Post-processing device and image forming system

Abstract

To prevent an increase in size and cost of a device.SOLUTION: A gap formation device 50 (gap formation means) for forming a gap between sheets by making a shearing force act on a sheet bundle PT configured by stacking a plurality of sheets P within a range of not causing shearing is provided. Further, a liquid injection nozzle 46 and a liquid storage tank 45 (liquid impregnating means) for impregnating a corner part PTx (part) of the sheet bundle PT, in which the gap is formed by the gap formation device 50, with a liquid, are provided.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This invention relates to a post-processing device that performs post-processing on a sheet, and an image forming system including the post-processing device and an image forming device.

Background Art

[0002] Conventionally, in a post-processing device that performs post-processing such as binding on a sheet bundle, after forming a gap between sheets in the sheet bundle, a technique of impregnating a liquid such as water into the portion where the gap is formed is known (see, for example, Patent Document 1). Specifically, the post-processing device disclosed in Patent Document 1 forms a gap between sheets by inserting a gear-shaped member into a corner of the sheet bundle or jetting air toward a corner of the sheet bundle, and jets a liquid into the portion where the gap is formed. Then, binding processing is performed on the portion of the sheet bundle where the liquid is jetted.

[0003] On the other hand, Patent Document 2 discloses a technique of performing binding processing without needles on a sheet bundle by a binding tool that does not use needles.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the post-processing device of Patent Document 1 is provided with a mechanism for inserting a gear-shaped member into a corner of the sheet bundle and a mechanism for jetting air toward a corner of the sheet bundle, the device has become large-sized and costly.

[0005] This invention has been made to solve the above-described problems, and an object thereof is to provide a post-processing device and an image forming system that are less likely to be large-sized and costly.

Means for Solving the Problems

[0006] The post-treatment device in this invention includes a gap forming means for applying a shearing force within a range where no shearing occurs to a stack of sheets formed by stacking a plurality of sheets to form a gap between the sheets, and a liquid impregnating means for impregnating a portion of the stack of sheets where the gap has been formed by the gap forming means with a liquid.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a post-treatment device and an image forming system that are less likely to be enlarged in size and increased in cost.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the redundant description thereof will be simplified or omitted as appropriate.

[0010] In FIG. 1, the image forming system 300 in the present embodiment will be described. As shown in FIG. 1, in the image forming system 300 in the present embodiment, a post-processing device 1 (sheet processing device) having a binding processing function is detachably installed in the body internal space W (a space provided between the document reading device 102 and the image forming unit 115) of the image forming apparatus 100. The body internal space W is a space capable of discharging the sheet P (the sheet P after printing) discharged from the image forming apparatus 100, and is also a space capable of taking out the discharged sheet P. That is, in a state where the post-processing device 1 is not installed, the body internal space W functions as a space (discharge unit) where the sheet P discharged from the image forming apparatus 100 is stacked. In the image forming system 300, the image forming apparatus 100 is a part other than the post-processing apparatus 1, mainly composed of an image forming unit 115, a main body feeding tray 112, a fixing unit 120, a document conveying apparatus 110, a document reading apparatus 102, and the like. An operation display panel 149 (operation display unit) for displaying various information in the image forming system 300 and inputting various commands is installed on the exterior of the image forming apparatus 100 (image forming system 300). Referring to FIGS. 1 to 4, the post-processing apparatus 1 is provided with a stiching apparatus 30 with needles, an internal tray 20, a pair of discharge rollers 15, a discharge tray 13, a plurality of pairs of conveying rollers 11 to 13, a stiching apparatus 40 without needles as a stiching means, and the like. Here, the post-processing apparatus 1 is disposed on the downstream side in the conveyance direction (the conveyance direction of the sheet P) with respect to the image forming apparatus 100. The post-processing apparatus 1 is an apparatus for performing a stiching process (stiching process with needles) on a plurality of printed sheets P discharged from the image forming apparatus 100 or performing a stiching process (stiching process without needles) on a sheet bundle PT set by hand. This will be described in detail later.

[0011] Hereinafter, with reference to FIG. 1, the image forming operation (printing operation) in the image forming apparatus 100 of the image forming system 300 will be described. In the image forming apparatus 100, first, the document D is conveyed (fed) from the document table in the direction of the arrow in the figure by the conveying rollers of the document conveying apparatus 110 and passes over the document reading apparatus 102. At this time, in the document reading apparatus 102, the image information of the document D passing above is optically read. Then, the optical image information read by the document reading apparatus 102 is converted into an electric signal and then transmitted to the writing apparatus 103. Then, from the writing apparatus 103, laser light based on the image information of the electric signal is emitted toward each of the photosensitive drums 105Y, 105M, 105C, and 105K for each color, and an exposure process is performed. Then, a charging process, an exposure process, and a development process are performed on the photosensitive drums 105Y, 105M, 105C, and 105K of the respective image forming units 104Y, 104M, 104C, and 104K, and desired images are respectively formed on the photosensitive drums 105Y, 105M, 105C, and 105K. After that, the images respectively formed on the photosensitive drums 105Y, 105M, 105C, and 105K are transferred and superimposed as a color image onto the intermediate transfer belt 178. Further, the color image formed on the intermediate transfer belt 178 is transferred to the sheet P fed and conveyed by the feed roller 197 from the main body feed tray 112 (second feeding unit) at a position facing the secondary transfer roller 189. After that, the sheet P onto which the color image has been transferred is conveyed to the position of the fixing unit 120. Then, the color image transferred onto the surface is fixed onto the sheet P.

