MEDIUM PROCESSING APPARATUS AND IMAGE FORMING SYSTEM

Abstract

A medium processing apparatus includes a liquid applier to apply liquid to a part of a medium to perform liquid application, a post-processing device to perform desired processing on a bundle of media including the medium subjected to the liquid application, a first liquid storage to store the liquid for the liquid application, a second liquid storage to store the liquid supplied to the first liquid storage, a liquid supplier to supply the liquid from the second liquid storage to the first liquid storage, a liquid detector to detect a liquid level of the liquid in the first liquid storage, and processing circuitry to control operations of the post-processing device and the liquid supplier. The circuitry changes a liquid level at which liquid supply 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.

Claims

1. A medium processing apparatus, comprising: a liquid applier to apply liquid to a part of a medium to perform a liquid application; a post-processing device to perform desired processing on a bundle of media including the medium subjected to the liquid application; a first liquid storage to store the liquid used for the liquid application by the liquid applier; a second liquid storage to store the liquid to be supplied to the first liquid storage; a liquid supplier to supply the liquid from the second liquid storage to the first liquid storage; a liquid detector to detect a liquid level of the liquid in the first liquid storage; and processing circuitry configured to control operations of the post-processing device and the liquid supplier, wherein 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.

2. The medium processing apparatus according to claim 1, wherein the processing circuitry causes the liquid supplier to perform a specified-level supply operation of supplying the liquid up to a first specified liquid level of the first liquid storage, when the liquid detector detects the liquid level in a time shorter than a predetermined time from a start of the liquid supply operation.

3. The medium processing apparatus according to claim 1, wherein the processing circuitry causes the liquid supplier to perform a specified-level supply operation of supplying the liquid up to a second specified liquid level of the first liquid storage, when the liquid detector detects the liquid level in a time longer than a predetermined time from a start of the liquid supply operation.

4. The medium processing apparatus according to claim 3, wherein the processing circuitry causes the liquid supplier to perform the specified-level supply operation of supplying the liquid up to the second specified liquid level of the first liquid storage and then discharge the liquid for a predetermined time in the first liquid storage.

5. The medium processing apparatus according to claim 3, wherein the processing circuitry causes the liquid supplier to perform the specified-level supply operation of supplying the liquid up to the second specified liquid level of the first liquid storage and then discharge the liquid in the first liquid storage after an elapse of a predetermined time.

6. The medium processing apparatus according to claim 3, wherein the processing circuitry changes a height of the second specified liquid level of the first liquid storage according to a use period.

7. An image forming system, comprising: an image forming apparatus to form an image on a plurality of media constituting the bundle of media; and the medium processing apparatus according to claim 1 to perform the desired processing on the bundle of media on which the image is formed by the image forming apparatus.

Description

BRIEF DESCRIPTION OF THE 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, wherein:

[0008] FIG. 1 is a diagram illustrating an overall configuration of an image forming system;

[0009] FIG. 2 is a diagram illustrating an internal structure of a post-processing apparatus according to a first embodiment;

[0010] FIG. 3 is a schematic view of an edge binder viewed from an upstream side in a conveyance direction;

[0011] FIG. 4 is a schematic view of an edge binder viewed from the side on which a liquid applier is located in a main scanning direction;

[0012] FIGS. 5A and 5B are schematic diagrams illustrating a configuration of a crimper of an edge binder;

[0013] FIG. 6 is a schematic view of a staple binder viewed from an upstream side in a conveyance direction;

[0014] FIG. 7 is a schematic view of a staple binder according to a modification, as viewed from an upstream side in a conveyance direction;

[0015] FIG. 8 is a block diagram illustrating a hardware configuration of control blocks that controls the post-processing apparatus according to the first embodiment;

[0016] FIGS. 9A and 9B are diagrams each illustrating a location and configuration of a second liquid storage tank in a post-processing apparatus;

[0017] FIG. 10 is a diagram illustrating a configuration of attachment and detachment of a second liquid storage tank in a post-processing apparatus;

[0018] FIG. 11 is a flowchart of a binding process performed by an edge binder;

[0019] FIGS. 12A, 12B, 12C, and 12D are diagrams illustrating positions of a liquid applier and a crimper during a binding process by an edge binder;

[0020] FIGS. 13A to 13H are diagrams illustrating positions of a liquid applier and a crimper during a binding process by an edge binder;

[0021] FIGS. 14A and 14B are diagrams illustrating examples of the correspondences between post-processing operation statuses and liquid supply/discharge modes;

[0022] FIG. 15 is a flowchart of a specified-level supply operation in activation of starting a post-processing apparatus;

[0023] FIGS. 16A, 16B, and 16C are diagrams illustrating an outline of a specified-level supply operation;

[0024] FIGS. 17A and 17B are diagrams illustrating an outline of a specified-level supply operation;

[0025] FIGS. 18A and 18B are diagrams illustrating an outline of a specified-level supply operation;

[0026] FIG. 19 is a flowchart of an overall control process including a liquid supply/discharge operation;

[0027] FIG. 20 is a flowchart of a control process of a job-preparation liquid supply operation;

[0028] FIGS. 21A, 21B, and 21C are diagrams illustrating examples of the liquid level of a first liquid storage in a job-preparation liquid supply operation;

[0029] FIG. 22 is a flowchart of a control process of a post-job liquid supply operation;

[0030] FIG. 23 is a flowchart of a binding process by an edge-binder, according to a modification;

[0031] FIGS. 24A and 24B are diagrams illustrating an outline of a liquid discharge operation which is one of liquid supply/discharge modes;

[0032] FIG. 25 is a flowchart of a control process of a liquid discharge operation of a post-processing apparatus;

[0033] FIG. 26 is a diagram illustrating an example of an operation screen of a post-processing apparatus;

[0034] FIGS. 27A and 27B are schematic views of a post-processing apparatus including controllers according to a first modification;

[0035] FIGS. 28A and 28B are schematic views of a post-processing apparatus including controllers according to a second modification;

[0036] FIG. 29 is a diagram illustrating an internal structure of a post-processing apparatus according to a second embodiment;

[0037] FIGS. 30A, 30B, and 30C are schematic views of an internal tray according to the second embodiment, viewed from a thickness direction of a sheet;

[0038] FIG. 31 is a schematic view of a crimper according to the second embodiment, viewed from a downstream side in a conveyance direction;

[0039] FIGS. 32A and 32B are schematic views of a liquid applier according to the second embodiment, viewed from a thickness direction of a sheet;

[0040] FIGS. 33A, 33B, and 33C are cross-sectional views of the liquid applier, taken along a line XXV-XXV of FIG. 32A;

[0041] FIGS. 34A, 34B, and 34C are cross-sectional views of the liquid applier taken along a line XXVI-XXVI of FIG. 32A;

[0042] FIG. 35 is a diagram illustrating a hardware configuration of control blocks of the post-processing apparatus according to the second embodiment;

[0043] FIG. 36 is a flowchart of post-processing of the post-processing apparatus according to the second embodiment; and

[0044] FIG. 37 is a diagram illustrating an overall configuration of an image forming system according to a modification.

[0045] The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views.

DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] 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.

[0049] A description is given below of an image forming system 1 according to an embodiment of the present disclosure, with reference to the drawings. FIG. 1 is a diagram illustrating an overall configuration of the image forming system 1. The image forming system 1 has, 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 FIG. 1, the image forming system 1 includes an image forming apparatus 2 having the image forming function and a post-processing apparatus 3 serving as a media processing apparatus having the post-processing function according to an embodiment of the present disclosure. In the image forming system 1, the image forming apparatus 2 and the post-processing apparatus 3 operate in conjunction with each other.

[0050] In the present embodiment, the sheet-shaped medium or sheet-shaped medium to be processed in the image forming system 1 is 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.

[0051] The image forming apparatus 2 forms an image on the sheet P and ejects the sheet P having the image to the post-processing apparatus 3. The image forming apparatus 2 includes an accommodation tray 211 that accommodates sheets P, a conveyor 212 that conveys a sheet P from the accommodation tray 211, and an image forming device 213 that forms an image on the sheet P conveyed by the conveyor 212. The image forming device 213 may be an inkjet system that forms an image using ink or an electrophotographic system that forms an image using toner. The image forming apparatus 2 also includes a controller 100a that controls various operations of the conveyor 212 and the image forming device 213. Since the image forming apparatus 2 has a typical configuration, a detailed description of the configuration is omitted.

[0052] FIG. 2 is a diagram illustrating an internal configuration of the post-processing apparatus 3 according to the first embodiment of the present disclosure. The post-processing apparatus 3 has a function that performs post-processing on the sheet P on which an image is formed by the image forming apparatus 2. 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).

[0053] 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.

[0054] 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.

[0055] The binding process ((including both the crimping and the staple binding) that is executable by the post-processing apparatus 3 includes 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.

[0056] The post-processing apparatus 3 includes the conveyance roller pairs 10 to 19 (conveyors) and the switcher 20. The conveyance roller pairs 10 to 19 convey, inside the post-processing apparatus 3, a sheet P supplied from the image forming apparatus 2. Specifically, the conveyance roller pairs 10 to 13 convey the sheet P along a first conveyance passage Ph1. The conveyance roller pairs 14 and 15 convey the sheet P along a second conveyance passage Ph2. The conveyance roller pairs 16 to 19 convey the sheet P along a third conveyance passage Ph3. A hole punch 132 is disposed between the conveyance roller pairs 10 and 11. The hole punch 132 performs punching on the sheet P conveyed by the conveyance roller pairs 10 and 11.

[0057] The first conveyance passage Ph1 is a passage extending to a first ejection tray 21 from a supply port through which the sheet P is supplied from the image forming apparatus 2. The second conveyance passage Ph2 is a passage branching from the first conveyance passage

[0058] Ph1 between the conveyance roller pairs 11 and 14 in the conveyance direction of the sheet and extending to a second ejection tray 26 via the internal tray 22. The third conveyance passage Ph3 is a passage branching from the first conveyance passage Ph1 between the conveyance roller pairs 11 and 14 in the conveyance direction of the sheet and extending to a third ejection tray 30.

[0059] The switcher 20 is disposed at a branching position of the first conveyance passage Ph1 and the second conveyance passage Ph2. The switcher 20 can be switched between a first position and a second position. The switcher 20 in the first position guides the sheet P to be ejected to the first ejection tray 21 through the first conveyance passage Ph1. The switcher 20 in the second position guides the sheet P conveyed through the first conveyance passage Ph1 to the second conveyance passage Ph2. At the timing when the trailing end of the sheet P entering the second conveyance passage Ph2 passes between the rollers of the conveyance roller pair 11, the conveyance roller pair 14 is rotated in the reverse direction so that the sheet P is guided to the third conveyance passage Ph3. The post-processing apparatus 3 further includes a plurality of sensors that detects the positions of the sheet P in the first conveyance passage Ph1, the second conveyance passage Ph2, and the third conveyance passage Ph3. Each of the multiple sensors is indicated by a black triangle in FIG. 2.

[0060] The post-processing apparatus 3 includes a first ejection tray 21. The sheet P that is output through the first conveyance passage Ph1 is placed on the first ejection tray 21. Among the sheets P supplied from the image forming apparatus 2, a sheet P not subjected to the binding process is ejected to the first ejection tray 21.

[0061] The post-processing apparatus 3 further includes the internal tray 22 serving as a placement tray, an edge-binding end fence 23, side fences 24L and 24R, an edge binder 25, a staple binder 155, and a second ejection tray 26. The internal tray 22, the edge-binding end fence 23, the side fences 24L and 24R, the edge binder 25, and the staple binder 155 perform the edge binding on the sheet bundle Pb including the plurality of sheets P conveyed through the second conveyance passage Ph2.

[0062] 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.

[0063] Among the sheets P supplied from the image forming apparatus 2, the sheet bundle Pb subjected to the edge binding is ejected to the second ejection tray 26. In the following description, the direction in which the sheet P is conveyed from the conveyance roller pair 15 toward the edge-binding end fence 23 is 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 apparatus 2 is moved toward the second ejection tray 26 by, for example, the conveyance roller pair 10 and then is moved toward the edge-binding end fence 23 by the conveyance roller pair 15. 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.

[0064] The sheets P that are sequentially conveyed through the second conveyance passage Ph2 are temporarily placed on the internal tray 22 serving as a placement tray. The edge-binding end fence 23 aligns the position, in the conveyance direction, of the sheet P or the sheet bundle Pb placed on the internal tray 22. The side fences 24L and 24R align the position, in the main scanning direction, of the sheet P or the sheet bundle Pb placed on the internal tray 22. The edge binder 25 and the staple binder 155 perform edge binding on the sheet bundle Pb aligned by the edge-binding end fence 23 and the side fences 24L and 24R. The conveyance roller pair 15 ejects the sheet bundle Pb subjected to the edge binding to the second ejection tray 26.

[0065] The post-processing apparatus 3 further includes a saddle-binding end fence 27, a saddle binder 28, a sheet folding blade 29, and the third ejection tray 30. The saddle-binding end fence 27, the saddle binder 28, and the sheet folding blade 29 perform the saddle binding on the sheet bundle Pb of the sheets P that are conveyed through the third conveyance passage Ph3. Among the sheets P supplied from the image forming apparatus 2, the sheet bundle Pb subjected to the saddle binding is ejected to the third ejection tray 30.

[0066] The saddle-binding end fence 27 aligns the positions of the sheets P that are sequentially conveyed through the third conveyance passage Ph3, in a direction in which the sheets P are conveyed. The saddle-binding end fence 27 can move between a binding position where the saddle-binding end fence 27 causes the center of the sheet bundle Pb to face the saddle binder 28 and a folding position where the saddle-binding end fence 27 causes the center of the sheet bundle Pb to face the sheet folding blade 29. The saddle binder 28 binds the center of the sheet bundle Pb aligned by the saddle-binding end fence 27 at the binding position. The sheet folding blade 29 folds, in half, the sheet bundle Pb placed on the saddle-binding end fence 27 at the folding position and causes the conveyance roller pair 18 to nip the sheet bundle Pb. The conveyance roller pairs 18 and 19 eject the sheet bundle Pb subjected to the saddle binding to the third ejection tray 30.

[0067] The post-processing apparatus 3 includes a first liquid storage tank 44 (a first liquid storage), and a liquid supply member 50 in the edge binder 25. The first liquid storage tank 44 and the liquid supply member 50 are omitted in FIG. 2. The post-processing apparatus 3 includes a liquid supply passage 45, a liquid supply pump 46 (a liquid supplier), a second liquid storage tank 47 (a part of a second liquid storage), and a second-liquid-storage-tank fixer 61 (a part of the second liquid storage) as a configuration for replenishing the first liquid storage tank 44 with the liquid. The liquid that is stored in the second liquid storage tank 47 is supplied to the first liquid storage tank 44 through the second-liquid-storage-tank fixer 61, the liquid supply pump 46, and the liquid supply passage 45.

[0068] A description is given of the edge binder 25.

[0069] FIG. 3 is a schematic view of an upstream side of the edge binder 25 in the conveyance direction. The edge binder 25 performs a liquid application process and a crimping process. FIG. 4 is a schematic diagram of the edge binder 25 viewed from the side on which a liquid applier 31 is disposed in the main scanning direction. As illustrated in FIG. 3, the edge binder 25 includes the liquid applier 31 that applies liquid to the sheets P, and a crimper 32 that is an example of a post-processing device and serves as a crimp binder. The liquid applier 31 and the crimper 32 are disposed downstream from the internal tray 22 in the conveyance direction and adjacent to each other in the main scanning direction.

[0070] The liquid applier 31 applies liquid that is stored in the first liquid storage tank 44 to the sheet P or the sheet bundle Pb placed on the internal tray 22. The application of the liquid to the sheet P or the sheet bundle Pb by the liquid applier 31 and the operation of the liquid applier 31 in applying the liquid are referred to as liquid application below. The liquid applying operation of the liquid applier 31 involving control processing is referred to as a liquid application process.

[0071] More specifically, the liquid that is stored in the first liquid storage tank 44 as 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 H.sub.2O. 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.

[0072] The liquid that is stored in the first liquid storage tank 44 may include an additive in addition to the main component. The liquid that is stored in the first liquid storage tank 44 may include residual chlorine used as tap water. Preferably, for example, the liquid that is stored in the first liquid storage tank 44 may 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.

[0073] 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).

[0074] As illustrated in FIGS. 3 and 4, the liquid applier 31 is movable in the main scanning direction together with the crimper 32 by a driving force transmitted from an edge-binder movement motor 55. The liquid applier 31 includes a lower pressure plate 33 serving as a receptacle for the sheet P or the sheet bundle Pb, an upper pressure plate 34, and a liquid-applier movement assembly 35. The components of the liquid applier 31 such as the lower pressure plate 33, the upper pressure plate 34, and the liquid-applier movement assembly 35 are held by the liquid application frame 31a and a base 48.

[0075] A liquid applier shaft 562 including a drive transmission gear 562a is fixed to a bottom face of the liquid application frame 31a that holds the components of the liquid applier 31. The liquid applier shaft 562 and the drive transmission gear 562a are held by the base 48 on which the liquid application frame 31a is disposed, so as to be rotatable in the forward and reverse directions. The drive transmission gear 562a meshes with an output gear 563a of a liquid-applier pivot motor 563. The liquid applier 31 can be rotated in the forward and reverse directions about the liquid applier shaft 562 on the base 48 by a driving force transmitted from the liquid-applier pivot motor 563 to the liquid applier shaft 562 via the output gear 563a and the drive transmission gear 562a.

