730 or 731 has turned OFF, the full load state is canceled.

[0106] At the same time, if it is determined in step S111 that the number of sheets stacked on the lower stacking tray 750 or the upper stacking tray 751 has not reached the upper limit of the number of stacked sheets (step S111: No), the CPU 412 proceeds to step S113 without notifying the image forming device 600 that the number of stacked sheets on the lower stacking tray 750 or the upper stacking tray 751 of the finisher 100 has reached an overload state.

[0107] The CPU 412 determines whether the job for all pages has been completed (step S113). If it is determined in step S113 that the job for all pages has not been completed (step S113: No), the CPU 412 returns to step S102 and continues processing to execute processing of subsequent jobs.

[0108] Meanwhile, if it is determined in step S113 that the job for all pages has been completed (step S113 : Yes), the printing process ends.

[0109] As described, according to the present embodiment, at a point in time when the number of stacked sheets being stacked on the lower stacking tray 750 or the upper stacking tray 751 has reached the upper limit of the number of stacked sheets, an overload is notified. Thus, including the case of stacking sheets subjected to perforation, the output of sheets is temporarily stopped at the most appropriate number of stacked sheets according to the sheets being stacked, so that the stacking failure and the falling of sheets described above can be prevented from occurring.

[0110] In the present embodiment, overload (i.e., whether the sheets stacked on the stacking tray have reached the upper limit of the number of stacked sheets or more) has been determined based on the count value of the stacked sheet number counter 4121 that counts the number of sheets being discharged onto the stacking tray, but, for example, it may be determined based on information on the number of sheets being output counted by the counter of the CPU circuit unit 630 of the image forming apparatus 600 or based on information on the number of sheets being received counted by the reception counter of the finisher control unit 636. In addition, the number of sheets may not be counted, and instead, control may be performed to use the height information of the lower stacking tray 750 or the upper stacking tray 751 and notify overload if the height has reached a certain reference height, or a sensor may be provided for detecting the height of the sheets stacked on the lower stacking tray 750 or the upper stacking tray 751 and determining whether the sheets have reached the upper limit of the number of stacked sheets based on the detection result of the sensor. That is, the finisher control unit 636 is configured to stop the stacking operation of the sheets on the stacking tray 750 / 751 according to the amount of sheets stacked on the stacking tray 750 / 751 used as the stacking unit. The amount of sheets stacked on the stacking tray 750 / 751 can be detected based on the count value being counted by the various counters as described above or based on the output values ​​of the various sensors.

[0111] When the image forming device 600 receives a job, the number of sheets that can be stacked and subjected to perforation is identified in advance, so that if the number of sheets scheduled to be stacked is equal to or greater than the upper limit of the number of stacked sheets, then, for example, it is possible to display a message on the screen on the display of the operation unit 601 or the personal computer 620 to notify that the stacking of the sheets is to be stopped once the upper limit of the number of stacked sheets has been reached, or to stack the sheets exceeding the upper limit on another stacking tray.

[0112] In the present embodiment, whether or not the punch hole forming process is to be performed is determined in step S103, but it is also possible to determine whether or not the punch hole forming process is to be performed by acquiring information indicating that punch holes have been initially performed on a sheet (hereinafter referred to as a pre-punched sheet) fed to the image forming apparatus 600 from the image forming apparatus 600 by the punch hole information acquiring unit 4123. Meanwhile, in the case where the pre-punched sheet has only small burrs and small protrusions in the height direction, it is possible to allow the user to set the maximum stackable amount without limiting even in the case where the sheet has punch holes.

[0113] [Determination Process of Upper Limit of Number of Stacked Sheets]

[0114] Now, refer to Fig.13 A method for determining the upper limit of the number of stacked sheets in the finisher 100 for determining overload of the number of stacked sheets is described.

[0115] Fig.13 4 is a flowchart showing a process for determining the upper limit of the number of stacked sheets based on the acquired job information. This flowchart is executed by the CPU 412 of the finisher control unit 636.

[0116] When executing the determination processing of the upper limit of the number of stacked sheets, first, the CPU 412 determines whether the stacking accuracy priority mode has been selected in the stacking setting of the finisher 100 (step S201 ).