[0012] After that, based on the user's selection of the printing mode, the sheet P will either be discharged from the image forming apparatus 100 by the first discharge roller pair 131 and fed into the post-processing apparatus 1, or be discharged from the image forming apparatus 100 by the second discharge roller pair 132 and stacked on the discharge tray 135.

[0013] Here, in the present embodiment, the post-processing apparatus 1 is connected (installed) to the internal space W of the image forming apparatus 1, and based on the user's selection, the sheet P discharged from the image forming apparatus 1 is conveyed to the post-processing apparatus 1, and post-processing is performed on the conveyed sheet P. By installing the post-processing apparatus 1 in the internal space W of the image forming apparatus 1, the internal space W can be effectively utilized, and the image forming system 300 can be downsized.

[0014] Referring to FIG. 2, the post-processing apparatus 1 in the present embodiment is configured to convey the sheet P fed from the image forming apparatus 100 to a conveyance path (a conveyance path indicated by a broken line in the figure, where three conveyance roller pairs 11 to 13 are installed), perform post-processing such as binding processing, or discharge it as it is without performing post-processing. Specifically, when a mode without post - processing is selected, the sheet P conveyed by the first to third conveying roller pairs 11 to 13 is discharged by the discharge roller pair 15 and placed on the discharge tray 13.

[0015] When the "sort mode (sorting process mode)" is selected, the sheet P is conveyed while being shifted by a predetermined amount in the width direction for each sheet P by the discharge roller pair 15 configured to be movable in the width direction (the direction perpendicular to the paper surface of FIG. 2), and is sequentially stacked on the discharge tray 13.

[0016] When the "stitching process mode (staple mode)" is selected, the sheet P conveyed by the first to third conveying roller pairs 11 to 13 is not discharged by the discharge roller pair 15 but is sequentially stacked on the internal tray 20. At this time, every time the sheet P is placed on the internal tray 20, the tapping roller 14 and the return roller 16 arranged above it move from the standby position to the position where they contact the sheet P (the uppermost sheet P in the sheet bundle PT), and the tapping roller 14 and the return roller 16 are rotationally driven counterclockwise in FIG. 2, respectively, so that the sheet P is conveyed (moved) toward the end fence 21. As a result, the rear ends (the rear ends in the conveying direction) of the plurality of sheets P (sheet bundle PT) abut against the end fence 21, and the positions of the plurality of sheets P in the conveying direction are aligned.

[0017] At this time, referring to FIG. 3, the jogger fences 22 (side fences) installed at both ends in the width direction of the internal tray 20 move in the width direction so as to sandwich the sheet P (sheet bundle PT) every time the sheet P is placed on the internal tray 20 (or after a desired number of sheets P are stacked), and the positions of the sheet P (sheet bundle PT) in the width direction are aligned. Then, a stitching process (stitching - with - needle closing process) is performed on the rear end of the sheet P (sheet bundle PT) whose conveying direction and width direction are aligned by the stitching device 30 with needles. Thereafter, the sheet P (sheet bundle PT) that has undergone the binding process is moved obliquely upward along the tray surface of the internal tray 20 by the reverse rotation of the return roller 16 (the clockwise rotation in FIG. 2), and is discharged onto the discharge tray 13 by being conveyed by the discharge roller pair 15.

[0018] Hereinafter, the characteristic configuration and operation of the post-processing device 1 in the present embodiment will be described in detail. Referring to FIG. 3 and the like, in the post-processing device 1 in the present embodiment, in addition to the sewing device 30 with needles that performs sewing processing with needles on the sheet bundle PT composed of a plurality of sheets P discharged from the image forming apparatus 100, a sewing device 40 without needles (sewing mechanism without needles) that performs sewing processing without needles on the sheet bundle PT manually (by hand) set by the user is installed in the hand insertion processing unit 41. This hand insertion processing unit 41 is installed in the post-processing device 1 installed in the body internal space W of the image forming system 300. The user inserts the sheet bundle PT from the front side (the side facing the operation display panel 149), and performs a binding process on the corner PTx (see FIGS. 8 and 9) of the sheet bundle PT without using a needle. In addition to the sewing device 40 without needles as the sewing means, this hand insertion processing unit 41 is provided with a gap forming device 50 as the gap forming means, a liquid injection nozzle 46 as the liquid impregnation means, etc., and is configured to be able to perform these processes (processable) in a state where the sheet bundle PT is inserted by hand. The gap forming device 50 and the liquid injection nozzle 46 will be described in detail later.

[0019] Here, the sewing device 40 without needles as the sewing means is configured to perform a sewing process without using a needle (metal needle) by a fastener 400. Specifically, referring to FIG. 5, the stitcher 40 without needles is provided with a fastener 400 composed of two members 400a and 400b having tooth-shaped uneven portions 400a1 and 400b1. Then, with respect to the corner portion PTx (see FIGS. 8 and 9) of the sheet bundle PT inserted into the hand-insertion processing unit 41, the fastener 400 forms unevenness in the thickness direction in the sheet bundle PT by pressing the tooth-shaped uneven portions 400a1 and 400b1, meshes the sheets P with each other, and performs a stitching operation. In the fastener 400, the first member 400a and the second member 400b are arranged substantially in the vertical direction. On the upper surface of the first member 400a, a tooth-shaped uneven portion 400a1 is formed. On the lower surface of the second member 400b, a tooth-shaped uneven portion 400b1 that meshes with the tooth-shaped uneven portion 400a1 of the first member 400a is formed, and it is configured to be relatively movable with respect to the first member 400a so as to sandwich the sheet bundle PT therebetween. Then, the stitching operation is performed in a state where the sheet bundle PT is sandwiched between the first member 400a and the second member 400b.

