Sheet processing apparatus and corresponding image forming system

Abstract

A sheet processing apparatus includes: a placement portion; a contact member to contact an end of the sheet on the placement portion to align the sheet; a pair of orthogonal aligners to align the sheet in an orthogonal direction to a contact direction in which the sheet is brought into contact with the contact member; and an orthogonal movement means to move at least one of the aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet. The at least one of the aligners has a face to face the sheet and a projection that protrudes toward the sheet. The face includes a face part to be opposed to an upstream portion of the sheet in the contact direction, with the sheet in contact with the contact member. The at least one of the aligners has the projection on the face part.

Description

SHEET PROCESSING APPARATUS AND CORRESPONDING IMAGE FORMING SYSTEM[Technical Field]

[0001] The present disclosure relates to a sheet processing apparatus and an image forming system. [Background Art]

[0002] Conventionally, a sheet processing apparatus has been known that includes a placement portion on which a sheet is to be placed; a contact member to contact an end of the sheet on the placement portion to align the sheet, a pair of orthogonal aligners that aligns the sheet in an orthogonal direction to a contact direction for contact with the contact member, and an orthogonal movement means to move at least one of the pair of orthogonal aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet.

[0003] For example, Patent Literature (PTL) 1 describes such a sheet processing apparatus as above, in which the aligners have respective alignment faces each at a predetermined angle to an introducing conveyance direction Y (contact direction) such that the distance between the alignment faces is larger on the downstream side than on the upstream side in the introducing conveyance direction Y. In the sheet processing apparatus, due to movement by the movement means, the alignment faces each move with the predetermined angle kept such that force FY in the introducing conveyance direction Y and force FX in a width direction X orthogonal to the introducing conveyance direction Y act on the sheet. Thus, for alignment of the sheet having its leading end in contact with a stopper, great alignment performance is achieved in the conveyance direction.[Citation List][Patent literature]

[0066] [PTL 1]Japanese Unexamined Patent Application Publication No. 2007-8597 [Summary of Invention] [Technical Problem]

[0004] An object of the present disclosure is to provide a sheet processing apparatus having a novel structure enabling great alignment performance in a contact direction.[Solution to Problem]

[0005] In order to achieve the above object, according to an embodiment of the present disclosure, a sheet processing apparatus includes: a placement portion on which a sheet is to be placed; a contact member to contact an end of the sheet on the placement portion to align the sheet; a pair of orthogonal aligners to align the sheet in an orthogonal direction to a contact direction in which the sheet is brought into contact with the contact member; and an orthogonal movement means to move at least one of the pair of orthogonal aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet. The at least one of the pair of orthogonal aligners has a face to face the sheet and a projection that protrudes toward the sheet. The face includes a face part to be opposed to an upstream portion of the sheet in the contact direction, with the sheet being in contact with the contact member. The at least one of the pair of orthogonal aligners has the projection on the face part of the face.[Advantageous Effects of Invention]

[0006] According to the present disclosure, a sheet processing apparatus can be provided that has a novel structure enabling great alignment performance in a contact direction. [Brief Description of Drawings]

[0007] 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. [FIGS. 1A and IB]FIGS. 1A and IB are diagrams illustrating example configurations of an image forming system.[FIG. 2]FIG. 2 is a functional block diagram of an image forming system.[FIG. 3]FIG. 3 is a functional block diagram of an image forming system. [FIG. 4]FIG. 4 is a diagram illustrating a hardware configuration of electric components in an image forming system.[FIG. 5]FIG. 5 is a diagram illustrating a conveyance path of an inner finisher.[FIG. 6]FIG. 6 is a diagram illustrating an operation of the inner finisher. [FIG. 7]FIG. 7 is a diagram illustrating the operation of the inner finisher. [FIG. 8]FIG. 8 is a diagram illustrating the operation of the inner finisher.[FIGS. 9 A and 9B]FIGS. 9A and 9B are diagrams illustrating the operation of the inner finisher.[FIG. 10]FIG. 10 is a diagram illustrating the operation of the inner finisher.[FIG. 11]FIG. 11 is a diagram illustrating the operation of the inner finisher.[FIG. 12]FIG. 12 is a diagram illustrating a mechanism including jogger fences for alignment in a width direction.[FIGS. 13 A and 13B]FIGS. 13 A and 13B are diagrams illustrating a disadvantage to be solved in an embodiment.[FIGS. 14A, 14B, and 14C]FIGS. 14A, 14B, and 14C are diagrams illustrating a disadvantage to be solved in an embodiment.[FIGS. 15 A, 15B, and 15C]FIGS. 15A, 15B, and 15C are diagrams illustrating an alignment operation with jogger fences in an embodiment.[FIGS. 16A and 16B]FIGS. 16A and 16B are diagrams illustrating a jogger- fence crosswise shift amount [mm].[FIG. 17]FIG. 17 is a diagram illustrating setting the height of a projection.[FIG. 18]FIG. 18 is a diagram illustrating setting the height of a projection.[FIG. 19]FIG. 19 is a diagram illustrating setting the inclination angle of a scooper.[FIG. 20]FIG. 20 is a diagram illustrating a configuration in which a plate-spring component is provided instead of a projection.[FIGS. 21A, 21B, and 21C]FIGS. 21A, 21B, and 21C are diagrams illustrating an alignment operation of jogger fences illustrated in FIG. 20.[FIG. 22]FIG. 22 is a diagram illustrating setting of the height of a projection.[FIGS. 23 A, 23B, and 23C]FIGS. 23A, 23B, and 23C are diagrams illustrating example configurations in which jogger fences are tumable.[FIGS. 24A, 24B, and 24C]FIGS. 24A, 24B, and 24C are diagrams illustrating an alignment operation by the example configurations in FIGS. 23A, 23B, and 23C.[FIG. 25]FIG. 25 illustrates an example configuration in which jogger fences are swingable. [FIGS. 26A, 26B, and 26C]FIGS. 26A, 26B, and 26C are diagrams illustrating trouble due to excessive movement. [FIGS. 27 A, 27B, and 27C]FIGS. 27A, 27B, and 27C illustrate an example configuration in which jogger fences protrude upstream in a sheet conveyance direction with respect to a sheet ejection roller.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.[Description of Embodiments]In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.Referring now to the drawings, embodiments of the present disclosure are described below. 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.

[0008] an image forming system including an image forming apparatus and a post-processing apparatus according to an embodiment of the present disclosure will be described. The image forming system will be now described. FIGS. 1A and IB are diagrams illustrating example configurations of an image forming system 1 including an inner finisher 100 as a postprocessing apparatus and an image forming apparatus 300. The inner finisher 100 corresponds to a post-processing apparatus disposed inside the body of the image forming apparatus 300 for avoidance of an increase in installation area. The inner finisher 100 can serve as a post-processing apparatus that is disposed outside the image forming apparatus 300 and is coupled to the image forming apparatus 300 as an aspect. FIG. 1A illustrates an example configuration regarding the image forming system 1 in which the image forming apparatus 300 and the inner finisher 100 are coupled together. The inner finisher 100 receives, from the image forming apparatus 300, a sheet on which an image is formed, followed by post-processing, such as binding.

