Medium Processing Apparatus and Image Forming System

This patent application is based on and claims priority pursuant to 35 U.S.C. § 119 (a) to Japanese Patent Application No. 2024-095443, filed on Jun. 12, 2024, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.

The present disclosure relates to a medium processing apparatus and an image forming system.

Various types of medium processing apparatuses have been proposed that bind a sheet bundle of stacked sheet media. Examples of binding processes performed by such medium processing apparatuses include a “stapling process” to penetrate a staple (a binding member) through a bundle of sheets to bind the bundle of sheets and a “crimping process” to press and deform a part of a bundle of sheets to bind the bundle of sheets.

In a configuration, for example, when liquid is applied to a sheet-shaped medium such as a paper sheet for crimping, the amount of liquid applied to the medium is adjusted in order to obtain an appropriate binding force.

The present disclosure described herein provides a medium processing apparatus that includes a liquid applier, a post-processing device, a first liquid storage, a second liquid storage, a liquid supplier, a liquid detector, and processing circuitry. The liquid applier applies liquid to a part of a medium to perform a liquid application. The post-processing device performs desired processing on a bundle of media including the medium subjected to the liquid application. The first liquid storage stores the liquid used for the liquid application by the liquid applier. The second liquid storage stores the liquid to be supplied to the first liquid storage. The liquid supplier supplies the liquid from the second liquid storage to the first liquid storage. The liquid detector detects a liquid level of the liquid in the first liquid storage. The processing circuitry controls operations of the post-processing device and the liquid supplier. The processing circuitry changes a liquid level at which supply of the liquid is stopped in a liquid supply operation executed by the liquid supplier, according to a remaining amount of the liquid in the first liquid storage.

The present disclosure described herein also provides an image forming system that includes an image forming apparatus and the medium processing apparatus. The image forming apparatus forms an image on a plurality of media constituting the bundle of media. The medium processing apparatus performs the desired processing on the bundle of media on which the image is formed by the image forming apparatus.

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.

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.

Embodiments of the present disclosure are described below with reference to the accompanying drawings. Note that identical parts are given identical reference signs and redundant descriptions are summarized or omitted accordingly.

A description is given below of an image forming systemaccording to an embodiment of the present disclosure, with reference to the drawings.is a diagram illustrating an overall configuration of the image forming system. The image forming systemhas, for example, a function of forming an image on a sheet P as an example of a sheet-shaped medium and a post-processing function of performing post-processing on the sheet P on which the image has been formed. As illustrated in, the image forming systemincludes an image forming apparatushaving the image forming function and a post-processing apparatusserving as a media processing apparatus having the post-processing function according to an embodiment of the present disclosure. In the image forming system, the image forming apparatusand the post-processing apparatusoperate in conjunction with each other.

In the present embodiment, the sheet-shaped medium or sheet-shaped medium to be processed in the image forming systemis described on the assumption that the medium is a sheet of “paper.” However, the object to be processed according to the present embodiment is not limited to a sheet of paper. For example, any type of medium can be used as long as an image can be formed on the medium according to an image forming process. Examples of the medium include a medium that can be an object of a folding process or a binding process, and the material and specification of the medium are not limited to any particular material and specification.

The image forming apparatusforms an image on the sheet P and ejects the sheet P having the image to the post-processing apparatus. The image forming apparatusincludes an accommodation traythat accommodates sheets P, a conveyorthat conveys a sheet P from the accommodation tray, and an image forming devicethat forms an image on the sheet P conveyed by the conveyor. The image forming devicemay be an inkjet system that forms an image using ink or an electrophotographic system that forms an image using toner. The image forming apparatusalso includes a controllerthat controls various operations of the conveyorand the image forming device. Since the image forming apparatushas a typical configuration, a detailed description of the configuration is omitted.

is a diagram illustrating an internal configuration of the post-processing apparatusaccording to the first embodiment of the present disclosure. The post-processing apparatushas a function that performs post-processing on the sheet P on which an image is formed by the image forming apparatus. An example of the post-processing according to the present embodiment is a binding process as a “crimping process” that binds, without staples, a plurality of sheets P on each of which an image is formed as a bundle of sheets P, which may be referred to as a sheet bundle. Another example of the post-processing according to the present embodiment is a binding process as a “stapling process” that binds, with staples, a plurality of the sheets P on each of which an image is formed as a bundle of sheets P (i.e., sheet bundle).

