Patent Grant
10781066
This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2018-102700 filed on May 29, 2018, the contents of which are hereby incorporated by reference.
The present disclosure relates to a sheet postprocessing device for performing postprocessing such as binding and folding process on a sheet on which an image has been formed by image forming apparatuses such as copiers and printers, and also relates to image forming systems provided with such a sheet postprocessing device.
Conventionally, sheet postprocessing devices are used which can perform postprocessing including binding process in which a plurality of sheets on which images have been formed by an image forming apparatus such as a copier or printer are stacked and the stacked bundle of sheets is bound with staples, as well as folding process in which twofold or threefold folding is performed on a bundle of sheets.
In such sheet postprocessing devices, sheets on which images have been formed are conveyed in a sheet conveying passage and stacked on a sheet tray. When a predetermined number of sheets are stacked on the sheet tray, binding or folding process is applied on a bundle of sheet on the sheet tray.
For example, there are known sheet postprocessing devices in which a predetermined number of sheets are stacked on the sheet tray and binding and folding process is applied on a bundle of sheets on the sheet tray.
Inconveniently, however, in the conventional sheet postprocessing devices mentioned above, when a sheet is stacked on a sheet tray from a sheet conveying passage, the conveyed sheet may make close contact with the stacked sheets to cause a jam (sheet jam).
According to one aspect of the present disclosure, a sheet postprocessing device includes a sheet conveying passage, a sheet tray, an inlet guide, a processing device, and a blowing device. Though the sheet conveying passage, a sheet on which an image has been formed is conveyed. The sheet tray is arranged downstream of the sheet conveying passage and has sheets stacked on it. The inlet guide is arranged at the downstream end of the sheet conveying passage and guides a sheet to the sheet tray. The processing device performs predetermined processing on a sheet stacked on the sheet tray. The blowing device blows air, from the upstream side in the sheet conveying direction, between the top face of the top-most sheet in the sheets stacked on the sheet tray and the bottom face of the subsequent sheet sent from the inlet guide into the sheet tray.
This and other objects of the present disclosure, and the specific benefits obtained according to the present disclosure, will become apparent from the description of embodiments which follows.
Hereinafter, with reference to the accompanying drawings, embodiments of the present disclosure will be described.
With reference to
As shown in
The sheet postprocessing device 30 performs on the sheets conveyed from the image forming apparatus 10 postprocessing such as punch hole-forming, binding, and folding. The sheet postprocessing device 30 is not limited to one which performs postprocessing on the sheets conveyed automatically from the image forming apparatus 10. Instead, it may be one which conveys on its own a sheet set on an unillustrated tray by a user to a position where postprocessing is possible to perform postprocessing on the sheet.
As shown in
The sheet postprocessing device 30 includes a sheet feeding port 36, a main discharge tray 38, a sub discharge tray 40, a retraction drum 41, a postprocessing controller 101, various switching members, various rollers, and the like. Through the sheet feeding port 36, the sheets discharged from a discharge portion 7 (see
The sheet feeding port 36 communicates with the main discharge port 37 with each other through a first conveying passage 42. A second conveying passage 43 which is connected to the first conveying passage 42 to branch off from it is connected to the sub discharge port 39. A third conveying passage 44 which is connected to the first conveying passage 42 to branch off from it is connected to the sheet folding unit 60. A fourth conveying passage 45 connected to the third conveying passage 44 to branch off from it curves along the circumference of the retraction drum 41 and joins the first conveying passage 42. The third conveying passage 44 is one example of “a sheet conveying passage” according to the present disclosure.
Sheets conveyed in through the sheet feeding port 36 are sent on to the downstream side by the registration roller pair 46. At the downstream end of the first conveying passage 42, a main discharge roller pair 47 for sending sheets out to the main discharge tray 38 is provided. The main discharge roller pair 47 is configured such that, when sending sheets on to the stapling unit 35, the rollers separate from each other to release the nip. The main discharge tray 38 mainly receives a bundle of sheets which has been bound in the stapling unit 35. It is also possible to receive sheets which are not post-processed or only punched on the main discharge tray 38.