[0009] FIG. IB illustrates an example configuration regarding the image forming system 1 in which the image forming apparatus 300, an inner-finisher optional device 200, and the inner finisher 100 are coupled together. The inner- finisher optional device 200 performs processing such as punching to a sheet on which an image is formed from the image forming apparatus 300, andthen the inner finisher 100 receives the sheet, followed by post-processing such as binding. The inner-finisher optional device 200 corresponds to an optional device that a user can purchase by selecting as an option.

[0010] Instead of or in addition to the inner-finisher optional device 200 that performs processing such as punching, an inner-finisher optional device 400 that performs processing such as folding can be coupled. The inner-finisher optional device 200 and the inner-finisher optional device 400 are optional and thus are detachably attachable. Such an optional device has an interface (VF) detachably attachable through a relay connector or drawer connector in a hardware manner.

[0011] FIGS. 2 and 3 are functional block diagrams of the image forming system 1. FIG. 2 is a functional block diagram of the image forming system 1 equipped with no inner-finisher option. The flow of a sheet is indicated with dashed lines, and the flow of a communication signal is indicated with a solid line. The image forming apparatus 300 forms an image on a sheet in a known electrophotographic process. The image forming apparatus 300 includes a display 301 that notifies a user of the states and operation details of various types of devices, an operation unit 302 that a user operates to set a mode or the number of copies, a sheet feeder303 that stores sheets and separately feeds the sheets one by one, and an image formation unit304 that forms a latent image on a photoconductor to transfer an image to a sheet. The image forming apparatus 300 further includes a fixing unit 305 that fixes the image transferred to a sheet and a controller 306 that controls such blocks.

[0012] The inner finisher 100 includes an inner-finisher processing unit 101 and an inner-finisher controller 102. The inner-finisher controller 102 receives an instruction for processing from the controller 306 of the image forming apparatus 300 through a communication line 307.The inner-finisher processing unit 101 performs specified processing to a specified sheet. The controllers 102 and 306 coupled through the communication line 307 can exchange information. Thus, information regarding modes and information regarding sheet size or timing are exchanged, enabling a systematic operation.

[0013] FIG. 3 is a functional block diagram of the image forming system 1 equipped with an option. The inner-finisher optional device 200 includes an inner-finisher optional-device processing unit 201 and a controller 202. The controller 202 receives an instruction for processing from the inner- finisher controller 102 through a communication line 103. The inner- finisher optional-device processing unit 201 performs specified processing to a specified sheet. Except for the above, the functional block diagram of FIG. 3 is similar to the functional block diagram of FIG. 2.

[0014] FIG. 4 is a hardware configuration diagram of electric components in the image forming system 1. As illustrated, the inner finisher 100 includes a central processing unit (CPU) 110 connected to various types of motors and various types of sensors through interfaces (UFs). The CPU 110 serves as an arithmetic means and controls the operation of the entire inner finisher 100.

[0015] The various types of motors include a conveyance motor 111, a sheet ejection motor 112, a jogger drive motor 113, and a staple drive motor 114. The various types of sensors include a conveyance sensor 115, a sheet ejection sensor 116, and a staple movement home -position (HP) sensor 117.

[0016] The inner-finisher optional device 200 and the inner-finisher optional device 400 as optional devices for the inner finisher 100 are connected to the CPU 110 of the inner finisher 100 through I / Fs such that the inner finisher 100 can control the respective operations of the inner- finisher optional device 200 and the inner-finisher optional device 400.

[0017] The inner- finisher optional device 200 includes a punching motor 210, a punch moving motor 211, a pre-punch sensor 212, a cover opening / closing sensor 213, a punching-unit HP sensor 214. The inner- finisher optional device 400 includes a folding motor 410, an inlet sensor 411, and a folding sensor 412.

[0018] The CPU 110 in the inner finisher 100 is connected to the controller 306 of the image forming apparatus 300 through an I / F such that the inner finisher 100 can be controlled in response to a processing signal from the image forming apparatus 300. The inner finisher 100 is optional and thus is detachably attachable as a hardware configuration, like the inner-finisher optional device 200 and the inner-finisher optional device 400.

[0019] FIG. 5 is a diagram illustrating the conveyance path of the inner finisher 100. An inlet roller 11 corresponds to the most upstream roller in the inner finisher 100. A conveyance roller 12 corresponds to the second roller in the inner finisher 100. A shift roller 13 serves as a roller that shifts a sheet widthwise in the inner finisher 100. A return roller 14 serves as a roller that conveys a sheet to a reference fence 18 to hit the sheet against the reference fence 18. A tapping roller 15 serves as a roller that conveys a sheet to the reference fence 18. A sheet ejection roller 16a corresponds to the most downstream roller in the inner finisher 100. A staple tray 17 serves as a tray that temporarily stores sheets for binding processing and corresponds to a placement portion on which sheets are to be placed. The reference fence 18 serves as a fence to contact the rear end of a sheet to align the sheet in the conveyance direction for binding processing and corresponds to a contact member. A stapler 19 serves as a device that performs binding processing. A sheet ejection tray 20 serves as a tray ontowhich a sheet is ejected. A sheet bundle subjected to binding processing can be also ejected onto the sheet ejection tray 20. An end fence 21 serves as a fence to contact the rear end of an ejected sheet to align the ejected sheet.

[0020] The inner finisher 100 has a mode for conveying and ejecting a sheet directly to the sheet ejection tray 20 (shift ejection mode) and a mode for causing the stapler 19 to staple sheets (staple mode). In the shift ejection mode, the inlet roller 11 receives the sheet conveyed from the image forming apparatus 300. The sheet is conveyed to the sheet ejection roller 16a and then is ejected to the sheet ejection tray 20.

[0021] In the staple mode, the inlet roller 11 receives the sheet conveyed from the image forming apparatus 300. The sheet is conveyed to the shift roller 13. Then, the tapping roller 15 and the return roller 14 convey the sheet onto the staple tray 17 in a switchback manner to the reference fence 18. Such an operation is repeated for a predetermined number of sheets. In response to conveyance of the last sheet to the reference fence 18, the stapler 19 staples a sheet bundle. Then, the sheet bundle is ejected to the sheet ejection tray 20 by the return roller 14 and the sheet ejection roller 16a.

[0022] FIGS. 6 to 11 are diagrams illustrating the movement of a sheet P in the inner finisher 100 in the staple mode. Referring to FIG. 6, the sheet P conveyed from the image forming apparatus 300 is brought into the inner finisher 100, followed by conveyance. Referring to FIG. 7, the sheet P is conveyed toward the sheet ejection tray 20 without being shifted with a sheetejection driven roller 16b remaining at a pressure release position. Referring to FIG. 8, after the sheet P passes through the shift roller 13, the tapping roller 15 taps the sheet P, so that the sheet P is switched back to the reference fence 18.