In the following description, the bundle of sheets may be referred to as a “sheet bundle Pb” as a bundle of media. In the present embodiment, a description is given of a liquid application process in a crimping process. However, liquid application performed in a stapling process is similar to the liquid application in the crimping process. In the following description, the term “binding process” indicates both the “crimping process” and the “stapling process.”

More specifically, the “crimping process” or “crimp binding process” according to the present embodiment is a process of applying pressure to a binding position corresponding to a part of a sheet bundle Pb to deform (i.e., pressure-deformed) the binding position, entangle the fibers of overlapping sheets P with each other, and thus bind the sheets P together. The crimping process partially binds the overlapping portions of the sheets P together to form a sheet bundle Pb. This crimping process is referred to as “crimping” in the following description.

The binding process ((including both the crimping and the staple binding) that is executable by the post-processing apparatusincludes edge binding and saddle binding. The edge binding is a process to bind an end (including an edge) of the sheet bundle Pb. The saddle binding (center binding) is a process to bind the center of the sheet bundle Pb.

The post-processing apparatusincludes the conveyance roller pairsto(conveyors) and the switcher. The conveyance roller pairstoconvey, inside the post-processing apparatus, a sheet P supplied from the image forming apparatus. Specifically, the conveyance roller pairstoconvey the sheet P along a first conveyance passage Ph. The conveyance roller pairsandconvey the sheet P along a second conveyance passage Ph. The conveyance roller pairstoconvey the sheet P along a third conveyance passage Ph. A hole punchis disposed between the conveyance roller pairsand. The hole punchperforms punching on the sheet P conveyed by the conveyance roller pairsand.

The first conveyance passage Phis a passage extending to a first ejection trayfrom a supply port through which the sheet P is supplied from the image forming apparatus. The second conveyance passage Phis a passage branching from the first conveyance passage

Phbetween the conveyance roller pairsandin the conveyance direction of the sheet and extending to a second ejection trayvia the internal tray. The third conveyance passage Phis a passage branching from the first conveyance passage Phbetween the conveyance roller pairsandin the conveyance direction of the sheet and extending to a third ejection tray.

The switcheris disposed at a branching position of the first conveyance passage Phand the second conveyance passage Ph. The switchercan be switched between a first position and a second position. The switcherin the first position guides the sheet P to be ejected to the first ejection traythrough the first conveyance passage Ph. The switcherin the second position guides the sheet P conveyed through the first conveyance passage Phto the second conveyance passage Ph. At the timing when the trailing end of the sheet P entering the second conveyance passage Phpasses between the rollers of the conveyance roller pair, the conveyance roller pairis rotated in the reverse direction so that the sheet P is guided to the third conveyance passage Ph. The post-processing apparatusfurther includes a plurality of sensors that detects the positions of the sheet P in the first conveyance passage Ph, the second conveyance passage Ph, and the third conveyance passage Ph. Each of the multiple sensors is indicated by a black triangle in.

The post-processing apparatusincludes a first ejection tray. The sheet P that is output through the first conveyance passage Phis placed on the first ejection tray. Among the sheets P supplied from the image forming apparatus, a sheet P not subjected to the binding process is ejected to the first ejection tray.

The post-processing apparatusfurther includes the internal trayserving as a placement tray, an edge-binding end fence, side fencesL andR, an edge binder, a staple binder, and a second ejection tray. The internal tray, the edge-binding end fence, the side fencesL andR, the edge binder, and the staple binderperform the edge binding on the sheet bundle Pb including the plurality of sheets P conveyed through the second conveyance passage Ph.

Examples of the “edge binding process” include, but not limited to, “parallel binding process,” “oblique binding process,” and “vertical binding process.” The “parallel binding process” is a process of binding the sheet bundle Pb along one side of the sheet bundle Pb parallel to the main scanning direction. The “oblique binding process” is a process of binding a corner of the sheet bundle Pb. The “vertical binding process” is a process of binding the sheet bundle Pb along one side of the sheet bundle Pb parallel to the conveyance direction.

Among the sheets P supplied from the image forming apparatus, the sheet bundle Pb subjected to the edge binding is ejected to the second ejection tray. In the following description, the direction in which the sheet P is conveyed from the conveyance roller pairtoward the edge-binding end fenceis defined as a “conveyance direction” of the sheet P. In other words, the “conveyance direction” herein corresponds to a direction in which the sheet P that has been ejected from the image forming apparatusis moved toward the second ejection trayby, for example, the conveyance roller pairand then is moved toward the edge-binding end fenceby the conveyance roller pair. The direction that is orthogonal to both the conveyance direction and a thickness direction of the sheet P is defined as a “main scanning direction” or a “width direction of the sheet P.”

