Sheet post-treatment device

Abstract

A sheet post-processing apparatus of an embodiment has a stacker, a pair of folding rollers, and a folding knife. The stacker loads a sheet. The folding knife folds the sheet by pushing the sheet loaded in the stacker into a nip of the folding rollers. The folding rollers are capable of switching between a first attitude in which the sheet is pushed into the nip by the folding knife and a second attitude in which a conveying direction of the sheet is different from a conveying direction of the sheet in the first attitude.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to a sheet post-processing device. BACKGROUND

[0002] A sheet post-processing device performs post-processing on a sheet conveyed from an image forming apparatus (for example, an MFP). For example, the sheet post-processing device has a processing section that performs a binding process or the like on a sheet. The sheet post-processing device sometimes also has a folding mechanism that bundles a plurality of sheets together and performs folding. The folding mechanism has a stacker, a pair of folding rollers, and a folding blade. The folding blade folds a sheet by pushing the sheet loaded on the stacker into a nip of the folding rollers.

[0003] A sheet that has passed through the folding rollers is discharged to a paper discharge tray. If the loadability of sheets on the paper discharge tray is taken into consideration, the direction of a sheet when conveyed to the paper discharge tray is expected to be downward from the horizontal direction.

[0004] Depending on the type of the processing section, the stacker sometimes needs to be inclined to the folding blade side from the vertical direction. In this case, the conveyance direction of a sheet conveyed by the folding rollers is obliquely upward. In order to change the advancing direction of the sheet to obliquely downward, a structure that changes the direction of a sheet by abutting against the sheet is sometimes provided on the sheet post-processing device. In order to change the direction of a sheet, a dedicated conveyance roller is also sometimes provided.

[0005] However, in the case where the abutting structure for changing the direction is used, when a sheet abuts against the abutting structure, the surface of the sheet can be damaged by friction. In the case where the dedicated conveyance roller is used, the structure sometimes becomes complicated, and it is difficult to achieve the miniaturization of the device. SUMMARY

[0006] The sheet post-processing device of the embodiment has a stacker that loads a sheet, a pair of folding rollers, and a folding blade that folds the sheet by pushing the sheet loaded on the stacker into a nip of the folding rollers, the folding rollers being capable of switching between a first attitude in which the sheet is pushed into the nip by the folding blade and a second attitude in which the conveyance direction of the sheet is different from the conveyance direction of the sheet in the first attitude. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 FIG. 1 is a diagram illustrating one example of an image forming system of the embodiment.

[0008] Figure 2 FIG. 2 is a block diagram illustrating the structure of the image forming system of the embodiment.

[0009] Figure 3is a configuration view of one example of a folding mechanism of a sheet post-processing apparatus of an embodiment.

[0010] Figure 4 is an explanatory view showing the operation of the folding mechanism.

[0011] Figure 5 is an explanatory view showing the operation of the folding mechanism.

[0012] Figure 6 is an explanatory view showing the operation of the folding mechanism.

[0013] Figure 7 is an explanatory view showing the operation of the folding mechanism.

[0014] Figure 8 is an explanatory view showing the operation of the folding mechanism.

[0015] Figure 9 is an explanatory view showing the operation of the folding mechanism. DETAILED DESCRIPTION

[0016] A sheet post-processing apparatus of an embodiment has a stacker, a pair of folding rollers, and a folding blade. The stacker loads a sheet. The folding blade folds the sheet loaded on the stacker by pushing the sheet into a nip of the folding rollers. The folding rollers are capable of switching between a first attitude and a second attitude. The first attitude is a state in which the sheet is pushed into the nip by the folding blade. The second attitude is an attitude in which a conveyance direction of the sheet is different from a conveyance direction of the sheet in the first attitude.

[0017] Hereinafter, a sheet post-processing apparatus of an embodiment will be described with reference to the drawings.

[0018] Figure 1 is a view showing one example of an image forming system 1 of an embodiment.

[0019] As shown in Figure 1 , the image forming system 1 includes an image forming apparatus 2 and a sheet post-processing apparatus 3. The sheet post-processing apparatus 3 is simply referred to as "post-processing apparatus 3".

