SHEET CONVEYING DEVICE, IMAGE FORMING APPARATUS, AND IMAGE FORMING SYSTEM

Abstract

A sheet conveying device includes a sheet stacker, a width-direction conveyor, and circuitry. The sheet stacker stacks multiple sheets including a sheet to form a sheet bundle on the sheet stacker. The width-direction conveyor conveys the sheet bundle on the sheet stacker in a width direction of the sheet. The circuitry is to control the width-direction conveyor to convey the sheet bundle on the sheet stacker to a given position in the width direction at a first speed or a second speed slower than the first speed, based on sheet information including a length of the sheet and a processing condition related to forming the sheet bundle.

Claims

1. A sheet conveying device comprising: a sheet stacker to stack multiple sheets including a sheet to form a sheet bundle on the sheet stacker; a width-direction conveyor to convey the sheet bundle on the sheet stacker in a width direction of the sheet; and circuitry configured to control the width-direction conveyor to: convey the sheet bundle on the sheet stacker to a given position in the width direction at: a first speed; or a second speed slower than the first speed, based on sheet information including: a length of the sheet; and a processing condition related to forming the sheet bundle.

2. The sheet conveying device according to claim 1, wherein the circuitry is further configured to: acquire: the sheet information from an image forming apparatus that forms an image on the sheet as an image forming process; and image processing conditions of the image forming process of the image forming apparatus; convey the sheet bundle at the first speed when no sheet of the multiple sheets in the sheet bundle satisfies any of the image processing conditions in addition to the length of the sheet in the sheet information; and convey the sheet bundle at the second speed when any one of the sheet of the multiple sheets in the sheet bundle satisfies any of the image processing conditions in addition to the length of the sheet.

3. The sheet conveying device according to claim 1, further comprising a sheet binder to bind the sheet bundle on the sheet stacker at a binding position as a biding operation, wherein the circuitry is further configured to convey the sheet bundle in the width direction to cause the binding position of the sheet bundle to face the sheet binder when the sheet binder performs a binding operation on the sheet bundle.

4. The sheet conveying device according to claim 3, wherein the circuitry is further configured to: determine a conveyance amount of the sheet bundle based on: the sheet information; the image processing conditions; and binding information related to the binding position; and convey the sheet bundle: at the first speed when no sheet of the multiple sheets in the sheet bundle satisfies any of the conveyance amount and the image processing conditions in addition to the length of the sheet in the sheet information; and at the second speed when any one of the sheet of the multiple sheets in the sheet bundle satisfies any of the conveyance amount and the image processing conditions in addition to the length of the sheet.

5. The sheet conveying device according to claim 1, wherein the processing condition includes an image forming face of the sheet.

6. The sheet conveying device according to claim 1, wherein the processing condition includes an image ratio of an image formed on the sheet.

7. The sheet conveying device according to claim 1, wherein the processing condition includes a number of the multiple sheets to form the sheet bundle on the sheet stacker.

8. The sheet conveying device according to claim 1, wherein the processing condition includes a position of an image formed on the sheet.

9. The sheet conveying device according to claim 1, wherein the sheet information includes a type or a thickness of the sheet.

10. The sheet conveying device according to claim 1, wherein the sheet stacker includes a conveyance-direction aligner to align an end in a conveyance direction, and a determination reference based on a length of the sheet is that the length of a part of the sheet in contact with the width-direction conveyor longer than the length of the sheet in contact with the conveyance-direction aligner.

11. The sheet conveying device according to claim 10, wherein the circuitry is further configured to decrease a speed of the sheet bundle conveyance to be slower than the first speed according to a length of the sheet exceeding a length of the conveyance-direction aligner when the length of the sheet in the conveyance direction corresponds to the determination reference.

12. The sheet conveying device according to claim 1, wherein the circuitry is further configured to perform the sheet bundle conveyance at a third speed faster than the first speed when the length of the sheet conveyed from an image forming apparatus does not correspond to a reference condition included in the processing condition.

13. The sheet conveying device according to claim 12, wherein the circuitry is further configured to: increase an acceleration time of the first speed, a speed of the first speed, or both; and convey the sheet at the third speed.

14. The sheet conveying device according to claim 1, wherein the circuitry is further configured to: decrease an acceleration time of the first speed, a speed of the first speed, or both; and convey the sheet at the second speed.

15. The sheet conveying device according to claim 1, wherein a setting of whether to change the sheet bundle conveyance speed based on sheet information related to a length of the sheet in the conveyance direction, a sheet bundle conveyance amount, a printing condition and a reference condition are adjustable via an operation unit included in an image forming apparatus.

16. An image forming apparatus comprising: a housing; an image forming device included in the housing to form an image on a sheet of a sheet bundle; and the sheet conveying device according to claim 1, the sheet conveying device detachably attached to the housing to convey the sheet on which the image is formed by the image forming device, to a given position.

17. An image forming system comprising: an image forming apparatus to form an image on a sheet; and the sheet conveying device according to claim 1, coupled to the image forming apparatus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein:

[0014] FIG. 1 is an external view of an example of a multifunction peripheral (MFP) as an image forming system according to an embodiment of the present disclosure;

[0015] FIG. 2 is an external view of another example of a multifunction peripheral (MFP) as an image forming system according to an embodiment of the present disclosure;

[0016] FIG. 3A is a diagram illustrating an example of a structure of a multifunction peripheral (MFP);

[0017] FIG. 3B is a diagram illustrating an example of a functional block of a multifunction peripheral (MFP) according to an embodiment of the present disclosure of FIG. 3A;

[0018] FIG. 4 is a diagram illustrating a functional block of a sheet binder according to an embodiment of the present disclosure;

[0019] FIG. 5 is a cross sectional view of a sheet binder according to an embodiment of the present disclosure;

[0020] FIG. 6 is a diagram illustrating an example of an operation process of a sheet binder according to the present embodiment;

[0021] FIG. 7A is a diagram illustrating a sheet binder according to the present embodiment;

[0022] FIG. 7B is a diagram illustrating an example of an operation process of the sheet binder of FIG. 7A;

[0023] FIG. 8 is a diagram illustrating the sheet binder according to the present embodiment, performing an operation subsequent to the operation process in FIG. 7;

[0024] FIG. 9 is a diagram illustrating the sheet binder according to the present embodiment, performing an operation subsequent to the operation process in FIG. 8;

[0025] FIG. 10 is a diagram illustrating the sheet binder according to the present embodiment, performing an operation subsequent to the operation process in FIG. 9;

[0026] FIG. 11 is a diagram illustrating the sheet binder according to the present embodiment, performing an operation subsequent to the operation process in FIG. 10;

[0027] FIG. 12 is a diagram illustrating the sheet binder according to the present embodiment, performing an operation subsequent to the operation process in FIG. 11;

[0028] FIG. 13A is a diagram illustrating a sheet binder according to the present embodiment;

[0029] FIG. 13B is a diagram illustrating an example of an operation process of the sheet binder of FIG. 13A;

[0030] FIG. 14 is a diagram illustrating the sheet binder according to the present embodiment, performing an operation subsequent to the operation process in FIG. 13B;

[0031] FIG. 15 is a diagram illustrating the sheet binder according to the present embodiment, performing an operation subsequent to the operation process in FIG. 14;

[0032] FIG. 16 is a diagram illustrating an operation process of a sheet binder according to the present embodiment;

[0033] FIG. 17 is a diagram illustrating an operation process of a sheet binder according to the present embodiment;

[0034] FIG. 18 is a diagram illustrating an operation process of a sheet binder according to the present embodiment;

[0035] FIGS. 19A and 19B are diagrams each illustrating a problem in an operation process of a sheet binder according to the present embodiment;

[0036] FIG. 20 is a diagram illustrating a problem in an operation process of a sheet binder according to the present embodiment;

[0037] FIGS. 21A and 21B are diagrams each illustrating a problem in an operation process of a sheet binder according to the present embodiment;

[0038] FIG. 22 is a diagram illustrating relative dimensions of a sheet binder and a medium according to the present embodiment;

[0039] FIGS. 23A and 23B are diagrams each illustrating a part of an operation of a sheet binder according to the present embodiment;

[0040] FIG. 24 is a flowchart of a sheet bundle conveyance control process of a sheet binder according to the present embodiment;

[0041] FIG. 25 is a flowchart of a sheet bundle conveyance control process of a sheet binder according to the present embodiment;

[0042] FIG. 26 is a flowchart of a sheet bundle conveyance control process of a sheet binder according to the present embodiment;

[0043] FIG. 27 is a diagram illustrating a speed control of a sheet bundle conveyance control according to the present embodiment;

[0044] FIGS. 28A, 28B and 28C are diagrams each illustrating an example of a speed control of a sheet bundle conveyance control according to the present embodiment; and

[0045] FIG. 29 is a diagram illustrating a processing condition used for a sheet bundle conveyance control according to the present embodiment.

