Post-processor and image forming system

Abstract

To provide a post-processor, in an embodiment having blower means, allowed to prevent improper stacking without causing rounding or buckling of a sheet during discharge.SOLUTION: A post-processor 102, to be mounted on an image forming apparatus 101, comprises discharge-sheet feeding means (discharge roller 26, first follower roll 27) that carries a sheet fed from the image forming apparatus 101 to a sheet-discharge tray 5 while giving strength to the same, blower means 14 that sends air toward the sheet-discharge tray 5, and a strength-enhancing member 31 that abuts against the sheet in a different position from the discharge-sheet feeding means and enhances the strength of the sheet, thus making it possible to change over the presence / absence of sending air from the blower means 14 and the presence / absence of strength-enhancement by the strength-enhancing member (second follower roll 31).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a post-processing device and an image forming system. [Background technology]

[0002] In an electrophotographic image forming apparatus, an image is fixed to a sheet-like medium such as paper (hereinafter simply referred to as "paper") by heating the paper, so the paper is hot immediately after being discharged. If such paper is stacked on the paper output tray while still hot, a phenomenon called blocking may occur in which the discharged paper sticks together due to the melted toner.

[0003] In order to solve such problems, a technique has been proposed in which the paper discharged onto the paper discharge tray is cooled by air blown from a cooling fan or the like (see, for example, Patent Document 1).

[0004] Patent document 1 discloses a configuration including an air blowing section that is positioned above the paper discharged from the reversing rollers by a predetermined dimension and above the paper output tray, and that blows air onto the paper loaded on the output tray and onto the paper ejected from the reversing rollers and protruding, and describes that the paper being reversed and transported and the paper loaded on the output tray can be cooled by blowing air from the air blowing section. Summary of the Invention [Problem to be solved by the invention]

[0005] However, when air is blown toward the paper output tray from a blowing unit such as a cooling fan provided above the paper output tray, the leading edge of the paper being output may be subjected to the blowing air, causing the leading edge to curl or droop. This phenomenon is particularly noticeable when outputting paper that is weak.

[0006] If paper continues to be discharged with its leading edge curled or drooping, it may get caught or buckle on the paper stacked on the paper discharge tray, resulting in stacking problems.

[0007] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a post-processing device that is equipped with a blower and that can prevent stacking failures without causing curling or buckling of sheets during discharge. [Means for solving the problem]

[0008] In order to solve the above problems, the post-processing device of the present invention is a post-processing device mounted on an image forming device, and comprises a paper discharge transport means for transporting paper fed from the image forming device to a paper discharge tray while stiffening the paper, an air blowing means for blowing air toward the paper discharge tray, and a stiffening reinforcement member that abuts the paper at a position different from the paper discharge transport means and reinforces the stiffening of the paper, and is characterized in that it is possible to switch between whether or not air is blown from the air blowing means and whether or not stiffening is reinforced by the stiffening reinforcement member. Effect of the Invention

[0009] According to the present invention, in an aspect in which a blower is provided, it is possible to provide a post-processing device that can prevent stacking failure without causing curling or buckling of sheets during sheet ejection. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic external view illustrating an example of a configuration of an image forming system according to the present invention. [Diagram 2] FIG. 2 is a side view showing a schematic configuration of a post-processing device. [Diagram 3] 4 is an explanatory diagram of a paper discharge guide plate and a paper discharge roller. FIG. [Figure 4] 11 is an explanatory diagram showing the axial positional relationship between a first driven roller, a second driven roller, and a paper discharge roller at a basic stop position. FIG. [Diagram 5] 4 is an explanatory diagram of a paper discharge guide plate and a paper discharge roller. FIG. [Figure 6] 13 is an explanatory diagram showing the axial positional relationship between the first driven roller, the second driven roller, and the paper discharge roller when stiffening is strengthened. FIG. [Figure 7] 2 is a block diagram showing an outline of a control circuit of the post-processing device; [Figure 8] 10 is a flowchart showing an example of control during paper ejection. [Figure 9] 10 is a flowchart showing an example of control during paper ejection. [Figure 10] 10 is a flowchart showing an example of control during paper ejection. [Figure 11] 10 is a flowchart showing an example of control during paper ejection. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The post-processing device and image forming system according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments, and may be modified, added, modified, deleted, or otherwise altered within the scope of what a person skilled in the art can conceive, and any embodiment is within the scope of the present invention as long as it provides the functions and effects of the present invention.