[0020] Here, the post-processing device 1 in the present embodiment is provided with a gap forming device 50 as a gap forming means, a liquid storage tank 45 and a liquid injection nozzle 46 as liquid impregnation means, a stitcher 40 without needles as a stitching means, etc. in the hand-insertion processing unit 41.

[0021] Referring to FIGS. 6(A) to (C), FIG. 7(A), etc., the gap forming device 50 functions as a gap forming means for forming a gap between sheets (between sheets P) by applying a shearing force to a sheet bundle PT formed by stacking a plurality of sheets P within a range where no shearing occurs (a range where the sheet bundle PT is not damaged). That is, the gap forming device 50 presses the sheet bundle PT from the front side and presses it (or generates a reaction force) from different positions on the back side, thereby applying a force to the overlapping sheets P and P to spread apart from each other (to form a larger gap) starting from the portion where the pressing force acts. In particular, in the present embodiment, since a shearing force is applied to the corner portion PTx of the sheet bundle PT (see FIG. 8 etc.), a larger gap can be formed between the overlapping sheets P compared to the case where a shearing force is applied to a portion different from the corner portion PTx. This is because the corner portion PTx is formed by two orthogonal sides, and when a shearing force acts thereon, a reaction force in the direction of forming a gap is likely to occur.

[0022] Specifically, as shown in FIG. 7(A) (and FIGS. 6(A) to (C)), the gap forming device 50 (gap forming means) includes a convex pressing member 51 that presses the sheet bundle PT from the front side, and a concave receiving member 52 that is disposed on the back side of the sheet bundle PT so as to sandwich the sheet bundle PT and be fitted to the convex pressing member 51. With this configuration, in FIG. 7(A), a shearing force as indicated by the black arrow and the white arrow acts on the sheet bundle PT between the convex pressing member 51 that moves downward (black arrow) and presses, and the concave receiving member 52 that is disposed to receive it, and gaps between the sheets as shown in FIGS. 6(B) and (C) are formed. Note that, for simplicity, FIG. 6 is illustrated in a posture facing one surface of the convex pressing member 51, and the setting surface (tray surface) of the hand insertion processing unit 41 is illustrated horizontally.

[0023] Here, in the present embodiment, as shown in FIG. 7(A), the tip of the convex pressing member 51 is formed to be sharp (triangular prism shape), and the concave receiving member 52 is formed to be square (square prism shape). However, the shapes of the convex pressing member 51 and the concave receiving member 52 are not limited to this. For example, as shown in FIG. 7(B), the tip of the convex pressing member 51 can be formed to be sharp (triangular prism shape), and the concave receiving member 52 can be formed in a triangular shape (triangular prism shape). Also, as shown in FIG. 7(C), the tip of the convex pressing member 51 can be formed in a planar shape (quadrangular prism shape), and the concave receiving member 52 can be formed in a quadrangular shape (quadrangular prism shape). Furthermore, as shown in FIG. 7(D), the tip of the convex pressing member 51 can be formed in a curved surface shape (semicylindrical shape), and the concave receiving member 52 can be formed in a curved surface shape (semicylindrical shape). Or, as shown in FIG. 7(E), the tip of the convex pressing member 51 can be formed in a curved surface shape (semicylindrical shape), and the concave receiving member 52 can be formed in a quadrangular shape (quadrangular prism shape).

[0024] Also, the gap forming device 50 in the present embodiment is provided with a moving mechanism for moving the convex pressing member 51 up and down. As such a moving mechanism, as shown in FIGS. 10(A) to (C), a crank 85 formed with a pin 85a that fits into a slider 51x formed on the convex pressing member 51, and a pressing motor 80 (see FIG. 13) for rotationally driving the crank 85 can be used. When the crank 85 rotates, the pin 85a moves relatively along the slider 51x, and in conjunction with this movement, the convex pressing member 51 moves up and down. The reference position (standby position) of the convex pressing member 51 is detected by a pressing home position sensor 81, and the amount of movement and the direction of movement of the convex pressing member 51 from the reference position can be grasped from the rotational speed (step number) and the rotational direction of the pressing motor 80. Note that, as the moving mechanism of the convex pressing member 51, as shown in FIGS. 11(A) to (C), a pinion gear 86 that meshes with a rack gear 51y formed on the convex pressing member 51, and a pressing motor 80 (see FIG. 13) for rotationally driving the pinion gear 86 can also be used.

[0025] Here, referring to FIG. 6(D) and the like, the liquid storage tank 45 and the liquid injection nozzle 46 function as liquid impregnation means for impregnating a portion (the corner portion PTx) of the sheet bundle PT in which a gap is formed by the gap forming device 50 (gap forming means) with a liquid such as water. Further, the liquid injection nozzle 46 (liquid impregnation means) is configured to inject liquid from the side facing the end face (the edge face) of the sheet bundle PT toward a portion (the corner portion PTx) of the sheet bundle PT in which a sufficient gap is formed. Specifically, a liquid such as water is stored in the liquid storage tank 45 (see FIGS. 3 and 4). The liquid injection nozzle 46 is connected to the liquid storage tank 45 via a tube. Then, when the liquid injection motor 83 (see FIG. 13) is driven, the liquid stored in the liquid storage tank 45 is injected from the liquid injection nozzle 46 at a wide angle, and the liquid is supplied to the corner portion PTx of the sheet bundle PT, and the corner portion PTx is impregnated with the liquid. At this time, since a relatively large gap is formed between the overlapping sheets P in the corner portion PTx of the sheet bundle PT, each sheet P constituting the sheet bundle PT is sufficiently supplied (impregnated) with liquid on both the front and back sides.