[0046] The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views.

DETAILED DESCRIPTION

[0047] It will be understood that if an element or layer is referred to as being on, against, connected to or coupled to another element or layer, then it can be directly on, against, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, if an element is referred to as being directly on, directly connected to or directly coupled to another element or layer, then there are no intervening elements or layers present. As used herein, the term connected/coupled includes both direct connections and connections in which there are one or more intermediate connecting elements. Like numbers refer to like elements throughout. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.

[0048] Spatially relative terms, such as beneath, below, lower, above, upper and the like may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements describes as below or beneath other elements or features would then be oriented above the other elements or features. Thus, term such as below can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors herein interpreted accordingly.

[0049] The terminology used herein is for describing particular embodiments and examples and is not intended to be limiting of exemplary embodiments of this disclosure. As used herein, the singular forms a, an, and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms includes and/or including, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0050] Embodiments of the present disclosure are described below with reference to the drawings. The same reference numerals are given to identical or corresponding constituent elements such as parts and members having the same reference numerals, and redundant descriptions thereof are omitted unless otherwise required.

[0051] Descriptions are given of a sheet processing apparatus according to the present disclosure, an image forming apparatus incorporating the sheet processing apparatus, and an image forming system incorporating the sheet processing device, with reference to the accompanying drawings. A sheet binder 100 as an example of a sheet processing apparatus to be described below is an example of a sheet binder that can be installed in the body of an image forming apparatus, in other words, a sheet binder installable in an in-body part of an image forming apparatus. However, the sheet processing apparatus according to the present disclosure is not intended to be limited to the in-body installation type. The sheet processing apparatus according to the present disclosure is to solve the problem that the disorder of medium alignment occurs when the size of a member provided inside the housing of the sheet processing apparatus is restricted for the purpose of reduction in size of the sheet processing apparatus, and the size of the member is relatively short with respect to the size of a medium and a medium bundle to be processed. Accordingly, the sheet processing apparatus is not limited to the in-body type as long as this object is achieved, and may be an apparatus that is separate from the image forming apparatus and forms an image forming system in cooperation with the image forming apparatus.

Embodiment of Image Forming System

[0052] FIGS. 1 and 2 are external views of a multifunction peripheral (MFP) 1 as an embodiment of an image forming system according to the present disclosure.

[0053] The MFP 1 is an apparatus having an image forming function of forming an image on a sheet S (typically, a paper sheet) as a sheet-shaped media, and a post-processing function of executing a predetermined sheet process (post-processing) on the sheet S on which the image is formed (recorded).

[0054] As illustrated in FIG. 1, the MFP 1 includes a housing 31 and an image forming device 32 inside the housing 31. The housing 31 is a box-shaped member having an internal space for accommodating components of the MFP 1. The housing 31 has an in-body space 33 that is accessible from the outside of the MFP 1. The in-body space 33 is located, for example, slightly above the center of the housing 31 in the vertical direction. The in-body space 33 is exposed to the outside through the cutting that is made by cutting out the outer wall of the housing 31.

[0055] Further, a hole puncher 200 and a sheet binder 100 are attachable to the in-body space 33. The sheet binder 100 functions as a sheet processing apparatus according to an embodiment of the present disclosure.

[0056] The image forming device 32 receives a sheet S that is picked up and conveyed from a sheet tray and ejects the sheet S to the hole puncher 200 and the sheet binder 100. The image forming device 32 may be an inkjet image forming device that forms an image with ink or an electrophotographic image forming device that forms an image with toner. Since the image forming device 32 has a typical configuration, a detailed description of the image forming device 32 will be omitted unless otherwise required.

[0057] The hole puncher 200 is disposed in the in-body space 33 of the MFP 1 and is located downstream from the image forming device 32 and upstream from the sheet binder 100 in a conveyance path of the sheet S from the image forming device 32 to the sheet binder 100.

[0058] The conveyance path is indicated by a dashed line and an arrow in FIG. 1. In other words, after the image forming device 32 has formed an image on the sheet S, the sheet S is conveyed to the hole puncher 200 in which a given hole punching process is performed on the sheet S. Then, the sheet S is conveyed to the sheet binder 100 in which the binding process is performed on the sheet S.

[0059] The hole puncher 200 is attachable to and detachable from the MFP 1. When the hole puncher 200 is removed, as illustrated in FIG. 2, the sheet S having an image formed by the image forming device 32 is directly conveyed to the sheet binder 100 so that the binding process is performed on the sheet S. Another processing unit that performs a given process on the sheet S may be disposed in the in-body space 33 at the position from which the hole puncher 200 is removed.

Configuration of Control of Sheet Processing Apparatus and Image Forming Apparatus

[0060] A description is now given of a configuration of a control configuration of the MFP 1 including the sheet binder 100, with reference to FIGS. 3A and 3B.

[0061] FIG. 3A is a diagram illustrating an example of a structure of a multifunction peripheral (MFP) 1.

[0062] FIG. 3B is a diagram illustrating an example of a functional block of the MFP 1 according to an embodiment of the present disclosure of FIG. 3A.

[0063] In FIGS. 3A and 3B, a conveyance path of the sheet S (flow of the sheet S) is indicated by an arrow in a broken line, and a path (flow of signals) of a communication signal (control signal) is indicated by an arrow in a solid line.

[0064] The MFP 1 includes an image forming apparatus 10 including a display 301, a control panel 302, and a sheet feeding device 303. The display 301 notifies the user of the state of various devices and the operation contents of the image forming system 1. The control panel 302 allows the user to set, for example, an operation mode and the number of copies. The sheet feeding device 303 stocks sheets S and feeds the sheets S one by one. The image forming apparatus 10 of the MFP 1 further includes an image forming device 304 and a fixing device 305. The image forming device 304 forms a latent image on a photoconductor and transfers the image to the sheet S. The fixing device 305 fixes the image transferred onto the sheet S. The image forming apparatus 10 of the MFP 1 further includes an image forming device controller 306 that controls various operations of the devices and units described above.

[0065] The sheet binder 100 as a sheet processing apparatus causes the image forming device controller 306 of the image forming apparatus 10 of the MFP 1 to instruct, through a communication line 307, the post-processing unit controller 102 to cause the post-processing unit 101 to perform the designated processing on the designated sheet S.

[0066] The image forming device controller 306 and the post-processing unit controller 102 are coupled to each other via the communication line 307 to exchange information between the image forming device controller 306 and the post-processing unit controller 102. By so doing, information on, for example, the operation mode of the post-processing, the size of the sheet S, and the timing of conveyance of the sheet S are exchanged to make the system operable.

[0067] The sheet processing control will be described below with an example of a form in which the post-processing unit controller 102 executes predetermined arithmetic processing and outputs a notification of the process contents to the post-processing unit 101. However, no limitation is indicated thereby, and the image forming device controller 306 may execute predetermined arithmetic processing and outputs a notification of the result to the post-processing unit 101 via the post-processing unit controller 102. The post-processing unit controller 102 includes an output sheet information acquirer to acquire an image processing condition from the MFP 1 in which an image is formed on the sheet S.

Hardware Configuration of MFP 1

[0068] A description is given of a hardware configuration of the sheet binder 100 included in the MFP 1 with reference to FIG. 4.

[0069] FIG. 4 is a diagram illustrating a functional block of the sheet binder 100 according to an embodiment of the present disclosure.

[0070] As illustrated in FIG. 4, the sheet binder 100 includes a central processing unit (CPU) 110 as a controller, and is connected to multiple motors as power sources for operating the respective mechanisms via an interface (I/F) 120. The CPU 110 is a calculation unit and controls the entire operation of the sheet binder 100.

[0071] The CPU 110 in the sheet binder 100 is connected to the image forming device controller 306 in the image forming apparatus 10 of the MFP 1 via the I/F 120, and controls the sheet binder 100 in accordance with a processing signal from the MFP 1. Since the sheet binder 100 is also an optional device, the hardware of the sheet binder 100 is detachable from the image forming apparatus 1.

[0072] Each of the drive motors has an encoder to detect the amount of driving force of the drive motor by the number of pulses, so that the drive motor can stop at the position of a specific amount of driving force starting from a specific timing. Further, the amount of driving force of each of the drive motors is measured based on the encoder pulse with the timing at which the sensor on the conveyance path is on or off as a base point, and the position of the end of the sheet S being conveyed can be detected based on the driving amount.