[0012] FIG. 1 is a schematic external view illustrating an example of the configuration of an image forming system. The image forming system 100 includes an image forming apparatus 101 and a post-processing apparatus 102 . The image forming apparatus 101 is, for example, an apparatus that forms an image on a medium by a known electrophotographic method. In the following description, paper will be described as an example of a medium to be processed by the image forming apparatus 101 and the post-processing apparatus 102, but the medium is not limited to paper as long as it is in sheet form.

[0013] In the image forming apparatus 101, paper is fed from the paper feed unit 70, transported along the transport path 80 in the direction indicated by D, and sent to the post-processing device 102. The paper fed into the post-processing device 102 is discharged after a predetermined post-processing is performed or without being subjected to post-processing.

[0014] FIG. 2 is a side view showing a schematic configuration of the post-processing device. The post-processing device 102 receives the paper discharged from the image forming device 101 from the direction indicated by D in the figure.

[0015] The post-processing device 102 of this embodiment is mounted on the image forming device 101 and comprises a paper discharge transport means that transports paper fed from the image forming device 101 to the paper discharge tray 5 while stiffening the paper, an air blowing means 14 that blows air toward the paper discharge tray 5, and a stiffening reinforcement member that abuts the paper at a position different from the paper discharge transport means and reinforces the stiffening of the paper, and it is possible to switch between whether or not to blow air from the air blowing means 14 and whether or not to reinforce the stiffening using the stiffening reinforcement member.

[0016] 2, the post-processing device 102 includes an inlet roller 10 located at the most upstream side of the paper transport path, a transport roller 11 located downstream of the inlet roller 10, a shift roller 12 that shifts the paper in a direction perpendicular to the transport direction (width direction), a paper discharge guide plate 13 rotatably provided near the paper discharge tray 5 on which the paper is placed, and a paper discharge roller 26 located at the most downstream side. Also, a transport sensor 62 and a paper discharge sensor 63 are provided on the transport path.

[0017] The paper discharge guide plate 13 has a rotation fulcrum 13a at one end, and is provided at the other end with a first driven roller 27 which constitutes a paper discharge conveying means together with the paper discharge roller 26, and a second driven roller 31 which is a stiffening member.

[0018] The post-processing device 102 of this embodiment can execute a "staple mode" in which a binding process is performed on the sheets discharged from the image forming device 101, a "sheet discharge mode" in which the sheets discharged from the image forming device 101 are directly conveyed and discharged without being subjected to post-processing, and a "shift sheet discharge mode" in which the sheets are only sorted and discharged. The user can appropriately select and set any of the modes.

[0019] The post-processing device 102 shown in FIG. 2 includes a stapler 50 as a means for performing a stapling process, and a staple tray 21 for stacking sheets of paper until the sheets are bound. The sheet feeder 21 also includes a reference fence 23a against which the leading edge of the sheet in the transport direction strikes during binding processing, and an end fence 23b against which the trailing edge of the ejected sheet strikes. The edges of the sheet in the transport direction that strike the reference fence 23a and the end fence 23b are aligned.

[0020] In addition, the roller 16 conveys the paper toward the reference fence 23a and strikes it against the reference fence 23a, the roller 15 conveys the paper toward the reference fence 23a, and a pair of jogger fences 22 align the edges of the paper in the width direction. The jogger fences can be displaced according to the size of the paper.

[0021] In the "staple mode", the post-processing device 102 receives and carries in the paper discharged from the image forming device 101 by the entrance rollers 10, transports the paper to the shift rollers 12, and then discharges the paper onto the staple tray 21. The post-processing device 102 switches back the paper by the action of the striking rollers 15 and return rollers 16, and transports the paper until the end of the paper hits the reference fence 23a. After transporting multiple sheets of paper in the same manner, the stapler 50 staples the paper stack, and the stapled paper stack is discharged to the paper discharge tray 5 by the rotation of the paper discharge rollers 26.