[0076] The lower pressure plate 33 and the upper pressure plate 34 are disposed downstream from the internal tray 22 in the conveyance direction. The sheet P or the sheet bundle Pb that is placed on the internal tray 22 is also placed on the lower pressure plate 33. The lower pressure plate 33 is disposed on a lower pressure plate holder 331. The upper pressure plate 34 is movable in the thickness direction of the sheet P or the sheet bundle Pb at a position where the upper pressure plate 34 faces the sheet P or the sheet bundle Pb placed on the internal tray 22. In other words, the lower pressure plate 33 and the upper pressure plate 34 are 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 tray 22 and interposed between the lower pressure plate 33 and the upper pressure plate 34. 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 plate 34 has a through hole 34a penetrating in the thickness direction at a position facing the liquid application member 501 (one end portion of a liquid supply member 50 (an example of a liquid absorber) to be described below, which corresponds to a tip portion) held via a holder 37 attached to a base plate 40.

[0077] The liquid-applier movement assembly 35 moves the upper pressure plate 34, the base plate 40, the holder 37, the liquid application member 501, the liquid supply member 50, and the first liquid storage tank 44 in the thickness direction of the sheet P or the sheet bundle Pb. The liquid-applier movement assembly 35 according to the present embodiment moves the upper pressure plate 34, the base plate 40, the holder 37, the liquid application member 501, the liquid supply member 50, and the first liquid storage tank 44 in conjunction with each other with a single liquid-applier movement motor 42. The liquid-applier movement assembly 35 includes, for example, the liquid-applier movement motor 42, a trapezoidal screw 38, a nut 39, the base plate 40, columns 41a and 41b, and coil springs 42a and 42b.

[0078] The liquid-applier movement motor 42 generates a driving force to move the upper pressure plate 34, the base plate 40, the holder 37, the liquid application member 501, the liquid supply member 50, and the first liquid storage tank 44. The trapezoidal screw 38 extends in the thickness direction of the sheet P or the sheet bundle Pb and is supported to the liquid application frame 31a such that the trapezoidal screw 38 is rotatable in the forward and reverse directions. The trapezoidal screw 38 is coupled to an output shaft of the liquid-applier movement motor 42 via, for example, a pulley and a belt. The nut 39 is screwed to the trapezoidal screw 38. The trapezoidal screw 38 is rotated in the forward and reverse directions by the driving force transmitted from the liquid-applier movement motor 42. The rotation of the trapezoidal screw 38 causes the nut 39 to reciprocate on the trapezoidal screw 38.

[0079] The base plate 40 is positioned apart from the upper pressure plate 34. The base plate 40 holds the liquid application member 501 with the tip portion of the liquid application member 501 protruding from the base plate 40 toward the upper pressure plate 34. The base plate 40 is coupled to the trapezoidal screw 38 via the nut 39 such that the base plate 40 can reciprocate along the trapezoidal screw 38 as the trapezoidal screw 38 rotates in the forward and reverse directions.

[0080] The columns 41a and 41b project from the base plate 40 toward the upper pressure plate 34 around the tip portion of the liquid application member 501. The columns 41a and 41b can relatively move with respect to the base plate 40 in the thickness direction. The columns 41a and 41b hold the upper pressure plate 34 with the respective ends closer to the lower pressure plate 33 than the other ends of the columns 41a and 41b. The other ends of the columns 41a and 41b opposite the ends closer to the lower pressure plate 33 are provided with stoppers that prevent the columns 41a and 41b from being removed from the base plate 40. The coil springs 42a and 42b are fitted around the columns 41a and 41b, respectively, between the base plate 40 and the upper pressure plate 34. The coil springs 42a and 42b bias the upper pressure plate 34 and the columns 41a and 41b toward the lower pressure plate 33 with respect to the base plate 40.

[0081] The liquid applier 31 performs liquid application on the sheet P or the sheet bundle Pb placed on the internal tray 22. Specifically, the liquid applier 31 brings the liquid application member 501 into 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.

[0082] The liquid applier 31 includes a first liquid-level sensor 43 (a first liquid detector), the first liquid storage tank 44, the liquid application member 501, the liquid supply member 50, and the holder 37. The first liquid storage tank 44 stores the liquid for performing liquid application on the sheet P or the sheet bundle Pb. The liquid stored in the first liquid storage tank 44 is detected by the first liquid-level sensor 43. The first liquid storage tank 44 is coupled to the base plate 40 via the holder 37.

[0083] The liquid application member 501, the liquid supply member 50 (liquid absorber) disposed in close contact with the liquid application member 501, and the first liquid storage tank 44 are held by the holder 37. The holder 37 is held by the base plate 40. The liquid supply member 50 has a first end in close contact with the liquid application member 501 and a second end immersed in the liquid stored in the first liquid storage tank 44. In other words, the second end of the liquid supply member 50 corresponds to a liquid immersion portion 502 that draws up the liquid and supplies the liquid to the liquid application member 501. The liquid application member 501 and the liquid supply member 50 are made of a material (e.g., sponge or fiber) having a high liquid absorption rate, such as an elastic resin formed of open cells.

[0084] Although the case where the liquid supply member 50 and the liquid application member 501 are separate bodies has been described above, the liquid supply member 50 and the liquid application member 501 may be a unified body formed of a material having a high liquid absorption rate. In other words, the liquid application member 501 may be part of the liquid supply member 50. In such a case, liquid can be supplied from the liquid supply member 50 to the liquid application member 501 more smoothly by the capillary phenomenon.

[0085] The edge binder 25 is coupled to the second liquid storage tank 47. The second liquid storage tank 47 is detachably attached to the edge binder 25 or the post-processing apparatus 3 (see FIG. 12). When the second liquid storage tank 47 is fixed (set) to the second-liquid-storage-tank fixer 61 (a part of the second liquid storage) in a given position, the liquid already stored in the second liquid storage tank 47 can be supplied to the first liquid storage tank 44.

[0086] The operation to supply liquid from the second liquid storage tank 47 to the first liquid storage tank 44 is executed in response to a decrease in the stored liquid amount (liquid level) in the first liquid storage tank 44. The stored liquid amount (liquid level) of the first liquid storage tank 44 is reduced by the liquid being consumed by the liquid application by the liquid applier 31. In other words, the operation of supplying liquid from the second liquid storage tank 47 to the first liquid storage tank 44 corresponds to the liquid supply operation needed with the execution of the process including the liquid application by the liquid applier 31.

[0087] When the second liquid storage tank 47 is set in the second-liquid-storage-tank fixer 61, the second-liquid-storage-tank fixer 61 is filled with a certain amount of the liquid in the second liquid storage tank 47. The second-liquid-storage-tank fixer 61 includes a setting detection sensor 51 (serving as a set detector) (see FIG. 10). When the setting detection sensor 51 detects the set state of the second liquid storage tank 47 to the second-liquid-storage-tank fixer 61 (see part (C) of FIG. 12), a signal indicating the set state is transmitted to the controller 100b. Thus, the controller 100b detects whether the second liquid storage tank 47 is set on the second-liquid-storage-tank fixer 61.

[0088] The first liquid storage tank 44 and the second liquid storage tank 47 are coupled to each other via the liquid supply passage 45. The liquid supply pump 46 is disposed near the second-liquid-storage-tank fixer 61. When the liquid supply pump 46 operates, liquid is supplied (replenished) from the second liquid storage tank 47 to the first liquid storage tank 44 via the liquid supply passage 45. Accordingly, the second-liquid-storage-tank fixer 61 is a component of the liquid supplier that executes a liquid supply operation to supply liquid from the second liquid storage tank 47 to the first liquid storage tank 44. The liquid supply passage 45 includes a flexible material. According to such a configuration, even if the first liquid storage tank 44 is moved by the liquid-applier movement assembly 35, liquid can be supplied from the second liquid storage tank 47 to the first liquid storage tank 44.

[0089] The amount of liquid supplied from the second liquid storage tank 47 to the first liquid storage tank 44 can be controlled in accordance with the detection result of the first liquid-level sensor 43. In other words, the controller 100b determines whether the stored liquid amount (liquid level) in the first liquid storage tank 44 based on the detection result of the first liquid-level sensor 43. In accordance with the determined stored liquid amount (liquid level) of the first liquid storage tank 44, the controller 100b controls the operation speed and time of the liquid supply pump 46. Thus, the controller 100b can adjust the amount of liquid to be replenished to the first liquid storage tank 44 to maintain the stored liquid amount (liquid level) in the first liquid storage tank 44 at a constant level of liquid.

[0090] A description is given below of the configuration of the crimper 32.

[0091] As illustrated in FIG. 3, the crimper 32 as a post-processing device presses and deforms at least a portion (liquid application position) of the sheet bundle Pb, to which liquid has been applied by the liquid applier 31, by serrated upper crimping teeth 32a and lower crimping teeth 32b, and crimps the sheets P of the portion to bind the sheet bundle Pb. In other words, the crimper 32 can bind the sheet bundle Pb without using staples. The components of the crimper 32 such as the upper crimping teeth 32a and the lower crimping teeth 32b are disposed on a crimping frame 32c. In the following description, such a way of pressing and deforming a given position on the sheet bundle Pb to bind the sheet bundle Pb may be referred to as crimping. In other words, the crimper 32 crimps and binds the sheet bundle Pb or performs the crimping on the sheet bundle Pb. The crimping and binding operation of the crimper 32 that involves control processing is referred to as crimping process.

[0092] FIGS. 5A and 5B are schematic diagrams illustrating the configuration of the crimper 32. As illustrated in FIGS. 5A and 5B, the crimper 32 includes the upper crimping teeth 32a and the lower crimping teeth 32b. The upper crimping teeth 32a and the lower crimping teeth 32b are disposed to face each other in the thickness direction of the sheet bundle Pb with the sheet bundle Pb supported by the internal tray 22 interposed between the upper crimping teeth 32a and the lower crimping teeth 32b. The upper crimping teeth 32a and the lower crimping teeth 32b have respective serrate faces facing each other. The serrate face of each of the upper crimping teeth 32a and the lower crimping teeth 32b includes concave portions and convex portions alternately formed. The concave portions and the convex portions of the upper crimping teeth 32a are shifted from those of the lower crimping teeth 32b such that the upper crimping teeth 32a are engaged with the lower crimping teeth 32b. The upper crimping teeth 32a and the lower crimping teeth 32b are brought into contact with and separated from each other by the driving force of a contact-separation motor 32d illustrated in FIG. 8.

[0093] In the process of supplying the sheets P of the sheet bundle Pb to the internal tray 22, the upper crimping teeth 32a and the lower crimping teeth 32b are separated from each other as illustrated in FIG. 5A. When all the sheets P of the sheet bundle Pb are placed on the internal tray 22, the upper crimping teeth 32a and the lower crimping teeth 32b are engaged with each other as illustrated in FIG. 5B by the driving force of the contact-separation motor 32d to press and deform the sheet bundle Pb in the thickness direction. As a result, the sheet bundle Pb held in the internal tray 22 is crimped and bound. The sheet bundle Pb thus crimped and bound is ejected to the second ejection tray 26 by the conveyance roller pair 15.

[0094] The configuration of the crimper 32 as a crimping assembly is not limited to the configuration of a moving assembly exemplified in the present embodiment, and may be any other suitable structure in which the upper crimping teeth 32a and the lower crimping teeth 32b of the crimping assembly engage with each other. For example, the crimping assembly may bring the upper crimping teeth 32a and the lower crimping teeth 32b into contact with each other and separate the upper crimping teeth 32a and the lower crimping teeth 32b from each other with a link mechanism and a driving source that simply rotates in the forward direction or that rotates the forward and backward directions (e.g., the crimping assembly disclosed in Japanese Patent No. 6057167). Alternatively, the crimping assembly may be a linear-motion-type crimping assembly that linearly performs crimping and separating operations of the upper crimping teeth 32a and the lower crimping teeth 32b with a screw assembly that converts the forward and backward rotational motions of a driving source into linear reciprocating motion.

[0095] As illustrated in FIG. 3, the edge binder 25 includes an edge-binder movement assembly 57. The edge-binder movement assembly 57 moves the edge binder 25 (in other words, the liquid applier 31 and the crimper 32) in the main scanning direction along the downstream end of the sheet P, which is placed on the internal tray 22, in the conveyance direction. The edge-binder movement assembly 57 includes, for example, the base 48, a guide shaft 49, the edge-binder movement motor 55, and a driving force transmission assembly 551 that transmits the driving force of the edge-binder movement motor 55 to the base 48, and a standby position sensor 540 (see FIG. 8).

[0096] The liquid applier 31 and the crimper 32 are attached to the base 48 such that the liquid applier 31 and the crimper 32 are adjacent to each other in the main scanning direction. As illustrated in FIGS. 3 and 4, the guide shaft 49 is disposed in the main scanning direction on the upstream side of a binding assembly base 116 in the conveyance direction and is held by multiple guide shaft brackets 49a and 49b. The guide shaft 49 is disposed to extend in the main scanning direction on the binding assembly base 116, and holds the base 48 to be movable in the main scanning direction. As illustrated in FIG. 4, the guide rail 115 is disposed in the downstream side of the binding assembly base 116 in the conveyance direction and extends in the main scanning direction. The guide rail 115 has a to-be-fitted portion 115a that fits a scanning roller 48a, which is rotatably disposed on the base 48, across the main scanning direction. In other words, the base 48 is movably held by the guide shaft 49 and the guide rail 115 in the main scanning direction on the binding assembly base 116.

[0097] The edge-binder movement motor 55 generates a driving force to move the edge binder 25. The driving force transmission assembly 551 transmits the driving force of the edge-binder movement motor 55 to the base 48 via pulleys 551a and 551b, a timing belt 551c, and a fastening portion 48b that fastens the base 48 and the timing belt 551c. As a result, the liquid applier 31 and the crimper 32 integrated by the base 48 move in the main scanning direction along the guide shaft 49.

[0098] The edge-binder movement motor 55 according to the present embodiment is, for example, a servo motor that can stop the edge binder 25 at a target position (a first liquid application position B1 (a first binding position B1) and a second liquid application position B2 (a second binding position B2) described below) without returning the edge binder 25 to an origin position (for example, a standby position HP described below) each time the edge binder 25 moves.

[0099] The post-processing apparatus 3 further includes a standby position sensor 540 and an encoder sensor 541. The standby position sensor 540 is, for example, a light-shielding optical sensor (see FIG. 8) to detect that the edge binder 25 has reached a standby position HP (see FIG. 12A). The encoder sensor 541 (see FIG. 8) is attached to an output shaft of the edge-binder movement motor 55. The controller 100b, which is described below, detects that the edge binder 25 has reached the standby position HP, based on a detection result of the standby position sensor 540. The controller 100b also counts pulse signals output from the encoder sensor 541 to ascertain the current position of the edge binder 25 moved from the standby position HP.

[0100] However, a specific method of stopping the edge binder 25 at the target position without returning the edge binder 25 to the standby position HP is not limited to the aforementioned example. As another example, the post-processing apparatus 3 may include a sensor that detects that the edge binder 25 has reached a predetermined target position.

[0101] As illustrated in FIG. 3, a crimper shaft 54 provided with a drive transmission gear 54a is fixed to a bottom face of the crimping frame 32c that holds the components of the crimper 32. The crimper shaft 54 and the drive transmission gear 54a are held by the base 48 on which the crimping frame 32c is disposed, so as to be rotatable in the forward and reverse directions. The drive transmission gear 54a meshes with an output gear 56a of a crimper pivot motor 56. The crimper 32 can be rotated in the forward and reverse directions about the crimper shaft 54 on the base 48 by a driving force transmitted from the crimper pivot motor 56 to the crimper shaft 54 via the output gear 56a and the drive transmission gear 54a.

[0102] In the above description, the edge binder 25 has a configuration of moving along the guide shaft 49 with the crimper 32 and the liquid applier 31 being integrated, embodiments of the present disclosure are not limited to the above-described configuration. For example, the crimper 32 and the liquid applier 31 may have a configuration of moving independently of each other.

[0103] A description is given below of the staple binder 155.

[0104] Specifically, a detailed description is given below of the staple binder 155 having a function of executing a stapling process. FIG. 6 is a schematic diagram illustrating the staple binder 155, viewed from the upstream side of the staple binder 155 in the conveyance direction. The staple binder 155 includes a stapler 62 that binds the sheet bundle Pb with staples. The stapler 62 is disposed downstream from the internal tray 22 in the conveyance direction and spaced apart from the edge binder 25 in the main scanning direction.

[0105] The stapler 62, which is an example of a post-processing device, has a configuration of performing so-called stapling (i.e., stapling process) to bind the sheet bundle Pb with a staple or staples. More specifically, the stapler 62 includes a stapling-part drive motor 62d illustrated in FIG. 8. The stapling-part drive motor 62d drives a stapling part 62a. The driving force of the stapling-part drive motor 62d causes a staple loaded in the stapling part 62a to penetrate through a sheet bundle Pb, so that the stapling part 62a binds the sheet bundle Pb. Since the stapler 62 has a typical configuration, a detailed description thereof will be omitted unless otherwise required.