The sheets P that are sequentially conveyed through the second conveyance passage Phare temporarily placed on the internal trayserving as a placement tray. The edge-binding end fencealigns the position, in the conveyance direction, of the sheet P or the sheet bundle Pb placed on the internal tray. The side fencesL andR align the position, in the main scanning direction, of the sheet P or the sheet bundle Pb placed on the internal tray. The edge binderand the staple binderperform edge binding on the sheet bundle Pb aligned by the edge-binding end fenceand the side fencesL andR. The conveyance roller pairejects the sheet bundle Pb subjected to the edge binding to the second ejection tray.

The post-processing apparatusfurther includes a saddle-binding end fence, a saddle binder, a sheet folding blade, and the third ejection tray. The saddle-binding end fence, the saddle binder, and the sheet folding bladeperform the saddle binding on the sheet bundle Pb of the sheets P that are conveyed through the third conveyance passage Ph. Among the sheets P supplied from the image forming apparatus, the sheet bundle Pb subjected to the saddle binding is ejected to the third ejection tray.

The saddle-binding end fencealigns the positions of the sheets P that are sequentially conveyed through the third conveyance passage Ph, in a direction in which the sheets P are conveyed. The saddle-binding end fencecan move between a binding position where the saddle-binding end fencecauses the center of the sheet bundle Pb to face the saddle binderand a folding position where the saddle-binding end fencecauses the center of the sheet bundle Pb to face the sheet folding blade. The saddle binderbinds the center of the sheet bundle Pb aligned by the saddle-binding end fenceat the binding position. The sheet folding bladefolds, in half, the sheet bundle Pb placed on the saddle-binding end fenceat the folding position and causes the conveyance roller pairto nip the sheet bundle Pb. The conveyance roller pairsandeject the sheet bundle Pb subjected to the saddle binding to the third ejection tray.

The post-processing apparatusincludes a first liquid storage tank(a first liquid storage), and a liquid supply memberin the edge binder. The first liquid storage tankand the liquid supply memberare omitted in. The post-processing apparatusincludes a liquid supply passage, a liquid supply pump(a liquid supplier), a second liquid storage tank(a part of a second liquid storage), and a second-liquid-storage-tank fixer(a part of the second liquid storage) as a configuration for replenishing the first liquid storage tankwith the liquid. The liquid that is stored in the second liquid storage tankis supplied to the first liquid storage tankthrough the second-liquid-storage-tank fixer, the liquid supply pump, and the liquid supply passage.

A description is given of the edge binder.

is a schematic view of an upstream side of the edge binderin the conveyance direction. The edge binderperforms a liquid application process and a crimping process.is a schematic diagram of the edge binderviewed from the side on which a liquid applieris disposed in the main scanning direction. As illustrated in, the edge binderincludes the liquid applierthat applies liquid to the sheets P, and a crimperthat is an example of a post-processing device and serves as a crimp binder. The liquid applierand the crimperare disposed downstream from the internal trayin the conveyance direction and adjacent to each other in the main scanning direction.

The liquid applierapplies liquid that is stored in the first liquid storage tankto the sheet P or the sheet bundle Pb placed on the internal tray. The application of the liquid to the sheet P or the sheet bundle Pb by the liquid applierand the operation of the liquid applierin applying the liquid are referred to as “liquid application” below. The liquid applying operation of the liquid applierinvolving control processing is referred to as a “liquid application process.”

More specifically, the liquid that is stored in the first liquid storage tankas liquid for the “liquid application” includes, as a main component, the liquid state of a compound of hydrogen and oxygen compound represented by the chemical formula HO. The liquid hydrogen-oxygen compound is at any temperature. For example, the liquid hydrogen-oxygen compound may be so-called warm water or hot water. The liquid hydrogen-oxygen compound is not limited to pure water. The liquid hydrogen-oxygen compound may be purified water or may contain ionized salts. The metal ion content ranges from so-called soft water to ultrahard water. In other words, the liquid hydrogen-oxygen compound is at any hardness.