[0022] In the "paper discharge mode" and "shift paper discharge mode," the post-processing device 102 conveys the paper conveyed from the image forming device 101 by the entrance rollers 10, the conveying rollers 11, the shift rollers 12, and the paper discharge rollers 26, and then discharges the paper to the paper discharge tray 5. The entrance sensor 61 detects the paper being conveyed.

[0023] In the "shift discharge mode," the shift roller 12 having a shift mechanism is moved a certain amount in the width direction perpendicular to the paper transport direction by a driving means (not shown). This movement shifts the paper, and the paper is discharged onto the paper discharge tray 5 by the paper discharge roller 26, where it is stacked one by one.

[0024] Near the discharge opening to the discharge tray 5, a discharge guide plate 13 is rotatably disposed. The paper discharge guide plate 13 has a rotation fulcrum 13a on one end side, and a first driven roller 27 and a second driven roller 31 on the other end side. The first driven roller 27 can be brought into contact with and separated from the discharge roller 26 by the rotation of the discharge guide plate 13. Hereinafter, the operation of separating the discharge roller 26 and the first driven roller 27 from each other will be referred to as the "opening operation" of the discharge guide plate 13, and the operation of bringing the discharge roller 26 into contact with the first driven roller 27 will be referred to as the "closing operation" of the discharge guide plate 13.

[0025] By closing the paper discharge guide plate 13, the paper is sandwiched in the nip formed by the paper discharge roller 26 and the first driven roller 27. The sandwiched paper is transported to the paper discharge tray 5 in a stiffened state and discharged.

[0026] The paper discharge tray 5 is displaced by a lifting mechanism (not shown), and the discharged papers are sequentially stacked on it. A cooling fan 14 serving as a blowing means is provided above the paper discharge tray 5. The cooling fan 14 blows air toward the paper discharge tray 5 to cool the paper discharged onto the paper discharge tray 5 and prevent blocking.

[0027] FIG. 3 is an explanatory diagram of the paper discharge guide plate 13 and the paper discharge rollers 26. As shown in FIG. The position of the paper discharge guide plate 13 shown in FIG. 3 is the basic stopping position during paper discharge. The discharge guide plate 13 is equipped with a pressure lever 32, a discharge guide plate motor 34, and a reduction gear 33 formed coaxially with the rotation fulcrum 32a of the pressure lever 32. The discharge guide plate motor 34 is formed, for example, of a step motor, and the amount of movement during opening and closing operations is detected by the number of driving pulses, thereby allowing the motor to be stopped at any position.

[0028] The discharge guide plate 13 is biased by a spring (not shown) in a direction in which the discharge roller 26 and the first driven roller 27 move apart. When the discharge guide plate motor 34 is driven by a predetermined amount, the pressure lever 32 rotates by the reduction gear 33 and presses the discharge guide plate 13. As a result, the first driven roller 27 is pressurized by the spring 28 via the bearing 29, forming a nip with the discharge roller 26.

[0029] FIG. 4 shows the axial positional relationship between the first driven roller 27, the second driven roller 31 and the paper discharge roller 26 at the basic stop position shown in FIG. The discharge roller 26 has flanges 26a on its outer circumferential surface (on both axial ends) that are larger in diameter than the main body portion. As shown in FIG. 3 and FIG. 4A, in the basic stop position, the second driven roller 31 and the flange 26a of the paper discharge roller 26 are spaced apart in the radial direction, forming a gap 24.

[0030] 4(B), the paper P is sandwiched in a nip formed by a main body portion, which is located lower than the flange 26a of the paper discharge roller 26, and the first driven roller 27, and a curved portion is formed by the protruding flange 26a. The curved portion of the paper P increases its rigidity, and the paper P is conveyed to the paper discharge tray 5 in a stiffened state and discharged.

[0031] In the basic stop position shown in Figs. 3 and 4, the second driven roller 31 does not participate in stiffening the paper.