[0106] As illustrated in FIG. 6, the staple binder 155 includes a staple-binder movement assembly 77. The staple-binder movement assembly 77 moves the staple binder 155 in the main scanning direction along a downstream end in the conveyance direction of the sheet P or the sheet bundle Pb placed on the internal tray 22. The staple-binder movement assembly 77 includes, for example, a base 78, the guide shaft 49, a staple-binder movement motor 80, and a driving force transmission assembly 81. The driving force transmission assembly 81 transmits a driving force of the staple-binder movement motor 80 to the base 78 via pulleys 81a and 81b, a timing belt 81c, and a fastening portion 78a that fastens the base 78 and the timing belt 81c. A stapler shaft 83 including a drive transmission gear 83a is fixed to a bottom face of a stapling frame 62b that holds the components of the stapler 62.

[0107] The stapler shaft 83 and the drive transmission gear 83a are held by the base 78 on which the stapling frame 62b is disposed, so as to be rotatable in the forward and reverse directions. The drive transmission gear 83a is engaged with an output gear 82a of the stapler pivot motor 82. The stapler 62 can be rotated in the forward and reverse directions about the stapler shaft 83 on the base 78 by a driving force transmitted from the stapler pivot motor 82 to the stapler shaft 83 via the output gear 82a and the drive transmission gear 83a.

[0108] The edge binder 25 and the staple binder 155 are supported by the common guide shaft 49. In other words, the edge-binder movement assembly 57 and the staple-binder movement assembly 77 move the edge binder 25 and the staple binder 155 in the main scanning direction along the common guide shaft 49. The edge-binder movement assembly 57 and the staple-binder movement assembly 77 can independently move the edge binder 25 and the staple binder 155.

[0109] A description is given below of a modification of the staple binder 155.

[0110] FIG. 7 illustrates a staple binder 155 as a modification of the staple binder 155. More specifically, FIG. 7 is a schematic diagram illustrating the staple binder 155 viewed from the upstream side thereof in the conveyance direction. The staple binder 155 is different from the staple binder 155 in that the staple binder 155 includes a second liquid applier 612 in addition to the stapler 62. As illustrated in FIG. 7, the staple binder 155 includes the second liquid applier 612 and the stapler 62. The second liquid applier 612 and the stapler 62 are disposed downstream from the internal tray 22 in the conveyance direction and adjacent to each other in the main scanning direction.

[0111] The second liquid applier 612 executes liquid application of applying liquid stored in a third liquid storage tank 73 to the sheet P or the sheet bundle Pb supported on the internal tray 22. A given area including a position to which the liquid application is performed on the sheet P or the sheet bundle Pb by the second liquid applier 612 corresponds to a binding position to be stapled by the stapler 62. As illustrated in FIG. 7, the second liquid applier 612 includes a second lower pressure plate 63, a second upper pressure plate 64, a second liquid-applier movement assembly 65, and a second liquid application assembly 66. The second liquid-applier movement assembly 65 includes, for example, a second liquid-applier movement motor 67, a second trapezoidal screw 68, a second nut 69, a second base plate 70, second columns 711a and 711b, and second coil springs 721a and 721b.

[0112] The second liquid application assembly 66 includes the third liquid storage tank 73, a second liquid supply member 75, a second liquid application member 74, and a second joint 76. Since the second liquid application assembly 66 and the liquid application assembly of the liquid applier 31 (including the first liquid storage tank 44, the liquid supply member 50, the liquid application member 501, and the holder 37) illustrated in FIGS. 3 and 4 have common configurations, redundant descriptions thereof will be omitted unless otherwise required. Since the stapler 62 has a configuration similar to the configuration of the staple binder 155 illustrated in FIG. 6, a detailed description thereof is omitted below unless otherwise required. Since the second liquid applier 612 and the liquid applier 31 that are illustrated in FIG. 3 have common pivot mechanisms, redundant descriptions thereof will be omitted unless otherwise required. The pivot mechanism of the second liquid applier 612 includes a liquid-applier pivot motor 563, an output gear 563a, drive transmission gear 562a, and a liquid applier shaft 562.

[0113] As with the staple binder 155 illustrated in FIG. 7, when the liquid application is also performed on the sheet P in the stapling process, the binding position is loosened and softened, thus allowing the staple to easily pass through. As a result, the number of sheets to be bound per sheet bundle Pb can be increased as compared with a case where the stapling process is performed without performing the liquid application.

[0114] A description is given below of a configuration of control blocks of the post-processing apparatus 3.

[0115] A description is given below of a control block of the post-processing apparatus 3, with reference to FIG. 8. FIG. 8 is a block diagram illustrating a hardware configuration for executing control processing in the post-processing apparatus 3. As illustrated in FIG. 8, the post-processing apparatus 3 includes a central processing unit (CPU) 101, a random-access memory (RAM) 102, a read-only memory (ROM) 103, a hard disk drive (HDD) 104, and an interface (I/F) 105. The CPU 101, the RAM 102, the ROM 103, the HDD 104, and the I/F 105 are connected to each other via a common bus 109.

[0116] The CPU 101 is an arithmetic device and controls the overall operation of the post-processing apparatus 3. The RAM 102 is a volatile storage medium that allows high speed reading and writing of data, and is used as a working area when the CPU 101 processes information. The ROM 103 is a read-only non-volatile storage medium, and stores programs such as firmware. The HDD 104 is a non-volatile storage medium that allows data to be read and written and has a relatively large storage capacity. The HDD 104 stores, for example, an operating system (OS), various control programs, and application programs.

[0117] By an arithmetic function of the CPU 101, the post-processing apparatus 3 processes, for example, a control program stored in the ROM 103 and an information processing program (application program) loaded into the RAM 102 from a storage medium such as the HDD 104. Such processing configures a software controller including various functional modules of the post-processing apparatus 3. The software controller thus configured cooperates with hardware resources of the post-processing apparatus 3 to construct functional blocks that implement functions of the post-processing apparatus 3. In other words, the CPU 101, the RAM 102, the ROM 103, the HDD 104, and the I/F 105 constitute at least part of a controller 100b, which is an example of a control device, to control the operation of the post-processing apparatus 3.

[0118] The I/F 105 is an interface that connects the conveyance roller pairs 10, 11, 14, and 15, the switcher 20, the side fences 24L and 24R, the contact-separation motor 32d, the crimper pivot motor 56, the liquid-applier movement motor 42, the liquid-applier pivot motor 563, the edge-binder movement motor 55, the stapling-part drive motor 62d, the stapler pivot motor 82, the staple-binder movement motor 80, the liquid supply pump 46, the movement sensor 40a, the first liquid-level sensor 43, the second liquid-level sensor 94, the setting detection sensor 51, the standby position sensor 540, the encoder sensor 541, a cover opening-closing sensor 542 and an operation panel 110 to the common bus 109.

[0119] The controller 100b controls, via the I/F 105, the operations of the conveyance roller pairs 10, 11, 14, and 15, the switcher 20, the side fences 24L and 24R, the contact-separation motor 32d, the crimper pivot motor 56, the liquid-applier movement motor 42, the liquid-applier pivot motor 563, the edge-binder movement motor 55, the stapling-part drive motor 62d, the stapler pivot motor 82, the staple-binder movement motor 80, and the liquid supply pump 46. The controller 100b acquires detection results of the movement sensor 40a, the first liquid-level sensor 43, the second liquid-level sensor 94, the setting detection sensor 51, the standby position sensor 540, the encoder sensor 541, and the cover opening-closing sensor 542. Although FIG. 8 illustrates only the components related to the edge binder 25 and the staple binder 155 that perform the edge binding, the components related to the saddle binder 28 that performs the saddle binding are also controlled by the controller 100b.

[0120] As illustrated in FIG. 1, the image forming apparatus 2 includes the operation panel 110. The operation panel 110 includes an operation section that receives instructions input by an operator and a display (which is an example of a notifier) that notifies the operator of information. The operation device includes, for example, hard keys and a touch screen overlaid on the display. The operation panel 110 acquires information from the user through the operation section and provides information to the user through the display. A specific example of the notifier is not limited to the display and may be a light-emitting diode (LED) lamp or a speaker. The post-processing apparatus 3 may include an operation panel 110 similar to the above-described operation panel 110 of the image forming apparatus 2.

[0121] As described above, the post-processing apparatus 3 implements the function of performing operation control related to the liquid application by software (control programs) executed by the CPU 101 with hardware resources included in the controller 100b.

[0122] The liquid application performed by the post-processing apparatus 3 may be performed in a form in which the staple binder 155 is provided with only the stapler 62 and the liquid application is performed using the liquid applier 31 of the edge binder 25. By contrast, the edge binder 25 may include only the crimper 32, and the liquid application may be performed in a mode in which the second liquid applier 612 is used. In other words, the post-processing apparatus 3 may have a configuration in which only one of the liquid applier 31 and the second liquid applier 612 performs the liquid application, regardless of the type of the binding process.

[0123] Further, in the above description, the staple binder 155 has a configuration of moving along the guide shaft 49 with the stapler 62 and the second liquid applier 612 being integrated. However, embodiments of the present disclosure are not limited to the above-described configuration. For example, the stapler 62 and the second liquid applier 612 may have a configuration of moving independently of each other.

[0124] A detailed description is given below of the second liquid storage tank 47.

[0125] With reference to FIGS. 9A, 9B, and 10, a description is given of the arrangement and configuration of the second liquid storage tank 47 in the post-processing apparatus 3. FIGS. 9A and 9B illustrate an example of the arrangement and configuration of the second liquid storage tank 47 that is an example of a main tank. FIG. 9A illustrates a state where an opening-and-closing cover 71 of the post-processing apparatus 3 is opened. FIG. 9B is a cross-sectional view of the post-processing apparatus 3 as viewed from a lateral side thereof, and illustrates a state where the cover 71 of the post-processing apparatus 3 is closed. As illustrated in FIG. 9A, the second liquid storage tank 47 is located so as to be accessible when the cover 71 of the post-processing apparatus 3 is open. As illustrated in FIG. 9B, the second liquid storage tank 47 and the second-liquid-storage-tank fixer 61 are disposed on the near side in a depth direction (e.g., X direction in FIG. 9B) of the post-processing apparatus 3.

[0126] The first liquid storage tank 44 is disposed on the far side in the depth direction (e.g., X direction in FIG. 9A or 9B) of the post-processing apparatus 3. A housing side plate 72 of the post-processing apparatus 3 is disposed between the location of the second liquid storage tank 47 and the second-liquid-storage-tank fixer 61 and the location of the first liquid storage tank 44 and so forth. The second-liquid-storage-tank fixer 61 is attached to the housing side plate 72 of the post-processing apparatus 3.

[0127] FIG. 10 illustrates a state in which the second liquid storage tank 47 is attachable to and detachable from the second-liquid-storage-tank fixer 61 and a state in which liquid Lis replenished to the second liquid storage tank 47. As illustrated in part (A) of FIG. 10, the second liquid storage tank 47 is attachable to and detachable from the second-liquid-storage-tank fixer 61 so that liquid L can be replenished to the first liquid storage tank 44. As illustrated in part (B) of FIG. 10, the second-liquid-storage-tank fixer 61 is provided with the setting detection sensor 51 serving as a setting detector that detects that the second liquid storage tank 47 is set on the second-liquid-storage-tank fixer 61.

[0128] When the setting detection sensor 51 detects the set state of the second liquid storage tank 47 to the second-liquid-storage-tank fixer 61 (see part (C) of FIG. 10), a signal indicating the set state is transmitted to the controller 100b. Thus, the controller 100b detects whether the second liquid storage tank 47 is set on the second-liquid-storage-tank fixer 61.

[0129] The second liquid-level sensor 94 (a second liquid detector) that detects the amount of liquid L stored in the second liquid storage tank 47 is disposed in the second-liquid-storage-tank fixer 61. The output value (voltage) of the second liquid-level sensor 94 is notified to the controller 100b. The controller 100b determines the output value (voltage) of the second liquid-level sensor 94 to determine whether the amount of liquid stored in the second-liquid-storage-tank fixer 61 is a required amount of liquid. When the controller 100b determines that the second liquid storage tank 47 is set on the second-liquid-storage-tank fixer 61 (i.e., is in a set state) based on the output signal of the setting detection sensor 51, the controller 100b turns on the second liquid-level sensor 94 such that the remaining amount of liquid (the amount of the liquid stored) in the second-liquid-storage-tank fixer 61 can be detected.

[0130] When the second liquid storage tank 47 is not set on the second-liquid-storage-tank fixer 61 (i.e., is in a non-set state), a liquid discharge port 471a of the second liquid storage tank 47 is closed by a liquid supply valve 471 so that liquid L does not leak. As illustrated in part (C) of FIG. 10, when the second liquid storage tank 47 is set to the second-liquid-storage-tank fixer 61, the liquid supply valve 471 is pushed up to open the liquid discharge port 471a of the second liquid storage tank 47. Thus, the liquid L can flow out from the second liquid storage tank 47 to the second-liquid-storage-tank fixer 61. As a result, the liquid L stored in the second liquid storage tank 47 flows out to the second-liquid-storage-tank fixer 61. The liquid L that has flowed out from the second liquid storage tank 47 is stored in the second-liquid-storage-tank fixer 61.

[0131] As a measurement to prevent liquid L from being frozen during maintenance of the post-processing apparatus 3, a liquid draining process may be performed to drain the liquid L in the post-processing apparatus 3. In the liquid draining process, the liquid L remaining in the first liquid storage tank 44 and the liquid supply passage 45 is supplied by the liquid supply pump 46 to the second-liquid-storage-tank fixer 61 via the liquid supply passage 45 in the reverse direction. For that purpose, the second-liquid-storage-tank fixer 61 is set to the capacity that can sufficiently store liquid L in the first liquid storage tank 44 and the liquid supply passage 45.

[0132] As illustrated in parts (B) and (C) of FIG. 10, the second-liquid-storage-tank fixer 61 is provided with a liquid drain plug 611. After the liquid L remaining in the first liquid storage tank 44 and the liquid supply passage 45 is reversely fed by the liquid supply pump 46 to the second-liquid-storage-tank fixer 61, the liquid drain plug 611 is opened to drain the liquid L stored in the second-liquid-storage-tank fixer 61 to the outside of the post-processing apparatus 3.

[0133] A description is given below of a binding process.

[0134] Specifically, a description is given below of a binding process executed by the edge binder 25 included in the post-processing apparatus 3. FIG. 11 is a flowchart of a process of executing one-point binding. FIGS. 12A, 12B, and 12C are diagrams illustrating the position shift of the edge binder 25 (the liquid applier 31 and the crimper 32) during the one-point binding. In FIGS. 12A, 12B, and 12C, the changes in the postures of the liquid applier 31 and the crimper 32 are not illustrated. The position (liquid application position) on a sheet P or a sheet bundle Pb onto which the liquid application is performed by the liquid applier 31 corresponds to the binding position on the sheet bundle Pb to be crimped by the crimper 32. For this reason, in the following description, the liquid application position and the binding position are denoted by the same reference sign (B1 or B2).

[0135] For example, the controller 100b starts the binding process illustrated in FIG. 11 when the controller 100b acquires an instruction to execute the binding process from the image forming apparatus 2. In the following description, the instruction to execute the binding process may be referred to as a binding command.

[0136] The binding command includes, for example, the type of the sheet P (including information affecting the spread of liquid, such as material and thickness), the number of sheets P of the sheet bundle Pb, the number of sheet bundles Pb to be bound, the binding position on the sheet bundle Pb, and the binding posture of the edge binder 25. In the following description, the number of sheets P of the sheet bundle Pb may be referred to as given number of sheets N whereas the number of sheet bundles Pb to be bound may be referred to as requested number of copies M.

[0137] The liquid applier 31 and the crimper 32 are assumed to be in a parallel binding posture and located at a standby position HP that is a position away in the width direction from the sheets P placed on the internal tray 22 at the start of the binding process as illustrated in FIG. 12A.

[0138] When the posture that is instructed by the binding command is the inclined binding posture, in step S1101, the controller 100b drives the liquid-applier pivot motor 563 and the crimper pivot motor 56 to pivot the liquid applier 31 and the crimper 32 of the edge binder 25 into the inclined binding posture. Alternatively, when the posture that is instructed by the binding command is the inclined binding posture, the crimper 32 alone may be pivoted to the inclined binding posture and the liquid applier 31 may not be pivoted in the forward and reverse directions. As a result, the driving assembly may be simplified as compared with a case where both the liquid applier 31 and the crimper 32 are pivoted in the forward and reverse directions, and thus the effects such as cost reduction, the downsizing of the apparatus, and the reduction of failures of devices are exhibited.

[0139] On the other hand, when the posture that is instructed by the binding command is the parallel binding posture, the controller 100b skips the aforementioned operation of pivoting the liquid applier 31 and the crimper 32 of the edge binder 25 to the inclined binding posture.

[0140] In step S1101, the controller 100b also drives the edge-binder movement motor 55 to move the edge binder 25 in the main scanning direction so that the liquid applier 31 faces the first liquid application position B1 instructed by the binding command. The controller 100b executes the operation of step S1101 before a first sheet P is conveyed to the internal tray 22 by the conveyance roller pairs 10, 11, 14, and 15.