[0020] The image forming apparatus 2 forms an image on a sheet-like recording medium such as paper. The recording medium is "sheet S". For example, the image forming apparatus 2 is an MFP (Multi-Function Peripherals) as a multifunction machine, a printer, a copier, or the like. The post-processing apparatus 3 performs post-processing on the sheet S conveyed from the image forming apparatus 2. The sheet S is not limited to paper, and also includes a plastic sheet such as an OHP (Overhead projector) sheet. The sheet S can be supplied from the image forming apparatus 2 to the post-processing apparatus 3, or can be manually supplied to the post-processing apparatus 3.

[0021] Figure 2 is a block diagram showing the structure of the image forming system 1 of the embodiment.

[0022] As shown in Figure 2 , the image forming apparatus 2 includes a control panel 11, a scanning section 12, a printing section 13, a paper feeding section 14, a paper discharging section 15, and an image forming control section 16.

[0023] The control panel 11 includes various keys or a touch panel or the like that accept user operations. For example, the control panel 11 accepts an input relating to the type of post-processing of the sheet S. The image forming apparatus 2 transmits information relating to the type of post-processing to the post-processing apparatus 3.

[0024] The scanning section 12 includes a reading section that reads image information of a copy target. The scanning section 12 transmits the read image information to the printing section 13.

[0025] The printing section 13 forms an output image by a developer such as toner based on the image information transmitted from the scanning section 12 or an external device. The output image is a "toner image". The printing section 13 transfers the toner image onto the surface of the sheet S. The printing section 13 applies heat and pressure to the toner image transferred onto the sheet S, and fixes the toner image on the sheet S.

[0026] The paper feeding section 14 supplies the sheet S to the printing section 13 one by one in accordance with the timing at which the printing section 13 forms the toner image.

[0027] The paper discharging section 15 conveys the sheet S discharged from the printing section 13 to the post-processing apparatus 3.

[0028] The image forming control unit 16 controls the overall operation of the image forming apparatus 2. The image forming control unit 16 controls the control panel 11, scanning unit 12, printing unit 13, paper feeding unit 14, and paper output unit 15. The image forming control unit 16 has control circuitry including a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory).

[0029] Next, the post-processing device 3 will be described.

[0030] like Figure 1 As shown, the post-processing unit 3 is adjacent to the image forming unit 2. The image forming unit 2 conveys the sheet S to the post-processing unit 3. The post-processing unit 3 performs post-processing specified by the control panel 11 on the conveyed sheet S. For example, the post-processing unit 3 performs binding and sorting processes. For example, the post-processing unit 3 performs a sheet folding process that folds the sheet S in half and discharges it.

[0031] The post-processing device 3 includes an infeed unit 20, a standby unit 21, a processing unit 22, an outlet unit 23, a post-processing control unit 24 (control unit), a folding mechanism 40, a pair of outlet rollers 44, and a paper outlet tray 46.

[0032] The receiving section 20 is connected downstream of the paper discharge section 15 in the conveying direction. The receiving section 20 receives the sheet S conveyed from the image forming apparatus 2.

[0033] The standby unit 21 temporarily holds the sheet S being transported from the image forming apparatus 2. The standby unit 21 is located above the processing unit 22. When the processing unit 22 is idle, the standby unit 21 causes the held sheet S to fall toward the processing unit 22.

[0034] The processing unit 22 performs post-processing on the incoming sheet S. For example, the processing unit 22 performs a sorting process to align and integrate multiple sheets S. For example, the processing unit 22 performs sheet binding processing on the stack of sheets formed by aligning multiple sheets S using staples or adhesive tape. Reference numeral 25 indicates a sheet binding device that binds the stack of sheets in the processing unit 22 using staples or the like. The processing unit 22 discharges the post-processed sheet S to the discharge unit 23.

[0035] The discharge section 23 includes a fixed tray 23a and a movable tray 23b. The fixed tray 23a is located on the upper part of the post-processing unit 3. The movable tray 23b is located on the side of the post-processing unit 3. The sheet S is discharged onto the fixed tray 23a and the movable tray 23b.