[0073] As illustrated in FIG. 4, the sheet binder 100 is connected, via the I/F 120, to a conveyance motor 151, an ejection motor 152, a binding unit movement motor 153, a jogger movement motor 154 that moves the jogger fences 22 in the main scanning direction, a crimping motor 156, a conveyance sensor 157, an ejection sensor 158, a binding unit position sensor 159, a jogger position sensor 160, a shift motor 163 that moves (shifts) a shift roller pair 13 in the main scanning direction, a tapping roller drive motor 164 that vertically moves and rotates the tapping roller 15, and a return roller drive motor 165 that drives the return roller 14. In the present embodiment, the jogger fences 22 and the jogger movement motor 154 correspond to a width-direction conveyor.

Configuration of Conveyance Path of Sheet Binder 100

[0074] A description is given below of a configuration of the conveyance path of a sheet S included in the sheet binder 100 as a sheet processing apparatus according to an embodiment of the present disclosure.

[0075] FIG. 5 is a cross sectional view of a conveyance path of the sheet binder 100 according to an embodiment of the present disclosure.

[0076] The sheet binder 100 is settable with multiple operation modes and is appropriately performed based on a set operation mode. The operation modes of the sheet binder 100 include, for example, a shift ejection mode and a staple binding mode. The shift ejection mode is an operation mode in which the sheet S is conveyed and ejected from the upstream part (the image forming device 32) to the ejection tray 20 without performing the binding process on the sheet S.

[0077] The staple binding mode is an operation mode in which a stapler 19 performs stapling on the sheet S. The operation mode that can be executed in the sheet binder 100 includes a crimp binding mode in which the crimp binder 26 performs crimp binding on the sheets S. The shift ejection mode and the staple binding mode will be described below while the description of the crimp binding mode will be omitted.

[0078] In the following description, it is assumed that even when only the stapler 19 is illustrated, the sheet binder 100 also includes the crimp binder 26 that crimps the end portion of multiple sheets S stacked on a tray and binds the multiple sheets S. For example, in FIG. 5, it is assumed that the crimp binder 26 is disposed at a position hidden in the depth direction (the front-to-rear direction) with respect to the stapler 19.

[0079] In the shift ejection mode, the sheet S conveyed from the MFP 1 is received by the entrance roller pair 11, conveyed to the ejection roller pair 16, and ejected to the ejection tray 20. The entrance roller pair 11, the conveyance roller pair 12, the shift roller pair 13, and the ejection roller pair 16 function as a first conveyor. A direction in which the sheet S is conveyed from the entrance roller pair 11 toward the ejection roller pair 16 is referred to as a first conveyance direction.

[0080] In the staple binding mode, the sheet S conveyed from the MFP 1 is received by the entrance roller pair 11, and conveyed in a first conveyance direction. Then, the sheet S is conveyed to the shift roller pair 13. When the sheet S has passed the shift roller pair 13, the tapping roller 15 is driven to convey the sheet S to be stacked on the sheet tray 17 as an internal tray. Subsequently, as the tapping roller 15 and a return roller 14 that function as a second conveyor are operated, the tapping roller 15 and the return roller 14 convey the sheet S in a second conveyance direction that is opposite to the first conveyance direction. The second conveyance direction at this time is a direction toward the reference fence 18 for aligning the end portion of the sheet S. Accordingly, the conveyance of the sheet S conveyed in the first conveyance direction is switched to the conveyance in the reverse direction. This conveyance is referred to as switchback conveyance.

[0081] In the case of the staple binding mode, the sheet S conveyed in the first conveyance direction is placed on the sheet tray 17 by the tapping roller 15 until the number of sheets reaches the number of sheets to be bound, and the conveyance in the second conveyance direction toward the reference fence 18 is repeatedly executed. When the last sheet S is conveyed to the reference fence 18, for example, the stapler 19 as a stapler performs the stapling process in which a staple (or staples) penetrate the end of a bundle of sheets S (sheet bundle Sb). The bound sheet bundle Sb is conveyed in the first direction by the ejection roller pair 16 as a first conveyor and is ejected to the ejection tray 20.

[0082] The sheet S or the sheet bundle Sb ejected to the ejection tray 20 is aligned by contacting an end of the sheet S or the sheet bundle Sb against an end fence 21.

Operation Process of Shift Ejection Mode

[0083] A description is now given of an operation process of a shift ejection mode among the conveyance and binding of sheets S in the sheet binder 100, with reference to multiple drawings.

[0084] FIG. 6 is a diagram illustrating an example of an operation process of the sheet binder 100 according to the present embodiment.

[0085] As illustrated in FIG. 6, the shift ejection mode starts when the sheet binder 100 receives the sheet S and conveys the sheet S in the first direction. This step is the same regardless of the operation mode.

[0086] Then, a subsequent operation is illustrated in FIGS. 7A and 7B.

[0087] FIG. 7A is a plan view of the sheet binder 100 and the conveyance path, viewed in a direction of the thickness of a sheet S.

[0088] FIG. 7B is a side view of the sheet binder 100 as viewed in the main scanning direction, and is a side view of the conveyance path.

[0089] The main scanning direction of the sheet S corresponds to a direction orthogonal to the first conveyance direction and the width direction of the sheet S when the sheet S is conveyed in the first conveyance direction. In other words, the main scanning direction in FIG. 7A is the vertical direction in the drawing, and the main scanning direction in FIG. 7B is the direction from the rear side to the front side in the drawing.

[0090] As illustrated in FIGS. 7A and 7B, by the time that the sheet S is conveyed in the first conveyance direction and the leading end of the sheet S in the conveyance direction (first direction) reaches the position of the ejection roller pair 16, an ejection driven roller 16b of the ejection roller pair 16 is changed from the nipping state where the ejection driven roller 16b is disposed close to an ejection drive roller 16a to the nip pressure releasing state where the ejection driven roller 16b is separated from the ejection drive roller 16a. The leading end of the sheet S corresponds to a leading portion of the sheet S in the first conveyance direction. Then, the shift roller pair 13 is moved in the width direction (main scanning direction) of the sheet S with the trailing end of the sheet S being passed through the conveyance roller pair 12. By so doing, the sheet S is conveyed while the conveyance position of the sheet S is shifted in the main scanning direction.

[0091] In FIG. 7A, the sheet S is shifted and conveyed from the vicinity of the center of the sheet binder 100 to the far side of the sheet binder 100 (the upper side in FIG. 7A). The shift roller pair 13 functioning as a medium shifter can also perform shift conveyance to the front side or the rear side of the sheet binder 100 (the lower side in FIG. 7A). By changing the direction of shift by each sheet or a set of given number of sheets, the shift roller pair 13 can perform an ejection process, which is called a sort process, in which the ejection position of the sheet or sheets is shifted by each copy of a sheet bundle Sb.

[0092] FIG. 8 is a diagram illustrating the sheet binder 100 according to the present embodiment, performing an operation subsequent to the operation process in FIG. 7.

[0093] Subsequently, as illustrated in FIG. 8, when the shift of the sheet S is completed, the ejection driven roller 16b is moved to the nip position to convey the sheet S toward the ejection tray 20.

[0094] FIG. 9 is a diagram illustrating the sheet binder 100 according to the present embodiment, performing an operation subsequent to the operation process in FIG. 8.

[0095] Subsequently, as illustrated in FIG. 9, the sheet S is ejected to the ejection tray 20 by the ejection roller pair 16.

[0096] As described above, when the sheet binder 100 is operated in the shift ejection mode, the sheet S is conveyed in the first direction alone.

Operation Process of Staple Binding Mode

[0097] A description is now given of an operation process of a staple binding mode among the conveyance operation and the binding operation of the sheet S in the sheet binder 100, with reference to multiple drawings.

[0098] The operation process of the crimp binding mode using the crimp binder 26 is substantially the same as the operation process of the staple binding mode using the stapler 19 that is a binder with staples, and the crimp-binding mode is different from the staple binding mode in that the binding process on the sheet bundle Sb is not the staple binding process but the crimp binding process.

[0099] FIG. 10 is similar to FIG. 6 described above and illustrates a state where the sheet S is received in the sheet binder 100.

[0100] FIG. 11 is a diagram illustrating the sheet binder 100 according to the present embodiment, performing an operation subsequent to the operation process in FIG. 10.

[0101] Subsequently, since the sheet S is conveyed without shifting the position as illustrated in FIG. 11, the ejection driven roller 16b remains at the nip pressure releasing position and the sheet S is conveyed in the first conveyance direction.

[0102] FIG. 12 is a diagram illustrating the sheet binder 100 according to the present embodiment, performing an operation subsequent to the operation process in FIG. 11.