[0032] FIG. 5 is an explanatory diagram of the discharge guide plate 13 and the discharge rollers 26, showing a state in which the stop position of the discharge guide plate 13 has been changed from the basic stop position shown in FIG.

[0033] By driving the discharge guide plate motor 34, the pressure lever 32 rotates in the direction R in the figure, and the discharge guide plate 13 is pressed and moves in a direction approaching the discharge roller 26. As a result, the first driven roller 27 forms a nip with the discharge roller 26, and the second driven roller 31 moves in the radial direction to a position overlapping the flange 26a of the discharge roller 26.

[0034] FIG. 6 shows the axial positional relationship between the first driven roller 27, the second driven roller 31 and the paper discharge roller 26 at the stop position shown in FIG. As shown in FIG. 5 and FIG. 6A, in a state changed from the basic stop position, an area 25 is formed where the second driven roller 31 and the flange 26a of the paper discharge roller 26 overlap in the radial direction.

[0035] 6B, the paper P is held in the nip formed by the main body portion, which is located lower than the flange 26a of the paper discharge roller 26, and the first driven roller 27, and a curved portion is formed by the protruding flange 26a, so that the paper P is stiffened. Furthermore, the paper P is also stiffened in the region 25 where the second driven roller 31 and the flange 26a of the paper discharge roller 26 overlap in the radial direction, so that the stiffening is strengthened. In this stiffened state, the paper P is transported to the paper discharge tray 5 and discharged.

[0036] When cooling fan 14 blows air toward discharge tray 5, the leading edge of discharged paper P may be subjected to the air and may curl or droop, but this can be prevented by strengthening the stiffening. As a result, the paper P stacked on discharge tray 5 does not get caught or buckle, and stacking failures can be prevented.

[0037] The post-processing device 102 of this embodiment can switch between blowing air from the cooling fan 14, which is a blowing means, and between strengthening stiffening by the second driven roller 31, which is a stiffening strengthening member. For example, when air is blown from the cooling fan 14, which is the blowing means, it is possible to control so that the paper P being discharged is automatically stiffened.

[0038] Moreover, the post-processing device 102 of this embodiment includes a paper information acquisition means and a control means for acquiring information about the paper P. The control means can switch between whether or not to blow air from the cooling fan 14, which is the air blowing means, and whether or not to strengthen the stiffness by the second driven roller 31, which is the stiffening strengthening member, based on the information about the paper P acquired by the paper information acquisition means.

[0039] The paper information acquiring means may constitute the control means, or may be a sensor that inputs a signal to the control means. Examples of the information related to the paper P include, but are not limited to, the thickness and size of the paper P.

[0040] FIG. 7 is a schematic block diagram of a control circuit constituting the control means provided in the post-processing device 102 of this embodiment. The CPU 105 is connected to the image forming apparatus 101 via UART and is capable of communicating with the image forming apparatus 101 . For example, it is possible to receive information about paper (processing mode, number of sheets, paper type, thickness, size, etc.) sent from the image forming apparatus 101 and execute processing corresponding to the received data.

[0041] Information output from various sensors is input to the CPU 105. Examples of the various sensors include an entrance sensor 61, a conveyance sensor 62, and a paper discharge sensor 63 disposed on the conveyance path, as well as a sensor for detecting the position of the paper discharge guide plate 13.

[0042] Further, a plurality of driver ICs (510 to 516) suitable for various motors included in the post-processing device 102 are connected to the external terminal of the CPU 105. The CPU 105 outputs signals to these driver ICs (510 to 516) to control the driving of the various motors connected thereto.

[0043] The various motors include an inlet motor 41 that drives the inlet roller 10, a conveying motor 42 that drives the conveying roller 11, a discharge motor 43 that drives the discharge roller 26, a shift motor 44 that drives the shift roller 12, a discharge guide plate motor 34, a discharge tray lifting motor 45, and a cooling fan drive motor 46.

[0044] 8 to 11 are flowcharts showing an example of a control flow during paper discharge in the post-processing device 102 of this embodiment.