[0036] like Figure 2As shown, the post-processing control unit 24 controls the overall operation of the post-processing device 3. That is, the post-processing control unit 24 controls the operation of the loading unit 20, the standby unit 21, the processing unit 22, the discharge unit 23, and the folding mechanism 40. Like the image forming control unit 16, the post-processing control unit 24 has a control circuit including a CPU, ROM, and RAM.

[0037] Figure 3 This is a structural diagram illustrating an example of the folding mechanism 40 of an embodiment.

[0038] like Figure 3 As shown, the folding mechanism 40 folds one or more sheets S in half. In this embodiment, a stack S' of sheets consisting of multiple sheets S is folded in half. For example, the number of sheets S constituting the stack S' can be set to 2 to 30. The direction along the conveying path of the stack S' of sheets supplied to the folding mechanism 40 is the sheet conveying direction D. The sheet conveying direction D is also simply referred to as the "conveyor direction". Figure 3 The direction orthogonal to the paper surface is the width direction of the sheet.

[0039] The folding mechanism 40 includes a stacker 55, a pair of folding rollers 41, a folding blade 43, and a rod 47.

[0040] The stacker 55 includes a guide member 56 and a support claw 57. The guide member 56 is flat. The surface of the guide member 56 opposite to the folding roller 41 is the loading surface 56a. The loading surface 56a is the surface for loading the sheet stack S'. The guide member 56 is positioned relative to the vertical direction ( Figure 3 The guide member 56 is tilted vertically (in the vertical direction). The guide member 56 is tilted so that the loading surface 56a faces obliquely upward. The back surface 56b of the guide member 56 is the opposite surface to the loading surface 56a.

[0041] The guide member 56 includes a first guide member 56A and a second guide member 56B. There is a gap 56C between the first guide member 56A and the second guide member 56B for the folding blade 43 to move forward and backward.

[0042] The support claw 57 is located on the second guide member 56B. The support claw 57 protrudes from the loading surface 56a. The support claw 57 supports the lower end of the sheet S loaded on the loading surface 56a. The support claw 57 is adjustable in height along the second guide member 56B.

[0043] A pair of folding rollers 41 are positioned approximately opposite the loading surface 56a of the guide member 56. The pair of folding rollers 41 form a clamping portion 42. For example, the folding rollers 41 are rubber rollers. One of the pair of folding rollers 41 is a drive roller 41A. The other of the pair of folding rollers 41 is a driven roller 41B.

[0044] The drive roller 41A is rotationally driven without moving in a fixed position. The drive roller 41A is rotationally driven by a drive source. For example, the drive source of the drive roller 41A is a direct current motor. The drive source transmits a driving force to the drive roller 41A. For example, the drive source of the drive roller 41A also transmits a driving force to the folding blade 43. "41a" is a rotational axis of the drive roller 41A.

[0045] The driven roller 41B can approach and move away from the drive roller 41A. The driven roller 41B is urged toward the drive roller 41A by an urging mechanism. The driven roller 41B rotates in response to the rotation of the drive roller 41A. "41b" is a rotational axis of the driven roller 41B.

[0046] The sheet stack S' is sandwiched by the folding blade 43 in the sandwiching portion 42 of the folding roller 41. The folding roller 41 folds the sheet stack S' inserted into the sandwiching portion 42 in half and feeds the folded sheet stack S' to the downstream side. The "transport direction" is a direction in which the folding roller 41 feeds the sheet stack S'.

[0047] As shown in FIG. 2, the driven roller 41B can be displaced by pivoting around the rotational axis 41a of the drive roller 41A. Figure 4

[0048] The drive roller 41A and the driven roller 41B can be switched between the first attitude PI and the second attitude P2 by a drive source (drive motor).

[0049] The first attitude PI is an attitude in which the drive roller 41A and the driven roller 41B are arranged in parallel with the loading surface 56a. In the first attitude PI, the drive roller 41A and the driven roller 41B are equal in distance from the loading surface 56a. In the first attitude PI, the transport direction of the sheet stack S' is slightly upward (obliquely upward) from the horizontal direction. The folding roller 41 in the first attitude PI can receive the sheet stack S' from the stacker 55.