[0023] Referring to FIGS. 9 A and 9B, the sheet P is conveyed by the tapping roller 15 and the return roller 14 until the sheet P contacts the reference fence 18, resulting in sheet alignment in the conveyance direction (contact direction). After contact the sheet P with the reference fence 18, a jogger fence 22 catches both sides of the sheet P, resulting in sheet alignment in the width direction (orthogonal direction to the contact direction). The jogger fence 22 includes a pair of jogger fences corresponding to a pair of orthogonal aligners. The jogger fence 22 will be described in detail later. Referring to FIG. 10, due to repetition of the process in FIG. 6 to FIGS. 9 A and 9B for a plurality of sheets P, the sheets P are stacked on top of each other on the staple tray 17, resulting in a sheet bundle Pt. Then, the stapler 19 staples the sheet bundle Pt. In this case, the sheet-ejection driven roller 16b moves to a nip position. Referring to FIG. 11, the stapled sheet bundle Pt is ejected onto the sheet ejection tray 20 by the sheet ejection roller 16a.

[0024] Next, an aligner in the inner finisher 100 as a feature in the present embodiment will be described. In the present embodiment, at least one of a pair of orthogonal aligners (jogger fences 22a and 22b) includes a projection protruding to a sheet and has a face facing the sheet. The face includes a portion opposed to an upstream portion in the contact direction (conveyance direction for contact) of the sheet in contact with a contact member (reference fence 18), and the projection is located on the portion. Thus, in the alignment by the jogger fences 22a and 22b, the jogger fences 22a and 22b contact the sheet first from the upstream side to align the sheet, leading to an improvement in the alignment quality in the conveyance direction of a sheet bundle Pt.

[0025] FIG. 12 is a diagram illustrating a mechanism including the jogger fences 22a and 22b for alignment in the width direction. The near jogger fence 22a and the far jogger fence 22b are each held by a jogger-fence sheet-crosswise movement shaft 23. The jogger-fence sheetcrosswise movement shaft 23 serves as a slide shaft for the jogger fence to move in the sheet width direction. Each jogger fence includes a sheet-bottom support portion 24. The sheetbottom support portion 24 supports sheets from below for alignment of a sheet bundle and also functions as a placement portion on which a sheet P is to be placed.

[0026] For example, each jogger fence reciprocates along the jogger-fence sheet-crosswise movement shaft 23 due to the jogger drive motor 113 (refer to FIG. 4). For example, such reciprocation can be achieved due to transmission of driving force with the jogger fences provided with racks engaging with pinions provided to the drive shaft of the jogger drive motor 113. Each jogger fence includes a projection 30 on its upstream side in the conveyance direction (on the side opposite to the side of location of the reference fence 18 in the conveyance direction), enabling the jogger fence to contact the sheet first from the upstream side in the conveyance direction to align the sheet. The projection 30 of each of the jogger fences 22a and 22b ranges from the lower end to the upper end of the corresponding jogger fence 22a or 22b and is identical in length to the corresponding jogger fence 22a or 22b in the direction orthogonal to the surface of the sheet P.

[0027] FIGS. 13A and 13B and FIGS. 14A, 14B, and 14C are diagrams illustrating disadvantages to be solved in the present embodiment. For example, a post-processing apparatus (e.g., a binding processing apparatus) has the following disadvantages in terms of a mechanism / control method in which alignment plates align a sheet P crosswise, namely, orthogonally to the sheet conveyance direction. That is, although alignment plates (jogger fences 22a and 22b) are ideally parallel to each other as in FIG. 13 A, due to the relationship in backlash or the center of gravity between components, the distance between the alignment plates is likely to be larger on the rear side than on the front side in the conveyance direction as in FIG. 13B. In that case, an alignment operation to a sheet P causes the alignment platesto have respective ends, on the side of location of the reference fence 18, in contact with the sheet P and push in the sheet P, as illustrated from left to right in FIG. 14B. Due to such pushing in, force F is applied to the sheet P from the alignment-plate downstream side. Thus, the sheet P is shifted upstream in the conveyance direction every time an alignment operation is performed. As a result, the alignment performance in the conveyance direction deteriorates as a disadvantage.

[0028] FIGS. 15A, 15B, and 15C are diagrams illustrating an alignment operation with the jogger fences in the present embodiment. In the alignment operation of the jogger fences in the present embodiment, the projections 30 enable the jogger fences to contact a sheet P first from the jogger-fence upstream side to align the sheet P. Thus, no force upstream in the conveyance direction acts on a sheet bundle Pt, leading to prevention of the occurrence of shift in the conveyance direction.

[0029] FIGS. 16A and 16B are diagrams illustrating a jogger- fence crosswise shift amount b [mm] due to backlash of a jogger fence. As illustrated in FIG. 16A or 16B, the jogger-fence crosswise shift amount b [mm] due to backlash is obtained by the following calculation, b = L-tan(c) where c represents a jogger-fence angle shift amount c [deg.] due to the backlash and L represents the distance [mm] between the leading end in contact with a sheet P and the rear end of the jogger fence at the time of alignment.The distance L [mm] between the leading end in contact with a sheet P and the rear end of the jogger fence at the time of alignment can be indicated as in FIG. 16A in a case where the jogger fence has a length in the conveyance direction longer than the length of the sheet or can be indicated as in FIG. 16B in a case where the jogger fence has a length in the conveyance direction shorter than the length of the sheet.

[0030] FIG. 17 is a diagram illustrating setting the height a of the projection 30 of each jogger fence. Setting the height a of the projection 30 from the jogger- fence face of each jogger fence to fulfdl the following condition: a > b [mm] enables to the jogger fence to contact a sheet first from the jogger- fence upstream side to align the sheet with the degree of backlash of each jogger fence taken into account. Preferably, the projection 30 provided to each jogger fence has a height a [mm] taking the backlash amount b [mm] obtained by the above-described mathematical expression into account, but this is not limiting because backlash of each jogger fence is likely to cause a sheet P to slant to a direction in which the jogger fence contacts the sheet first from the upstream side.

[0031] Lengthening the sheet contact position of each jogger fence as much as possible in the conveyance direction enables a further enhancement in the alignment quality of the joggerfences in the sheet width direction. Thus, preferably, the length L in the conveyance direction of each jogger fence is set as long as possible within a range allowing alignment for the size of any sheet to be aligned.Since a favorable height a of the projection 30 is obtained by the above-described mathematical expression, even in a case where the length in the conveyance direction of each jogger fence is set as long as possible, the projection 30 can be set to have a minimum height suitable to the set length in the conveyance direction. Thus, a reduction can be made in the size in the stroke direction of each jogger fence, leading to prevention of an increase in the size of the apparatus.