[0045] FIG. 8 is a flow chart showing a flow of automatically strengthening the stiffness of the discharged paper P when air is blown from the cooling fan 14, which is the blowing means. As shown in Fig. 8(A), after paper discharge starts, it is determined whether or not air is being blown from the cooling fan 14 (S001). If the cooling fan 14 is turned ON, that is, if the cooling fan is driven to blow air, the stop position of the paper discharge guide plate 13 is changed to the position shown in Fig. 5 and Fig. 6 (S002). On the other hand, if air is not being blown from the cooling fan 14, the stop position of the paper discharge guide plate 13 is set to the basic stop position shown in Fig. 3 and Fig. 4 (S003).

[0046] FIG. 8B is a flow chart showing whether or not the stiffening of the paper is strengthened in the operation shown in FIG. 8A. As shown in Fig. 8(B), after paper discharge starts, it is determined whether or not air is being blown from the cooling fan 14 (S101). If the cooling fan 14 is turned ON, that is, if the cooling fan is driven to blow air, stiffening is strengthened by the operation shown in step S002 in Fig. 8(A) (S102). On the other hand, if air is not being blown from the cooling fan 14, stiffening is not strengthened.

[0047] Similarly, in the following flow charts, the step of stiffening the sheet is intended to change the stop position of the sheet discharge guide plate 13 to the position shown in FIG. 5 and FIG.

[0048] FIG. 9 is a flowchart showing a flow of controlling stiffening based on the thickness of the paper P being discharged, as an example of a mode in which the control means switches between blowing air from the cooling fan 14, which is the air blowing means, and stiffening using the stiffening reinforcement member, based on information about the paper P.

[0049] After paper ejection begins, it is determined whether or not cooling fan 14 is blowing air (S201). If cooling fan 14 is turned ON to blow air, the thickness of paper P is determined (S202). If paper P is not thick paper, stiffening is performed (S102). On the other hand, if cooling fan 14 is not blowing air, or if air is blown but paper P is thick paper, stiffening is not performed.

[0050] In this way, it is possible to set and control in advance so that stiffening is performed on thin paper that is easily affected by the blown air, and not on thick paper that is stiff, based on the thickness of the paper P to be discharged. As a result, stacking problems can be prevented when discharging thin paper. It is also possible to reduce the risk of stiffening marks being left when stiffening thick paper, or damage to the formed image.

[0051] FIG. 10 is a flowchart showing a flow of controlling air blowing and stiffening based on the thickness of the paper P being discharged, as an example of a mode in which the control means switches between blowing air from the cooling fan 14, which is the air blowing means, and switching between strengthening stiffening by the stiffening strengthening member, based on information about the paper P.

[0052] After starting to eject the paper, the thickness of the paper P is determined (S301). If the paper P is not thick paper, the cooling fan 14 is turned on to start blowing air (S302), and stiffening is further performed (S102). On the other hand, if the paper P is thick paper, the cooling fan 14 does not blow air, and stiffening is not performed.

[0053] In this way, it is possible to set and control in advance, based on the thickness of the paper P to be discharged, so that cooling and stiffening by blowing air is performed on thin paper, which is highly productive and easily becomes hot, and cooling and stiffening by blowing air are not performed on stiff thick paper, which is less productive and does not easily become hot. As a result, blocking and stacking problems can be prevented when discharging thin paper. It is also possible to reduce the risk of stiffening marks being left or damage to the formed image when stiffening thick paper.

[0054] FIG. 11 is a flowchart showing a flow of controlling air blowing and stiffening based on the thickness and size of the paper P being discharged, as an example of a mode in which the control means switches between blowing air from the cooling fan 14, which is the air blowing means, and switching between strengthening stiffening by the stiffening strengthening member, based on information about the paper P.

[0055] After paper ejection begins, the thickness of the paper P is determined (S401). If the paper P is not thick paper, the size of the paper P is further determined (S402). If the size of the paper P is small, the cooling fan 14 is turned ON to start blowing air (S403), and stiffening is further performed (S404). On the other hand, if the paper P is thick paper, or if the paper P is not thick paper but is large in size, no air is blown from the cooling fan 14, and stiffening is not performed.