[0103] Subsequently, as illustrated in FIG. 12, the sheet S whose trailing end has passed through the shift roller pair 13 falls onto the sheet tray 17 as an internal tray along with the aid of gravity. Then, the tapping roller 15 comes into contact with the sheet S placed on the sheet tray 17 and conveys the sheet S in the second conveyance direction. As a result, the sheet S is conveyed in a manner of switchback conveyance toward the reference fence 18 while being placed on the sheet tray 17.

[0104] FIG. 13A is a diagram illustrating the sheet binder 100 according to the present embodiment.

[0105] FIG. 13B is a diagram illustrating an example of an operation process of the sheet binder 100 of FIG. 13A.

[0106] Subsequently, as illustrated in FIGS. 13A and 13B, the sheet S is conveyed due to the switchback conveyance by the tapping roller 15 and the return roller 14 until the end portion of the sheet S contacts the reference fence 18 as a conveyance-direction aligner. The end portion of the sheet S corresponds to the leading end of the sheet S in conveyance in the second conveyance direction. After the end portion of the sheet S contacts the reference fence 18, a front side jogger fence 22a and a back side jogger fence 22b, each functioning as a width-direction aligner, sandwich the sheet S so that the end portion of the sheet S in the lateral direction (width direction) contacts the front side jogger fence 22a and the back side jogger fence 22b. The front side jogger fence 22a and the back side jogger fence 22b may be referred to as jogger fences 22. Due to this operation, an alignment is performed on the end portions of the sheets S stacked on the sheet tray 17 in the width direction.

[0107] By repeatedly executing the processes from FIG. 10 to FIGS. 13A and 13B, multiple sheets S are stacked on the sheet tray 17. The number of repetitions corresponds to the number of sheets S included in the sheet bundle Sb.

[0108] FIG. 14 is a diagram illustrating the sheet binder 100 according to the present embodiment, performing an operation subsequent to the operation process in FIG. 13.

[0109] Subsequently, as illustrated in FIG. 14, after the sheets S are placed on one another (stacked) on the sheet tray 17, the stapler 19 is used to perform the staple binding on a part (a part of the end portion) of the sheet bundle Sb. When the staple binding is performed, the ejection driven roller 16b moves to the nip position.

[0110] FIG. 15 is a diagram illustrating the sheet binder 100 according to the present embodiment, performing an operation subsequent to the operation process in FIG. 14.

[0111] Subsequently, as illustrated in FIG. 15, the sheet bundle Sb is ejected to the ejection tray 20 by the ejection roller pair 16.

Embodiment of Sheet Processing Apparatus

[0112] A detailed description is given below of a configuration of the sheet binder 100 as an example of a sheet processing apparatus according to an embodiment of the present disclosure.

[0113] FIGS. 16 and 17 are diagrams illustrating an operation process of the sheet binder 100 according to the present embodiment. More specifically, FIGS. 16 and 17 are diagrams illustrating an example of the relation of the position of the sheet bundle Sb to be subjected to the binding operation and the position at which the stapler 19 is to face the sheet bundle Sb when the binding operation is performed on the sheet bundle Sb.

[0114] As illustrated in FIG. 16, it is assumed that the staple binding is performed at the position in the depth direction (in the direction toward upward in the drawing) in the sheet binder 100. The binding position 25 as a position where the binding operation is performed on the sheet bundle Sb in this case is a position illustrated by a dotted line in the drawing.

[0115] Due to the restriction of the depth dimension of the sheet binder 100, even if the stapler 19 is moved to the limit position in the depth direction when the crimp binder 26 is moved and retracted to the limit position in the depth direction, the stapler 19 may not reach the position facing the binding position 25 as illustrated in FIG. 16.

[0116] In order to address this inconvenience, the sheet binder 100 according to the present embodiment performs a sheet bundle conveyance to cause the binding position 25 to reach the given position to face the stapler 19.

[0117] FIG. 17 illustrates an example of such operation described above.

[0118] The operation in which the sheet binder 100 conveys the sheet bundle Sb to the front side in the sheet binder 100 with the sheet bundle Sb being nipped by the front side jogger fence 22a and the back side jogger fence 22b is an example of a sheet bundle conveyance.

[0119] A description is given below of the conveyance direction in the sheet bundle conveyance.

[0120] As described above, the conveyance direction in which the sheet S placed on the sheet tray 17 is conveyed toward the reference fence 18 is defined as the second conveyance direction in the present embodiment. In other words, the conveyance direction in the sheet bundle conveyance corresponds to a direction orthogonal to the second conveyance direction. In other words, the conveyance direction in the sheet bundle conveyance also corresponds to a direction orthogonal to the first conveyance direction. When the dimension of the sheet S along the first conveyance direction and the second conveyance direction is defined as the length of the sheet S, the direction orthogonal to the first conveyance direction and the second conveyance direction is a direction orthogonal to the length direction of the sheet S, and thus corresponds to the width direction of the sheet S. Accordingly, the conveyance direction in the sheet bundle conveyance to be described below corresponds to the width direction of the sheet S or the sheet bundle Sb. The width direction of the sheet S or the sheet bundle Sb is referred to as a third conveyance direction in the present embodiment. In other words, the sheet bundle conveyance corresponds to an operation of conveying the sheet bundle Sb in the third conveyance direction. In other words, the sheet bundle conveyance corresponds to an operation of moving the front side jogger fence 22a and the back side jogger fence 22b in the third conveyance direction (the width direction of the sheet S) with the sheet bundle Sb being nipped by the front side jogger fence 22a and the back side jogger fence 22b.

[0121] When forming the sheet bundle Sb and performing the binding operation on the sheet bundle Sb in the control process of the sheet binder 100 achieved by the arithmetic processing of the CPU 110 included in the post-processing unit controller 102 as a controller, the sheet bundle conveyance corresponds to an operation executed after the sheet bundle Sb is aligned and before the binding operation is performed. In a case where the binding position 25 is not at the position to face the stapler 19, the sheet bundle conveyance is executed to convey the sheet bundle Sb in the width direction by the jogger fences 22 (i.e., the front side jogger fence 22a and the back side jogger fence 22b) to bring the binding position 25 to face the stapler 19.

[0122] In other words, the sheet bundle conveyance is executed after the operation illustrated in FIG. 14 and before the operation illustrated in FIG. 15 is executed in the operation in the staple binding mode described above. In other words, as illustrated in FIG. 14, the jogger fences 22 align the end portion of the sheet bundle Sb in the third conveyance direction in a state where a given number of sheets S is stacked on the sheet tray 17 and the end portions of the sheets S in the conveyance direction are brought to contact the reference fence 18 and aligned in the second conveyance direction. In other words, the sheets S of the sheet bundle Sb are aligned in the width direction. Subsequently, as illustrated in FIG. 15, before the staple binding is performed, the sheet bundle conveyance is performed on the sheet bundle Sb. By so doing, the binding position 25 reaches the position to face the stapler 19.

[0123] The position of the stapler 19 and the position of the crimp binder 26 illustrated in FIGS. 16 and 17 may be switched. Further, when the binding position 25 is set not on the back side but on the front side of the sheet binder 100, the sheet bundle conveyance may be executed from the front side to the back side.

Description of Sheet Bundle Conveyance

[0124] A description is given of movements that may be generated on a sheet bundle Sb in the sheet bundle conveyance described above.

[0125] FIG. 18 is a diagram illustrating an operation process of the sheet binder 100 according to the present embodiment.

[0126] FIGS. 19A and 19B are diagrams each illustrating a problem in an operation process of the sheet binder 100 according to the present embodiment.

[0127] In other words, FIGS. 18 and 19 are diagrams illustrating an example of alignment disorder that may be generated at the start of sheet bundle conveyance.

[0128] As illustrated in FIG. 18, due to the restriction of the housing size of the sheet binder 100, the sheet tray 17 is shorter than the length of the sheet S (the sheet bundle Sb) to be subjected to the staple binding mode. The sheet tray 17 as a sheet stacker has a structure to receive the sheet S by the ejection tray 20 by a relatively short length with respect to the length of the sheet S. In other words, when the sheets S are stacked to form the sheet bundle Sb, the sheet bundle Sb is stacked on the sheet tray 17 and the ejection tray 20.

[0129] Accordingly, as illustrated in FIG. 18, when the jogger fences 22 press the sheet bundle Sb to start the sheet bundle conveyance, the position of the side end of the sheet bundle Sb that is pressed by the jogger fences 22 is located closer to the reference fence 18 than to the ejection tray 20. As a result, among the sheets S of the sheet bundle Sb, the sheet S in contact with the ejection tray 20 is likely to be a load during conveyance, and the sheet bundle Sb may be inclined with the contact portion C1 with the back side jogger fence 22b as a starting point at the start of conveyance.