The liquid that is stored in the first liquid storage tankmay include an additive in addition to the main component. The liquid that is stored in the first liquid storage tankmay include residual chlorine used as tap water. Preferably, for example, the liquid that is stored in the first liquid storage tankmay include, as an additive, a colorant, a penetrant, a pH adjuster, a preservative such as phenoxyethanol, a drying inhibitor such as glycerin, or a combination thereof. Since water is used as a component of ink used for inkjet printers or ink used for water-based pens, such water or ink may be used for the “liquid application.”

The water is not limited to the specific examples described above. The water may be water in a broad sense such as hypochlorous acid water or an ethanol aqueous solution diluted for disinfection. However, tap water may be used simply to enhance the binding strength after the binding process because tap water is easy to obtain and store. A liquid including water as a main component as exemplified above enhances the binding strength of the sheet bundle Pb, in comparison with a liquid of which the main component is not water (liquid).

As illustrated in, the liquid applieris movable in the main scanning direction together with the crimperby a driving force transmitted from an edge-binder movement motor. The liquid applierincludes a lower pressure plateserving as a receptacle for the sheet P or the sheet bundle Pb, an upper pressure plate, and a liquid-applier movement assembly. The components of the liquid appliersuch as the lower pressure plate, the upper pressure plate, and the liquid-applier movement assemblyare held by the liquid application frameand a base.

A liquid applier shaftincluding a drive transmission gearis fixed to a bottom face of the liquid application framethat holds the components of the liquid applier. The liquid applier shaftand the drive transmission gearare held by the baseon which the liquid application frameis disposed, so as to be rotatable in the forward and reverse directions. The drive transmission gearmeshes with an output gearof a liquid-applier pivot motor. The liquid appliercan be rotated in the forward and reverse directions about the liquid applier shafton the baseby a driving force transmitted from the liquid-applier pivot motorto the liquid applier shaftvia the output gearand the drive transmission gear

The lower pressure plateand the upper pressure plateare disposed downstream from the internal trayin the conveyance direction. The sheet P or the sheet bundle Pb that is placed on the internal trayis also placed on the lower pressure plate. The lower pressure plateis disposed on a lower pressure plate holder. The upper pressure plateis movable in the thickness direction of the sheet P or the sheet bundle Pb at a position where the upper pressure platefaces the sheet P or the sheet bundle Pb placed on the internal tray. In other words, the lower pressure plateand the upper pressure plateare disposed to face each other in the thickness direction of the sheet P or the sheet bundle Pb with the sheet P or the sheet bundle Pb placed on the internal trayand interposed between the lower pressure plateand the upper pressure plate. In the following description, the thickness direction of the sheet P or the sheet bundle Pb may be referred to simply as “thickness direction.” Further, the upper pressure platehas a through holepenetrating in the thickness direction at a position facing the liquid application member(one end portion of a liquid supply member(an example of a liquid absorber) to be described below, which corresponds to a tip portion) held via a holderattached to a base plate.

The liquid-applier movement assemblymoves the upper pressure plate, the base plate, the holder, the liquid application member, the liquid supply member, and the first liquid storage tankin the thickness direction of the sheet P or the sheet bundle Pb. The liquid-applier movement assemblyaccording to the present embodiment moves the upper pressure plate, the base plate, the holder, the liquid application member, the liquid supply member, and the first liquid storage tankin conjunction with each other with a single liquid-applier movement motor. The liquid-applier movement assemblyincludes, for example, the liquid-applier movement motor, a trapezoidal screw, a nut, the base plate, columnsand, and coil springsand

The liquid-applier movement motorgenerates a driving force to move the upper pressure plate, the base plate, the holder, the liquid application member, the liquid supply member, and the first liquid storage tank. The trapezoidal screwextends in the thickness direction of the sheet P or the sheet bundle Pb and is supported to the liquid application framesuch that the trapezoidal screwis rotatable in the forward and reverse directions. The trapezoidal screwis coupled to an output shaft of the liquid-applier movement motorvia, for example, a pulley and a belt. The nutis screwed to the trapezoidal screw. The trapezoidal screwis rotated in the forward and reverse directions by the driving force transmitted from the liquid-applier movement motor. The rotation of the trapezoidal screwcauses the nutto reciprocate on the trapezoidal screw.

The base plateis positioned apart from the upper pressure plate. The base plateholds the liquid application memberwith the tip portion of the liquid application memberprotruding from the base platetoward the upper pressure plate. The base plateis coupled to the trapezoidal screwvia the nutsuch that the base platecan reciprocate along the trapezoidal screwas the trapezoidal screwrotates in the forward and reverse directions.