[0141] In step S1102, the controller 100b rotates the conveyance roller pairs 10, 11, 14, and 15 to store the sheet P, on which the image has been formed by the image forming apparatus 2, onto the internal tray 22. In step S1102, the controller 100b also moves the side fences 24L and 24R in the main scanning direction to align the position of the sheet P or the sheet bundle Pb placed on the internal tray 22 in the main scanning direction. In short, the controller 100b performs so-called jogging.

[0142] In step S1103, the controller 100b causes the liquid applier 31 facing the first liquid application position B1 to perform the liquid application onto the first liquid application position B1 of the sheet P placed on the internal tray 22 in the immediately preceding step S1102, based on the liquid application control data adjusted in advance. In other words, the controller 100b drives the liquid-applier movement motor 42 to bring the liquid application member 501 into contact with the first liquid application position B1 on the sheet P placed on the internal tray 22 (see FIG. 12B). In the liquid application process in step S1103, the controller 100b adjusts the position at which the liquid application member 501 applies liquid to the sheet P in accordance with the type of the sheet P and the binding position included in the binding command. The controller 100b adjusts the amount of pressing the liquid application member 501 against the sheet P. In other words, the controller 100b controls the driving of the liquid-applier movement motor 42 based on the adjusted control data, and adjusts the amount of movement of the liquid application member 501 with respect to the first liquid application position B1 of the sheet P placed on the internal tray 22.

[0143] In step S1104, the controller 100b determines whether the number of sheets P placed on the internal tray 22 has reached the given number of sheets N instructed by the binding command. When the controller 100b determines that the number of sheets P placed on the internal tray 22 has not reached the given number of sheets N (NO in step S1104), the controller 100b executes the operations of steps S1102 to S1104 again until the number of sheets P placed on the internal tray 22 reaches the given number of sheets N (YES in step S1104). In other words, the controller 100b executes the processing of steps S1102 to S1104 each time the sheet P is conveyed to the internal tray 22 by the conveyance roller pairs 10, 11, 14, and 15. The liquid application by the liquid applier 31 may be performed not only on all of the plurality of sheets P included in the sheet bundle Pb but also on only some of the plurality of sheets P included in the sheet bundle Pb.

[0144] When the controller 100b determines that the number of sheets P placed on the internal tray 22 has reached the given number of sheets N (YES in step S1104), in step S1105, the controller 100b drives the edge-binder movement motor 55 to move the edge binder 25 in the main scanning direction such that the crimper 32 faces the first binding position B1 as illustrated in FIG. 12C.

[0145] In step S1106, the controller 100b causes the crimper 32 to crimp the sheet bundle Pb placed on the internal tray 22. In step S1107, the controller 100b causes the conveyance roller pair 15 to eject the sheet bundle Pb thus crimped by the crimper 32 to the second ejection tray 26. Specifically, the controller 100b drives the contact-separation motor 32d to cause the upper crimping teeth 32a and the lower crimping teeth 32b to pinch the first binding position B1 on the sheet bundle Pb placed on the internal tray 22. The sheet bundle Pb is pressed and deformed between the upper crimping teeth 32a and the lower crimping teeth 32b, and thus the sheet bundle Pb is crimped. Then, the controller 100b rotates the conveyance roller pair 15 to eject the sheet bundle Pb thus crimped and bound to the second ejection tray 26.

[0146] The sheet bundle Pb that is supported on the internal tray 22 has a crimping area (corresponding to the first binding position B1) sandwiched between the upper crimping teeth 32a and the lower crimping teeth 32b in step S1106. The crimping area overlaps with a liquid application area (corresponding to the first liquid application position B1) contacted by a distal end of the liquid application member 501 in step S1103. In other words, the crimper 32 crimps an area to which liquid is applied by the liquid applier 31 on the sheet bundle Pb placed on the internal tray 22. The crimping area that is pinched by the upper crimping teeth 32a and the lower crimping teeth 32b may completely or partially overlap with the liquid application area contacted by the distal end of the liquid application member 501, to obtain a sufficient binding strength.

[0147] In step S1108, the controller 100b determines whether the number of sheet bundles Pb thus ejected to the second ejection tray 26 has reached the requested number of copies M indicated by the binding command. When the controller 100b determines that the number of sheet bundles Pb thus ejected has not reached the requested number M of copies (NO in step S1108), the controller 100b executes the operations of step S1102 and subsequent steps again. In other words, when the controller 100b determines that the number of sheet bundles Pb thus ejected has not reached the requested number of copies M (NO in step S1108), the controller 100b repeats the operations of steps S1102 to S1108 until the number of sheet bundles Pb ejected to the second ejection tray 26 reaches the requested number of copies M (YES in step S1108).

[0148] On the other hand, when the controller 100b determines that the number of sheet bundles Pb output to the second ejection tray 26 has reached the requested number of copies M (YES in step S1108), in step S1109, the controller 100b drives the edge-binder movement motor 55 to move the edge binder 25 (the liquid applier 31 and the crimper 32) to the standby position HP as illustrated in FIG. 12D. When the posture that is instructed by the binding command is the oblique binding posture, in step S1109, the controller 100b also drives the liquid-applier pivot motor 563 and the crimper pivot motor 56 to rotate the liquid applier 31 and the crimper 32 into the parallel binding posture. On the other hand, when the posture that is instructed by the binding command is the parallel binding posture, the controller 100b skips the aforementioned operation of rotating the liquid applier 31 and the crimper 32 to the parallel binding posture. As a result, the edge binder 25 (the liquid applier 31 and the crimper 32) returns to the standby position HP position illustrated in FIG. 12D. In steps S1101 and S1109, the execution order of the movement in the main scanning direction and the rotation in the forward and reverse directions of the liquid applier 31 and the crimper 32 is not limited to the aforementioned order and may be reversed.

[0149] FIGS. 13A to 13H are diagrams illustrating the positions of the edge binder 25 during execution of two-point binding. A detailed description of points common to the process described with reference to FIGS. 12A to 13H may be omitted, and differences will be mainly described. As illustrated in FIG. 13A, it is assumed that the edge binder 25 is located at the standby position HP at the start point of the two-point binding. The first binding position B1 and the second binding position B2 are positions separated from each other in the main scanning direction. In FIGS. 13A to 13H, the case where two sheets P are crimped and bound (i.e., N=2) is illustrated. In the case of executing the two-point binding, the number of sheets P included in the sheet bundle Pb is not limited to two, and the two-point binding can be performed on a sheet bundle Pb having the same number of sheets as the number of sheets that can be bound in one-point binding.

[0150] Before a first sheet P1 for a sheet bundle Pb is supplied to the internal tray 22, the controller 100b moves the edge binder 25 in the main scanning direction such that the liquid applier 31 can face the first liquid application position B1 (see FIG. 13B). As illustrated in FIG. 13B, the liquid applier 31 is disposed at a position at which the liquid applier 31 can face the first binding position B1. In such a state, the controller 100b causes the first sheet P1, on which an image has been formed by the image forming apparatus 2, to be placed on the internal tray 22 and performs a jogging process on the first sheet P1. In response to the placement of the first sheet P1 on the internal tray 22, the controller 100b causes the liquid applier 31 to apply the liquid to the first liquid application position B1 of the first sheet P1.

[0151] Subsequently, as illustrated in FIG. 13C, the controller 100b causes the edge binder 25 to move in the main scanning direction such that the liquid applier 31 faces the second liquid application position B2 of the first sheet P1. Then, the controller 100b causes the liquid applier 31 to apply the liquid to the second liquid application position B2 of the first sheet P1.

[0152] In response to the application of the liquid to the first liquid application position B1 and the second liquid application position B2 of the first sheet P1, the controller 100b causes a second sheet P2 for the sheet bundle Pb to be placed on the internal tray 22 and performs the jogging process on the second sheet P2 in a state where the liquid applier 31 is disposed at a position which the liquid applier 31 can face the second liquid application position B2 as illustrated in FIG. 13D. In response to the placement of the second sheet P2 on the internal tray 22, the controller 100b causes the liquid applier 31 to apply the liquid to the second liquid application position B2 of the second sheet P2.

[0153] Then, as illustrated in FIG. 13E, the controller 100b causes the edge binder 25 to move in the main scanning direction such that the liquid applier 31 faces the first liquid application position B1 of the second sheet P2. Subsequently, the controller 100b causes the liquid applier 31 to apply the liquid at the first liquid application position B1 of the second sheet P2.

[0154] In other words, the controller 100b controls the conveyance roller pairs 10, 11, 14, and 15 and the liquid applier 31 to repeat the conveyance of the sheet P and the liquid application to the first liquid application position B1 and the second liquid application position B2 until the number of sheets P placed on the internal tray 22 reaches the given number of sheets N. At this time, the controller 100b causes the liquid applier 31 to apply the liquid to the B-th sheet P (B<N) in the order of the first liquid application position B1 and the second liquid application position B2. The controller 100b also causes the liquid applier 31 to apply the liquid to the (B+1)-th sheet P in the order of the second liquid application position B2 and the first liquid application position B1. In other words, the controller 100b changes the order in which the liquid applier 31 applies the liquid to the first liquid application position B1 and the second liquid application position B2 for each sheet P. The controller 100b also causes the edge binder 25 to move from one side of the first liquid application position B1 and the second liquid application position B2 to the other side of the first liquid application position B1 and the second liquid application position B2 in the shortest distance without passing through the standby position HP.

[0155] Subsequently, in response to a determination that the number of sheets P placed on the internal tray 22 has reached the given number of sheets N, the controller 100b causes the edge binder 25 to move in the main scanning direction such that the crimper 32 faces the first binding position B1 as illustrated in FIG. 13F. The controller 100b causes the crimper 32 to perform crimping on the first binding position B1 of the sheet bundle Pb placed on the internal tray 22.

[0156] Then, as illustrated in FIG. 13G, the controller 100b causes the edge binder 25 to move in the main scanning direction such that the crimper 32 faces the second binding position B2. The controller 100b causes the crimper 32 to perform crimping on the second binding position B2 of the sheet bundle Pb placed on the internal tray 22.

[0157] In the example illustrated in FIGS. 13A to 13H, the liquid is finally applied to the first binding position B1, and the crimping is performed in the order of the first binding position B1 and the second binding position B2. On the other hand, when the liquid is finally applied to the second binding position B2, crimping is performed in the order of the second binding position B2 and the first binding position B1.

[0158] The controller 100b outputs the sheet bundle Pb crimped and bound at the first binding position B1 and the second binding position B2 to the second ejection tray 26. Further, as illustrated in FIG. 13H, the controller 100b causes the edge binder 25 to move to the standby position HP.

[0159] Although an example in which one or two positions of the sheet bundle Pb are crimped and bound has been described in the above-described embodiment, an embodiment of the present disclosure is also applicable to a case in which three or more positions of the sheet bundle Pb spaced apart from each other in the main scanning direction are crimped and bound. In this case, the controller 100b causes the liquid applier 31 to apply the liquid to three or more liquid application positions (corresponding to the crimp binding positions) and causes the crimper 32 to perform crimping. According to an embodiment of the present disclosure, the productivity of crimping can be enhanced even when three or more positions are crimped and bound.

[0160] However, it is not necessary to apply the liquid to all the liquid application positions (corresponding to crimping (binding) positions) for all the sheets P included in the sheet bundle Pb. For example, when crimping is performed on three liquid application positions (corresponding to crimping (binding) positions) apart from each other in the main scanning direction, the controller 100b may cause the liquid applier 31 to apply the liquid to three liquid application positions (corresponding to crimping (binding) positions) of an E-th sheet P1 (E<N2), apply the liquid to two liquid application positions (corresponding to crimping (binding) positions) of an (E+1)-th sheet P2, and apply the liquid to one liquid application position (corresponding to a crimping (binding) position) of an (E+2)-th sheet P2.

[0161] A description is given below of a liquid supply/discharge operation in activation of a post-processing apparatus.

[0162] A description is given below of the correspondence between the operation status of the post-processing apparatus 3 (referred to as post-processing operation status) and the liquid supply/discharge mode executed in accordance with the operation status when the controller 100b performs a liquid supply/discharge operation. FIGS. 14A and 14B illustrate examples of the correspondence between the post-processing operation status and the liquid supply/discharge mode.

[0163] In the following description, the term liquid supply/discharge operation means that liquid used for liquid application is transferred between the second liquid storage tank 47 and the first liquid storage tank 44 by the liquid supply pump 46. In other words, the term liquid supply/discharge operation includes both an operation of supplying (replenishing) liquid from the second liquid storage tank 47 to the first liquid storage tank 44 by the liquid supply pump 46 and an operation of feeding (discharging) liquid from the first liquid storage tank 44 to the second liquid storage tank 47 by the liquid supply pump 46.

[0164] For example, the post-processing operation status is classified into activation of post-processing apparatus (such as the turn-on of the post-processing apparatus 3 or the return from an energy saving mode) that corresponds to the time when the post-processing apparatus 3 is activated, standby, and opening or closing of cover in activation and other statuses in FIG. 14A. The post-processing operation status further includes forced execution of liquid supply operation and forced execution of liquid discharge operation by a user operation on the operation section.

[0165] In the case of the crimping process in FIG. 14B, the status is classified into preparation for crimping job, during execution of crimping job, and after crimping job. The term crimping used herein means a crimping process accompanied with liquid application. Further, the term job used herein means a binding operation based on an instruction of executing a binding process transmitted from the image forming apparatus 2 to the post-processing apparatus 3.

[0166] At timings such as on activation of post-processing apparatus (FIG. 14A) and during execution of crimping job (FIG. 14B), the controller 100b executes a specified-level supply operation as a liquid supply/discharge mode. Depending on the frequency of use by the user, it is possible to select not to perform the specified-level supply operation, for example, on activation of post-processing apparatus.

[0167] A description is given below of a control process of the specified-level supply operation on activation.

[0168] Specifically, a process of the specified-level supply operation executed on activation and other statuses is described with reference to the flowchart of FIG. 15. The control process according to the flowchart is executed by the controller 100b. First, when the control process of the specified-level supply operation on activation and other statuses is started, in step S1501, the controller 100b energizes the liquid amount detector (e.g., the first liquid-level sensor 43 and the second liquid-level sensor 94). In the following description, the position of the liquid surface when the remaining amount of the liquid (liquid remaining amount) stored in the first liquid storage tank 44 or the second liquid storage tank 47 is a specified amount is referred to as liquid level. In addition, the state in which a specified amount of liquid is present is referred to as a specified liquid level is present.

[0169] In step S1502, the controller 100b checks whether the liquid is present at a specified liquid level in the second liquid storage tank 47 with the second liquid-level sensor 94.

[0170] If the liquid is present at the specified liquid level in the second liquid storage tank 47 (YES in step S1502), in step S1503, the controller 100b checks whether the liquid is present at a specified liquid level in the first liquid storage tank 44 with the first liquid-level sensor 43.

[0171] When the liquid is present at the specified liquid level in the first liquid storage tank 44 (YES in step S1503), the energization for liquid amount detection (of the first liquid-level sensor 43 and the second liquid-level sensor 94) is turned off in step S1504 and ends the control process of the specified-level supply operation on activation.

[0172] When the liquid is not present at the specified liquid level in the second liquid storage tank 47 in step S1502 (NO in step S1502), the notification of liquid replenishment is performed in step S1505. The notification of liquid replenishment is executed, for example, by the controller 100b causing the operation panel 110 to display the information for prompting the user to replenish the liquid to the second liquid storage tank 47. The operation panel 110 serves as a notification device that notifies the storage state of the liquid in the second liquid storage tank 47.

[0173] The user confirms the notification of liquid replenishment, and performs certain operations such as opening of the cover 71 of the post-processing apparatus 3, replenishment of liquid to the second liquid storage tank 47, and closing of the cover 71. The post-processing apparatus 3 includes the cover opening-closing sensor 542, which is an example of an opening-and-closing detector, to detect opening and closing of the cover 71.

[0174] In step S1506, the controller 100b receives, as a trigger, an opening or closing signal of the cover 71 transmitted from the cover opening-closing sensor 542 disposed in the post-processing apparatus 3. After the reception of the trigger, the process returns to step S1502, and the controller 100b determines whether the liquid storage state of the second liquid storage tank 47 is a state in which the liquid is detected at the specified liquid level in the second liquid storage tank 47.

[0175] The presence of the liquid in the second liquid storage tank 47 may be checked during the specified-level supply operation on activation and other statuses as described above, or may be constantly monitored independently of the specified-level supply operation.

[0176] If the liquid is not present at the specified liquid level in the first liquid storage tank 44 (NO in step S1503), the controller 100b performs the specified-level supply operation of the liquid. In the specified-level supply operation, first, the controller 100b starts driving the liquid supply pump 46 in step S1507. Following the step S1507, the controller 100b checks again whether the specified liquid level is present in the first liquid storage tank 44 in step S1508. When the liquid stored in the first liquid storage tank 44 is detected by the first liquid-level sensor 43 in step S1508 (YES in step S1508), in step S1509, the controller 100b turns off the energization of the second liquid-level sensor 94 and the first liquid-level sensor 43 that are an example of the liquid amount detector.