[0130] When the conveyance speeds of the jogger fences 22 are fast, the sheet bundle Sb cannot follow the movement of the jogger fences 22 and are more likely to be inclined. On the other hand, when the conveyance speeds of the jogger fences 22, the sheet bundle Sb is likely to follow the movement of the jogger fences 22, and thus the inclination is less likely to occur. The decrease due to the inclination of the sheet bundle Sb due to the sheet bundle conveyance is more likely to occur as the length of the sheet S increases with respect to the lengths of the jogger fence 22 (the dimension of the jogger fences 22 in the second conveyance direction) and as the length of the portion of the sheet S beyond the jogger fence 22 increases.

[0131] Further, when the weight of the sheet bundle Sb (determined by the sheet length, the sheet thickness, the number of sheets, and the image) is relatively heavy, the end portion of the sheet bundle Sb that is hard to move is pushed by the jogger fences 22, and thus, the sheet S tends to be inclined more easily.

[0132] Further, as illustrated in FIG. 18, when the image (formed image G) formed on the sheet S is located in the area from the contact portion C1 of the jogger fences 22 (the back side jogger fence 22b) more than the area from the reference fence 18 to the contact portion C1 of the jogger fences 22 (the back side jogger fence 22b), the center of gravity of the sheet bundle Sb is located closer to the ejection tray 20 than the contact portion C1. Accordingly, the center of gravity of the sheet bundle Sb is located beyond the range that can be pushed by the jogger fences 22, and thus the sheet bundle Sb is likely to be inclined.

[0133] As illustrated in FIG. 19A, the aligned sheets S may be displaced from each other due to the momentum of the inclination of the sheet bundle Sb, and this movement may lead to the alignment disorder of the sheet bundle Sb. Even though FIG. 19B illustrates an example of the sheet bundle Sb in duplex printing, alignment disorder remarkably occurs when the friction between adjacent sheets (coefficient of friction of the sheets S) is relatively low.

[0134] Further, as illustrated in FIG. 19B, when the images (formed images G) formed on both sides of the sheet S are located in the area from the contact portion C1 of the jogger fences 22 (the back side jogger fence 22b) more than the area from the reference fence 18 to the contact portion C1 of the jogger fences 22 (the back side jogger fence 22b), the center of gravity of the sheet bundle Sb is located closer to the ejection tray 20 than the contact portion C1. Accordingly, the center of gravity of the sheet bundle Sb is located beyond the range that can be pushed by the jogger fences 22, and thus the sheet bundle Sb is likely to be inclined. In the duplex image formation, the formed images G are in contact with each other. Accordingly, the image is most likely to be disturbed when the image aspect ratio is large (e.g., solid image). Even in the case of duplex image formation, when the image aspect ratio is small (e.g., only a few characters), the alignment disorder is less likely to occur. In the single-sided image formation, the formed images G are not contacted with each other.

[0135] Accordingly, compared with duplex image formation, even when the image aspect ratio is large, the alignment disturbance is less likely to occur.

[0136] As illustrated in FIG. 19B, when the sheet bundle Sb includes a large number of sheets, the alignment disorder occurs on multiple sheets, so that the alignment disorder of the sheet bundle Sb increases.

[0137] FIG. 20 is a diagram illustrating a problem in an operation process of the sheet binder 100 according to the present embodiment.

[0138] FIGS. 21A and 21B are diagrams each illustrating a problem in an operation process of the sheet binder 100 according to the present embodiment.

[0139] In other words, FIGS. 20, 21A and 21B are diagrams illustrating an example of alignment disorder that may be generated when the sheet bundle conveyance is completed.

[0140] Accordingly, as illustrated in FIG. 20, the jogger fences 22 move in the width direction to convey the sheet bundle Sb, and even if the movement of the jogger fences 22 is stopped at the timing when the sheet bundle Sb reaches a given position, the inertial force is applied to the sheet bundle Sb. Due to the influence of the inertia force, the sheet bundle Sb is not completely stopped at the same stop position at the same time as the jogger fence 22 is stopped, and the force of rotating the sheet bundle Sb is applied to the sheet bundle Sb in the state where the contact portion C2 with the front side jogger fence 22a of the jogger fences 22 is a starting point. As a result, the sheet bundle Sb may be inclined from the aligned state due to the influence of the inertial force of each sheet S.

[0141] Further, when the weight of the sheet bundle Sb (determined by the sheet length, the sheet thickness, the number of sheets, and the image) is relatively heavy, the end portion of the sheet bundle Sb that is hard to move is pushed by the jogger fences 22, and thus, the sheet S tends to be inclined more easily.

[0142] Accordingly, as illustrated in FIG. 20, like the movement of inclination of the sheet S at the start of the sheet bundle conveyance, the length of the sheet S is longer than the length of the jogger fences 22, and the sheet S is easily inclined as the length of the portion of the sheet S exceeding the jogger fences 22 increases.

[0143] Further, as illustrated in FIG. 20, when the images (formed images G) formed on both sides of the sheet S are located in the area from the contact portion C2 of the jogger fences 22 (the front side jogger fence 22a) more than the area from the reference fence 18 to the contact portion C2 of the jogger fences 22 (the front side jogger fence 22a), the center of gravity of the sheet bundle Sb is located closer to the ejection tray 20 than the contact portion C2. Accordingly, the center of gravity of the sheet bundle Sb is located beyond the range that can be pushed by the jogger fences 22, and thus the sheet bundle Sb is likely to be inclined. In the duplex image formation, the formed images G are in contact with each other. Accordingly, the image is most likely to be disturbed when the image aspect ratio is large (e.g., solid image). Even in the case of duplex image formation, when the image aspect ratio is small (e.g., only a few characters), the alignment disorder is less likely to occur. In the single-sided image formation, the formed images G are not contacted with each other. Accordingly, compared with duplex image formation, even when the image aspect ratio is large, the alignment disturbance is less likely to occur.

[0144] As illustrated in FIG. 21B, as the number of sheets S of the sheet bundle Sb increases, the deviation amount of the whole sheet bundle Sb increases.

[0145] In either case where the sheet bundle conveyance is started or where the sheet bundle conveyance is completed, a gap is likely to be generated between the sheet bundle Sb and the front side jogger fence 22a when the front side jogger fence 22a starts the conveyance earlier than the back side jogger fence 22b, and the sheet bundle Sb is likely to be inclined when the gap is large, and thus the alignment failure is likely to occur.

[0146] Further, a gap may be formed due to elastic deformation or backlash of the jogger mechanism caused by the inertial force of the sheet bundle Sb. Accordingly, it is desirable to perform the sheet bundle conveyance without a gap between the front side jogger fence 22a and the back side jogger fence 22b by setting the stop position of the jogger fences 22 in consideration of the simultaneous start of the front side jogger fence 22a and the back side jogger fence 22b and the elastic deformation and the backlash of the mechanism.

[0147] In FIGS. 19A, 19B, 21A and 21B, the inclination of the sheet bundle Sb due to the influence of the gap is exaggerated for easy understanding of the inclination of the sheet bundle Sb.

Relation of Sheet Length and Jogger Fences 22

[0148] FIG. 22 is a diagram illustrating relative dimensions of the length of the sheet S and the length of the jogger fences 22 in the sheet binder 100.

[0149] As illustrated in FIG. 22, a length (jogger length) from the reference fence 18 to the farthest end of the jogger fences 22 is defined as L1. Further, the length of the sheet S (sheet length) when the end portion of the sheet S is aligned with the reference fence 18 is referred to as L2. Further, the sheet length obtained by subtracting the jogger length (L1) from the sheet length (L2), in other words, a non-contact sheet length that is the length of the sheet S of a portion that may not contact the jogger fences 22 is referred to as L3.

[0150] In either case where the sheet bundle conveyance is started or where the sheet bundle conveyance is completed, there are conditions that the sheet bundle Sb is likely to be inclined depending on the state of the sheet bundle Sb. Among these conditions, the influence of the length of the non-contact sheet length (L3) that is not in contact with the jogger fences 22 is particularly large. In other words, as the non-contact sheet length (L3) is longer, the ratio of the sheet S pushed by the jogger fences 22 is smaller. As a result, the jogger fences 22 push a part of the trailing end of the sheet S (the side closer to the reference fence 18). Even though the pressed portion easily follows the movement of the jogger fences 22 in the sheet bundle conveyance, the portion other than the pressed portion may not follow the movement of the jogger fences 22 and remains unmoved due to the inertial force. Accordingly, only a part of the whole single sheet moves and the other part remains, and thus, the sheet is likely to be inclined.

[0151] As a reference threshold value for determining whether or not the conveyance speed of the sheet bundle Sb in the sheet bundle conveyance (also corresponding to the conveyance speed of the jogger fences 22) is set to the standard speed, the sheet length that is the length of the sheet S is set to a reference sheet length (L). The standard speed is set when the reference sheet length (L)=the jogger length (L1). The standard speed is defined as a first speed.