[0032] FIG. 18 is a diagram illustrating setting, in a case where each jogger fence is provided with a plurality of projections 31 and 32, the height a of each projection. As illustrated in FIG. 18, for an enhancement in alignment quality to sheets that are to be aligned and are different in size, each jogger fence may have its jogger-fence face provided with a plurality of projections each having a height a set based on the above-described mathematical expression including the distance L between the leading end in contact with a sheet P and the rear end of the jogger fence. The subscript 1 of the distance LI and the height al relates to a projection 31 for a small size, and the subscript 2 of the distance L2 and the height a2 relates to a projection 32 for a large size.

[0033] FIG. 19 is a diagram illustrating setting, in a case where each jogger fence includes a projection 33 provided with a scooper 34, the inclination angle e of the scooper 34. As illustrated in FIG. 19, the projection 33 of each jogger fence may be provided with the scooper 34 having an outward inclination toward the reference fence 18. The relationship between the inclination angle e [deg.] of a scooper and the jogger-fence angle shift amount c [deg.] (refer to FIGS. 16A and 16B) is set to fulfill the following condition: e > c [deg.]. Thus, even when a sheet small in size with respect to the projections in the conveyance direction is aligned, each jogger fence can contact the sheet first from the upstream side to alight the sheet. Regarding a sheet small in size with respect to the projections in the conveyance direction, if no scoopers are provided, the sheet is likely to be caught by the jogger-fence projections at the time of sheet ejection (refer to FIG. 11). However, the provision of the scoopers 34 enables prevention of such a possible disadvantage.

[0034] FIG. 20 illustrates a configuration in which a projection is implemented by a plate-spring component 40 on the upstream side of the alignment face of each jogger fence. Each platespring component 40 has a length, in the direction orthogonal to the surface of a sheet P, identical to the length of the corresponding jogger fence 22a or 22b. Such a plate-spring component may be replaced with an elastic member, such as a pressure spring, a sponge, rubber, or an elastic resin material. Similarly to the configuration in FIG. 17, in the presentconfiguration, the height a of each projection is set based on the above-described mathematical expression including the distance L between the leading end in contact with a sheet P and the rear end of the jogger fence. Thus, each jogger fence can contact the sheet P first from the upstream side to align the sheet, leading to prevention of the occurrence of shift in the conveyance direction.

[0035] FIGS. 21A, 21B, and 21C are diagrams illustrating the alignment operation of the jogger fences illustrated in FIG. 20. According to the alignment operation illustrated from left to right in FIGS. 21A, 21B, and 21C, even in a case where control is performed such that a portion on the jogger-fence upstream side of each plate-spring component 40 contacts a sheet P at the time of alignment and then further pushes in the sheet P, the plate-spring components 40 can each elastically absorb the excessive push. Thus, the present configuration enables not only a stable alignment operation in the conveyance direction but also a stable alignment operation in the sheet width direction.

[0036] FIG. 22 is a diagram illustrating setting, in a case where each jogger fence is provided with a plurality of elastic members 41 and 42, the height a of a projection in each elastic member. As illustrated in FIG. 22, each jogger fence may have a jogger-fence face provided with a plurality of elastic members, such as plate springs. Two or more elastic members each having its projection having a height a set based on the above-described mathematical expression including the distance L between the leading end in contact with a sheet P and the rear end of the jogger fence are attached to each jogger fence. Thus, an enhancement can be made in alignment quality in the sheet width direction per sheet size, similarly to the configuration in FIG. 18. The subscript 1 of the distance LI and the height al relates to the projection of an elastic member 41 for a small size, and the subscript 2 of the distance L2 and the height a2 relates to the projection of an elastic member 42 for a large size.

[0037] In a case where control is performed such that, at the time of alignment of a sheet, the projections each contact the sheet and then further push in the sheet, the elastic members disposed at the position LI are different in the amount of contraction from the elastic members disposed at the position L2. The restoring force F [N] of a spring is given by the following expression: F = kx where k represents a spring constant [N / m] and x represents an amount of contraction [m] with respect to the equilibrium length. In a case where the elastic members are set to have the same spring constant k, the difference in the amount of contraction between the elastic members causes difference in restoring force between the elastic members, leading to a deterioration in alignment quality in the sheet width direction. In order to avoid such a deterioration, the elastic members disposed at the position LI and the elastic members disposed at the position L2 may each have a spring constant k causing an elastic force corresponding to an amount of contraction such that the respective restoringforces F of the springs are identical or the restoring force F at each position is small. Thus, a further enhancement can be made in alignment quality in the sheet width direction.

[0038] Example configurations in FIGS. 23A, 23B, and 23C to FIG. 25 will be described as other configurations enabling functions similar to the function of the plate- spring components 40 in FIG. 20. FIGS. 23 A, 23B, and 23Cillustrate example configurations in which each jogger fence is turnable. FIGS. 24A, 24B, and 24C are diagrams illustrating an alignment operation by the example configurations in FIGS. 23 A, 23B, and 23C. As illustrated in FIGS. 23 A, 23B, and 23C, each jogger fence includes a sheet-bottom support portion 24 provided with a turn support 50 such that each jogger fence is tumable to a slider 51 held on a jogger-fence sheet-crosswise movement shaft 23. Torsion springs 52 each keep a posture enabling the jogger fences to contact a sheet first from the upstream side to align the sheet. Specifically, the torsion springs 52 each have both ends fastened, respectively, to a fastener 24a of the corresponding sheet-bottom support portion 24 and a fastener 51a of the corresponding slider 51 such that turning force is applied to open the front end in the conveyance direction, as illustrated in FIG. 23A. Against such turning force, provided is a stopper 53 that enables locking in a turned posture with a desired amount of protrusion a on the upstream side. Although FIGS. 23B and 23C illustrates a configuration in which the near jogger fence 22a is turnable, the far jogger fence 22b turns reversely to the near jogger fence 22a as a similar configuration.

[0039] For an alignment operation illustrated in FIGS. 24A, 24B, and 24C, each jogger fence is turnable around the turn support 50. Thus, even in a case where excessive movement of the jogger fences occurs in an alignment operation, the jogger fences can be each made parallel to the sheet length direction. Thus, sheet buckling at the time of alignment by the jogger fences or sheet jumping at the time of retraction after the alignment operation can be prevented, leading to a stable alignment operation in the sheet width direction. In the present configuration, a turn mechanism is provided on the side of location of the lower face of each jogger fence, enabling a reduction in the size of each jogger fence.

[0040] FIG. 25 illustrates an example configuration in which each jogger fence is swingable. In the example configuration, swing supports 60, such as hinges, are provided on the jogger-fence downstream side, enabling the jogger fences to swing. Even in a case where excessive movement of the jogger fences occurs in an alignment operation, the jogger fences can be each made parallel to the sheet length direction. Thus, sheet buckling at the time of alignment by the jogger fences or sheet jumping at the time of retraction after the alignment operation can be prevented, leading to a stable alignment operation in the sheet width direction. Provided are springs 61 and stoppers 62. The springs 61 apply turning force to reduce the distance between the rear ends in the conveyance direction (to make the distance between therear ends smaller than the distance between the front ends in the conveyance direction). Against such turning force, the stoppers 62 each enable locking in a turned posture with a desired amount of protrusion a on the upstream side. In the present configuration, no additional component is required in the height direction of each jogger fence, enabling a reduction in the size in the height direction of each jogger fence.