[0117] If it is determined in step S201 that the stacking accuracy priority mode has not been selected (step S201: No), the CPU 412 sets the upper limit of the number of stacked sheets to F (step S216). Since the upper limit F of the number of stacked sheets is in an unlimited state, the upper limit F of the number of stacked sheets is the maximum number of stackable sheets of the finisher 100.

[0118] Meanwhile, if it is determined in step S201 that stacking accuracy priority has been selected (step S201 : YES), the CPU 412 determines whether punching processing has been performed on the stacked sheets based on the acquired job information (step S202 ).

[0119] If it is determined in step S202 that the punching process is not performed on the sheet (step S202: No), the CPU 412 sets the upper limit of the number of stacked sheets to F (step S216). The upper limit of the number of stacked sheets in a state where punching is not provided on the sheet is set to the upper limit F of the number of stacked sheets according to the present embodiment, but it may be arbitrarily set according to a process other than punching or grammage information of the sheet.

[0120] If it is determined in step S202 that punching processing has been performed on the sheets (step S202 : YES), the CPU 412 determines whether the punching pattern provided on the stacked sheets is a center punch based on the acquired job information (step S203 ).

[0121] If it is determined in step S203 that the perforation mode is center perforation (step S203: Yes), the CPU 412 determines whether the grammage of the sheets being stacked is less than a predetermined amount (step S204). This is because, as described above, thin paper is more likely to be affected by the burrs and flash of the perforations, and the stacked sheet bundle is greatly distorted.

[0122] If it is determined in step S204 that the grammage of the sheets being stacked is less than the predetermined amount (step S204 : YES), the CPU 412 sets the upper limit of the number of stacked sheets of the lower stack tray 750 or the upper stack tray 751 to A (step S205 ).

[0123] Meanwhile, if it is determined that the grammage of the sheets being stacked is equal to or greater than the predetermined amount (step S204 : NO), the CPU 412 sets the upper limit of the number of stacked sheets of the lower stack tray 750 or the upper stack tray 751 to B (step S206 ).

[0124] If it is determined in step S203 that the perforation pattern is not center perforation (step S203: No), the CPU 412 further determines whether the perforation pattern is single perforation (step S207).

[0125] If it is determined in step S207 that the punching mode is single punching (step S207 : YES), the CPU 412 determines whether the grammage of the sheets being stacked is smaller than a predetermined amount (step S208 ).

[0126] If it is determined in step S208 that the grammage of the sheets being stacked is less than the predetermined amount (step S208 : YES), the CPU 412 sets the upper limit of the number of stacked sheets of the lower stack tray 750 or the upper stack tray 751 to D (step S209 ).

[0127] Meanwhile, if it is determined that the grammage of the sheets being stacked is equal to or greater than the predetermined amount (step S208 : NO), the CPU 412 sets the upper limit of the number of stacked sheets of the lower stack tray 750 or the upper stack tray 751 to E (step S210 ).

[0128] Meanwhile, if it is determined in step S207 that the puncturing mode is not single puncturing (step S207: No), the CPU 412 determines whether the puncturing mode is double puncturing (step S211).

[0129] If it is determined in step S211 that the punching mode is double punching (step S211 : YES), the CPU 412 determines whether the grammage of the sheets being stacked is smaller than a predetermined amount (step S212 ).

[0130] If it is determined in step S212 that the grammage of the sheets being stacked is less than the predetermined amount (step S212 : YES), the CPU 412 sets the upper limit of the number of stacked sheets of the lower stack tray 750 or the upper stack tray 751 to C (step S213 ).

[0131] Meanwhile, if it is determined that the grammage of the sheets being stacked is equal to or greater than the predetermined amount (step S212 : NO), the CPU 412 sets the upper limit of the number of stacked sheets of the lower stack tray 750 or the upper stack tray 751 to E (step S214 ).

[0132] In addition, if it is determined in step S211 that the punching mode is not double punching (step S211: No), the CPU 412 determines that the punching mode is different from the prescribed mode and sets the upper limit of the number of stacked sheets of the lower stacking tray 750 or the upper stacking tray 751 to E (step S215).