[0050] The second attitude P2 is an attitude of the folding roller 41 located at a position where the driven roller 41B is displaced in the axis direction of rotation around the rotational axis 41a. In the second attitude P2, the driven roller 41B is greater in distance from the loading surface 56a than the drive roller 41A. In the second attitude P2, the transport direction of the sheet stack S' is different from that in the first attitude PI. The transport direction of the sheet stack S' in the second attitude P2 is the horizontal direction or is slightly downward (obliquely downward) from the horizontal direction.

[0051] The arrangement direction of the folding roller 41 in the second attitude P2 is parallel to the arrangement direction of the discharge roller 44. The sandwiching portion 42 of the folding roller 41 in the second attitude P2 is positioned opposite the sandwiching portion 45 of the discharge roller 44.

[0052] ​The lever 47 connects the drive roller 41A and the driven roller 41B. Since the driven roller 41B can be displaced by tilting the lever 47, the first posture P1 and the second posture P2 of the folding roller 41 can be switched.

[0053] The folding blade 43 is a plate-shaped member. The folding blade 43 is located opposite the clamping portion 42 of the folding roller 41 in the first posture P1. In this embodiment, the folding blade 43 has a length in a direction orthogonal to the loading surface 56a of the guide member 56. Since the loading surface 56a is inclined relative to the vertical direction, the folding blade 43 is inclined relative to the horizontal direction. For example, the folding blade 43 is made of a metal such as stainless steel.

[0054] The folding blade 43 can reciprocate to insert and remove its leading edge relative to the clamping portion 42 of the folding roller 41. For example, the folding blade 43 reciprocates via a slider-crank mechanism. The folding blade 43 enters the clamping portion 42 while pushing the center position of the sheet stack S' toward the clamping portion 42. The folding blade 43 avoids the clamping portion 42 while keeping the sheet stack S' in the clamping portion 42 (see reference). Figure 6 ).

[0055] A pair of discharge rollers 44 are located downstream of the folding roller 41 in the conveying direction. The pair of discharge rollers 44 form a clamping portion 45. One of the pair of discharge rollers 44 is a drive roller. The other of the pair of discharge rollers 44 is a driven roller. The drive roller rotates in a fixed position without moving. The driven roller can approach and move away from the drive roller. The driven roller is forceped towards the drive roller by a force-applying mechanism. The sheet stack S' (folded body) conveyed by the folding roller 41 is clamped in the clamping portion 45 of the discharge roller 44. The discharge roller 44 conveys the folded body inserted into the clamping portion 45. The conveying direction of the discharge roller 44 to the folded body is horizontal or diagonally downward. The conveying direction of the discharge roller 44 to the folded body is the same as the conveying direction of the sheet stack S' in the second posture P2 of the folding roller 41.

[0056] The folding roller 41 and the discharge roller 44 can be driven to rotate independently of each other or to rotate synchronously by a drive source.

[0057] like Figure 3 As shown, the paper discharge tray 46 is located downstream of the discharge roller 44 in the conveying direction. The paper discharge tray 46 loads the folded body conveyed from the discharge roller 44. When the paper discharge tray 46 is located at the position where the folded body conveyed from the discharge roller 44 is directly discharged, it can suppress the disorder of the loading posture of the folded body, thus improving the loading performance of the folded body.

[0058] A loading unit may be located above the stacker 55. The loading unit performs binding processing on the stack of sheets S' before it is conveyed to the folding mechanism 40.

[0059] like Figure 1As shown, a door 20a is provided on the downstream side of the in-feed section 20 of the post-processing device 3. The door 20a switches the transport destination of the sheet S to either one of the processing section 22 and the folding mechanism 40. When the sheet folding processing is not performed, the door 20a transports the sheet S to the standby section 21. When the sheet folding processing is performed, the door 20a transports the sheet S to the folding mechanism 40.

[0060] Next, the operation of the folding mechanism 40 will be described.

[0061] As shown, the sheet S conveyed from the image forming device 2 is supplied via the sheet path 54. The stapling device can also perform the stapling processing on the sheet stack S' composed of a plurality of sheets S. Figure 1

[0062] As shown, the sheet stack S' supplied to the folding mechanism 40 is loaded on the loading surface 56a of the stacker 55. The central position (the central position in the sheet transport direction) of the sheet stack S' opposes the nip 42 of the folding roller 41. The folding roller 41 is in the first attitude PI. Figure 5 The folding blade 43 pushes the central position of the sheet stack S' out toward the nip 42 of the folding roller 41. As shown, the folding blade 43 pushes the central position of the sheet stack S' into the nip 42. The folding blade 43 retreats after pushing the sheet stack S' into the nip 42.