[0041] Referring to FIGS. 23A and 23B and FIG. 25, the respective configurations enable turning around a support. Regarding a favorable amount of turning, as illustrated in FIGS. 15 A, 15B, and 15C, preferably, each jogger fence turns by an amount that causes the corresponding jogger fence to be parallel to the sheet conveyance direction (that is, until the set projecting height a [mm] of each jogger fence decreases to zero).

[0042] FIGS. 26A, 26B, and 26C are diagrams illustrating trouble due to excessive movement that can be prevented by the configurations illustrated in FIGS. 20 to 25. FIGS. 26A, 26B, and 26C illustrate the behavior of a sheet P due to excessive movement. As illustrated from left to right, a state where, at the time of alignment, the jogger fences align a sheet with a space narrower than the width of the sheet between the jogger fences is referred to as excessive movement. In a case where the jogger fences push a sheet in an area less in width than the sheet, an unstable sheet behavior occurs due to sheet buckling depending on the thickness or number of sheets P or body at the time of alignment by the jogger fences or due to sheet jumping, as illustrated in the right drawing, at the time of retraction after the alignment operation. Thus, a deterioration is likely to occur in alignment quality in the width direction of sheets P.

[0043] FIGS. 27A, 27B, and 27C illustrate an example configuration in which the jogger fences 22a and 22b protrude upstream in the sheet conveyance direction with respect to sheet ejection rollers 16a.As illustrated in FIG. 27C, the jogger fence 22a has a first portion 22al downstream in the sheet conveyance direction (in the direction of an arrow A in FIGS. 27A and 27B) with respect to the sheet ejection rollers 16a, in which the first portion 22al faces a side end of a sheet in the staple tray 17. The jogger fence 22b has a first portion 22bl downstream in the sheet conveyance direction with respect to the sheet ejection rollers 16a, in which the first portion 22b 1 faces the other side end of the sheet in the staple tray 17. The jogger fence 22a has a second portion 22a2 as an extension provided upstream in the sheet conveyance direction with respect to the sheet ejection rollers 16a and upstream of the upstream end in the sheet conveyance direction of the staple tray 17, in which the second portion 22a2 faces a side end of a sheet located upstream in the sheet conveyance direction with respect to the sheet ejection rollers 16a. The jogger fence 22b has a second portion 22b2 as an extension provided upstream in the sheet conveyance direction with respect to the sheet ejection rollers16a and upstream of the upstream end in the sheet conveyance direction of the staple tray 17, in which the second portion 22b2 faces the other side end of the sheet located upstream in the sheet conveyance direction with respect to the sheet ejection rollers 16a.

[0044] A sheet portion located upstream in the sheet conveyance direction indicated by the arrow A in FIGS. 27A and 27B with respect to the sheet ejection rollers 16a protrudes from the staple tray 17 and is drooping due to its own weight as illustrated in FIG. 27B. The respective second portions 22a2 and 22b2 of the jogger fences 22a and 22b protrude downward with respect to the sheet ejection rollers 16a so as to face the side ends of the drooping sheet portion. Thus, the jogger fences can align the corresponding sheet P with the second portions 22a2 and 22b2 in contact with the side ends of the sheet portion that protrudes from the staple tray 17 and is drooping.

[0045] As indicated with dashed lines in FIG. 27A, the sheet ejection rollers 16a are longer than sheet-ejection driven rollers 16b and return rollers 14 in the sheet width direction. The sheet ejection rollers 16a each have an outer end, in the width direction, located outside the corresponding sheet-ejection driven roller 16b and return roller 14. Thus, depending on the width size of a sheet, the jogger fences 22a and 22b are likely to interfere with the sheet ejection rollers 16a. Therefore, the jogger fence 22a has a lower portion provided with a recess 22a3 in order to avoid interference with the corresponding sheet ejection roller 16a. The jogger fence 22b has a lower portion provided with a recess 22b3 in order to avoid interference with the corresponding sheet ejection roller 16a.

[0046] As illustrated in FIG. 27C, the second portions 22a2 and 22b2 are each provided with such a projection 30 as in one of the embodiments described above. Thus, the jogger fences 22a and 22b can contact a sheet P first from the upstream side in the sheet conveyance direction to align the sheet P. Thus, no force upstream in the conveyance direction acts on a sheet bundle Pt, leading to prevention of the occurrence of shift in the conveyance direction.

[0047] An embodiment in which a plurality of projections 31 and 32 is provided (refer to FIG. 18) or an embodiment in which a plurality of elastic members 41 and 42 is provided (refer to FIG. 22) can be applied to the jogger fences 22a and 22b illustrated in FIGS. 27A to 27C. In a case where such embodiments are applied to the jogger fences 22a and 22b, the first portions 22al and 22b 1 are each provided with a projection 31 or an elastic member 41, and the second portions 22a2 and 22b2 are each provided with a projection 32 or an elastic member 42.

[0048] An embodiment in which a projection 33 having an inclination is provided (refer to FIG. 19) can be applied to the jogger fences 22a and 22b illustrated in FIGS. 27A to 27C. In this case, the jogger fence 22a is provided with a projection 33 with an inclination ranging from the firstportion 22al to the second portion 22a2, and the jogger fence 22b is provided with a projection 33 with an inclination ranging from the first portion 22b 1 to the second portion 22b2. In a case where an embodiment in which a plate-spring component 40 is provided (refer to FIG. 20) is applied to the jogger fences 22a and 22b illustrated in FIGS. 27A to 27C, the second portions 22a2 and 22b2 are each provided with a portion having a height a in a projection.

[0049] Preferred embodiments of the present disclosure have been described above, but the present disclosure is not limited to such particular embodiments. Unless otherwise particularly limited in the above description, various modifications and alterations may be made without departing from the scope of the gist of the present disclosure in the claims. For example, a conveyor is used to place a sheet on a placement portion. However, a sheet having moved due to its own weight may be placed on the placement portion. The placement portion includes a placement tray. However, the placement portion may be only the upward supports of jogger fences on which a sheet is to be placed. As an example, a plurality of sheets is stacked on the placement portion and then is aligned in a predetermined posture at a predetermined reference position in a sheet processing apparatus, followed by postprocessing, such as stapling. The present disclosure can be applied to a dedicated sheet processing apparatus for alignment that aligns sheets and then ejects the sheets without any particular additional processing. As an example, a plurality of sheets is stacked on the placement portion, but the present disclosure can be applied to a sheet processing apparatus in which a single sheet is placed on a placement portion. For example, the present disclosure can be applied to a sheet processing apparatus that aligns sheets in a predetermined posture at a predetermined reference position in the sheet processing apparatus, performs predetermined processing, such as folding processing, to the sheets, and then ejects the sheets.