[0026] Then, as shown in FIG. 6(E), a binding process is performed on the portion (the corner portion PTx) of the sheet bundle PT impregnated with liquid by the liquid injection nozzle 46 (liquid impregnation means) by the stitchless binding device 40 as binding means. At this time, since each sheet P constituting the sheet bundle PT is sufficiently impregnated with liquid on both the front and back sides, the entanglement of the unevenness between the sheets P increases compared to the case where this is not the case, and the binding processability by the stitchless binding device 40 is improved. Then, the post-processing device 1 in the present embodiment does not install a mechanism for inserting a gear-shaped member into the corner of the sheet bundle PT or a mechanism for jetting air toward the corner PTx of the sheet bundle PT. Instead, a gap forming device 50 with a simple configuration that generates a shearing force in the sheet bundle PT to form a large gap between the sheets is installed, and liquid is supplied to the portion where the gap is formed. As a result, it is difficult for the post-processing device 1 to become large-sized and costly. In particular, in the image forming system 300 in the present embodiment, since the post-processing device 1 is installed in the in-body space W with limited space in the image forming apparatus 100, the post-processing device 1 miniaturized like that of the present embodiment is useful.

[0027] Here, in the present embodiment, the gap forming device 50 (gap forming means) is configured to be able to hold the sheet bundle PT when the binding process for the sheet bundle PT is performed by the binding device 40 without needles (binding means). Specifically, as shown in FIG. 6(E), when the binding process is performed by the binding device 40 without needles on the corner PTx of the sheet bundle PT impregnated with liquid by the liquid injection nozzle 46 (when the binding process portion M is formed), the sheet bundle PT is pressed by the convex pressing member 51 so that the upper surface does not float. Thereby, when the binding process is performed by the binding device 40 without needles, a problem that the sheet bundle PT is displaced and the accuracy of the binding process is reduced is alleviated.

[0028] Here, referring to FIG. 8, the gap forming device 50 (gap forming means) applies a shearing force to the corner PTx of the sheet bundle PT. And the binding device 40 without needles (binding means) is configured to perform the binding process on a portion outside (diagonally downward to the right in FIG. 8.) the portion where the shearing force acts at the corner PTx. That is, in the sheet bundle PT, with respect to the portion where the convex pressing member 51 (gap forming device 50) abuts, a binding process portion M (the portion that has been bound) is formed by the binding device 40 without needles in the outside portion (diagonally downward to the right in FIG. 8.). By setting such a positional relationship, a series of operations from forming a large gap at the corner PTx of the sheet bundle PT, injecting liquid into that portion, to performing the binding process after that can be carried out efficiently.

[0029] Also, in the present embodiment, the gap forming device 50 (gap forming means) is configured to reduce the shearing force applied to the sheet bundle PT to a second predetermined value smaller than the first predetermined value after causing the shearing force applied to the sheet bundle PT to reach the first predetermined value. Specifically, when the convex pressing member 51 moves downward from the reference position and reaches the position shown in FIG. 6(B), the shearing force generated in the sheet bundle PT reaches the first predetermined value (the maximum value and a value at which shearing cannot occur). At this time, although a gap between the sheets P is formed to some extent at the corner PTx of the sheet bundle PT, the gap is not sufficient. However, thereafter, when the convex pressing member 51 moves upward and reaches the position shown in FIG. 6(C), the shearing force generated in the sheet bundle PT decreases to the second predetermined value (< the first predetermined value). At this time, at the corner PTx of the sheet bundle PT, a large gap is formed between the sheets P by being slightly released from the tight shearing state. Since such behavior of the sheet bundle PT occurs, after performing the vertical movement of the convex pressing member 51 as described above, liquid injection by the liquid injection nozzle 46 is performed to enhance the invasiveness of the liquid into the sheet bundle PT.

[0030] Hereinafter, a series of manual operations performed by the hand insertion processing unit 41 will be described with reference to FIGS. 6(A) to 6(E). First, the user sets the sheet bundle PT in the hand insertion processing unit 41. At this time, the sheet bundle PT is abutted against the first stopper portion 42 and the second stopper portion 43 (see FIG. 3), and the position of the sheet bundle PT (corner PTx) with respect to the stitchless binding device 40, the gap forming device 50, and the liquid injection nozzle 46 is determined. When the manual staple button 5 (see FIGS. 4 and 13) is pressed by the user, as shown in FIG. 6(A), the convex pressing member 51 gradually moves downward from the reference position. Then, as shown in FIG. 6(B), when the convex pressing member 51 descends to a position where it presses the sheet bundle PT between the concave receiving portion 52, its movement is temporarily stopped. After that, as shown in FIG. 6(C), when the convex pressing member 51 ascends to a position where the gap between the sheets of the sheet bundle PT becomes maximum, its ascent is stopped. Then, as shown in FIG. 6(D), in that state, liquid injection from the liquid injection nozzle 46 to the corner portion PTx of the sheet bundle PT is performed. After that, as shown in FIG. 6(E), when the convex pressing member 51 ascends to a position where it properly presses the sheet bundle PT, its ascent is stopped, and a stitchless binding process by the stitchless binding device 40 is performed on the corner portion PTx of the sheet bundle PT.