[0063] Figure 6 As shown, the folding roller 41 rotates while pinching the sheet stack S' and folds the sheet stack S'. Since the transport direction of the folding roller 41 in the first attitude PI is obliquely upward, the folded sheet stack S' is sent obliquely upward. The transport of the sheet stack S' is temporarily stopped in the state where the folding roller 41 pinches the sheet stack S'.

[0064] As shown, the attitude of the folding roller 41 is switched from the first attitude PI to the second attitude P2 in the state where the folding roller 41 pinches the sheet stack S'. Since the transport direction of the folding roller 41 in the second attitude P2 is horizontal or obliquely downward, the folded portion of the sheet stack S' is also horizontal or obliquely downward. Figure 7 As shown, the rotational drive of the folding roller 41 is restarted. The folded sheet stack S' is fed to the nip 45 of the discharge roller 44 and is transported by the discharge roller 44. The folded sheet stack S' is a "folded body". The discharge roller 44 transports the folded body in the horizontal direction or obliquely downward. The folded body is discharged to the paper discharge tray 46 (refer to

[0065] and Figure 8 ).

[0066] As shown, the attitude of the folding roller 41 is switched from the first attitude PI to the second attitude P2 in the state where the folding roller 41 pinches the sheet stack S'. Since the transport direction of the folding roller 41 in the second attitude P2 is horizontal or obliquely downward, the folded portion of the sheet stack S' is also horizontal or obliquely downward. Figure 9 Figure 1 As shown, the rotational drive of the folding roller 41 is restarted. The folded sheet stack S' is fed to the nip 45 of the discharge roller 44 and is transported by the discharge roller 44. The folded sheet stack S' is a "folded body". The discharge roller 44 transports the folded body in the horizontal direction or obliquely downward. The folded body is discharged to the paper discharge tray 46 (refer to Figure 3 and ).

[0067] ​​At the time when the sheet bundle S' leaves the folding roller 41, the folding roller 41 is returned from the second posture P2 to the first posture P1 (refer to Figure 5 ).

[0068] In the post-processing device 3 of the present embodiment, the folding roller 41 is capable of switching between the first posture P1 and the second posture P2. In the post-processing device 3, by setting the folding roller 41 to the second posture P2 after the folding roller 41 receives the sheet bundle S' in the first posture P1, it is possible to change the orientation of the sheet bundle S' to horizontal or obliquely downward. The post-processing device 3 is capable of discharging the folded sheet bundle S' (folding body) to the paper discharge tray 46 in the horizontal or obliquely downward posture, and thus it is possible to suppress the confusion of the loading posture of the folding body in the paper discharge tray 46. The post-processing device 3 is excellent in terms of the loading property of the folding body because of the good loading posture of the folding body in the paper discharge tray 46.

[0069] In the post-processing device 3, the direction of the sheet bundle S' is changed by the folding roller 41, and thus compared to the case where a dedicated conveying roller for changing the direction of the sheet is provided, it is possible to simplify the device structure. The post-processing device 3 is capable of realizing the downsizing of the device.

[0070] In the post-processing device 3, the direction of the sheet bundle S' is changed by the folding roller 41, and thus compared to the case where the direction is changed by making the sheet abut against the abutting structure within the device, it is possible to suppress the application of a large frictional force to the sheet bundle S' and to reduce the damage received by the sheet bundle S'.

[0071] The folding roller 41 is capable of switching between the first posture P1 and the second posture P2 by the rotation around the rotation axis 41a of the drive roller 41A. Since the rotation axis 41a of the drive roller 41A is used, it is possible to simplify the mechanism for rotating the folding roller 41.

[0072] Since the arrangement direction of the folding roller 41 in the first posture is parallel to the loading surface 56a, it is possible to smoothly guide the sheet bundle S' to the clamping portion 42 by the folding blade 43.