[0050] In each illustrated embodiment, a pair of orthogonal aligners is moved by an orthogonal movement means, but one of the orthogonal aligners may be moved. Such orthogonal aligners are each provided with a projection protruding orthogonally inward from the corresponding orthogonal aligner, but such a projection may be provided to one of the orthogonal aligners. Thus, depending on possible combinations, numerous variations are available.

[0051] Depending on possible patterns of movement of the pair of aligners, three variations are available. That is, the three variations are as follows: a case where only the near jogger fence 22a moves, a case where only the far jogger fence 22b moves, and a case where both of the jogger fences 22a and 22b move. Furthermore, three variations are available depending on the presence or absence of a projection. That is, the three variations are as follows: a case where only the near jogger fence 22a has a projection, a case where only the far jogger fence22b has a projection, and a case where the jogger fences 22a and 22b each have a projection. Therefore, nine variations resulting from multiplying the three variations and the three variations together are available.

[0052] In any variation, in a case where, regardless of the relationship in angle between the sheet opposed faces of the aligners, at least part of the sheet opposed face of the moving aligner makes contact with a sheet to start to push the sheet, a condition that the part is located upstream is a sufficient condition for solving the disadvantages. The reason is as follows.

[0053] In both a case where one of the aligners moves and a case where both of the aligners move, contact starts between an orthogonally shifted sheet and a moving aligner. It is assumed that, at the point in time when the contact starts, the sheet is out of contact with the other aligner. In this case, due to the moment of the pushing force to the sheet, after the contact starts, around an imaginary center of the frictional force between the upper face of the placement portion or the upper face of a lower sheet and the lower face of the sheet being pushed, the sheet turns. The imaginary center is located downstream of the point at where the aligner pushes the sheet in contact. Thus, the moment turns the sheet such that the downstream side of the sheet approaches a contact aligner. When the sheet, which is being shifted orthogonally while turning due to continuous pushing, contact a part of the other aligner, the subsequent turn and movement of the sheet are determined by the upstream / downstream positional relationship between the contact part of the other aligner and the pushing point or the relationship in strength between the frictional force between the sheet and the contact part and the frictional force between the sheet and the pushing point. Regarding the turn and movement, in a case where the contact part is located further upstream (hereinafter, referred to as pattern 1), the moment of turning around the contact part causes the downstream side of the sheet to approach the contact aligner. In contrast, in a case where the contact part is located further downstream (hereinafter, referred to as pattern 2), the moment of turning around the contact part causes the downstream side of the sheet to move away from the contact aligner. In general, no pattern 2 occurs. At the point in time when the sheet contacts a part of the other aligner, the sheet has turned to some extent due to continuous pushing. Thus, due to the presence of such an amount of turning, the accuracy of posture or backlash tolerance of the other aligner and the backlash tolerance of the moving aligner are easy to implement to the extent that no pattern 2 occurs. As a result, in a case where, regardless of the relationship in angle between the sheet opposed faces of the aligners, at least part of the sheet opposed face of a moving aligner contacts a sheet to start to push the sheet, a condition that the part is located upstream is a sufficient condition for solving the disadvantages.

[0054] The effects described in the embodiments of the present disclosure are listed as most preferable effects derived from the present disclosure, and thus effects according to the present disclosure are not limited to the effects in the embodiments of the present disclosure.

[0055] The above descriptions are examples and the following aspects of the present disclosure have respective particular effects. Reference signs in parentheses with which constituents are denoted in each aspect indicate the corresponding members. However, the constituents are not limited to the members.First aspectAccording to a first aspect, a sheet processing apparatus (e.g., the inner finisher 100) includes: a placement portion (e.g., the staple tray 17) on which a sheet is to be placed; a contact member (e.g., the reference fence 18) to contact an end of the sheet on the placement portion to align the sheet; a pair of orthogonal aligners (e.g., the near jogger fence 22a and the far jogger fence 22b) to align the sheet in an orthogonal direction to a contact direction in which the sheet is brought into contact with the contact member; and an orthogonal movement means (e.g., the jogger-fence sheet-crosswise movement shaft 23) to move at least one of the pair of orthogonal aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet. The at least one of the pair of orthogonal aligners includes a projection (e.g., the jogger-fence projection 30, the projection 31, the projection 32, the plate-spring component 40, the elastic member 41, or the elastic member 42) protruding to the sheet and has a face to face the sheet. The face includes a face part to be opposed to an upstream portion of the sheet in the contact direction, with the sheet being in contact with the contact member. The at least one of the pair of orthogonal aligners has the projection on the face part of the face.According to the first aspect, since the projection is provided to the alignment face of the at least one of the pair of orthogonal aligners, the at least one of the pair of orthogonal aligners can contact first from the upstream side of the at least one of the pair of orthogonal aligners in an alignment operation to align the sheet. Thus, the force upstream in the contact direction can be prevented from acting on a sheet or a sheet bundle, leading to prevention of the occurrence of shift in the sheet conveyance direction. That is, an improvement can be made in alignment quality in the sheet contact direction.

[0056] Second aspectAccording to a second aspect, in the sheet processing apparatus of the first aspect, an amount of protrusion (e.g., the amount of protrusion a) of the projection is larger than an amount of displacement of the face part in a direction in which the face part moves away from the sheet in the orthogonal direction due to an inclination of the at least one of the pair of orthogonal aligners with respect to the contact direction due to, for example, backlash.In the second aspect, setting the height of the projection with the above-described mathematical expression enables the at least one of the pair of orthogonal aligners to contact the sheet first from the upstream side of the at least one of the pair of orthogonal aligners to align the sheet with the degree of backlash of the at least one of the pair of orthogonal aligners taken into account (an improvement in alignment quality in the sheet contact direction). Even in a case where the at least one of the pair of orthogonal aligners has a length set as long as possible in the contact direction for an improvement in alignment quality in the sheet contact direction, a favorable height of the projection is obtained by the above-described mathematical expression. Thus, the projection can be set to have a minimum height suitable to the set length in the contact direction of the at least one of the pair of orthogonal aligners. Thus, a reduction can be made in the size in the stroke direction of the at least one of the pair of orthogonal aligners, leading to prevention of an increase in the size of the apparatus.

[0057] Third aspectAccording to a third aspect, in the sheet processing apparatus of the first aspect or the second aspect, the projection has an inclined face (e.g., the scooper 34) in which an amount of protrusion of a leading end of the projection decreases as the projection is closer to the contact member.According to the third aspect, since the projection of the at least one of the pair of orthogonal aligners has an outward inclination toward the contact member, the sheet is prevented from being caught by the projection of the at least one of the pair of orthogonal aligners at the time of sheet conveyance (an improvement in alignment quality in the sheet contact direction and prevention of trouble such as damage occurrence due to being caught by the projection at the time of conveyance after sheet alignment). Even when a short- size sheet shorter in size than the projection in the contact direction is conveyed, the at least one of the pair of orthogonal aligners can contact the sheet first from the upstream side of the at least one of the pair of orthogonal aligners (an improvement in alignment quality in the sheet contact direction) to align the sheet.