[0031] Here, in the present embodiment, it is also possible to configure such that the time from when the liquid injection nozzle 46 (liquid impregnation means) impregnates the liquid into the portion (corner portion PTx) of the sheet bundle PT until the stitch binding device 40 (binding means) performs a binding process on the portion (corner portion PTx) of the sheet bundle PT can be adjusted. In such a case, since the degree of impregnation of the liquid into the corner portion PTx of the sheet bundle PT can be adjusted, the binding processability by the stitch binding device 40 can also be adjusted. For example, when the thickness (sheet thickness) of each sheet P constituting the sheet bundle PT is thick, the binding processability deteriorates compared to the case where it is thin. Therefore, the above-described time (impregnation time) is adjusted to be longer.

[0032] Also, in the present embodiment, it is possible to configure such that the time from when the gap forming device 50 (gap forming means) forms a gap in the sheet bundle PT until the liquid injection nozzle 46 (liquid impregnation means) impregnates the liquid into the portion (corner portion PTx) of the sheet bundle PT can be adjusted. In such a case, since it becomes possible to adjust the time to start the liquid impregnation into the corner portion PTx of the sheet bundle PT, it becomes possible to adjust the amount of liquid impregnated into the corner portion PTx of the sheet bundle PT. Therefore, it also becomes possible to adjust the binding processability by the needle binding device 40. For example, when the thickness (sheet thickness) of each sheet P constituting the sheet bundle PT is thick, the impregnation property deteriorates compared to the case where it is thin. Therefore, it is necessary to adjust the above-mentioned time (impregnation start time) to be earlier.

[0033] Further, in the present embodiment, the gap forming device 50 (gap forming means) can be configured to be adjustable in at least one of the position where a shearing force is applied to the sheet bundle PT and the magnitude of the shearing force (in the case of the present embodiment, the pressing force by the convex pressing member 51). In such a case, it becomes possible to adjust the size of the gap between the sheets formed by the gap forming device 50 to an optimum value according to the thickness, type, number of sheets, etc. of the sheet bundle PT (sheet P).

[0034] Also, referring to FIG. 9, in the present embodiment, the gap forming device 50 (gap forming means) can also be configured to form a fold line N at the corner portion PTx by applying a shearing force to the corner portion PTx of the sheet bundle PT. Specifically, as described above with reference to FIG. 6(C), there is a step in which the pressing force of the convex pressing member 51 becomes maximum (the first predetermined value). However, the pressing force is set to such an extent that the fold line N is formed at the corner portion PTx. By forming the fold line N at the corner portion PTx of the sheet bundle PT in this way, it becomes easier for the user to roll up the other portions while holding the corner portion PTx of the sheet bundle PT after the binding process. In particular, by forming the fold line N substantially parallel to the binding process portion M formed at the corner portion PTx by the needleless binding device 40 (binding means), such ease of rolling is improved. Also, by forming a fold N at the corner PTx of the sheet bundle PT, the liquid infiltrated into the corner PTx is blocked at the portion of the fold N, making it difficult for the liquid to penetrate into other portions of the sheet bundle PT. Therefore, the problem that the entire sheet bundle PT is infiltrated with liquid and the image on the sheet P bleeds due to the liquid is reduced.

[0035] Hereinafter, with reference to FIG. 12, an example of specific control performed by the hand-fed processing unit 41 (needleless stitching mechanism) will be described. First, when the sheet bundle PT is inserted into the hand-fed processing unit 41 by the user (step S1) and the manual staple button 5 is pressed (step S2), the descent of the convex pressing member 51 is started (step S3). Then, when the descent amount (movement amount) of the convex pressing member 51 reaches Z1 (the state in FIG. 6(B)), the movement of the convex pressing member 51 is temporarily stopped (steps S4, S5). Then, when the ascent of the convex pressing member 51 is started (step S6) and the ascent amount (movement amount) of the convex pressing member 51 reaches Z2 (the state in FIG. 6(C)), the movement of the convex pressing member 51 is temporarily stopped (steps S7, S8). Thereafter, liquid injection from the liquid injection nozzle 46 is performed on the corner PTx where a large gap is formed in the sheet bundle PT (step S9). Then, stitching processing by the needleless stitching device 40 on the corner PTx is performed (step S10), and this flow ends.

[0036] Such control is performed by the control unit 200 of the post-processing device 1 illustrated in FIG. 13 (and FIGS. 1, 4, etc.). Here, as shown in FIG. 13, the control unit 200 of the post-processing device 1 is connected to the control unit 350 of the image forming apparatus 100 via the interface 70. Further, the control unit 350 of the image forming apparatus 100 is connected to the operation display panel 149, each driving member of the image forming apparatus 100, each sensor, etc. via the interface 360. Further, the control unit 200 of the post-processing device 1 is connected via the interface 72 to a conveyance motor 73 that rotationally drives the conveyance roller pairs 11 to 13, the tapping roller 14, the return roller 16, etc., a discharge motor 74 that rotationally drives the discharge roller pair 15, a staple driving motor 75 that drives the stapling device 30 with needles, a conveyance sensor 76 installed in the conveyance path, a discharge sensor 77 installed at the discharge port, a staple HP sensor 78 that detects the reference position of the stapling device 30 with needles, the pressing motor 80 described above, a pressing home position sensor 81, a liquid injection motor 83, a manual staple button 5, etc. Then, by the overall control system of the image forming system 300 configured as described above, various operations in the image forming system 300 described so far are executed.