[0133] A mode different from the prescribed mode means that the mode provides perforation in the conveying direction of the sheet or the mode provides perforation processing only for a part of the sheet. Even according to such a case, the upper limit of the number of stacked sheets can be arbitrarily set according to the stackability. At the same time, in the case where the perforation processing is performed only on a small part of the sheet (such as on a part of the corner of the sheet), the height will not change greatly, so that the upper limit of the number of stacked sheets may not change.

[0134] The operations described above in the present embodiment can be implemented by having the program stored in a CPU installed in the image forming apparatus 600 or a CPU installed in the sheet processing apparatus 200. In addition, the operations can be implemented by various methods such as a method for reading a control program online from an external server or a cloud, or by reading and executing a program from a personal computer for operating the image forming system.

[0135] As described above, according to the present embodiment, in the case where a large number of sheets to which perforations are applied are stacked, the upper limit of the number of stacked sheets on the stacking tray can be set to the most appropriate number of stacked sheets according to the perforation pattern applied to the sheets or the grammage of the sheets, and since the number of sheets to be stacked on the stacking tray is limited, stacking failure or falling of subsequent sheets from the tray can be prevented even in the case of stacking sheets to which perforations are provided.

[0136] The present invention is not limited to the embodiments described above, and various modifications may be made within the scope of the present invention, including all technical matters in the technical ideas disclosed in the claims may be the object of the present invention. The embodiments described above have illustrated preferred examples, but a person of ordinary skill in the art may implement various alternative examples, modified examples, deformation examples, and improved examples based on the contents disclosed in this specification, all of which may be included in the technical fields disclosed in the appended claims.

[0137] [Industrial Applicability]

[0138] The present invention can be applied to a sheet stacking device for stacking sheets.

[0139] [Reference Symbol List]

[0140] 1: Image forming system (image forming device) / 100: Sheet stacking device / 200: Perforating processing device / 512, 513, 514: Conveying unit (conveying roller pair) / 515: Discharging unit (upper sheet discharging roller pair) / 600: Image forming device (image forming device main body) / 636: Control unit (finisher control unit) / 751: Stacking unit (upper stacking tray).

Claims

1. A sheet stacking device, comprising: a conveying unit configured to convey the sheet in a predetermined conveying direction; a discharge unit configured to discharge the sheet conveyed by the conveying unit; a stacking unit configured to stack the sheets discharged from the discharge unit; as well as a control unit configured to stop a stacking operation of the sheets on the stacking unit according to an amount of the sheets stacked on the stacking unit, The control unit is configured as follows: In a case where sheets having no perforations provided thereon are stacked on the stacking unit, a stacking operation of the sheets on the stacking unit is stopped in response to a first amount of sheets being stacked on the stacking unit, and In a case where sheets having perforations provided thereon are stacked on the stacking unit, a stacking operation of the sheets on the stacking unit is stopped in response to sheets of an amount less than the first amount being stacked on the stacking unit.

2. The sheet stacking device according to claim 1, The control unit is configured as follows: When sheets having perforations provided at first positions are stacked on the stacking unit, a stacking operation of the sheets on the stacking unit is stopped in response to a second amount of sheets smaller than the first amount being stacked on the stacking unit, and When sheets having perforations provided at a second position different from the first position are stacked on the stacking unit, stacking operation of the sheets on the stacking unit is stopped in response to a third amount of sheets smaller than the second amount being stacked on the stacking unit.

3. The sheet stacking device according to claim 2, wherein the first position is an upstream edge portion in the sheet conveying direction, and The first position is a central portion in the sheet conveying direction.

4. The sheet stacking device according to any one of claims 1 to 3, The control unit is configured as follows: When sheets of a first grammage having perforations provided at a first position are stacked on the stacking unit, a stacking operation of the sheets on the stacking unit is stopped in response to a fourth amount of sheets smaller than the first amount being stacked on the stacking unit, and When sheets of a second grammage smaller than the first grammage having perforations provided thereon are stacked on the stacking unit, the stacking operation of the sheets on the stacking unit is stopped in response to a fifth amount of sheets smaller than the fourth amount being stacked on the stacking unit.