[0177] When the period of time from the start of driving of the liquid supply pump 46 in step S1507 to the turn-off of the liquid amount detection in step S1509 is less than T5 seconds (YES in step S1510), the controller 100b causes the driving of the liquid supply pump 46 to further continue for T2 seconds in step S1511. Then, the controller 100b stops the liquid supply pump 46 in step S1512, and ends the control process of the specified-level supply operation on activation and other statuses.

[0178] When the period of time from the start of driving of the liquid supply pump 46 in step S1507 to the turn-off of the liquid amount detection in step S1509 is equal to or longer than T5 seconds (NO in step S1510), the controller 100b causes the driving of the liquid supply pump 46 to further continue for T2 seconds in step S1513. Then, the liquid supply pump 46 is stopped in step S1514.

[0179] In step S1515, the controller 100b starts driving of the liquid supply pump 46 for reverse rotation. After step S1515, in step S1516, the process is on standby for T4 seconds, and the liquid is discharged in the meantime. After the liquid is discharged, the controller 100b stops the liquid supply pump 46 in step S1517, and ends the control process of the specified-level supply operation on activation and other statuses.

[0180] The liquid supply pump 46 is set to have a constant amount of flow per unit time. For this reason, in the specified-level supply operation by the liquid supply pump 46, the liquid supply pump 46 is driven for T2 seconds which is a predetermined time after the detection with the first liquid-level sensor 43 that is an example of the liquid amount detector. The controller 100b stops the liquid supply pump 46 after the elapse of the predetermined time, thus allowing the liquid to be supplied to a certain liquid level.

[0181] The amount of flow per unit time of the liquid supply pump 46 is set to be constant. Accordingly, in the specified-level supply operation, the controller 100b drives the liquid supply pump 46 for T2 seconds which is a predetermined time after the detection with the first liquid-level sensor 43 that is an example of the liquid amount detector. After the predetermined time has elapsed, the controller 100b stops the liquid supply pump 46. Then, the controller 100b starts driving of the liquid supply pump 46 for reverse rotation, and the liquid supply pump 46 is driven for T4 seconds that is a predetermined time. The controller 100b stops the liquid supply pump 46 after the elapse of the predetermined time, thus allowing the liquid to be supplied to the certain liquid level.

[0182] The liquid supply pump 46 is driven for a predetermined time T2 seconds in step S1513, and the liquid supply pump 46 is stopped. A predetermined time may be elapsed from the stop of the driving of the liquid supply pump 46 in step S1514 to the start of the driving of the liquid supply pump 46 for reverse rotation in step S1515. The predetermined time is set to an appropriate time depending on the liquid permeation time due to the capillary phenomenon of the liquid supply member 50.

[0183] In the specified-level supply operation, the sensing with the first liquid-level sensor 43 and the second liquid-level sensor 94 is used as a trigger for stopping the liquid supply pump 46. Accordingly, the liquid level of the liquid stored in the first liquid storage tank 44 on activation can be stabilized at the same height every time.

[0184] In the specified-level supply operation performed when the liquid is not present at the predetermined liquid level in the first liquid storage tank 44 in step S1503 (NO in step S1503), the controller 100b starts driving the liquid supply pump 46 in step S1507. When the liquid is not detected by the first liquid-level sensor 43 (NO in step S1508), in step S1518, the controller 100b waits until T1 seconds elapses. If the first liquid-level sensor 43 does not detect the liquid even after the T1 seconds have elapsed, it is assumed that the liquid supply pump 46 has failed or liquid has leaked. Therefore, the controller 100b performs error stop processing in step S1519. Further, following the error stop processing, the controller 100b performs abnormality notification with, e.g., the operation panel 110 in step S1520, and ends the control process of the specified-level supply operation on activation and other statuses.

[0185] A description is given below of an outline of a specified-level supply operation that is one of the liquid supply/discharge modes with reference to FIGS. 16A, 16B, 16C, 17A, 17B, 18A, and 18B. FIG. 16A illustrates an example of an empty state of liquid in the first liquid storage tank 44. At this time, the liquid supply member 50 may be wet due to moisture contained therein or may be dried due to the evaporation of moisture, depending on the elapsed time from the use in the previous liquid applying operation.

[0186] When the driving of the liquid supply pump 46 in the step S1507 is started from the empty state as illustrated in FIG. 16A, liquid is supplied from the second liquid storage tank 47 to the first liquid storage tank 44 as illustrated in FIG. 16B. As illustrated in FIGS. 16A and 16B, the first liquid-level sensor 43 includes a pair of electrode pins having different lengths. Accordingly, as illustrated in FIG. 16B, as the liquid level of the liquid in the first liquid storage tank 44 rises, the electrode pins come into contact with the liquid in the order from the longer one to the shorter one of the pair of electrode pins.

[0187] Then, as illustrated in FIG. 16C, when the liquid in the first liquid storage tank 44 reaches the shorter electrode pin, the pair of electrode pins are electrically connected to each other. Thus, the first liquid-level sensor 43 detects the liquid in the first liquid storage tank 44. The liquid level (i.e., the amount of liquid stored in the first liquid storage tank 44) detected when the first liquid-level sensor 43 detects the liquid in the first liquid storage tank 44 is referred to as a detection liquid level.

[0188] A wall 43a is disposed between the pair of electrode pins. The wall 43a is preferably formed with a part of the first liquid storage tank 44.

[0189] Further, as in the state illustrated in FIG. 17A, the liquid supply pump 46 continues to be driven to supply the liquid from the second liquid storage tank 47 to the first liquid storage tank 44. In FIG. 17A, the liquid level reaches a predetermined position beyond the higher electrode pin (i.e., the shorter electrode pin) of the pair of electrode pins. The liquid level (i.e., the amount of liquid stored in the first liquid storage tank 44) at this time is referred to as a reference liquid level (first predetermined liquid level).

[0190] Further, as in the state illustrated in FIG. 17B, the liquid supply pump 46 continues to be driven to supply the liquid from the second liquid storage tank 47 to the first liquid storage tank 44 even beyond the first predetermined liquid level. In FIG. 17B, the liquid level exceeds the first predetermined liquid level and reaches the predetermined position. The liquid level (i.e., the amount of liquid stored in the first liquid storage tank 44) at this time is referred to as a second predetermined liquid level.

[0191] Then, the liquid stored in the first liquid storage tank 44 is sucked up by the action of capillary phenomenon of the liquid supply member 50.

[0192] FIG. 18A illustrates a case where the supply of the liquid is stopped at the first predetermined liquid level. FIG. 18A also illustrates a case where the liquid supply member 50 is immersed in the liquid. A description is given below of a case where the liquid level (initial liquid level) of the first liquid storage tank 44 on, e.g., activation of the post-processing apparatus 3 is higher than the liquid level (liquid permeation boundary level Lth) which is a boundary at which the liquid supply member 50 is immersed in the liquid.

[0193] The period of time from the start of driving the liquid supply pump 46 (the start of liquid supply) in step S1507 until the first liquid-level sensor 43 detects the liquid in step S1509 and the energization of the first liquid-level sensor 43 is turned off is defined as an elapsed time of T5 seconds. In this case, the elapsed time of T5 seconds is shorter than the time (liquid permeation supply time Tth) from the liquid permeation boundary level Lth to the liquid detection. In this way, if the liquid supply member 50 is already immersed in liquid, no downtime for liquid suction occurs.

[0194] In other words, according to the specified-level supply operation in the case where liquid remains in the first liquid storage tank 44, the liquid supply operation of changing the liquid level for stopping the liquid supply is performed according to the detection result by the first liquid-level sensor 43. Thus, the time until the entire area of the supply member is immersed in the liquid can be shorten and the liquid application amount can be stabilized.

[0195] FIG. 18B illustrates a supply operation in a case where the initial liquid level is lower than the liquid permeation boundary level Lth. FIG. 18B also illustrates a case where the liquid supply member 50 is not immersed in liquid. In this case, the liquid level (initial liquid level) of the first liquid storage tank 44 on, e.g., activation of the post-processing apparatus 3 is lower than the liquid level (liquid permeation boundary level Lth) that is the boundary at which the liquid supply member 50 is immersed in the liquid. Accordingly, the elapsed time of T5 seconds is longer than the liquid permeation supply time Tth.

[0196] In this case, it takes time to immerse the liquid application member 501 of the liquid supply member 50 by the capillary phenomenon. For this reason, when the elapsed time of T5 seconds from the start of liquid supply in step S1507 to liquid detection in step S1509 is longer than the liquid permeation supply time Tth, as illustrated in FIG. 18B, in step S1513, the controller 100b does not stop the liquid supply pump 46 and continues driving to supply the liquid during T2 seconds which is the elapsed time from the turn-off of the liquid amount detector in step S1509 until the liquid reaches the second predetermined liquid level. Then, the liquid supply pump 46 is started to be driven for reverse rotation in step S1515, and discharges the liquid from the first liquid storage tank 44 to the second liquid storage tank 47 in step S1515. In order to discharge the liquid from the second predetermined liquid level to the reference liquid level (i.e., the first predetermined liquid level), the controller 100b causes the liquid supply pump 46 to perform the liquid discharge for a predetermined time period in which the driving of the liquid supply pump 46 for reverse rotation is continued until the elapsed time T4 passes. Then, the controller 100b stops the liquid supply pump 46 in step S1517, and ends the process of the specified-level supply operation on activation.

[0197] As described above, when no liquid remains in the first liquid storage tank 44, the time for the liquid to permeate the liquid supply member 50 can be shortened by increasing the area of the liquid supply member 50 that is immersed in the liquid.

[0198] The supply operation illustrated in FIG. 18B can also prevent the liquid level of the first liquid storage tank 44 from becoming too high and the liquid from dripping from the tip of the liquid supply member 50.

[0199] Ensuring the time until the liquid permeates the liquid supply member 50 allows the liquid to be reliably applied to the medium. In addition, since the liquid application is not performed in a case where the predetermined time has not elapsed, the time can be shortened according to the situation.

[0200] Since the time until the liquid permeates the liquid supply member 50 varies depending on the use period, the liquid can be applied in an optimal amount.

[0201] In the case where an electrode sensor is used as the first liquid-level sensor 43, the constant energization of the electrode sensor has a risk that an electrolytic corrosion phenomenon may occur in an electrode formed of metal and the electrode may corrode. In addition, since the voltage is always applied to the liquid, the liquid may be electrolyzed. Consequently, a failure such as adhesion of foreign substances to the electrode or dissolution of the electrode might occur. In consideration of such a failure, the voltage is applied to the first liquid-level sensor 43 as the electrode sensor (i.e., the energization is ON) only when the detection of the liquid stored in the first liquid storage tank 44 is performed.

[0202] In the present embodiment, the electrode sensor has been described as an example of the first liquid-level sensor 43. However, the first liquid detector is not limited to the electrode sensor and may be other types of sensors. For example, a float sensor or a capacitance sensor may be used to detect the presence of the liquid. Further, the first liquid-level sensor 43 is not limited to a sensor that detects the liquid level (liquid surface) of the liquid in the first liquid storage tank 44, and may be any sensor that can detect the presence or absence of the liquid in the first liquid storage tank 44 (the amount of the liquid stored).

[0203] A description is given below of an overview of a control process of a binding operation including a liquid supply/discharge operation.

[0204] FIG. 19 is a flowchart of the entire control process including the liquid supply/discharge operation to the liquid applier 31 of the edge binder 25. The control process according to the flowchart is executed by the controller 100b.

[0205] First, when the control process of the binding operation is started, in step S1901, the controller 100b performs a job-preparation liquid supply operation as a preparation before job execution. The job-preparation liquid supply operation will be described in detail with reference to FIG. 18. In step S1902, the controller 100b performs the movement, liquid application, and binding operation of the liquid applier 31 and the crimper 32 of the edge binder 25. Details of the movement, liquid application, and binding operation are the same as those described as the binding process in FIG. 11. Finally, the controller 100b executes the post-job liquid supply operation as the completion operation in step S1903. The post-job liquid supply operation will be described in detail with reference to FIG. 22.

[0206] FIG. 20 is a flowchart of a control process of the job-preparation liquid supply operation. When an execution command of the binding process is received from the user, the control process of the job-preparation liquid supply operation is started. Before the liquid applier 31 and the crimper 32 are moved, the liquid applier 31 and the crimper 32 are made ready for the liquid application process.

[0207] When the controller 100b receives the request for checking the presence of liquid, in step S2001, the controller 100b energizes the second liquid-level sensor 94 and the first liquid-level sensor 43 as the liquid amount detector in order to check whether the liquid is present at the specified liquid level. Energizing the first liquid-level sensor 43 and the second liquid-level sensor 94 brings the first liquid-level sensor 43 and the second liquid-level sensor 94 into a detectable state.

[0208] In step S2002, the controller 100b checks whether the liquid is present at the specified liquid level in the second liquid storage tank 47 with the second liquid-level sensor 94. If the liquid is present at the specified liquid level in the second liquid storage tank 47 (YES in step S2002), in step S2003, the controller 100b checks whether the liquid is present at the specified liquid level in the first liquid storage tank 44 with the first liquid-level sensor 43.

[0209] If the liquid is present at the specified liquid level in the first liquid storage tank 44 (YES in step S2003), in step S2004, the controller 100b turns off the energization of the second liquid-level sensor 94 and the first liquid-level sensor 43, which is an example of a liquid amount detector, and ends the control process of the job-preparation liquid supply operation. Turning off the energization of the first liquid-level sensor 43 and the second liquid-level sensor 94 brings the first liquid-level sensor 43 and the second liquid-level sensor 94 into an undetectable state.

[0210] If the liquid is not present at the specified liquid level in the second liquid storage tank 47 (NO in step S2002), in step S2005, the controller 100b performs the notification of liquid replenishment. When the user replenishes the second liquid storage tank 47 with liquid and closes the cover 71 of the post-processing apparatus 3, in step S2006, the controller 100b receives, as a trigger, a signal indicating that the cover 71 has been closed with the liquid replenishment. The check of the presence of the liquid in the second liquid storage tank 47 may be executed in the job-preparation liquid supply operation as described above, or may be executed at a timing independent of the binding process.

[0211] When the liquid is not present at the specified liquid level in the first liquid storage tank 44 (NO in step S2003), the controller 100b performs a predetermined-amount supply operation. In the predetermined-amount supply operation, first, the controller 100b de-energizes the second liquid-level sensor 94 and the first liquid-level sensor 43 (liquid amount detector) in step S2007, and starts driving of the liquid supply pump 46 as a preparatory operation for liquid application in step S2008. In step S2009, the controller 100b continues driving the liquid supply pump 46 for T3 seconds in step S2009. Then, the controller 100b stops the liquid supply pump 46 in step S2010, and ends the control process of the job-preparation liquid supply operation as the preparation supply operation. Since the liquid supply pump 46 is set to have a constant amount of flow per unit time, driving the liquid supply pump 46 for T3 seconds in the predetermined-amount supply operation can supply a constant amount of liquid.

[0212] In the predetermined-amount supply operation, the sensing with the liquid detection unit is not performed as a trigger for stopping the liquid supply pump 46. Accordingly, the time required for the supply operation is constant, and the process can be immediately shifted to the subsequent process. Thus, the processing time of the entire binding process can be shortened to enhance the productivity.

[0213] An outline of the predetermined-amount supply operation, which is one of the liquid supply/discharge operations, is described below with reference to FIGS. 21A, 21B, and 21C. The first liquid storage tank 44 illustrated in FIG. 21A illustrates a state where the liquid is higher than the detection liquid level as the predetermined liquid level. At this time, as described above, the liquid is present at the specified liquid level in the first liquid storage tank 44 (YES in step S2003), and the controller 100b ends the control process of the job-preparation liquid supply operation.

[0214] The first liquid storage tank 44 illustrated in FIG. 21B illustrates a state in which the liquid is less than the detection liquid level. This is a case where the post-processing apparatus 3 is used in a low-humidity environment or the evaporation of the liquid progresses due to a long elapsed time from the previous use. As described above, this is a case where the liquid is not present at the specified liquid level in the first liquid storage tank 44 (NO in step S2003), and the controller 100b performs the predetermined-amount supply operation.

[0215] As the preparatory operation for liquid application, in step S2009, the controller 100b continues the driving of the liquid supply pump 46 for T3 seconds. Then, the controller 100b stops the liquid supply pump 46 in step S2010, and ends the control process of the job-preparation liquid supply operation. In this state, as illustrated in FIG. 21C, the liquid level of the first liquid storage tank 44 is close to the reference liquid level, but does not become a certain liquid level because the liquid level at the start of the predetermined-amount supply operation varies.

[0216] FIG. 22 is a flowchart of a control process of the post-job liquid supply operation. After the binding operation is completed, the liquid supply operation is performed in preparation for the next binding process.

[0217] First, the controller 100b checks whether there is an execution command of the following post-processing. In other words, in step S2201, the controller 100b checks whether there is the next binding command when the post-processing is consecutively executed. When there is the next binding command (execution command of the subsequent processing) to be consecutively executed (YES in step S2201), the controller 100b finishes the control process of the post-job liquid supply operation, and starts the next binding process.

[0218] When there is no next binding command to be consecutively executed (NO in step S2201), in step S2202, the controller 100b energizes the second liquid-level sensor 94 and the first liquid-level sensor 43 (liquid amount detector) in order to check whether the liquid is at the specified liquid level.