At the downstream end of the second conveying passage 43, a sub discharge roller pair 48 for sending sheets out to the sub discharge tray 40 is provided. The sub discharge tray 40 mainly receives sheets which are discharged without being post-processed or which have only been punched at the postprocessing device 30.
The punch hole forming device 33 is arranged between the sheet feeding port 36 and the registration roller pair 46 so as to face the first conveying passage 42 from above. The punch hole forming device 33 applies punching process on a sheet conveyed through the first conveying passage 42 with predetermined timing.
The stapling unit 35 is arranged on the downstream side of the first conveying passage 42 to face it from below. The stapling unit 35 applies stacking process by stacking a plurality of sheets to form a bundle of sheets, as wells as applies binding process by binding a bundle of stacked sheets with a staple.
The retraction drum 41, when binding a plurality of bundles of sheets successively, if a previous bundle is being bound, retracts the first sheet of the subsequent bundle on the outer circumferential face of the retraction drum 41 temporarily, and then conveys it to the stapling unit 35 with the second sheet overlapping the first one.
Next, the sheet folding unit 60 in the sheet postprocessing device 30 will be described. In the following description, for convenience, “a sheet S” can be a single sheet S or a bundle of a plurality of sheets S.
As shown in
The sheet folding unit 60 includes a sheet inlet passage 61, a sheet tray 63, and an aligning member 65. The sheet inlet passage 61 leads to the downstream end of the third conveying passage 44. The sheet tray 63 is composed of an upstream-side sheet stacking portion 63a and a downstream-side sheet stacking portion 63b on which sheets S conveyed in from the sheet inlet passage 61 are stacked. The aligning member 65 aligns the position of sheets S stacked on the sheet tray 63.
The sheet folding unit 60 is provided with a first folding device (folding device) 70, a sheet entrance path 81, and a second folding device (folding device) 90. The first folding device (folding device) 70 performs first folding process on a sheet S. The sheet S on which first folding process has been applied by the first folding device 70 can enter a sheet entrance path 81. The second folding device (folding device) 90 performs second folding process on the sheet S on which first folding process has been applied by the first folding device 70. The first folding device (folding device) 70, the second folding device (folding device) 90, and a stapling device 67 are examples of “a processing device” according to the present invention. The processing device performs predetermined processing on a sheet S stacked on the sheet tray 63.
The sheet folding unit 60 further includes a conveyance destination switching member 83 and a lower discharge tray (discharge tray) 87. The conveyance destination switching member 83 switches the conveyance destination of the sheet S on which first folding process has been applied by the first folding device 70. The lower discharge tray 87 receives a sheet S discharged from a lower discharge port (sheet discharge port) 85.
The sheet inlet passage 61 is a passage for conveying into the sheet folding unit 60 the sheet S which has been conveyed through the third conveying passage 44. The sheet inlet passage 61 is composed of an inlet guide 611 which guides a sheet S. At a downstream end of the inlet guide 611, an inlet roller pair 612 for sending the sheet S into the sheet folding unit 60 is provided.
The upstream-side sheet stacking portion 63a and the downstream-side sheet stacking portion 63b are composed of, for example, a plate-like member, and they are provided so as to describe a straight line extending obliquely from upper right to lower left inside the sheet folding unit 60 (that is, so as to incline downward toward the downstream side). Specifically, the upstream-side sheet stacking portion 63a is arranged on the upstream side of a push-out mechanism 71, which will be described later, in the sheet conveying direction. On the other hand, the downstream-side sheet stacking portion 63b is arranged apart from the upstream-side sheet stacking portion 63a, on the downstream side of the push-out mechanism 71 in the sheet conveying direction. Arranged above the upstream-side sheet stacking portion 63a is the stapling device 67 which applies binding process on a bundle of sheets which is folded at the first folding device 70.