[0152] In this case, when the relation of the sheet length (L2)>the jogger length (L1) is satisfied, it is desirable to convey the sheet bundle at a low speed lower than the standard speed. On the other hand, when the relation of the jogger length (L1)>the sheet length (L2) is satisfied, the sheet bundle conveying speed may not be decreased. In this case, the speed may be faster than the standard speed in order to enhance productivity. A speed slower than the standard speed is defined as a second speed, and a speed faster than the standard speed is defined as a third speed.

[0153] As the non-contact sheet length (L3) increases, the sheet bundle Sb is more likely to be inclined. For this reason, it is desirable to decrease the speed of the sheet bundle conveyance according to the size of the non-contact sheet length (L3). Accordingly, the speeds of the sheet bundle conveyance in the cases of long L3 when the non-contact sheet length (L3) is long, middle L3 when the non-contact sheet length (L3) is middle, and short L3 when the non-contact sheet length (L3) is short are desirable to have a relation of short L3>middle L3>long L3.

Relation of Sheet Bundle Conveyance Amount and Binding Position 25

[0154] FIGS. 23A and 23B are diagrams each illustrating a part of an operation of the sheet binder 100 according to the present embodiment. In other words, FIGS. 23A and 23B illustrate the relation of the amount of the sheet bundle conveyance and the binding position 25.

[0155] The binding position 25 is different depending on the sheet size and the binding mode (e.g., crimp binding, lower-left side stapling, upper-left side stapling, two-staple binding). Accordingly, the required amount of conveyance (A [mm]) in the sheet bundle conveyance are different depending on the binding modes. Depending on the binding modes, the amount of the conveyance of the sheet bundle Sb in the sheet bundle conveyance is small. For this reason, the movement of the sheet bundle Sb may be completed before the sheet bundle Sb is inclined. In other words, the adjustment of the speed in the sheet bundle conveyance may not be performed.

Processing Flow of Sheet Bundle Conveyance

[0156] A descriptions is given below of a control process of the sheet bundle conveyance, with reference to the flowchart of FIG. 24.

[0157] The sheet bundle conveyance includes a process of determining the conveyance speed of the sheet S (the sheet bundle Sb) by the jogger fences 22 based on sheet information that is information about the sheet S (sheet bundle Sb) as an object to be conveyed. The sheet information includes information indicating the sheet length L2 as length information of a sheet, information indicating a position of the formed image G (image forming face), information indicating an image aspect ratio, information on the number of sheets of the sheet bundle Sb, information on a thickness of the sheet S (paper thickness), information on a coefficient of friction (frictional coefficient) of the sheet S, and information on a conveyance amount of the sheet bundle Sb. These pieces of the sheet information may be input via the image forming device controller 306 of the image forming apparatus 10 of the MFP 1, or may be input via an input interface and stored in a storage area of the post-processing unit controller 102 in a case where the sheet binder 100 includes the input interface.

First Embodiment

[0158] FIG. 24 is a flowchart of a first embodiment of a control process of a sheet bundle conveyance.

[0159] In the present embodiment, the sheet bundle conveyance speed is subjected to any one of normal speed control, deceleration control, and acceleration control according to the image processing conditions such as the sheet length, the image aspect ratio, the image forming face, the number of sheets, the image position, the amount of the sheet bundle conveyance, and the sheet thickness.

[0160] First, the CPU 110 of the post-processing unit controller 102 determines whether or not the sheet length (L2) is longer than the reference sheet length (L) (step S2401). When the sheet length (L2) is longer than the reference sheet length (L) (YES in step S2401), the CPU 110 determines whether the processing condition corresponds to the contents in Appendix C illustrated in FIG. 29 (step S2402). The processing condition corresponds to a condition related to the process performed before the sheet S is stacked on the sheet tray 17 (before accumulation). In other words, the printing condition in the MFP 1 correspond to this condition.

[0161] As in Appendix C illustrated in FIG. 29, the processing condition (printing condition) includes contents such as duplex printing and image aspect ratio X % or more, single-sided printing and image aspect ratio Y % or more, the number of sheets is N or more, the image position is more on the ejection side than on the jogger contact area, and sheet thickness T [gsm] or more. Each items of the processing condition may be informed from the image forming device controller 306 of the MFP 1 to the post-processing unit controller 102 or may be directly input via an interface provided to the post-processing unit controller 102 of the sheet binder 100. In any case, it is assumed that the processing condition for the sheet bundle Sb as an object to be processed is stored in the storage area of the post-processing unit controller 102 before the sheet bundle conveyance is performed.

[0162] In the present example, for example, it is assumed that duplex printing and image aspect ratio 50% or more, single-sided printing and image aspect ratio 80% or more, the number of sheets is 5 or more, the image position is more on the ejection side than on the jogger contact area, and sheet thickness 106 [gsm] or more are stores as the processing conditions.

[0163] In step S2402, when even one sheet of the sheets S included in the sheet bundle Sb satisfies any of the processing conditions defined in Appendix C (YES in step S2402), the speed of movement of the jogger fences 22 is set to a speed slower than the standard speed (step S2403). In step S2402, when no sheet of the sheets S included in the sheet bundle Sb corresponds to any of the processing conditions defined in Appendix C (NO in step S2402), the speed of movement of the jogger fences 22 is set to the standard speed (step S2406).

[0164] Subsequent to step S2403 or step S2406, the sheet bundle conveyance is executed at the set speed of movement (step S2404).

[0165] In step S2401, when the sheet length (L2) is not longer than the reference sheet length (L) (NO in step S2401), if the sheet length (L2) is the same as the reference sheet length (L) (YES in step S2405), the speed of movement of the jogger fences 22 is set as the standard speed (step S2406). In step S2405, when the sheet length (L2) is not the same as the reference sheet length (L) (NO in step S2405), the speed of movement of the jogger fences 22 is set to a speed higher than the standard speed (step S2407).

[0166] Subsequent to step S2406 or step S2407, the sheet bundle conveyance is executed at the set speed of movement (step S2404).

Second Embodiment

[0167] FIG. 25 is a flowchart of a second embodiment of a control process of a sheet bundle conveyance.

[0168] Also in the present embodiment, the speed of the sheet bundle conveyance is subjected to any one of normal speed control, deceleration control, and acceleration control according to the image processing conditions such as the sheet length, the image aspect ratio, the image forming face, the number of sheets, the image position, the amount of the sheet bundle conveyance, and the sheet thickness.

[0169] First, the CPU 110 of the post-processing unit controller 102 determines whether or not the sheet length (L2) is longer than the reference sheet length (L) (step S2501). When the sheet length (L2) is longer than the reference sheet length (L) (YES in step S2501), the CPU 110 determines whether a sheet bundle conveyance amount A (see FIGS. 23A and 23B) is greater than the reference value B (step S2502). When the sheet bundle conveyance amount A is greater than the reference value B (YES in step S2502), the CPU 110 determines whether the processing condition corresponds to the contents in Appendix C illustrated in FIG. 29 (step S2503).

[0170] In step S2503, when even one sheet of the sheets S included in the sheet bundle Sb satisfies any of the processing conditions defined in Appendix C (YES in step S2503), the speed of movement of the jogger fences 22 is set to a speed slower than the standard speed (step S2504). In step S2503, when no sheet of the sheets S included in the sheet bundle Sb corresponds to any of the processing conditions defined in Appendix C (NO in step S2503), the speed of movement of the jogger fences 22 is set to the standard speed (step S2507).

[0171] Subsequent to step S2504 or step S2507, the sheet bundle conveyance is executed at the set speed of movement (step S2505).

[0172] In step S2501, when the sheet length (L2) is not longer than the reference sheet length (L) (NO in step S2501), if the sheet length (L2) is the same as the reference sheet length (L) (YES in step S2506), the speed of movement of the jogger fences 22 is set as the standard speed (step S2507). In step S2506, when the sheet length (L2) is not the same as the reference sheet length (L) (NO in step S2506), the speed of movement of the jogger fences 22 is set to a speed faster than the standard speed (step S2508).

[0173] In step S2502, when the sheet bundle conveyance amount A is not greater than the reference value B (NO in step S2502), the CPU 110 sets the speed of movement of the jogger fences 22 to the standard speed (step S2507).

[0174] Subsequent to step S2507 or step S2508, the sheet bundle conveyance is executed at the set speed of movement (step S2505).

[0175] In other words, when the sheet bundle conveyance amount A is smaller than the reference value B (for example, 0.5 mm), the deceleration control may not be performed. When the sheet length (L2) is equal to the reference sheet length (L) without any of the reference value determinations, the normal speed control may be performed. On the other hand, when the sheet length (L2) is shorter than the reference sheet length (L), the acceleration control may be performed to enhance the productivity.