[0037] <Modification Example 1> As shown in FIG. 14, in the post-processing device 1 (stapling mechanism without needles) in Modification Example 1, a thickness detection sensor 60 (thickness detection means) capable of detecting the thickness of the sheet bundle PT set in the manual processing unit 41 is installed. As the thickness detection sensor 60, for example, one that moves from the reference position to the position where it contacts the upper surface of the sheet bundle PT set in the manual processing unit 41 and indirectly detects the thickness of the sheet bundle PT from the moving distance at that time can be used. And in Modification Example 1, based on the thickness of the sheet bundle PT detected by the thickness detection sensor 60, the position and pressing force for pressing the sheet bundle PT by the convex pressing member 51 are adjusted, or the timing and injection time for starting the injection of the liquid from the liquid injection nozzle 46 are adjusted. Thereby, good stapling processing can be performed regardless of the thickness of the sheet bundle PT.

[0038] <Modification Example 2> As shown in FIG. 15, in the post-treatment device 1 (needleless sewing mechanism) in Modification Example 2, the gap forming device 50 (gap forming means) includes a convex pressing member 51 that presses the sheet bundle PT from the front side, and an elastic member 53 that is deformed so as to be fitted to the convex pressing member 51 while sandwiching the sheet bundle PT on the back side of the sheet bundle PT. As shown in FIGS. 15(A) to (C) (corresponding to FIGS. 6(A) to (C) described above), the elastic member 53 is recessed in accordance with the tip shape of the convex pressing member 51 (in the example of FIG. 15, it is pointed) as the magnitude of the pressing force of the convex pressing member 51 changes. At this time, since a shearing force is generated on the sheet member PT by the pressing force of the convex pressing member 51 and the reaction force from the deformed elastic member 53, a gap between the sheets is formed at the corner portion PTx. Even when the gap forming device 50 is configured in this way, the same inventive effects as those obtained by using FIGS. 6 and the like above can be obtained.

[0039] <Modification Example 3> As shown in FIGS. 16 and 17, in the post-treatment device 1 (needleless sewing mechanism) in Modification Example 3, the gap forming device 50 (gap forming means) includes a first convex pressing member 51 that presses the sheet bundle PT from the front side, and a second convex pressing member 54 that presses the sheet bundle PT from the back side and is arranged so as to face the first convex pressing member 51 while sandwiching the sheet bundle PT. As shown in FIGS. 16(A) to (C) (corresponding to FIGS. 6(A) to (C) described above), the second convex pressing member 54 is arranged offset to the side of the corner with respect to the first convex pressing member 51, and is configured to be vertically movable in the direction of the white arrow with the position shown in FIG. 16(A) as a reference position (standby position) by a second moving mechanism configured in the same manner as the moving mechanism of the first convex pressing member 51. Then, as the first convex pressing member 51 descends, the second convex pressing member 54 ascends, or as the first convex pressing member 51 ascends, the second convex pressing member 54 descends, thereby generating an optimal shearing force on the sheet bundle PT and forming a gap between the sheets at the corner portion PTx. Even when the gap forming device 50 is configured in this way, the same inventive effects as those obtained using FIG. 6 and the like can be achieved. Note that the tip shapes of the first and second convex pressing members 51 and 54 may be sharp as shown in FIG. 16(A), may be flat as shown in FIG. 16(B), or may be curved as shown in FIG. 16(C).

[0040] <Modification Example 4> As shown in FIG. 18, in Modification Example 4, the image forming system 300 in the image forming apparatus 100 has an in-body space W, and a punching device 90 as a second post-processing device (optional device) is installed upstream (upstream in the sheet conveyance direction) of the post-processing device 1 (first post-processing device). This punching device 90 has a punch unit 91 installed inside, and when a punching mode is selected by the user, it performs a punching process (punching) on the sheet P inserted from the image forming apparatus 100. This punching device 90 is configured to convey the sheet P discharged from the image forming apparatus 100 toward the post-processing device 1 regardless of whether the punching process is performed. And also in Modification Example 4, the post-processing device 1 is configured and operates in the same manner as described with reference to FIGS. 2 to 12 and the like. Even in the image forming system 300 configured in this way, the post-processing device 1 will be relatively miniaturized and cost-reduced. Note that in Modification Example 4, a punching device 90 capable of performing a punching process is installed as the second post-processing device, but it is also possible to install a device capable of performing another process as the second post-processing device. Also, in Modification Example 4, the second post-processing device 90 is arranged upstream of the first post-processing device 1, but the second post-processing device 90 can also be arranged downstream of the first post-processing device 1.

[0041] As described above, the post-processing apparatus 1 in the present embodiment is provided with a gap forming device 50 (gap forming means) that applies a shearing force within a range where no shearing occurs to a sheet bundle PT formed by stacking a plurality of sheets P to form a gap between the sheets. Further, a liquid injection nozzle 46 and a liquid storage tank 45 (liquid impregnation means) for impregnating a liquid into the corner portion PTx (portion) of the sheet bundle PT in which a gap is formed by the gap forming device 50 are provided. This makes it difficult for the post-processing apparatus 1 to increase in size and cost.