[0073] Since the arrangement direction of the folding roller 41 in the second posture P2 is parallel to the arrangement direction of the discharge roller 44, it is possible to smoothly guide the sheet bundle S' to the discharge roller 44.

[0074] Since the clamping portion 42 of the folding roller 41 in the second posture P2 is located at a position opposite to the clamping portion 45 of the discharge roller 44, it is possible to smoothly guide the sheet bundle S' to the clamping portion 45 of the discharge roller 44.

[0075] In the embodiment, the folding roller 41 can switch the first attitude PI and the second attitude P2 by pivoting around the rotation axis 41a of the drive roller 41A, but the center of pivoting for switching the first attitude PI and the second attitude P2 is not limited to the rotation axis of the drive roller. For example, the center of pivoting can also be the gripping portion of the folding roller.

[0076] The post-processing device 3 of the embodiment is provided with the discharge roller 44, but the post-processing device can also be free of the discharge roller.

[0077] In the post-processing device 3 of the embodiment, the protruding length of the stack S' of sheets fed out by the folding roller 41 can also be detected by an optical sensor or the like (refer to Figure 7 ). The post-processing control section 24 can control the operation of the folding roller 41 based on the detected value, and switch the folding roller 41 from the first attitude PI to the second attitude P2 (refer to Figure 2 and Figure 8 ).

[0078] According to at least one embodiment described above, the folding roller 41 can discharge the stack S' of sheets (folding body) to the paper discharge tray 46 in a horizontal or obliquely downward attitude by switching the first attitude PI and the second attitude P2, and thus is excellent in terms of loadability of the folding body in the paper discharge tray 46. In the post-processing device 3, since the device structure can be simplified, the device can be downsized. In the post-processing device 3, the damage to the folding body can be reduced.

[0079] Although several embodiments have been described, these embodiments are presented by way of example only, and are not intended to limit the scope of the invention. Indeed, these novel embodiments can be embodied in a multitude of other ways and can be practiced or carried out in various embodiments. Various other modifications and variations to these embodiments can be possible in light of the above teachings without departing from the spirit and scope of the invention. These embodiments and other embodiments thereof are included within the scope of the invention and are encompassed by the claims as written.

Claims

1. A sheet post-processing apparatus, comprising: Stacker, for loading sheets; A pair of folding rollers; and A folding knife folds the sheet in half by pushing it into the clamping portion of the folding roller. The folding roller can switch between a first posture and a second posture. The first posture is the posture in which the sheet is pushed into the clamping part by the folding knife. The second posture is the posture in which the conveying direction of the sheet is different from the conveying direction of the sheet in the first posture.

2. The sheet post-processing apparatus according to claim 1, wherein, The folding roller can switch between the first posture and the second posture by rotating about a rotation axis of the folding roller.

3. The sheet post-processing apparatus according to claim 1, wherein, The sheet post-processing apparatus also includes a pair of discharge rollers that discharge the sheet conveyed from the folding roller in the second posture.

4. The sheet post-processing apparatus according to claim 1, wherein, The stacker has a loading surface for loading the sheets. In the first posture, the folding rollers are arranged in a direction parallel to the loading surface.

5. The sheet post-processing apparatus according to claim 3, wherein, In the second posture, the arrangement direction of the folding rollers is parallel to the arrangement direction of the discharge rollers.

6. The sheet post-processing apparatus according to claim 3, wherein, In the second posture, the clamping part of the folding roller is opposite to the clamping part of the discharge roller.

7. The sheet post-processing apparatus according to claim 1, wherein, The stacker has an upwardly angled loading surface for loading the sheets. In the first posture, the conveying direction of the sheet by the folding roller is obliquely upward.

8. The sheet post-processing apparatus according to claim 7, wherein, In the second posture, the conveying direction of the sheet by the folding roller is diagonally downward.

9. The sheet post-processing apparatus according to claim 3, wherein, Downstream of the discharge roller is a paper discharge tray, which loads the sheet conveyed from the discharge roller.

10. The sheet post-processing apparatus according to claim 9, wherein, The paper discharge tray is located at the position where the sheet conveyed from the discharge roller is directly discharged.

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