[0219] In step S2203, the controller 100b checks whether a specified liquid level is present in the second liquid storage tank 47 with the second liquid-level sensor 94. If the liquid is present at the specified liquid level in the second liquid storage tank 47 (YES in step S2203), in step S2204, the controller 100b checks whether the liquid is present at the specified liquid level in the first liquid storage tank 44 with the first liquid-level sensor 43.

[0220] If the liquid is present at the specified liquid level in the first liquid storage tank 44 (YES in step S2204), in step S2205, the controller 100b de-energizes the second liquid-level sensor 94 and the first liquid-level sensor 43 (liquid amount detector), and ends the control process of the job-preparation liquid supply operation.

[0221] If the liquid is not present at the specified liquid level in the second liquid storage tank 47 (NO in step S2203), in step S2206, the controller 100b performs the notification of liquid replenishment. When the user replenishes the second liquid storage tank 47 with liquid and closes the cover 71 of the post-processing apparatus 3, in step S2207, the controller 100b receives, as a trigger, a signal indicating that the cover 71 has been closed with the liquid replenishment. The check of the presence of the liquid in the second liquid storage tank 47 may be executed in the job-preparation liquid supply operation as described above, or may be executed at a timing independent of the binding process.

[0222] If the liquid is not present at the specified liquid level in the first liquid storage tank 44 (NO in step S2204), the controller 100b performs the specified-level supply operation of the liquid. In the specified-level supply operation, first, the controller 100b starts driving the liquid supply pump 46 in step S2208. The controller 100b checks the presence of liquid in the first liquid storage tank 44 again in step S2209. If the first liquid storage tank 44 is filled with liquid to the extent that the liquid can be detected by the first liquid-level sensor 43 (YES in step S2209), the controller 100b de-energizes the second liquid-level sensor 94 and the first liquid-level sensor 43 (liquid amount detector) in step S2210. In step S2211, the controller 100b further continues driving the liquid supply pump 46 for T2 seconds (sec). Then, the controller 100b stops the liquid supply pump 46 in step S2212, and ends the control process of the post-job liquid supply operation on activation.

[0223] The amount of flow per unit time of the liquid supply pump 46 is set to be constant. Accordingly, in the specified-level supply operation, the controller 100b drives the liquid supply pump 46 for T2 seconds which is a predetermined time after the detection with the first liquid-level sensor 43 that is an example of a liquid amount detector. The controller 100b stops the liquid supply pump 46 after the elapse of the predetermined time, thus allowing the liquid to be supplied to the certain liquid level. In the specified-level supply operation, the sensing with the first liquid-level sensor 43 and the second liquid-level sensor 94 is performed as a trigger for stopping the liquid supply pump 46. Accordingly, the liquid level of the liquid stored in the first liquid storage tank 44 after the job can be stabilized at the same height every time.

[0224] In the specified-level supply operation, when the controller 100b starts driving the liquid supply pump 46 in step S2208 and the liquid is not detected by the first liquid-level sensor 43 (NO in step S2209), in step S2213, the controller 100b waits until T1 seconds elapse. If the first liquid-level sensor 43 does not detect the liquid even after T1 seconds have elapsed, it is assumed that the liquid supply pump 46 has failed or has leaked. Therefore, the controller 100b performs error stop processing in step S2214, performs an abnormality notification with the operation panel 110 in step S2215, and ends the control process of the post-job liquid supply operation.

[0225] FIG. 23 is a flowchart of a control process of a binding process according to a modification. The difference from the control process of the binding process illustrated in FIG. 11 is that a liquid supply operation in consecutive liquid applications is performed when the number of times of consecutive liquid applications exceeds a predetermined number of times.

[0226] For example, the controller 100b starts the binding process illustrated in FIG. 23 when the controller 100b acquires an execution command of the binding process from the image forming apparatus 2. In the following description, the execution command of the binding process may be referred to as a binding command.

[0227] The binding command includes, for example, the type of the sheet P (including information affecting the spread of liquid, such as material and thickness), the number of sheets P of the sheet bundle Pb, the number of sheet bundles Pb to be bound, the binding position on the sheet bundle Pb, and the binding posture of the edge binder 25. In the following description, the number of sheets P of the sheet bundle Pb may be referred to as given number of sheets N whereas the number of sheet bundles Pb to be bound may be referred to as requested number of copies M. The liquid applier 31 and the crimper 32 are assumed to be in a parallel binding posture and located at a standby position HP that is a position away in the width direction from the sheets P placed on the internal tray 22 at the start of the binding process as illustrated in FIG. 12A.

[0228] When the posture that is instructed by the binding command is the inclined binding posture, in step S2301, the controller 100b drives the liquid-applier pivot motor 563 and the crimper pivot motor 56 to pivot the liquid applier 31 and the crimper 32 of the edge binder 25 into the inclined binding posture. Alternatively, when the posture that is instructed by the binding command is the inclined binding posture, the crimper 32 alone may be pivoted to the inclined binding posture and the liquid applier 31 may not be pivoted in the forward and reverse directions. As a result, the driving assembly may be simplified as compared with a case where both the liquid applier 31 and the crimper 32 are pivoted in the forward and reverse directions, and thus the effects such as cost reduction, the downsizing of the apparatus, and the reduction of failures of devices are exhibited.

[0229] On the other hand, when the posture that is instructed by the binding command is the parallel binding posture, the controller 100b skips the aforementioned operation of pivoting the liquid applier 31 and the crimper 32 of the edge binder 25 to the inclined binding posture. In step S2301, the controller 100b also drives the edge-binder movement motor 55 to move the edge binder 25 in the main scanning direction so that the liquid applier 31 faces the first liquid application position B1 instructed by the binding command. The controller 100b executes the operation of step S2101 before a first sheet P is conveyed to the internal tray 22 by the conveyance roller pairs 10, 11, 14, and 15.

[0230] In step S2302, the controller 100b rotates the conveyance roller pairs 10, 11, 14, and 15 to store the sheet P, on which the image has been formed by the image forming apparatus 2, onto the internal tray 22. In step S2302, the controller 100b also moves the side fences 24L and 24R to align the position of the sheet P or the sheet bundle Pb placed on the internal tray 22 in the main scanning direction. In short, the controller 100b performs so-called jogging.

[0231] In step S2303, the controller 100b causes the liquid applier 31 facing the first liquid application position B1 to perform the liquid application onto the first liquid application position B1 of the sheet P placed on the internal tray 22 in the immediately preceding step S2302, based on the liquid application control data adjusted in advance. In other words, the controller 100b drives the liquid-applier movement motor 42 to bring the liquid application member 501 into contact with the first liquid application position B1 on the sheet P placed on the internal tray 22 (see FIG. 12B). In the liquid application process in step S2303, the controller 100b adjusts the position at which the liquid application member 501 applies liquid to the sheet P in accordance with the type of the sheet P and the binding position included in the binding command. The controller 100b adjusts the amount of pressing the liquid application member 501 against the sheet P. In other words, the controller 100b controls the driving of the liquid-applier movement motor 42 based on the adjusted control data, and adjusts the amount of movement of the liquid application member 501 with respect to the first liquid application position B1 of the sheet P placed on the internal tray 22.

[0232] In step S2304, the controller 100b determines whether the number of sheets P placed on the internal tray 22 has reached the given number of sheets N instructed by the binding command. When the controller 100b determines that the number of sheets P placed on the internal tray 22 has not reached the given number of sheets N (NO in step S2304), the controller 100b executes the operations of steps S2302 to S2304 again until the number of sheets P placed on the internal tray 22 reaches the given number of sheets N (YES in step S2304). In other words, the controller 100b executes the processing of steps S2302 to S2304 each time the sheet P is conveyed to the internal tray 22 by the conveyance roller pairs 10, 11, 14, and 15. The liquid application by the liquid applier 31 may be performed not only on all of the plurality of sheets P included in the sheet bundle Pb but also on only some of the plurality of sheets P included in the sheet bundle Pb.

[0233] When the controller 100b determines that the number of sheets P placed on the internal tray 22 has reached the given number of sheets N (YES in step S2304), in step S2305, the controller 100b drives the edge-binder movement motor 55 to move the edge binder 25 in the main scanning direction such that the crimper 32 faces the first binding position B1 as illustrated in FIG. 12C.

[0234] In step S2306, the controller 100b causes the crimper 32 to crimp the sheet bundle Pb placed on the internal tray 22. In step S2307, the controller 100b causes the conveyance roller pair 15 to eject the sheet bundle Pb thus crimped by the crimper 32 to the second ejection tray 26. Specifically, the controller 100b drives the contact-separation motor 32d to cause the upper crimping teeth 32a and the lower crimping teeth 32b to pinch the first binding position B1 on the sheet bundle Pb placed on the internal tray 22. The sheet bundle Pb is pressed and deformed between the upper crimping teeth 32a and the lower crimping teeth 32b, and thus the sheet bundle Pb is crimped. Then, the controller 100b rotates the conveyance roller pair 15 to eject the sheet bundle Pb thus crimped and bound to the second ejection tray 26.

[0235] The sheet bundle Pb that is supported on the internal tray 22 has a crimping area (corresponding to the first binding position B1) sandwiched between the upper crimping teeth 32a and the lower crimping teeth 32b in step S2306. The crimping area overlaps with a liquid application area (corresponding to the first liquid application position B1) contacted by the distal end (distal end position) of the liquid application member 501 in step S2303. In other words, the crimper 32 crimps an area to which liquid is applied by the liquid applier 31 on the sheet bundle Pb placed on the internal tray 22. The crimping area that is pinched by the upper crimping teeth 32a and the lower crimping teeth 32b may completely or partially overlap with the liquid application area contacted by the distal end of the liquid application member 501, to obtain a sufficient binding strength.

[0236] In step S2308, the controller 100b determines whether the number of times of consecutive liquid applications reaches a predetermined number of times K. In the description of the present embodiment, the predetermined number of times K corresponding to the threshold of the number of times of consecutive liquid applications is, for example, 1000 times.

[0237] When the number of times of consecutive liquid applications exceeds the predetermined number of times (1000 times) (YES in step S2308), the amount of liquid in the first liquid storage tank 44 is not sufficient. In step S2309, the controller 100b temporarily interrupts the binding process and performs the liquid supply operation in consecutive liquid applications. The liquid supply operation in consecutive liquid applications is the same as the liquid supply operation in activation described in FIG. 15, that is, the specified-level supply operation, and therefore a detailed description of the operation flow is omitted below.

[0238] In step S2310, the controller 100b determines whether the number of sheet bundles Pb thus ejected to the second ejection tray 26 has reached the requested number of copies M indicated by the binding command. When the controller 100b determines that the number of sheet bundles Pb thus ejected has not reached the requested number M of copies (NO in step S2310), the controller 100b executes the operations of step S2302 and subsequent steps again. In other words, when the controller 100b determines that the number of sheet bundles Pb thus ejected has not reached the requested number of copies M (NO in step S2310), the controller 100b repeats the operations of steps S2302 to S2310 until the number of sheet bundles Pb ejected to the second ejection tray 26 reaches the requested number of copies M (YES in step S2310).

[0239] On the other hand, when the controller 100b determines that the number of sheet bundles Pb output to the second ejection tray 26 has reached the requested number of copies M (YES in step S2310), in step S2311, the controller 100b drives the edge-binder movement motor 55 to move the edge binder 25 (the liquid applier 31 and the crimper 32) to the standby position HP as illustrated in FIG. 12D. When the posture that is instructed by the binding command is the oblique binding posture, in step S2311, the controller 100b also drives the liquid-applier pivot motor 563 and the crimper pivot motor 56 to rotate the liquid applier 31 and the crimper 32 into the parallel binding posture. On the other hand, when the posture that is instructed by the binding command is the parallel binding posture, the controller 100b skips the aforementioned operation of rotating the liquid applier 31 and the crimper 32 to the parallel binding posture. As a result, the edge binder 25 (the liquid applier 31 and the crimper 32) returns to the standby position HP position illustrated in FIG. 12D. In steps S2301 and S2311, the execution order of the movement in the main scanning direction and the rotation in the forward and reverse directions of the liquid applier 31 and the crimper 32 is not limited to the aforementioned order and may be reversed.

[0240] A description is given below of a liquid discharge operation and a control process of the liquid discharge operation.

[0241] Specifically, a description is given below of a liquid discharge control of controlling a liquid discharge operation executable in the post-processing apparatus 3. FIGS. 24A and 24B are diagrams illustrating an outline of a liquid discharge operation which is one of liquid supply/discharge modes. FIG. 25 is a flowchart of an example of a control process of the liquid discharge operation (liquid discharge control process). The liquid discharge operation used herein is to feed the liquid stored in the first liquid storage tank 44 to the second liquid storage tank 47 by the liquid supply pump 46. In other words, the liquid is fed in a direction opposite to the liquid supply direction in the above-described liquid supply operation.

[0242] When the post-processing apparatus 3 is used, at least one of the first liquid storage tank 44, the liquid supply member 50, and the liquid application member 501 is filled with liquid. On the other hand, during maintenance of the post-processing apparatus 3, at least one of the liquid supply member 50 and the liquid application member 501 may be removed. In this case, an operation of emptying the first liquid storage tank 44 may be needed in order to prevent the liquid from leaking from the first liquid storage tank 44. In addition, an operation of emptying the first liquid storage tank 44 may be needed in order to prevent contamination by the liquid when the post-processing apparatus 3 is not used for a long period of time. For example, in such a case, i.e., in a case where the inside of the first liquid storage tank 44 is to be emptied, the liquid discharge operation is executed.

[0243] When the liquid discharge operation is selected as the liquid supply/discharge mode, the liquid discharge control process is started. When the liquid discharge control process is started, the controller 100b drives (rotates in reverse) the liquid supply pump 46 for a predetermined time (Tr seconds) in step S2501 to suck up the liquid from the first liquid storage tank 44 (see FIG. 24A). As a result, the liquid in the first liquid storage tank 44 is fed to the second-liquid-storage-tank fixer 61 and thus the liquid is discharged from the first liquid storage tank 44. Accordingly, the liquid level of the second-liquid-storage-tank fixer 61 rises and the liquid level of the first liquid storage tank 44 lowers. As a result, the first liquid storage tank 44 is empty (see FIG. 24B). The predetermined time Tr, which is the operation time of the liquid supply pump 46, is set to, for example, a time during which the liquid in the first liquid storage tank 44 and the liquid in the liquid supply member 50 and/or the liquid application member 501 are sufficiently discharged. The controller 100b drives (rotates in reverse) the liquid supply pump 46 for the predetermined time Tr, and ends the liquid discharge control process.

[0244] The liquid discharge operation as the liquid supply/discharge mode may be executed by a user's selection of a desired mode on an operation screen of the operation panel 110 as illustrated in FIG. 26. In other words, when the user wants to select the forced supply operation which is an operation of forcibly supplying the liquid, the user selects forced liquid supply on the operation screen. When the user wants to select the liquid discharge operation, the user selects liquid discharge on the operation screen. Further, the user can also provide an instruction to execute the filling supply operation or the additional supply operation as a liquid supply/discharge mode via the operation panel 110.

[0245] The controller 100b of the post-processing apparatus 3 in the above description is described as a configuration in which the controller 100b is provided separately from the controller 100a of the image forming apparatus 2, as illustrated in FIG. 1. However, embodiments of the present disclosure are not limited to the above-described configuration. For example, as illustrated in FIG. 27A, the controller 100B of the post-processing apparatus 3 may be disposed in the image forming apparatus 2. Further, as illustrated in FIG. 27B, the controller 100b of the post-processing apparatus 3 may be integrated with the controller 100a of the image forming apparatus 2.

[0246] As illustrated in FIG. 28A, the controller 100b of the post-processing apparatus 3 may be divided into a controller 100b1 (e.g., a driver system such as a motor) and a controller 100b2 (a detector such as a sensor) according to the function, and the controller 100b2 of the post-processing apparatus 3 may be disposed in the image forming apparatus 2. Further, as illustrated in FIG. 28B, the controller 100b2 of the post-processing apparatus 3 disposed in the image forming apparatus 2 may be integrated with the controller 100a of the image forming apparatus 2.

[0247] A description is given below of a post-processing apparatus 3A according to a second embodiment.

[0248] The post-processing apparatus 3A according to the second embodiment is described with reference to FIGS. 29 to 37. Components common to those of the post-processing apparatus 3 according to the first embodiment are attached with the same or like reference signs, and detailed descriptions may be omitted.

[0249] An edge binder 251 of the post-processing apparatus 3A according to the second embodiment is different from the edge binder 25 of the post-processing apparatus 3 according to the first embodiment in which the liquid applier 31 and the crimper 32 are arranged side by side, in that the edge binder 251 includes a crimper 32 only and a liquid applier 131 is disposed on the upstream side in a conveyance passage. Such a configuration allows a given number of sheets P to be stacked after the liquid application process and conveyed to the crimper 32 of the edge binder 251 disposed at a downstream position of the conveyance passage in the direction in which the sheet P is conveyed. Accordingly, the productivity of the binding process performed by the crimper 32 is enhanced.