[0042] In the present embodiment, the present invention is applied to the image forming system 300 in which the color image forming apparatus 100 is installed. However, the present invention can naturally be applied to an image forming system in which a monochrome image forming apparatus is installed. Further, in the present embodiment, the present invention is applied to the image forming system 300 in which the electrophotographic image forming apparatus 100 is installed. However, the application of the present invention is not limited to this, and the present invention can also be applied to an image forming system in which an image forming apparatus of another method (for example, an inkjet image forming apparatus, a stencil printing machine, etc.) is installed. Further, in the present embodiment, the present invention is applied to the post-processing apparatus 1 connected to the image forming apparatus 100. However, the present invention can also be applied to a stand-alone post-processing apparatus not connected to the image forming apparatus. Further, in the present embodiment, a stitchless binding mechanism including a stitchless binding device 40 (binding means), a gap forming device 50 (gap forming means), a liquid injection nozzle 46, and a liquid storage tank 45 (liquid impregnation means) is provided in the manual processing unit 41. However, such a stitchless binding mechanism can be provided inside the apparatus instead of the stitch binding mechanism including the stitch binding device 30, the internal tray 20, etc., or the stitch binding mechanism and the stitchless binding mechanism can be provided side by side inside the apparatus. Also, in the present embodiment, the gap forming device 50 (gap forming means) forms a gap between the sheets, and after the liquid injection nozzle 46 and the liquid storage tank 45 (liquid impregnation means) impregnate the gap with liquid, the stitchless binding device 40 (binding means) performs stitchless binding processing. However, the processing performed after impregnating the liquid is not limited to stitchless binding processing, and any processing that improves the subsequent processability by impregnating the liquid into the sheet bundle PT may be used. For example, it is also possible to perform stitched binding processing or punching processing (perforation processing) after impregnating the liquid into the sheet bundle PT. Further, in the present embodiment, gap forming processing, liquid impregnation processing, and binding processing are performed on the corner portion PTx of the sheet bundle PT. However, gap forming processing, liquid impregnation processing, and binding processing can also be performed on portions other than the corner portion PTx of the sheet bundle PT. And even in such cases, the same effects as those of the present embodiment can be obtained.

[0043] Note that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be appropriately changed within the scope of the technical idea of the present invention, in addition to what is suggested in the present embodiment. Also, the number, position, shape, etc. of the above-described constituent members are not limited to the present embodiment, and can be set to appropriate numbers, positions, shapes, etc. suitable for implementing the present invention.

Explanation of Reference Numerals

[0044] 1 Post-treatment device (sheet processing device), 5 Manual staple button (manual staple start button), 30 Stitched binding device, 40 Stitchless binding device (binding means), 41 Manual insertion processing unit (manual insertion tray), 42 First stopper unit, 43 Second stopper unit, 45 Liquid storage tank (liquid impregnation means), 46 Liquid injection nozzle (liquid impregnation means), 50 Gap forming device (gap forming means), 51 Convex pressing member, 52 Concave receiving member, 53 Elastic member, 54 Second convex pressing member, 60 Thickness detection sensor, 90 Punching device (second post-processing device), 100 Image forming apparatus, 149 Operation display panel (operation display unit), 300 Image forming system, 400 Fastener, P Sheet, PT Sheet bundle, PTx Corner, M Binding processing unit, N Fold line, W Inner barrel space.

[0045] Note that the aspect in the present invention can also be, for example, a combination of the following Supplementary Notes 1 to 18. (Supplementary Note 1) Gap forming means for forming a gap between sheets by applying a shearing force within a range where no shearing occurs to a sheet bundle formed by stacking a plurality of sheets, Liquid impregnation means for impregnating a portion of the sheet bundle in which the gap has been formed by the gap forming means with a liquid, A post-processing device characterized by comprising the above. (Supplementary Note 2) A post-processing device according to Supplementary Note 1, further comprising binding means for performing a binding process on a portion of the sheet bundle impregnated with a liquid by the liquid impregnation means. (Supplementary Note 3) The post-processing device according to Supplementary Note 2, wherein the binding means performs a binding process on the sheet bundle without using a needle by a fastener. (Supplementary Note 4) The post-processing device according to Supplementary Note 2 or Supplementary Note 3, wherein the time from when the liquid impregnation means impregnates a portion of the sheet bundle with a liquid until the binding means performs a binding process on the portion of the sheet bundle is configured to be adjustable. (Supplementary Note 5) The gap forming means applies the shearing force to the corner portion of the sheet bundle, The binding means is configured to perform a binding process on a portion outside the portion where the shearing force acts at the corner portion, and is a post-processing apparatus according to any one of appendices 2 to 4. (Appendix 6) The gap forming means is configured to form a fold at the corner portion by applying the shearing force to the corner portion, and is a post-processing apparatus according to any one of appendices 2 to 5. (Appendix 7) The fold is formed substantially parallel to the binding process portion formed at the corner portion by the binding means, and is a post-processing apparatus according to appendix 6. (Appendix 8) The gap forming means is configured to be able to press the sheet bundle when the binding process on the sheet bundle by the binding means is performed, and is a post-processing apparatus according to any one of appendices 2 to 7. (Appendix 9) The gap forming means, the liquid impregnation means, and the binding means are installed in a manual processing unit that can process the sheet bundle in a state where the sheet bundle is manually inserted, and is a post-processing apparatus according to any one of appendices 2 to 8. (Appendix 10) The post-processing apparatus according to any one of appendices 1 to 9, wherein the time from forming the gap in the sheet bundle by the gap forming means to impregnating the liquid into the portion of the sheet bundle by the liquid impregnation means is adjustable. (Appendix 11) The gap forming means is configured to be able to adjust at least one of the position where the shearing force is applied to the sheet bundle and the magnitude of the shearing force, and is a post-processing apparatus according to any one of appendices 1 to 10. (Appendix 12) The gap forming means is configured to reduce the shearing force applied to the sheet bundle to a second predetermined value smaller than the first predetermined value after reaching the first predetermined value, and is a post-processing apparatus according to any one of appendices 1 to 11. (Appended Note 13) The gap forming means includes a convex pressing member that presses the sheet bundle from the front side, and a concave receiving member that is disposed on the back side of the sheet bundle so as to be fitted to the convex pressing member with the sheet bundle interposed therebetween. The post-processing apparatus according to any one of Appended Notes 1 to 12, characterized in that it comprises the above. (Appended Note 14) The gap forming means includes a convex pressing member that presses the sheet bundle from the front side, and an elastic member that is disposed on the back side of the sheet bundle so as to be deformed to be fitted to the convex pressing member with the sheet bundle interposed therebetween. The post-processing apparatus according to any one of Appended Notes 1 to 12, characterized in that it comprises the above. (Appended Note 15) The gap forming means includes a first convex pressing member that presses the sheet bundle from the front side, and a second convex pressing member that presses the sheet bundle from the back side and is disposed so as to face the first convex pressing member with the sheet bundle interposed therebetween. The post-processing apparatus according to any one of Appended Notes 1 to 12, characterized in that it comprises the above. (Appended Note 16) The liquid impregnation means injects liquid from the side facing the end face of the sheet bundle into the portion of the sheet bundle where the gap is formed. The post-processing apparatus according to any one of Appended Notes 1 to 15, characterized in that it has the above feature. (Appended Note 17) An image forming apparatus capable of forming an image on a sheet, The post-processing apparatus according to any one of Appended Notes 1 to 16, An image forming system, characterized in that it comprises the above. (Appended Note 18) The image forming apparatus is capable of discharging a sheet on which an image is formed, and a space inside the body is formed in which the discharged sheet can be taken out. The post-processing apparatus is installed in the space inside the body of the image forming apparatus. The image forming system according to Appended Note 17, characterized in that it has the above feature.