[0056] In this way, it is possible to set and control in advance based on the thickness and size of the paper P to be discharged so that cooling by blowing air and strengthening of stiffness are performed for thin paper and small paper, which are highly productive and easily heated, and cooling by blowing air and strengthening of stiffness are not performed for thick paper and large paper, which are less productive and less likely to heat up, based on the thickness and size of the paper P to be discharged. As a result, blocking can be efficiently prevented, stacking failure during paper discharge can be prevented, and the risk of paper damage due to strengthening of stiffness can be reduced.

[0057] For example, aspects of the present invention are as follows. <1> A post-processing device mounted in an image forming apparatus, a paper discharge conveying means for conveying the paper conveyed from the image forming apparatus to a paper discharge tray while stiffening the paper; a blowing unit for blowing air toward the paper discharge tray; a stiffening member that abuts against the paper at a position different from the paper discharge conveying means and reinforces the stiffness of the paper, The post-processing device is characterized in that it is possible to switch between blowing air from the blowing means and strengthening the stiffening by the stiffening strengthening member. <2> A rotatable paper discharge guide plate and a paper discharge roller are provided. The discharge guide plate has a pivot point on one end side, and is provided with a first driven roller constituting the discharge conveying means together with the discharge roller on the other end side, and a second driven roller which is the stiffening reinforcement member. <1> 2 is a post-processing device according to the first embodiment. <3> The present invention is characterized in that, when the air is blown from the air blowing means, the paper to be discharged is stiffened. <1> or <2> 2 is a post-processing device according to the first embodiment. <4> The printing method includes: a paper information acquisition unit that acquires information about the paper; and a control unit. The control means is configured to switch between blowing air from the blowing means and stiffening the sheet by the stiffening member based on information about the sheet acquired by the sheet information acquisition means. <1> from <3> 13. The post-processing device according to claim 12, <5> The information about the paper is at least one of the thickness and the size of the paper. <4> 2 is a post-processing device according to the first embodiment. <6> An image forming apparatus, <1> from <5> and a post-processing device according to any one of claims 1 to 4. [Explanation of symbols]

[0058] 5 Output tray 10 Entrance roller 11 Transport roller 12 Shift Roller 13 Paper ejection guide plate 13a Pivot point 14 Blowing means (cooling fan) 26 Paper ejection roller 26a Flange part 27 First driven roller 31 Second driven roller 32 Pressure lever 33 Reduction Gear 34 Paper ejection guide plate motor 100 Image forming system 101 Image forming device 102 Aftertreatment device P paper [Prior art documents] [Patent documents]

[0059] [Patent Document 1] JP 2010-256781 A

Claims

1. A post-processing device mounted in an image forming apparatus, a paper discharge conveying means for conveying the paper conveyed from the image forming apparatus to a paper discharge tray while stiffening the paper; a blowing unit for blowing air toward the paper discharge tray; a stiffening member that abuts against the paper at a position different from the paper discharge conveying means and reinforces the stiffness of the paper, 3. A post-processing device comprising: a post-processing device that is capable of switching between blowing air from the blowing means and strengthening the stiffening member.

2. A rotatable paper discharge guide plate and a paper discharge roller are provided.

2. The post-processing device according to claim 1, wherein the discharge guide plate has a pivot point at one end and a first driven roller that constitutes the discharge transport means together with the discharge roller at the other end, and a second driven roller that is the stiffening reinforcement member.

3. 3. The post-processing device according to claim 1, wherein, when the air is blown from the air blowing means, stiffening is performed on the discharged paper.

4. The printing method includes: a paper information acquisition unit that acquires information about the paper; and a control unit.

3. The post-processing device according to claim 1, wherein the control means switches between blowing air from the air blowing means and stiffening the sheet by the stiffening reinforcement member based on information about the sheet acquired by the sheet information acquisition means.

5. 5. The post-processing device according to claim 4, wherein the information about the paper is at least one of the thickness and size of the paper.

6. 3. An image forming system comprising: an image forming apparatus; and the post-processing apparatus according to claim 1.

Images