Third Embodiment

[0176] FIG. 26 is a flowchart of a third embodiment of a control process of a sheet bundle conveyance.

[0177] Also in the present embodiment, the speed of the sheet bundle conveyance is subjected to any one of normal speed control, deceleration control, and acceleration control according to the image processing conditions such as the sheet length, the image aspect ratio, the image forming face, the number of sheets, the image position, the amount of the sheet bundle conveyance, and the sheet thickness.

[0178] First, the CPU 110 of the post-processing unit controller 102 determines whether or not the sheet length (L2) is longer than the reference sheet length (L) (step S2601). When the sheet length (L2) is longer than the reference sheet length (L) (YES in step S2601), the CPU 110 determines whether the processing condition corresponds to the contents in Appendix C illustrated in FIG. 29 (step S2602).

[0179] In step S2602, when even one sheet of the sheets S included in the sheet bundle Sb satisfies any of the processing conditions defined in Appendix C (YES in step S2602), the speed of movement of the jogger fences 22 is set to a speed slower than the standard speed with the degree of deceleration (stepless deceleration) according to the non-contact sheet length (L3) (step S2603). In step S2602, when no sheet of the sheets S included in the sheet bundle Sb corresponds to any of the processing conditions defined in Appendix C (NO in step S2602), the speed of movement of the jogger fences 22 is set to the standard speed (step S2606).

[0180] Subsequent to step S2603 or step S2606, the sheet bundle conveyance is executed at the set speed of movement (step S2604).

[0181] In step S2601, when the sheet length (L2) is not longer than the reference sheet length (L) (NO in step S2601), if the sheet length (L2) is the same as the reference sheet length (L) (YES in step S2605), the speed of movement of the jogger fences 22 is set as the standard speed (step S2606). In step S2605, when the sheet length (L2) is not the same as the reference sheet length (L) (NO in step S2605), the speed of movement of the jogger fences 22 is set to a speed faster than the standard speed (step S2607).

[0182] Subsequent to step S2606 or step S2607, the sheet bundle conveyance is executed at the set speed of movement (step S2604).

[0183] As described above, in the third embodiment, the deceleration is varied according to the amount by which the sheet length (L2) exceeds the reference sheet length (L), in other words, non-contact sheet length (L3)=(sheet length (L2)reference sheet length (L)). The speed control according to the present embodiment greatly changes depending on whether or not the sheet length (L2) is the same as the reference sheet length (L), for example, as illustrated in FIG. 27.

[0184] FIG. 27 is a diagram illustrating a speed control of a sheet bundle conveyance control according to the present embodiment.

[0185] When the sheet length (L2) is shorter than the reference sheet length (L), the moving speed of the jogger fences 22 is constant. On the other hand, when the sheet length (L2) is longer than the reference sheet length (L), the moving speed of the jogger fences 22 is decelerated at a constant rate according to the degree of the length. In other words, in the third embodiment, when the sheet length (L2) of the sheet S (sheet bundle Sb) whose end portion is aligned on the reference fence 18 is longer than the reference sheet length (L) that is a reference corresponding to the length of the sheet S in the portion in contact with the jogger fence 22, the speed of the sheet bundle conveyance is decelerated according to the length (L3) of the sheet S in the portion not in contact with the jogger fence 22.

[0186] The condition of whether or not the speed of the sheet bundle conveyance needs to be changed, which is determined according to the operation mode distinguished by alignment accuracy priority or productivity priority set by the user, the processing conditions defined in Appendix C, and the reference values used in the determination can be changed to any value via the control panel 302 as an operation unit.

[0187] Description of Normal Speed Control, Deceleration Control, and Acceleration Control of Sheet Bundle Conveyance Speed A description is given of the setting of the moving speed of the jogger fences 22 in the sheet bundle conveyance described above as the first embodiment, the second embodiment and the third embodiment, with reference to FIGS. 28A, 28B and 28C.

[0188] FIGS. 28A, 28B and 28C illustrate the relation of the speed of the jogger fences 22 (jogger moving speed) and the elapsed time from the start of conveyance of the sheet bundle Sb to the completion of conveyance of the sheet bundle Sb.

[0189] The amount of conveyance of the sheet bundle Sb is the same in any of the normal speed control (standard speed), the deceleration control, and the acceleration control.

[0190] In the setting of the jogger moving speed in the sheet bundle conveyance, for example, as illustrated in FIG. 28A, the acceleration control may be executed with the acceleration during the control being constant and only the jogger moving speed after the control being changeable.

[0191] As illustrated in FIG. 28B, deceleration control or acceleration control may be performed by the acceleration while the jogger moving speed is kept constant.

[0192] As illustrated in FIG. 28C, both the acceleration and the jogger moving speed may be controlled to be changed.

[0193] According to the present embodiment described above, when conveying the sheet bundle Sb, the setting of the sheet bundle conveying speed is changed depending on the relation of the sizes of the sheets S of the sheet bundle Sb and the mechanism for conveying the sheet bundle Sb and the processing condition performed on the sheets S in advance.

[0194] By so doing, the sheet bundle Sb is prevented from being misaligned during conveyance of the sheet bundle Sb.

[0195] The present disclosure is not limited to specific embodiments described above, and numerous additional modifications and variations are possible in light of the teachings within the technical scope of the appended claims. It is therefore to be understood that the disclosure of this patent specification may be practiced otherwise by those skilled in the art than as specifically described herein, and such, modifications, alternatives are within the technical scope of the appended claims. Such embodiments and variations thereof are included in the scope and gist of the embodiments of the present disclosure and are included in the embodiments described in claims and the equivalent scope thereof.

[0196] Aspects of the present disclosure are, for example, as follows.

Aspect 1

[0197] In Aspect 1, a sheet conveying device includes a sheet stacker, a width-direction conveyor, and a controller. The sheet stacker stacks multiple sheets including a sheet. The width-direction conveyor is conveyable of the multiple sheets stacked in the sheet stacker in a width direction of the multiple sheets. The controller is to control an operation of the width-direction conveyor. The controller controls a sheet bundle conveyance in which the width-direction conveyor conveys a sheet bundle stacked on the sheet stacker to a given position in the width direction, and set a conveyance speed of the sheet bundle in the sheet bundle conveyance to one of a first speed or a second speed slower than the first speed, based on sheet information including a length of the sheet and a processing condition related to a forming process of the sheet bundle.

Aspect 2

[0198] In Aspect 2, the sheet conveying device according to Aspect 1 further includes an output sheet information acquirer to acquire the sheet information from an image forming apparatus that forms an image on the sheet and an image processing condition according to a process by the image forming apparatus. The controller is further to set the conveyance speed to the first speed when the conveyance speed does not correspond to a reference condition of the processing condition in addition to length information included in the sheet information obtained by the output sheet information acquirer, and set the conveyance speed to the second speed when the conveyance speed corresponds to the reference condition of the processing condition in addition to the length information.

Aspect 3

[0199] In Aspect 3, the sheet conveying device according to Aspect 1 or Aspect 2 further includes a sheet binder to bind the multiple sheets stacked by the sheet stacker. The controller is further to convey the sheet bundle in the width direction to cause a binding position at which the sheet bundle is bound to face the sheet binder when the sheet binder performs a binding operation on the sheet bundle.

Aspect 4

[0200] In Aspect 4, in the sheet conveying device according to Aspect 3, the controller is further to determine a sheet bundle conveyance amount based on the sheet information and information related to the binding position, based on the sheet information, the processing condition, and the binding position information, and perform the sheet bundle conveyance at the first speed when the conveyance speed does not at all correspond to any reference condition of the sheet bundle conveyance amount and the processing condition, and the second speed slower than the first speed when the conveyance speed corresponds to the reference condition of the sheet bundle conveyance amount and the processing condition, in addition to length information of the sheet.

Aspect 5

[0201] In Aspect 5, in the sheet conveying device according to any one of Aspects 1 to 4, the processing condition is an image forming face of the sheet.

Aspect 6

[0202] In Aspect 6, in the sheet conveying device according to any one of Aspects 1 to 5, the processing condition is an image ratio in image formation performed on the sheet.

Aspect 7

[0203] In Aspect 7, in the sheet conveying device according to any one of Aspects 1 to 6, the processing condition is a number of sheets stacked to form a sheet bundle.

Aspect 8

[0204] In Aspect 8, in the sheet conveying device according to any one of Aspects 1 to 7, the processing condition is a position on which the image is formed on the sheet.

Aspect 9

[0205] In Aspect 9, in the sheet conveying device according to any one of Aspects 1 to 8, the sheet information indicates a type or a thickness of the sheet.