[0058] Fourth aspectAccording to a fourth aspect, the sheet processing apparatus of any one of the first to third aspects includes a plurality of projections (e.g., the projection 31, the projection 32, the elastic member 41, or the elastic member 42), including the projection, at different positions in the contact direction.According to the fourth aspect, two or more protrusions are provided to the at least one of the pair of orthogonal aligners and are each used depending on a sheet size. Thus, an enhancement can be made in alignment quality in the sheet width direction per sheet size (an improvement in alignment quality in the sheet width direction).

[0059] Fifth aspectAccording to a fifth aspect, in the sheet processing apparatus of any one of the first to fourth aspects, the projection includes an elastic member (e.g., the plate-spring component 40, an elastic member 41, or the elastic member 42) deformable in the orthogonal direction. According to the fifth aspect, since the elastic member, such as a plate spring, is provided to the alignment face of the at least one of the pair of orthogonal aligners, the at least one of the pair of orthogonal aligners can contact the sheet first from the upstream side of the at least one of the pair of orthogonal aligners in an alignment operation to align the sheet. Thus, force upstream in the contact direction can be prevented from acting on a sheet or a sheet bundle, leading to prevention of the occurrence of shift in the sheet contact direction. Even in a case where excessive movement of the at least one of the pair of orthogonal aligners occurs in an alignment operation, the elastic member, such as a plate spring, a pressure spring, or an elastic resin, can absorb the amount of excessive movement. Thus, sheet buckling at the time of alignment due to the pair of orthogonal aligners or sheet jumping at the time of retraction after the alignment operation can be prevented, leading to a stable alignment operation in the sheet width direction (improvements in alignment quality in the sheet contact direction and the sheet width direction).

[0060] Sixth aspectAccording to a sixth aspect, the sheet processing apparatus of the fifth aspect includes a plurality of elastic members (e.g., the plate-spring component 40, the elastic member 41, or the elastic member 42), including the elastic member, deformable in the orthogonal direction. The plurality of elastic members are disposed at different positions in the contact direction, and are different in elastic force.According to the sixth aspect, the plurality of elastic members at different attachment positions of the at least one of the pair of orthogonal aligners are different in the amount of protrusion a and the amounts of spring contraction on the upstream and downstream sides in the contact direction of the at least one of the pair of orthogonal aligners are different. In a case where each elastic member has the same set elastic force, the difference in the amount of contraction between the elastic members causes difference in restoring force between the elastic members, leading to a deterioration in alignment quality in the sheet width direction. Thus, the elastic members disposed at different positions are each set to have elastic force corresponding to the amount of contraction such that the respective restoring forces of the springs are identical or a small restoring force is obtained at each spring. Thus, a further enhancement can be made in alignment quality in the sheet width direction (an improvement in alignment quality in the sheet width direction).

[0061] Seventh aspectAccording to a seventh aspect, in the sheet processing apparatus of any one of the first to sixth aspects, the at least one of the pair of orthogonal aligners (e.g., the near jogger fence 22a or the far jogger fence 22b) includes an extension (e.g., the second portion 22a2 or the second portion 22b2) disposed further upstream than an upstream end in the contact direction of the placement portion (e.g., the staple tray 17). The at least one of the pair of orthogonal aligners has the projection (e.g., the projection 31, the projection 32, the elastic member 41, or the elastic member 42) on the extension (e.g., the second portion 22a2 or the second portion 22b2).According to the seventh aspect, the sheet can be aligned with the at least one of the pair of orthogonal aligners (e.g., the near jogger fence 22a or the far jogger fence 22b) in contact with a side end of a sheet portion protruding from the upstream end in the contact direction of the placement portion (e.g., the staple tray 17). In addition, the sheet can be aligned due to contact on the upstream side of the at least one of the pair of orthogonal aligners in an alignment operation.

[0062] Eighth aspectAccording to an eighth aspect, a sheet processing apparatus (e.g., the inner finisher 100) includes: a placement portion (e.g., the staple tray 17) on which a sheet is to be placed; a contact member (e.g., the reference fence 18) to contact an end of the sheet on the placement portion to align the sheet; a pair of orthogonal aligners (e.g., the near jogger fence 22a and the far jogger fence 22b) to align the sheet in an orthogonal direction to a contact direction in which the sheet is brought into contact with the contact member; and an orthogonal movement means (e.g., the jogger-fence sheet-crosswise movement shaft 23) to move at least one of the pair of orthogonal aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet. The at least one of the pair of orthogonal aligners is turnable around a turn support (e.g., the turn support 50 or the swing support 60) parallel to a direction perpendicular to an upper face of the sheet in contact with the contact member.Ninth aspectAccording to a ninth aspect, in the sheet processing apparatus of the eighth aspect, the at least one of the pair of orthogonal aligners that is tumable turns, due to movement by the orthogonal movement means, to transition from a first posture in which an upstream portion in the contact direction of the at least one of the pair of orthogonal aligners contacts the sheet, which is in contact with the contact member, early to a second posture in which the at least one of the pair of orthogonal aligners is parallel to an opposed side of the sheet.According to the eighth and ninth aspects, the pair of orthogonal aligners in an alignment operation can contact the sheet first from the upstream side of the at least one of the pair of orthogonal aligners in an alignment operation to align the sheet. Thus, the force upstream in the contact direction can be prevented from acting on a sheet or a sheet bundle, leading toprevention of the occurrence of shift in the sheet contact direction. Even in a case where excessive movement of the at least one of the pair of orthogonal aligners occurs in an alignment operation, the at least one of the pair of orthogonal aligners can turn to be parallel to the sheet length direction. Thus, sheet buckling at the time of alignment due to the pair of orthogonal aligners or sheet jumping at the time of retraction after the alignment operation can be prevented, leading to a stable alignment operation in the sheet width direction (improvements in alignment quality in the sheet contact direction and the sheet width direction).

[0063] Tenth aspectAccording to a tenth aspect, a sheet processing apparatus (e.g., the inner finisher 100) includes: a placement portion (e.g., the staple tray 17) on which a sheet is to be placed; a contact member (e.g., the reference fence 18) to contact an end of the sheet on the placement portion to align the sheet; a pair of orthogonal aligners (e.g., the near jogger fence 22a and the far jogger fence 22b) to align the sheet in an orthogonal direction to a contact direction in which the sheet is brought into contact with the contact member; and an orthogonal movement means (e.g., the jogger-fence sheet-crosswise movement shaft 23) to move at least one of the pair of orthogonal aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet. The at least one of the pair of orthogonal aligners transitions, due to movement by the orthogonal movement means, from a first posture to a second posture. In the first posture, an upstream portion of the at least one of the pair of orthogonal aligners in the contact direction contacts the sheet, which is in contact with the contact member, earlier. In the second posture, the at least one of the pair of orthogonal aligners is parallel to an opposed side of the sheet.According to the tenth aspect, even in a case where excessive movement of the at least one of the pair of orthogonal aligners occurs in an alignment operation, the elasticity or turn of the at least one of the pair of orthogonal aligners enables the at least one of the pair of orthogonal aligners to be parallel to the sheet length direction. Thus, sheet buckling at the time of alignment due to the pair of orthogonal aligners or sheet jumping at the time of retraction after the alignment operation can be prevented, leading to a stable alignment operation in the sheet width direction (improvements in alignment quality in the sheet contact direction and the sheet width direction).