[0250] Since the direction in which the conveyance roller pairs 10, 11, and 14 convey the sheet P is opposite to the conveyance direction defined above, the direction in which the conveyance roller pairs 10, 11, and 14 convey the sheet P is defined as a reverse conveyance direction in the following description. A direction that is orthogonal to both the opposite conveyance direction and the thickness direction of the sheet P is defined as the main scanning direction or the width direction of the sheet P. The liquid application position on a sheet P or a sheet bundle Pb onto which liquid application is performed by the liquid applier 131 corresponds to the binding position on the sheet bundle Pb to be crimped by the crimper 32. For this reason, in the following description, the liquid application position and the binding position are described with the same reference sign B1.

[0251] FIG. 29 is a diagram illustrating an internal configuration of the post-processing apparatus 3A according to the second embodiment. As illustrated in FIGS. 30A, 30B, and 30C, the edge binder 251 includes only the crimper 32. As illustrated in FIG. 29, the crimper 32 and the staple binder 156 are disposed downstream from the internal tray 22 in the conveyance direction. In addition, the crimper 32 and the staple binder 156 are located to face a downstream end, in the conveyance direction, of the sheet bundle Pb placed on the internal tray 22 and is movable in the main scanning direction. Further, the crimper 32 and the staple binder 156 are respectively rotatable in the forward and reverse directions about a crimper shaft 340 and a stapler shaft 84 both extending in the thickness direction of the sheet bundle Pb placed on the internal tray 22. In other words, the crimper 32 and the staple binder 156 bind, at a desired angle, a desired position in the main scanning direction on the sheet bundle Pb placed on the internal tray 22 in, for example, corner oblique binding, parallel one-point binding, or parallel two-point binding.

[0252] The crimper 32 presses and deforms the sheet bundle Pb with the serrate upper crimping teeth 32a and the serrate lower crimping teeth 32b to bind the sheet bundle Pb. In the following description, such a binding way may be referred to as crimping. In other words, the crimper 32 crimps and binds the sheet bundle Pb or performs the crimping on the sheet bundle Pb. On the other hand, the staple binder 156 passes the staple through a binding position on the sheet bundle Pb placed on the internal tray 22, thus allowing the sheet bundle Pb to be stapled.

[0253] FIGS. 30A, 30B, and 30C are schematic views of the internal tray 22 as viewed from the thickness direction of the sheet bundle Pb. FIG. 31 is a schematic diagram illustrating the crimper 32 as viewed from the downstream side in the conveyance direction. As illustrated in FIGS. 30A, 30B, and 30C, the crimper 32 and the staple binder 156 are disposed downstream from the internal tray 22 in the conveyance direction. The crimper 32 is movable in the main scanning direction along the surface of the sheet bundle Pb placed on the internal tray 22. The crimper 32 is rotatable in the forward and reverse directions about the crimper shaft 340 extending in the thickness direction of the sheet bundle Pb placed on the internal tray 22.

[0254] Similarly, the staple binder 156 is movable in the main scanning direction of the sheet bundle Pb. The staple binder 156 is rotatable in the forward and reverse directions about the stapler shaft 84 extending in thickness direction of the sheet bundle Pb. Since the other components of the staple binder 156 are similar to those of the staple binder 155 (see FIG. 6) of the post-processing apparatus 3 according to the first embodiment, a detailed description thereof is omitted.

[0255] As illustrated in FIG. 31, the crimper 32 includes a guide rail 337 extending in the main scanning direction at a position downstream from the internal tray 22 in the conveyance direction. The crimper 32 includes a crimper movement motor 238 as a driving source. A base 48 supporting a crimping frame 32c has a fastening portion 48b for a timing belt 240c at the bottom of the base 48. Accordingly, the driving force of the crimper movement motor 238 is transmitted to the base 48 by a drive transmission assembly 240 that includes pullies 240a and 240b, the timing belt 240c, and the fastening portion 48b. Thus, the crimper 32 is moved in the main scanning direction along the surface of the sheet bundle Pb placed on the internal tray 22 (in other words, the guide rail 337). The crimper shaft 340 including a drive transmission gear 340a is fixed to a bottom face of the crimping frame 32c that holds the components of the crimper 32.

[0256] The crimper shaft 340 and the drive transmission gear 340a are held by the base 48 on which the crimping frame 32c is disposed, so as to be rotatable in the forward and reverse directions. The drive transmission gear 340a meshes with an output gear 239a of a crimper pivot motor 239. When the driving force of the crimper pivot motor 239 is transmitted to the crimper shaft 340 via the output gear 239a and the drive transmission gear 340a, the crimper 32 rotates in the forward and reverse directions on the base 48 about the crimper shaft 340 extending in the thickness direction of the sheet P placed on the internal tray 22. The guide rail 337, the crimper movement motor 238, the crimper pivot motor 239, the crimper shaft 340, and the drive transmission assembly 240 constitute at least part of a driving assembly of the crimper 32 according to the present embodiment.

[0257] The crimper 32 is movable between the standby position HP illustrated in FIG. 30A and a position where the crimper 32 faces the first binding position B1 illustrated in FIGS. 30B and 30C. The standby position HP2 is a position away in the main scanning direction from the sheet bundle Pb placed on the internal tray 22. The first binding position B1 is a position on the sheet bundle Pb placed on the internal tray 22. However, the specific position of the first binding position B1 is not limited to the example of FIGS. 30A, 30B, and 30C, and the first binding position B1 may be any one or more positions in the main scanning direction in a downstream end in the conveyance direction of the sheet P.

[0258] The posture of the crimper 32 changes between a parallel binding posture illustrated in FIG. 30B and an oblique binding posture illustrated in FIG. 30C. In other words, the crimper 32 is rotatable in the forward and reverse directions about the crimper shaft 340. The parallel binding posture is a posture of the crimper 32 in which the longitudinal direction of the upper crimping teeth 32a and the lower crimping teeth 32b (i.e., a rectangular crimping trace) is along the main scanning direction. The oblique binding posture is a posture of the crimper 32 in which the longitudinal direction of the upper crimping teeth 32a and the lower crimping teeth 32b (i.e., the rectangular crimping trace) is inclined with respect to the main scanning direction.

[0259] The pivot angle (an angle of the upper crimping teeth 32a and the lower crimping teeth 32b with respect to the main scanning direction) in the inclined binding posture is not limited to the example of FIG. 30C, and may be any angle provided that the upper crimping teeth 32a and the lower crimping teeth 32b face the sheet bundle Pb placed on the internal tray 22.

[0260] The post-processing apparatus 3A includes the liquid applier 131 and a hole punch 132, which is an example of a processor. The liquid applier 131 and the hole punch 132 are disposed upstream from the internal tray 22 in the opposite conveyance direction. In addition, the liquid applier 131 and the hole punch 132 are disposed at different positions in the opposite conveyance direction to simultaneously face one sheet P that is conveyed by the conveyance roller pairs 10 to 19.

[0261] The liquid applier 131 and the hole punch 132 according to the present embodiment are disposed between the conveyance roller pairs 10 and 11. However, the arrangement of the liquid applier 131 is not limited to the example of FIG. 29. For example, in a case where an inserter 6 is disposed between the image forming apparatus 2 and the post-processing apparatus 3A as illustrated in FIG. 37, the liquid applier 131 may be disposed inside the inserter 6 located upstream from the post-processing apparatus 3A in a direction in which the sheet P is conveyed from the image forming apparatus 2 to the post-processing apparatus 3A. An example of the inserter 6 is an apparatus that allows a pre-printed medium, which is conveyed to the post-processing apparatus 3A together with the sheet P conveyed from the image forming apparatus 2, to be fed as a cover sheet, an insertion sheet, or a partition sheet without passing through the image forming apparatus 2.

[0262] As illustrated in FIG. 32A, the conveyance roller pair 11 is located at a position at which the conveyance roller pair 11 does not overlap, in the main scanning direction, with the first liquid application position B1 on the sheet P to which liquid has been applied by a liquid application head 146 of the liquid applier 131. This arrangement is to prevent the amount of liquid at the first liquid application position B1 from decreasing due to multiple roller pairs pressing the first liquid application position B1 when the conveyance roller pair 11 conveys the sheet P. As a result, when the sheet P reaches the crimper 32 disposed downstream from the liquid applier 131 in the opposite conveyance direction, the amount of liquid at the first liquid application position B1 is sufficient to maintain the binding strength. Accordingly, the binding strength of the sheet bundle Pb is prevented from decreasing due to a decrease in the amount of liquid at the first liquid application position B1 (corresponding to the first binding position B1) while the sheet P is conveyed.

[0263] In addition, a plurality of paired rollers included in the conveyance roller pair 11 are located at positions at which the multiple roller pairs do not overlap with the first liquid application position B1 on the sheet P in the main scanning direction, which can thus prevent the conveying performance of the sheet P from being worse due to the adhesion of liquid to the roller pairs and further prevent a conveyance jam caused by the worsened conveying performance of the sheet P.

[0264] Although only the conveyance roller pair 11 has been described above, similarly, the roller pairs included in the conveyance roller pairs 14 and 15 are also preferably located at positions at which the roller pairs do not overlap with the first liquid application position B1 on the sheet P in the main scanning direction.

[0265] The liquid applier 131 applies liquid to the sheet P that is conveyed by the conveyance roller pairs 10 and 11. In the following description, the application of liquid may be referred to as liquid application. The hole punch 132 punches a hole in the sheet P that is conveyed by the conveyance roller pairs 10 and 11 such that the hole penetrates the sheet P in the thickness direction of the sheet P. The processor disposed near the liquid applier 131 is not limited to the hole punch 132. Alternatively, the processor may be an inclination corrector that corrects an inclination or skew of the sheet P that is conveyed by the conveyance roller pairs 10 and 11.

[0266] FIGS. 32A and 32B are schematic views of the liquid applier 131 according to the second embodiment, viewed from the thickness direction of the sheet P. FIGS. 33A, 33B, and 33C are cross-sectional views of the liquid applier 131 taken along line XXV-XXV of FIG. 32A. FIGS. 34A, 34B, and 34C are cross-sectional views of the liquid applier 131 taken along line XXVI-XXVI of FIG. 32A. As illustrated in FIGS. 32A to 34C, the liquid applier 131 includes a pair of guide shafts 133a and 133b, a pair of pulleys 134a and 134b, endless annular belts 135 and 136, a liquid-applier movement motor 137, a standby position sensor 138 (see FIG. 35), and a liquid application unit 140.

[0267] The pair of guide shafts 133a and 133b extend in the main scanning direction at positions spaced apart from each other in the reverse conveyance direction. The pair of guide shafts 133a and 133b are supported by a pair of side plates 4a and 4b of the post-processing apparatus 3A. The pair of guide shafts 133a and 133b support the liquid application unit 140 such that the liquid application unit 140 can move in the main scanning direction.

[0268] The pair of pulleys 134a and 134b is disposed between the guide shafts 133a and 133b in the reverse conveyance direction. On the other hand, the pulleys 134a and 134b are apart from each other in the main scanning direction. The pulleys 134a and 134b are supported by a frame of the post-processing apparatus 3A so as to be rotatable in the forward and reverse directions about the respective shafts extending in the thickness direction of the sheet P.

[0269] The endless annular belt 135 is looped around the pair of pulleys 134a and 134b. The endless annular belt 135 is coupled to the liquid application unit 140 by a connection 135a. The endless annular belt 136 is looped around the pulley 134a and a driving pulley 137a that is fixed to an output shaft of the liquid-applier movement motor 137. The liquid-applier movement motor 137 generates a driving force to move the liquid application unit 140 in the main scanning direction.

[0270] As the liquid-applier movement motor 137 rotates, the endless annular belt 136 circulates around the pulley 134a and the driving pulley 137a to rotate the pulley 134a. As the pulley 134a rotates, the endless annular belt 135 circulates between the pair of pulleys 134a and 134b. Thus, the liquid application unit 140 moves in the main scanning direction along the pair of guide shafts 133a and 133b. The liquid application unit 140 reciprocates in the main scanning direction in response to switching of the rotation direction of the liquid-applier movement motor 137.

[0271] The standby position sensor 138 detects that the liquid application unit 140 has reached a standby position HP1 (see FIGS. 32A and 32B) in the main scanning direction. The standby position sensor 138 then outputs a standby position signal indicating the detection result to the controller 100b, which will be described below with reference to FIG. 35. The standby position sensor 138 is, for example, an optical sensor including a light emitter and a light receiver. At the standby position HP1, the liquid application unit 140 blocks an optical path between the light emitter and the light receiver. The standby position sensor 138 outputs the standby position signal in response to the light output from the light emitter not being received by the light receiver. The specific configuration of the standby position sensor 138 is not limited to the configuration described above.

[0272] As illustrated in FIGS. 33A, 33B, and 33C, the conveyance passage inside the post-processing apparatus 3A is defined by an upper guide plate 5a and a lower guide plate 5b, which are spaced apart from each other in the thickness direction of the sheet P. The liquid application unit 140 is located at a position to face an opening of the upper guide plate 5a. In other words, the liquid application unit 140 is disposed to face the conveyance passage (a position at which the liquid application unit 140 can face the sheet P) through the opening of the upper guide plate 5a.

[0273] As illustrated in FIGS. 32A to 34C, the liquid application unit 140 includes a base 141, a rotary bracket 142, a liquid storage tank 143, a liquid-application-head mover 144, a holder 145, the liquid application head 146, columns 147a and 147b, a pressure plate 148, coil springs 149a and 149b, the application-head pivot motor 150, the application-head movement motor 151 (see FIG. 35), and a standby angle sensor 152 (see FIG. 35).

[0274] The base 141 is supported by the pair of guide shafts 133a and 133b so as to be slidable in the main scanning direction. The base 141 is coupled to the endless annular belt 135 by the connection 135a. The base 141 supports the components 142 to 152 of the liquid application unit 140.

[0275] The rotary bracket 142 is attached to the lower face of the base 141 so as to be rotatable in the forward and reverse directions about an axis extending in the thickness direction of the sheet P. The rotary bracket 142 is rotated with respect to the base 141 by a driving force transmitted from the application-head pivot motor 150. The rotary bracket 142 retains the liquid storage tank 143, the liquid-application-head mover 144, the holder 145, the liquid application head 146, the columns 147a and 147b, the pressure plate 148, and the coil springs 149a and 149b.

[0276] The standby angle sensor 152, which is also illustrated in FIG. 35, detects that the rotary bracket 142 has reached a standby angle. The standby angle sensor 152 then outputs a standby angle signal indicating the detection result to the controller 100b. The standby angle is, for example, an angle at the time of performing parallel binding. The standby angle sensor 152 is, for example, an optical sensor including a light emitter and a light receiver. The rotary bracket 142 at the standby angle blocks an optical path between the light emitter and the light receiver. The standby angle sensor 152 outputs the standby angle signal in response to the light output from the light emitter not being received by the light receiver. However, the specific configuration of the standby angle sensor 152 is not limited to the above-described example.

[0277] FIG. 32A illustrates the rotary bracket 142 in a position for the parallel binding that is performed by the crimper 32 disposed downstream from the liquid applier 131 in a direction in which the sheet P is conveyed. FIG. 32B illustrates the rotary bracket 142 in a position for the oblique binding (i.e., corner binding) that is performed by the crimper 32 disposed downstream from the liquid applier 131 in the direction in which the sheet P is conveyed.

[0278] The liquid storage tank 143 stores liquid to be applied to the sheet P. The liquid-application-head mover 144 is attached to the liquid storage tank 143 so as to be movable (e.g., up and down) in the thickness direction of the sheet P. The liquid-application-head mover 144 moves with respect to the liquid storage tank 143 by a driving force transmitted from the application-head movement motor 151. The holder 145 is attached to a lower end of the liquid-application-head mover 144. The liquid application head 146 projects from the holder 145 toward the conveyance passage (downward in the present embodiment). The liquid that is stored in the liquid storage tank 143 is supplied to the liquid application head 146. The liquid application head 146 is made of a material having a high liquid absorption (e.g., sponge or fiber).

[0279] The columns 147a and 147b project downward from the holder 145 around the liquid application head 146. The columns 147a and 147b are movable with respect to the holder 145 relatively in the thickness direction. The columns 147a and 147b hold the pressure plate 148 at lower ends thereof. The pressure plate 148 has a through hole 148a at a position to face the liquid application head 146. The coil springs 149a and 149b are inserted to the outsides of the columns 147a and 147b between the holder 145 and the pressure plate 148. The coil springs 149a and 149b bias the columns 147a and 147b and the pressure plate 148 in a direction away from the holder 145.

[0280] As illustrated in FIGS. 33A and 34A, before the sheet P is conveyed to the position where the sheet P faces the opening of the upper guide plate 5a, the pressure plate 148 is positioned at or above the opening. Subsequently, when the sheet P that is conveyed by the conveyance roller pairs 10 and 11 stops at a position where the first liquid application position B1 on the sheet P faces the opening, the application-head movement motor 151 is rotated in a first direction. As a result, the liquid-application-head mover 144, the holder 145, the liquid application head 146, the columns 147a and 147b, the pressure plate 148, and the coil springs 149a and 149b move down together, and the pressure plate 148 contacts the sheet P. The first liquid application position B1 is a position (i.e., the first binding position B1) to be crimped and bound by the edge binder 251 (i.e., the crimper 32).