The columnsandproject from the base platetoward the upper pressure platearound the tip portion of the liquid application member. The columnsandcan relatively move with respect to the base platein the thickness direction. The columnsandhold the upper pressure platewith the respective ends closer to the lower pressure platethan the other ends of the columnsand. The other ends of the columnsandopposite the ends closer to the lower pressure plateare provided with stoppers that prevent the columnsandfrom being removed from the base plate. The coil springsandare fitted around the columnsand, respectively, between the base plateand the upper pressure plate. The coil springsandbias the upper pressure plateand the columnsandtoward the lower pressure platewith respect to the base plate.

The liquid applierperforms liquid application on the sheet P or the sheet bundle Pb placed on the internal tray. Specifically, the liquid applierbrings the liquid application memberinto contact with the sheet P or the sheet bundle Pb to perform liquid application on at least one sheet P of the sheet bundle Pb.

The liquid applierincludes a first liquid-level sensor(a first liquid detector), the first liquid storage tank, the liquid application member, the liquid supply member, and the holder. The first liquid storage tankstores the liquid for performing liquid application on the sheet P or the sheet bundle Pb. The liquid stored in the first liquid storage tankis detected by the first liquid-level sensor. The first liquid storage tankis coupled to the base platevia the holder.

The liquid application member, the liquid supply member(liquid absorber) disposed in close contact with the liquid application member, and the first liquid storage tankare held by the holder. The holderis held by the base plate. The liquid supply memberhas a first end in close contact with the liquid application memberand a second end immersed in the liquid stored in the first liquid storage tank. In other words, the second end of the liquid supply membercorresponds to a liquid immersion portionthat draws up the liquid and supplies the liquid to the liquid application member. The liquid application memberand the liquid supply memberare made of a material (e.g., sponge or fiber) having a high liquid absorption rate, such as an elastic resin formed of open cells.

Although the case where the liquid supply memberand the liquid application memberare separate bodies has been described above, the liquid supply memberand the liquid application membermay be a unified body formed of a material having a high liquid absorption rate. In other words, the liquid application membermay be part of the liquid supply member. In such a case, liquid can be supplied from the liquid supply memberto the liquid application membermore smoothly by the capillary phenomenon.

The edge binderis coupled to the second liquid storage tank. The second liquid storage tankis detachably attached to the edge binderor the post-processing apparatus(see). When the second liquid storage tankis fixed (set) to the second-liquid-storage-tank fixer(a part of the second liquid storage) in a given position, the liquid already stored in the second liquid storage tankcan be supplied to the first liquid storage tank.

The operation to supply liquid from the second liquid storage tankto the first liquid storage tankis executed in response to a decrease in the stored liquid amount (liquid level) in the first liquid storage tank. The stored liquid amount (liquid level) of the first liquid storage tankis reduced by the liquid being consumed by the liquid application by the liquid applier. In other words, the operation of supplying liquid from the second liquid storage tankto the first liquid storage tankcorresponds to the liquid supply operation needed with the execution of the process including the liquid application by the liquid applier.

When the second liquid storage tankis set in the second-liquid-storage-tank fixer, the second-liquid-storage-tank fixeris filled with a certain amount of the liquid in the second liquid storage tank. The second-liquid-storage-tank fixerincludes a setting detection sensor(serving as a set detector) (see). When the setting detection sensordetects the set state of the second liquid storage tankto the second-liquid-storage-tank fixer(see part (C) of), a signal indicating the set state is transmitted to the controller. Thus, the controllerdetects whether the second liquid storage tankis set on the second-liquid-storage-tank fixer.

The first liquid storage tankand the second liquid storage tankare coupled to each other via the liquid supply passage. The liquid supply pumpis disposed near the second-liquid-storage-tank fixer. When the liquid supply pumpoperates, liquid is supplied (replenished) from the second liquid storage tankto the first liquid storage tankvia the liquid supply passage. Accordingly, the second-liquid-storage-tank fixeris a component of the liquid supplier that executes a liquid supply operation to supply liquid from the second liquid storage tankto the first liquid storage tank. The liquid supply passageincludes a flexible material. According to such a configuration, even if the first liquid storage tankis moved by the liquid-applier movement assembly, liquid can be supplied from the second liquid storage tankto the first liquid storage tank.