[0064] Eleventh aspectAccording to an eleventh aspect, an image forming system (e.g., the image forming system 1) includes: an image forming apparatus (e.g., the image forming apparatus 300) to form an image on a sheet as a recording medium; and a post-processing apparatus (e.g., the inner finisher 100) to perform post-processing to the sheet on which the image is formed by theimage forming apparatus. The image forming system uses the sheet processing apparatus according to any one of the first to tenth aspects as the post-processing apparatus.According to the eleventh aspect, the effects in the first to tenth aspects can be achieved. The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and / or features of different illustrative embodiments may be combined with each other and / or substituted for each other within the scope of the present invention.This patent application is based on and claims priority to Japanese Patent Application No. 2024-013513, filed on January 31, 2024, and 2024-082861, filed on May 21, 2024, in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein.[Reference Signs List]

[0065] 1: Image forming system11 : Inlet roller12: Conveyance roller13: Shift roller14: Return roller15: Tapping roller16a: Sheet ejection roller16b: Sheet-ejection driven roller17: Staple tray18: Reference fence19: Stapler20: Sheet ejection tray21: End fence22: Jogger fence22a: Near jogger fence22b: Far jogger fence23: Jogger-fence sheet-crosswise movement shaft24: Sheet-bottom support portion24a: Fastener30: Jogger-fence projection31: Projection33: Projection34: S cooper40: Plate- spring component41: Elastic member42: Elastic member50: Turn support51: Slider52: Torsion spring51a: Fastener53: Stopper60: Swing support61: Spring62: Stopper100: Inner finisher101: Inner-finisher processing unit102: Inner-finisher controller103: Communication line110: Central processing unit (CPU)200: Inner-finisher optional device201: Inner-finisher optional-device processing unit202: Controller210: Punching motor211: Punch moving motor212: Pre-punch sensor213: Cover opening / closing sensor214: Punching-unit home-position (HP) sensor300: Image forming apparatus301: Display302: Operation unit303: Sheet feeder304: Image formation unit305: Fixing unit306: Controller307: Communication line400: Inner-finisher optional device410: Folding motor411: Inlet sensor412: Folding sensorFX: ForceFY: ForceE: DistanceX: Width directionY : Introducing conveyance direction

Claims

[CLAIMS]

1. A sheet processing apparatus, comprising: a placement portion on which a sheet is to be placed; a contact member to contact an end of the sheet on the placement portion to align the sheet; a pair of orthogonal aligners to align the sheet in an orthogonal direction to a contact direction in which the sheet is brought into contact with the contact member; and an orthogonal movement means to move at least one of the pair of orthogonal aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet, wherein the at least one of the pair of orthogonal aligners has a face to face the sheet and a projection that protrudes toward the sheet, the face includes a face part to be opposed to an upstream portion of the sheet in the contact direction, with the sheet being in contact with the contact member, and the at least one of the pair of orthogonal aligners has the projection on the face part of the face.

2. The sheet processing apparatus according to claim 1, wherein an amount of protrusion of the projection is larger than an amount of displacement of the face part in a direction in which the face part moves away from the sheet in the orthogonal direction due to an inclination of the at least one of the pair of orthogonal aligners with respect to the contact direction.

3. The sheet processing apparatus according to claim 1 or 2, wherein the projection has an inclined face in which an amount of protrusion of the projection that protrudes toward the sheet decreases from upstream to downstream in the contact direction.

4. The sheet processing apparatus according to any one of claims 1 to 3, further comprising a plurality of projections, including the projection, at different positions in the contact direction.

5. The sheet processing apparatus according to any one of claims 1 to 4, wherein the projection includes an elastic member to deform in the orthogonal direction.

6. The sheet processing apparatus according to claim 5, wherein the projection includes a plurality of elastic members, including the elastic member, to deform in the orthogonal direction, and the plurality of elastic members are at different positions in the contact direction and are different in elastic force.

7. The sheet processing apparatus according to any one of claims 1 to 6, wherein the at least one of the pair of orthogonal aligners includes an extension disposed further upstream than an upstream end of the placement portion in the contact direction, and the at least one of the pair of orthogonal aligners has the projection on the extension.

8. A sheet processing apparatus, comprising: a placement portion on which a sheet is to be placed; a contact member to contact an end of the sheet on the placement portion to align the sheet; a pair of orthogonal aligners to align the sheet in an orthogonal direction to a contact direction in which the sheet is brought into contact with the contact member; and an orthogonal movement means to move at least one of the pair of orthogonal aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet, wherein the at least one of the pair of orthogonal aligners is tumable around a turn support parallel to a direction perpendicular to an upper face of the sheet in contact with the contact member.

9. The sheet processing apparatus according to claim 8, wherein the at least one of the pair of orthogonal aligners turns, due to movement by the orthogonal movement means, to transition from a first posture to a second posture, wherein in the first posture, an upstream portion of the at least one of the pair of orthogonal aligners in the contact direction contacts the sheet, which is in contact with the contact member, earlier than a downstream portion of the at least one of the pair of orthogonal aligners in the contact direction, and in the second posture, the at least one of the pair of orthogonal aligners is parallel to an opposed side of the sheet that is opposed to the at least one of the pair of orthogonal aligners.

10. A sheet processing apparatus comprising: a placement portion on which a sheet is to be placed; a contact member to contact an end of the sheet on the placement portion to align the sheet; a pair of orthogonal aligners to align the sheet in an orthogonal direction to a contact direction in which the sheet is brough into contact with the contact member; and an orthogonal movement means to move at least one of the pair of orthogonal aligners in the orthogonal direction between a separation position and a contact position with respect to the sheet, wherein the at least one of the pair of orthogonal aligners transitions, due to movement by the orthogonal movement means, from a first posture to a second posture, wherein in the first posture, an upstream portion of the at least one of the pair of orthogonal aligners in the contact direction contacts the sheet, which is in contact with the contactmember, earlier than a downstream portion of the at least one of the pair of orthogonal aligners in the contact direction, and wherein in the second posture, the at least one of the pair of orthogonal aligners is parallel to an opposed side of the sheet that is opposed to the at least one of the pair of orthogonal aligners.

11. An image forming system, comprising: an image forming apparatus to form an image on the sheet; and the sheet processing apparatus according to any one of claims 1 to 10 to perform postprocessing to the sheet on which the image is formed by the image forming apparatus.

Images