[0281] As the application-head movement motor 151 keeps rotating in the first direction even after the pressure plate 148 contacts the sheet P, the coil springs 149a and 149b are compressed to further move down the liquid-application-head mover 144, the holder 145, the liquid application head 146, and the columns 147a and 147b. As a result, as illustrated in FIGS. 33B and 34B, the lower face of the liquid application head 146 contacts the sheet P through the through hole 148a. As a result, the liquid contained in the liquid application head 146 is applied to the sheet P.

[0282] Further rotation of the application-head movement motor 151 in the first direction further strongly presses the liquid application head 146 against the sheet P as illustrated in FIGS. 33C and 34C. Accordingly, the amount of liquid applied to the sheet P increases. In short, the liquid applier 131 changes the pressing force of the liquid application head 146 against the sheet P to adjust the amount of liquid applied to the sheet P.

[0283] On the other hand, the rotation of the application-head movement motor 151 in the second direction opposite to the first direction moves up the liquid-application-head mover 144, the holder 145, the liquid application head 146, the columns 147a and 147b, the pressure plate 148, and the coil springs 149a and 149b together. As a result, as illustrated in FIGS. 33A and 34A, the liquid application head 146 and the pressure plate 148 are separated from the sheet P. In other words, the liquid applier 131 includes the liquid application head 146 that can be separated from the sheet P.

[0284] FIG. 35 is a block diagram illustrating a hardware configuration of control blocks that control the operation of the post-processing apparatus 3A according to the second embodiment. As illustrated in FIG. 35, the post-processing apparatus 3A has a configuration in which a central processing unit (CPU) 101, a random-access memory (RAM) 102, a read-only memory (ROM) 103, a hard disk drive (HDD) 104, and an interface (I/F) 105 are connected via a common bus 109.

[0285] The CPU 101 is an arithmetic device and controls the overall operation of the post-processing apparatus 3A. The RAM 102 is a volatile storage medium that allows high speed reading and writing of data, and is used as a working area when the CPU 101 processes information. The ROM 103 is a read-only non-volatile storage medium, and stores programs such as firmware. The HDD 104 is a non-volatile storage medium that allows data to be read and written and has a relatively large storage capacity. The HDD 104 stores, for example, an operating system (OS), various control programs, and application programs.

[0286] The post-processing apparatus 3A processes, by an arithmetic function of the CPU 101, e.g., a control program stored in the ROM 103 and an information processing program (or application program) loaded into the RAM 102 from a storage medium such as the HDD 104. With such processing, a software controller including various functional modules of the post-processing apparatus 3A is configured. The software controller thus configured is combined with hardware resources of the post-processing apparatus 3A mounted in the post-processing apparatus 3A to configure functional blocks that implement functions of the post-processing apparatus 3A. In other words, the CPU 101, the RAM 102, the ROM 103, the HDD 104, and the I/F 105 constitute at least part of the controller 100b, which is an example of a control device, to control the operation of the post-processing apparatus 3A.

[0287] The I/F 105 is an interface that connects the conveyance roller pairs 10, 11, 14, and 15, the switcher 20, the side fences 24L and 24R, the crimper movement motor 238, the crimper pivot motor 239, a contact-separation motor 32d, a liquid-applier movement motor 137, an application-head pivot motor 150, an application-head movement motor 151, a standby position sensor 138, a standby angle sensor 152, a hole punch 132, and an operation panel 110 to the common bus 109.

[0288] The controller 100b controls, via the I/F 105, the operations of the conveyance roller pairs 10, 11, 14, and 15, the switcher 20, the side fences 24L and 24R, the crimper movement motor 238, the crimper pivot motor 239, the contact-separation motor 32d, the liquid-applier movement motor 137, the application-head pivot motor 150, the application-head movement motor 151, and the hole punch 132. The controller 100b acquires detection results from the standby position sensor 138 and the standby angle sensor 152 through the I/F 105. Although FIG. 35 mainly illustrates the components of the edge binder 251 (the crimper 32) that executes the edge binding and the liquid applier 131, the components of the saddle binder 28 that executes saddle binding are controlled by the controller 100b in a similar manner.

[0289] As illustrated in FIG. 37, the image forming apparatus 2 includes the operation panel 110. The operation panel 110 includes an operation section that receives instructions input by an operator and a display (which is an example of a notifier) that notifies the operator of information. The operation device includes, for example, hard keys and a touch screen overlaid on the display. The operation panel 110 acquires information from the user through the operation section and provides information to the user through the display. The post-processing apparatus 3A may include an operation panel 110 similar to the above-described operation panel 110.

[0290] FIG. 36 is a flowchart of post-processing of the post-processing apparatus 3A according to the second embodiment. Specifically, FIG. 36 is a flowchart of a process in executing the one-point binding illustrated in FIGS. 30A to 30C.

[0291] For example, the controller 100b executes the post-processing illustrated in FIG. 36 in response to acquisition of an instruction (denoted below as post-processing command) of executing the post-processing from the image forming apparatus 2. The post-processing command includes, for example, the number of sheets P of the sheet bundle Pb (denoted below as given number of sheets Np), the number of sheet bundles Pb to be subjected to binding process (denoted below as requested number of sheets Mp), the first binding position B1 (corresponding to the first liquid application position B1), the angle of the first binding position B1 (corresponding to the angle of the first liquid application position B1), the type of binding process (parallel binding process or oblique binding process), and a process that is executed in parallel with the liquid application process (punching a hole in the present embodiment). At the start of the post-processing, the liquid application unit 140 is at the standby position HP1 illustrated in FIGS. 32A and 32B, and the rotary bracket 142 is held at the standby angle (corresponding to the parallel binding posture) at the standby position HP1.

[0292] First, the controller 100b drives the liquid-applier movement motor 137 to move the liquid application unit 140 (corresponding to a liquid application device) in the main scanning direction, thus causing the liquid application head 146 to move from the standby position HP1 to the position where the liquid application head 146 can face the first liquid application position B1 (see FIG. 32B, the position corresponding to the first binding position B1 illustrated in FIG. 30B and FIG. 30C). If the type of the binding process instructed by the post-processing command is oblique binding process, in step S3601, the controller 100b drives the application-head pivot motor 150 to rotate the rotary bracket 142. Thus, the liquid application head 146 is rotated from the standby angle to the liquid application angle corresponding to the oblique binding posture. It can be ascertained, based on pulse signals output from rotary encoders of the liquid-applier movement motor 137 and the application-head pivot motor 150, that the liquid application head 146 has reached the position where the liquid application head 146 can face the first liquid application position B1. If the type of the binding process instructed by the post-processing command is parallel binding process, the controller 100b omits the above-described operation of rotating the rotary bracket 142. In other words, the liquid application unit 140 moves in the main scanning direction while holding the rotary bracket 142 at the standby angle.

[0293] In step S3601, the controller 100b further drives the crimper movement motor 238 to move the crimper 32 from the standby position HP2 to the position where the crimper 32 can face the first binding position B1 as illustrated in FIGS. 30A and 30B. Alternatively, if the type of the binding process instructed by the post-processing command is oblique binding process, in step S3601, the controller 100b drives the crimper pivot motor 239 to rotate the crimper 32 from the standby angle to the crimping angle corresponding to the oblique binding posture. It can be ascertained, based on pulse signals output from rotary encoders of the crimper movement motor 238 and the crimper pivot motor 239, that the crimper 32 has reached the position where the crimper 32 can face the first binding position B1. In a case where the type of the binding process instructed by the post-processing command is parallel binding process, the controller 100b omits the above-described operation of rotating the crimper 32. In other words, the crimper 32 moves in the main scanning direction while maintaining the standby angle.

[0294] In step S3602, the controller 100b drives the conveyance roller pairs 10 and 11 to start conveying the sheet P on which an image is formed by the image forming apparatus 2. In step S3603, the controller 100b determines whether the first liquid application position B1 on the sheet P has faced the liquid application unit 140 (more specifically, the liquid application head 146). When the controller 100b determines that the first liquid application position B1 on the sheet P has not faced the liquid application unit 140 (NO in S3603), the controller 100b continues causing the conveyance roller pairs 10 and 11 to convey the sheet P until the first liquid application position B1 on the sheet P faces the liquid application unit 140 (YES in S3603). When the controller 100b determines that the first liquid application position B1 on the sheet P has faced the liquid application head 146 (YES in step S3603), in step S3604, the controller 100b causes the conveyance roller pairs 10 and 11 to stop conveying the sheet P. It can be ascertained, based on a pulse signal output from a rotary encoder of a motor that drives the conveyance roller pairs 10 and 11, that the first liquid application position B1 on the sheet P has faced the liquid application head 146.

[0295] In step S3605, the controller 100b causes the liquid application unit 140 to execute the process of applying liquid to the first liquid application position B1 on the sheet P. More specifically, the controller 100b rotates the application-head movement motor 151 in the first direction to bring the liquid application head 146 into contact with the first liquid application position B1 on the sheet P. The controller 100b changes the pressing force of the liquid application head 146 (i.e., the amount of rotation of the application-head movement motor 151) depending on the amount of liquid to be applied to the sheet P.

[0296] The amount of liquid that is applied to the sheet P may be the same for all the sheets P of the sheet bundle Pb or may be different for each sheet P. For example, the controller 100b may decrease the amount of liquid applied to a sheet P conveyed later. The amount of rotation of the application-head movement motor 151 can be ascertained based on a pulse signal output from a rotary encoder of the application-head movement motor 151.

[0297] In step S3606, the controller 100b drives the conveyance roller pairs 10, 11, 14, and 15 to place a sheet P on the internal tray 22. In step S3606, the controller 100b also moves the side fences 24L and 24R in the main scanning direction to align the position of the sheet P or the sheet bundle Pb placed on the internal tray 22 in the main scanning direction. In short, the controller 100b performs so-called jogging.

[0298] In step S3607, the controller 100b determines whether the number of sheets P placed on the internal tray 22 has reached the given number of sheets Np indicated by the post-processing command. When the controller 100b determines that the number of sheets P placed on the internal tray 22 has not reached the given number of sheets Np (NO in step S3607), the controller 100b executes the operations of steps S3602 to S3607 again until the number of sheets P placed on the internal tray 22 reaches the given number of sheets Np (YES in step S3607).

[0299] By contrast, when the controller 100b determines that the number of sheets P that are placed on the internal tray 22 has reached the given number of sheets Np (YES in S3607), in step S3608, the controller 100b causes the crimper 32 to crimp the first binding position B1 (corresponding to the first liquid application position B1 on the sheet P) on the sheet bundle Pb to which liquid has been applied by the liquid application unit 140. In step S3608, the controller 100b also rotates the conveyance roller pair 15 to eject the crimped sheet bundle Pb to the second ejection tray 26.

[0300] In step S3609, the controller 100b determines whether the number of sheet bundles Pb thus ejected to the second ejection tray 26 has reached the requested number of copies Mp indicated by the post-processing command. When the controller 100b determines that the number of the sheet bundles Pb ejected to the second ejection tray 26 has not reached the requested number of copies Mp (NO in step S3609), the controller 100b repeats the processing of steps S3602 to S3609 until the number of the sheet bundles Pb ejected to the second ejection tray 26 reaches the requested number of copies Mp (YES in step S3609).

[0301] When the controller 100b determines that the number of sheet bundles Pb ejected to the second ejection tray 26 reaches the requested number of copies Mp (YES in step S3609), in step S3610, the controller 100b drives the liquid-applier movement motor 137 to move the liquid application unit 140 to the standby position HP1 (see FIGS. 32B) and drives the crimper movement motor 238 to move the crimper 32 to the standby position HP2 (see FIG. 30A). When the posture that is instructed by the post-processing operation is the oblique binding posture, in step S3610, the controller 100b drives the application-head pivot motor 150 and the crimper pivot motor 239 to rotate the liquid application unit 140 and crimper 32 and the parallel binding posture (standby angle) into the parallel binding posture. On the other hand, when the posture that is instructed by the post-processing command is the parallel binding posture, the operation of rotating the liquid application unit 140 and the crimper 32 to the parallel binding posture (standby angle) is skipped. In steps S3601 and S3610, the execution order of the movement in the main scanning direction and the rotation in the forward and reverse directions of the liquid application unit 140 and the crimper 32 is not limited to the aforementioned order and may be reversed.

[0302] The present disclosure can be applied to not only the edge binder 25 that executes edge binding but also to the saddle binder 28 that executes saddle stitching.

[0303] The configuration in which the controller 100b of the post-processing apparatus 3A according to the second embodiment illustrated in FIG. 29 is provided separately from the controller 100a of the image forming apparatus 2 similarly with FIG. 1 has been described, but it is not limited to such a configuration. For example, as illustrated in FIG. 27A, the controller 100b of the post-processing apparatus 3A may be disposed in the image forming apparatus 2. Further, as in the configuration of FIG. 27B, the controller 100b of the post-processing apparatus 3A may be integrated with the controller 100a of the image forming apparatus 2.

[0304] As in the configuration of FIG. 28A, the controller 100b of the post-processing apparatus 3A may be divided into a controller 100b1 (e.g., a driver system such as a motor) and a controller 100b2 (a detector such as a sensor) according to the function, and the controller 100b2 of the post-processing apparatus 3A may be disposed in the image forming apparatus 2. Further, as in the configuration of FIG. 28B, the controller 100b2 of the post-processing apparatus 3A disposed in the image forming apparatus 2 may be integrated with the controller 100a of the image forming apparatus 2.

[0305] As described above, the control method by the controller 100b described above is implemented by cooperation between hardware resources of a computer and a program as computer software. In other words, the control method may be a method executed by a computer causing an arithmetic device, a storage device, an input device, an output device, and a control device to operate in cooperation with each other based on a program. The program may be written in, for example, a storage device or a storage medium and distributed with the storage device or the storage medium, or may be distributed through, for example, an electric communication line.

[0306] The present disclosure is not limited to the above-described embodiments, and numerous additional modifications and variations are possible in light of the teachings. The technical contents included in the technical ideas described in the appended claims are included within the scope of the present disclosure. The above-described embodiments represent examples, and various modifications can be achieved by those skilled in the art from the disclosed contents. Such modifications are included in the technical scope described in the scope of claims.

[0307] Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above.

[0308] The functionality of the elements disclosed herein may be implemented using circuitry or processing circuitry which includes general purpose processors, special purpose processors, integrated circuits, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and/or combinations thereof which are configured or programmed, using one or more programs stored in one or more memories, to perform the disclosed functionality. Processors are considered processing circuitry or circuitry as they include transistors and other circuitry therein. In the disclosure, the circuitry, units, or means are hardware that carry out or are programmed to perform the recited functionality. The hardware may be any hardware disclosed herein which is programmed or configured to carry out the recited functionality.

[0309] There is a memory that stores a computer program which includes computer instructions. These computer instructions provide the logic and routines that enable the hardware (e.g., processing circuitry or circuitry) to perform the method disclosed herein. This computer program can be implemented in known formats as a computer-readable storage medium, a computer program product, a memory device, a record medium such as a CD-ROM or DVD, and/or the memory of an FPGA or ASIC.

[0310] Aspects of the present disclosure are as follows.

[0311] The aspects of the present disclosure are, for example, as follows.

First Aspect

[0312] A medium processing apparatus includes: a liquid applier to perform liquid application on a part of at least one medium; a post-processing device to perform processing on a medium bundle including the at least one medium on which the liquid application is performed in the liquid applier; a first liquid storage to store liquid used for liquid application by the liquid applier; a second liquid storage to store the liquid to be supplied to the first liquid storage; a liquid supplier to supply the liquid from the second liquid storage to the first liquid storage; a first liquid detector to detect a liquid level of the liquid in the first liquid storage; and a controller to control operations of the post-processing device and the liquid supplier. The controller changes a liquid level at which liquid supply 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.

Second Aspect

[0313] In the medium processing apparatus according to the first aspect, the controller causes the liquid supplier to perform a specified-level supply operation of supplying the liquid up to a first predetermined liquid level of the first liquid storage, when the first liquid detector detects the liquid level in a time shorter than a predetermined time from a start of the liquid supply operation.

Third Aspect

[0314] In the medium processing apparatus according to the first aspect, the controller causes the liquid supplier to perform a specified-level supply operation of supplying the liquid up to a second predetermined liquid level of the first liquid storage, when the first liquid detector detects the liquid level in a time longer than a predetermined time from a start of the liquid supply operation.

Fourth Aspect

[0315] In the medium processing apparatus according to the third aspect, the controller causes the liquid supplier to perform the specified-level supply operation of supplying the liquid up to the second predetermined liquid level of the first liquid storage and then discharge the liquid for a predetermined time in the first liquid storage.

Fifth Aspect

[0316] In the medium processing apparatus according to any one of the first to fourth aspects, the controller causes the liquid supplier to perform the specified-level supply operation of supplying the liquid up to the second predetermined liquid level of the first liquid storage and then discharge the liquid in the first liquid storage after an elapse of a predetermined time.

Sixth Aspect

[0317] In the medium processing apparatus according to the first, third, or fourth aspect, the controller changes a height of the second predetermined liquid level of the first liquid storage according to a use period.

Seventh Aspect

[0318] An image forming system includes: an image forming apparatus to form an image on a medium; and the medium processing apparatus according to any one of the first to sixth aspects to perform the processing on a plurality of media on which the image has been formed by the image forming apparatus.