Prior Art Documents

Patent Documents

[0046]

Patent Document 1

Claims

1. Gap forming means for applying a shearing force within a range where no shearing occurs to a stack of multiple sheets to form a gap between the sheets; Liquid impregnating means for impregnating a portion of the stack of sheets in which the gap has been formed by the gap forming means with a liquid; A post-treatment device, characterized by comprising the above.

2. The post-treatment device according to claim 1, further comprising binding means for performing a binding process on a portion of the stack of sheets impregnated with the liquid by the liquid impregnating means.

3. The post-treatment device according to claim 2, wherein the binding means performs a binding process on the stack of sheets without using a needle by means of a binder.

4. The post-treatment device according to claim 2 or claim 3, wherein the time from when the liquid impregnating means impregnates a portion of the stack of sheets with the liquid until the binding means performs a binding process on the portion of the stack of sheets is configured to be adjustable.

5. The gap forming means applies the shearing force to a corner portion of the stack of sheets; The post-treatment device according to claim 2 or claim 3, wherein the binding means is configured to perform a binding process on a portion outside the portion where the shearing force is applied at the corner.

6. The post-treatment device according to claim 2 or claim 3, wherein the gap forming means is configured to form a crease at the corner by applying the shearing force to the corner.

7. The post-treatment device according to claim 6, wherein the crease is formed substantially parallel to a binding process portion formed at the corner by the binding means.

8. The post-treatment device according to claim 2 or claim 3, wherein the gap forming means is configured to be able to hold the stack of sheets when the binding means performs a binding process on the stack of sheets.

9. The post-treatment device according to claim 2 or claim 3, wherein the gap forming means, the liquid impregnating means, and the binding means are installed in a manual processing unit that can process the stack of sheets in a state where the stack of sheets is inserted by hand.

10. The post-treatment device according to claim 1 or claim 2, wherein the time from when the gap forming means forms the gap in the stack of sheets until the liquid impregnating means impregnates a portion of the stack of sheets with the liquid is configured to be adjustable.

11. The post-treatment device according to claim 1 or claim 2, characterized in that the gap forming means is configured to be able to adjust at least one of the position where the shearing force acts on the sheet bundle and the magnitude of the shearing force.

12. The post-treatment device according to claim 1 or claim 2, characterized in that the gap forming means is configured to reduce the shearing force acting on the sheet bundle to a second predetermined value smaller than the first predetermined value after reaching the first predetermined value.

13. The post-treatment device according to claim 1 or claim 2, characterized in that the gap forming means includes a convex pressing member that presses the sheet bundle from the front side and a concave receiving member that is disposed on the back side of the sheet bundle so as to be fitted to the convex pressing member with the sheet bundle sandwiched therebetween.

14. The post-treatment device according to claim 1 or claim 2, characterized in that the gap forming means includes a convex pressing member that presses the sheet bundle from the front side and an elastic member that is deformed so as to be fitted to the convex pressing member with the sheet bundle sandwiched on the back side of the sheet bundle.

15. The post-treatment device according to claim 1 or claim 2, characterized in that the gap forming means includes a first convex pressing member that presses the sheet bundle from the front side and a second convex pressing member that presses the sheet bundle from the back side and is disposed opposite to the first convex pressing member with the sheet bundle sandwiched therebetween.

16. The post-treatment device according to claim 1 or claim 2, characterized in that the liquid impregnation means injects liquid from the side facing the end face of the sheet bundle into the portion of the sheet bundle where the gap is formed.

17. An image forming apparatus capable of forming an image on a sheet, The post-treatment device according to claim 1 or claim 2, An image forming system, characterized by comprising the same.

18. The image forming apparatus is capable of discharging a sheet on which an image is formed, and a space inside the body is formed in which the discharged sheet can be taken out. The image forming system according to claim 17, characterized in that the post-treatment device is installed in the space inside the body of the image forming apparatus.

Images