Aspect 10

[0206] In Aspect 10, in the sheet conveying device according to any one of Aspects 1 to 9, the sheet stacker includes a conveyance-direction aligner to align an end in a conveyance direction. A reference condition of a length of the sheet in the conveyance direction is that the sheet in contact with the conveyance-direction aligner is longer than the length in the conveyance direction of the sheet contactable with the width-direction aligner.

Aspect 11

[0207] In Aspect 11, in the sheet conveying device according to Aspect 10, the speed of the sheet bundle conveyance is slower than the first sheet according to the length exceeding a reference condition when the length of the sheet in the conveyance direction corresponds to the reference condition.

Aspect 12

[0208] In Aspect 12, in the sheet conveying device according to any one of Aspects 1 to 11, the controller is further to perform the sheet bundle conveyance at a third speed faster than the first speed when the length of the sheet conveyed from an image forming apparatus does not correspond to a reference condition included in the processing condition.

Aspect 13

[0209] In Aspect 13, in the sheet conveying device according to any one of Aspects 1 to 12, the controller is further to increase an acceleration time of the first speed, a speed of the first speed, or both, and convey the sheet at the third speed.

Aspect 14

[0210] In Aspect 14, in the sheet conveying device according to any one of Aspects 1 to 13, the controller is further to decrease an acceleration time of the first speed, a speed of the first speed, or both, and convey the sheet at the second speed.

Aspect 15

[0211] In Aspect 15, in the sheet conveying device according to any one of Aspects 1 to 14, a setting of whether to change the sheet bundle conveyance speed based on sheet information related to a length of the sheet in the conveyance direction, a sheet bundle conveyance amount, a printing condition and the reference condition are adjustable via an operation unit included in an image forming apparatus.

Aspect 16

[0212] In Aspect 16, an image forming apparatus includes a housing, an image forming device included in the housing to form an image on a sheet of a sheet bundle; and the sheet conveying device according to any one of Aspects 1 to 15. The sheet conveying device is detachably attached to the housing to convey the sheet on which the image is formed by the image forming device, to a given position.

Aspect 17

[0213] In Aspect 17, an image forming system includes an image forming apparatus to form an image on a sheet, and the sheet processing apparatus according to any one of Aspects 1 to 15 coupled to the image forming apparatus.

Aspect 18

[0214] In Aspect 18, a sheet conveying device includes a sheet stacker, a width-direction conveyor, and a controller. The sheet stacker stacks multiple sheets including a sheet to form a sheet bundle on the sheet stacker. The width-direction conveyor conveys the sheet bundle on the sheet stacker in a width direction of the sheet. The circuitry is to control the width-direction conveyor to convey the sheet bundle on the sheet stacker to a given position in the width direction at a first speed or a second speed slower than the first speed, based on sheet information including a length of the sheet and a processing condition related to forming the sheet bundle.

Aspect 19

[0215] In Aspect 19, in the sheet conveying device according to Aspect 18, the circuitry is further to acquire the sheet information from an image forming apparatus that forms an image on the sheet as an image forming process and image processing conditions of the image forming process of the image forming apparatus, convey the sheet bundle at the first speed when no sheet of the multiple sheets in the sheet bundle satisfies any of the image processing conditions in addition to the length of the sheet in the sheet information, and convey the sheet bundle at the second speed when any one of the sheet of the multiple sheets in the sheet bundle satisfies any of the image processing conditions in addition to the length of the sheet.

Aspect 20

[0216] In Aspect 20, the sheet conveying device according to Aspect 18 or Aspect 19 further includes a sheet binder to bind the sheet bundle on the sheet stacker at a binding position as a biding operation. The circuitry is further to convey the sheet bundle in the width direction to cause the binding position of the sheet bundle to face the sheet binder when the sheet binder performs a binding operation on the sheet bundle.

Aspect 21

[0217] In Aspect 21, in the sheet conveying device according to Aspect 20, the circuitry is further to determine a conveyance amount of the sheet bundle based on the sheet information, the image processing conditions, and binding information related to the binding position, and convey the sheet bundle at the first speed when no sheet of the multiple sheets in the sheet bundle satisfies any of the conveyance amount and the image processing conditions in addition to the length of the sheet in the sheet information and at the second speed when any one of the sheet of the multiple sheets in the sheet bundle satisfies any of the conveyance amount and the image processing conditions in addition to the length of the sheet.

Aspect 22

[0218] In Aspect 22, in the sheet conveying device according to any one of Aspects 18 to 21, the processing condition includes an image forming face of the sheet.

Aspect 23

[0219] In Aspect 23, in the sheet conveying device according to any one of Aspects 18 to 22, the processing condition includes an image ratio of an image formed on the sheet.

Aspect 24

[0220] In Aspect 24, in the sheet conveying device according to any one of Aspects 18 to 23, the processing condition includes a number of the multiple sheets to form the sheet bundle on the sheet stacker.

Aspect 25

[0221] In Aspect 25, in the sheet conveying device according to any one of Aspects 18 to 24, the processing condition includes a position of an image formed on the sheet.

Aspect 26

[0222] In Aspect 26, in the sheet conveying device according to any one of Aspects 18 to 25, the sheet information includes a type or a thickness of the sheet.

Aspect 27

[0223] In Aspect 27, in the sheet conveying device according to any one of Aspects 18 to 26, the sheet stacker includes a conveyance-direction aligner to align an end in a conveyance direction. A reference condition of a length of the sheet in the conveyance direction is that the sheet in contact with the conveyance-direction aligner is longer than the length in the conveyance direction of the sheet to which the width-direction aligner is contactable.

Aspect 28

[0224] In Aspect 28, in the sheet conveying device according to Aspect 27, the circuitry is further to decrease a speed of the sheet bundle conveyance to be slower than the first speed according to a length of the sheet exceeding a length of the conveyance-direction aligner when the length of the sheet in the conveyance direction corresponds to the determination reference.

Aspect 29

[0225] In Aspect 29, in the sheet conveying device according to any one of Aspects 18 to 28, the circuitry is further to perform the sheet bundle conveyance at a third speed faster than the first speed when the length of the sheet conveyed from an image forming apparatus does not correspond to a reference condition included in the processing condition.

Aspect 30

[0226] In Aspect 30, in the sheet conveying device according to any one of Aspects 18 to 29, the circuitry is further to increase an acceleration time of the first speed, a speed of the first speed, or both, and convey the sheet at the third speed.

Aspect 31

[0227] In Aspect 31, in the sheet conveying device according to any one of Aspects 18 to 30, the circuitry is further to decrease an acceleration time of the first speed, a speed of the first speed, or both, and convey the sheet at the second speed.

Aspect 32

[0228] In Aspect 32, in the sheet conveying device according to any one of Aspects 18 to 31, a setting of whether to change the sheet bundle conveyance speed based on sheet information related to a length of the sheet in the conveyance direction, a sheet bundle conveyance amount, a printing condition and a reference condition are adjustable via an operation unit included in an image forming apparatus.

Aspect 33

[0229] In Aspect 33, an image forming apparatus includes a housing, an image forming device, and the sheet conveying device according to any one of Aspects 18 to 32. The image forming device is included in the housing to form an image on a sheet of a sheet bundle. The sheet conveying device is detachably attached to the housing to convey the sheet on which the image is formed by the image forming device, to a given position.

Aspect 34

[0230] In Aspect 34, an image forming system includes an image forming apparatus to form an image on a sheet, and the sheet conveying device according to any one of Aspects 18 to 32, coupled to the image forming apparatus.

[0231] The present disclosure is not limited to specific embodiments described above, and numerous additional modifications and variations are possible in light of the teachings within the technical scope of the appended claims. It is therefore to be understood that, the disclosure of this patent specification may be practiced otherwise by those skilled in the art than as specifically described herein, and such, modifications, alternatives are within the technical scope of the appended claims. Such embodiments and variations thereof are included in the scope and gist of the embodiments of the present disclosure and are included in the embodiments described in claims and the equivalent scope thereof.

[0232] The effects described in the embodiments of this disclosure are listed as the examples of preferable effects derived from this disclosure, and therefore are not intended to limit to the embodiments of this disclosure.

[0233] The embodiments described above are presented as an example to implement this disclosure. The embodiments described above are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, or changes can be made without departing from the gist of the invention. These embodiments and their variations are included in the scope and gist of this disclosure and are included in the scope of the invention recited in the claims and its equivalent.

[0234] Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above.

[0235] Each of the functions of the described embodiments may be implemented by one or more processing circuits or circuitry. Processing circuitry includes a programmed processor, as a processor includes circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC), digital signal processor (DSP), field programmable gate array (FPGA), and conventional circuit components arranged to perform the recited functions.