5. The sheet stacking device according to any one of claims 1 to 4, wherein the control unit is configured to, when sheets having perforations provided thereon are stacked on the stacking unit, change the amount of sheets based on which the stacking operation of the sheets on the stacking unit is stopped according to the number of rows of perforations provided on the sheets being stacked on the stacking unit.

6. The sheet stacking device according to any one of claims 1 to 5, wherein the control unit is configured to execute a first mode and a second mode, and The control unit is configured as follows: In the first mode, In a case where sheets having perforations provided thereon are stacked on the stacking unit, a stacking operation of the sheets on the stacking unit is stopped in response to sheets of an amount less than the first amount being stacked on the stacking unit, and In the second mode, In a case where sheets having perforations provided thereon are stacked on the stacking unit, a stacking operation of the sheets on the stacking unit is stopped in response to a maximum stackable amount of sheets of the stacking unit being stacked on the stacking unit.

7. An image forming system comprising: an image forming device configured to form an image on a sheet and discharge the sheet on which the image has been formed; a punching device configured to provide punch holes on a sheet being discharged from the image forming device based on an instruction from the image forming device; as well as According to the sheet stacking device according to any one of claims 1 to 6, sheets being discharged from the main body of the image forming apparatus are stacked on the sheet stacking device.

8. An information processing device, comprising: a memory configured to store a control program configured to control a stacking operation of sheets on a stacking device on which sheets that have been subjected to a punching process by a punching device and sheets that have been conveyed from an image forming device and have not been subjected to a punching process by the punching device are stacked; as well as a processor configured to execute the control program, Wherein, in a state in which the program is executed by the processor, when sheets that have been subjected to a predetermined perforation process are stacked on the stacking device, the processor is configured to stop stacking of sheets on the stacking device based on a number of stacked sheets that is smaller than an upper limit of the number of stacked sheets in a case in which predetermined sheets that have not yet been subjected to a predetermined perforation process are stacked on the stacking device.

9. The information processing device according to claim 8, wherein the processor is configured to obtain grammage information of the sheets subjected to perforation processing being stacked on the stacking device, and in, In a case where the grammage of a sheet of a predetermined size that has been perforated has been obtained and is less than a predetermined value, the processor is configured to stop stacking the sheets on the stacking device based on the number of stacked sheets that is smaller than the upper limit of the number of stacked sheets to the stacking device when the grammage of the sheet of the predetermined size is equal to or greater than the predetermined value.

10. The information processing device according to claim 8, wherein the processor acquires information on the number of rows of perforations on the sheets which have been subjected to the perforation process and stacked on the stacking device, and in, When the number of rows of perforations on the predetermined sheet being acquired is one, the processor is configured to stop stacking of sheets on the stacking device based on the number of stacked sheets that is smaller than an upper limit on the number of stacked sheets in a case where multiple rows of perforations are provided on the predetermined sheet.

11. The information processing device according to claim 8, wherein the processor acquires position information of perforations on the predetermined sheets that have been subjected to perforation processing and are stacked on the stacking device, and in, In a case where the position of the perforation being acquired is approximately the center in the sheet conveying direction, the processor is configured to stop the stacking of sheets on the stacking device based on the number of stacked sheets that is smaller than the upper limit of the number of stacked sheets in a case where the position of the perforation being provided on the predetermined sheet is close to the trailing edge in the sheet conveying direction.

12. A sheet stacking device on which sheets sent from an upstream device in a sheet conveying direction are stacked, the sheet stacking device comprising: a conveying unit configured to convey the sheet sent from the upstream side device; a discharge unit configured to discharge the sheet being conveyed by the conveying unit; a stacking unit configured to stack the sheets being discharged from the discharge unit; as well as a control unit configured to acquire perforation presence information of the sheets stacked on the stacking unit from the upstream side device, and control the discharge unit so that an upper limit of the number of stacked sheets of the sheets being stacked on the stacking unit is changed, Wherein, in a case where predetermined sheets identified as having predetermined perforations provided thereon are stacked on the stacking unit, the control unit is configured to control the discharge unit to stop stacking of sheets on the stacking unit based on the number of stacked sheets that is smaller than an upper limit of the number of stacked sheets of the predetermined sheets identified as not having the predetermined perforations provided thereto.

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