The aligning member 65 includes an upper moving member 651, a lower moving member 652, and width-adjusting members 653a and 653b. The upper and lower moving members 651 and 652 align the leading edge and the trailing edge of sheets S stacked on the upstream-side and downstream-side sheet stacking portions 63a and 63b. The width-adjusting members 653a and 653b align the side ends of sheets S in the sheet width direction perpendicular to the sheet conveying direction.
The upper moving member 651 is fitted to an upstream-side belt 655 stretched between an upstream-side driving pulley 654a and an upstream-side driven pulley 654b which are arranged under the upstream-side sheet stacking portion 63a. The lower moving member 652 is fitted to a downstream-side belt 657 stretched between a downstream-side driving pulley 656a and a downstream-side driven pulley 656b which are arranged under the downstream-side sheet stacking portion 63b. The lower moving member 652 sustains the leading edge of a sheet S. Moving the upper and lower moving members 651 and 652 according to the size of sheets S (length in the sheet conveying direction) allows the position of the sheets S stacked on the upstream-side and downstream-side sheet stacking portions 63a and 63b to be aligned in the sheet conveying direction (that is, in the longitudinal direction of sheets S).
A pair of width-adjusting member 653a is provided on the upstream-side sheet stacking portion 63a at an interval in the sheet width direction (in the direction perpendicular to the plane of
Alignment by the aligning member 65 is performed every time a sheet S is stacked on the sheet tray 63. When sheets S reach a predetermined number, they are aligned by the aligning member 65, and are then moved to the position for binding process or folding process.
Above the upstream-side and downstream-side sheet stacking portions 63a and 63b, elastic upstream-side and downstream-side paddles 66a and 66b are provided respectively. The upstream-side and downstream-side paddles 66a and 66b rotate in the clockwise direction in
The first folding device 70 includes a push-out mechanism 71 and a first folding roller pair 75. The push-out mechanism 71 pushes out a sheet S. The first folding roller pair 75 performs folding process on a sheet S pushed out by the push-out mechanism 71.
The push-out mechanism 71 is arranged between the upstream-side and downstream-side sheet stacking portions 63a and 63b, under the first folding roller pair 75. The push-out mechanism 71 has a folding blade 72 made of sheet metal which makes contact with the bottom face of the sheet S. The push-out mechanism 71 has a motor and a transmission mechanism (neither of them is illustrated) which makes the folding blade 72 move perpendicularly to the bottom face of a sheet S. The folding blade 72 pushes out a sheet S and feeds it to a first nip portion N1, which will be described later, of the first folding roller pair 75.
As shown in
Between the first and second rollers 76 and 77, the first nip portion N1 is formed to which a sheet S is fed in by the folding blade 72 of the push-out mechanism 71 (see
On the downstream side of the first nip portion N1 of the first folding roller pair 75, there is provided a first discharge conveying passage 88 which leads to the lower discharge port 85 (see
The sheet entrance path 81 is connected to the first discharge conveying passage 88 to branch off from it. The conveyance destination switching member 83 is provided at the branch portion between the sheet entrance path 81 and the first discharge conveying passage 88, and by pivoting, it switches the conveyance destination of a sheet S on which first folding process has been applied between the first discharge conveying passage 88 and the sheet entrance path 81.
The sheet entrance path 81 is provided so that a sheet S on which first folding process has been applied by the first folding device 70 can enter it to retract while being bent. The sheet entrance path 81 is arranged opposite the first roller 76 across the conveyance destination switching member 83. The sheet entrance path 81 is curved in the direction along the circumferential face of the second roller 77.
The sheet entrance path 81 is formed so as to correspond to the thickness of the maximum number of sheets S allowing folding process by the sheet folding unit 60. For example, when folding process can handle one to five sheets, the sheet entrance path 81 is structured to have a space big enough to allow entry of sheets S with the thickness of five folded sheets S (the thickness after first folding process, that is, the thickness corresponding to ten sheets).
At the downstream end of the sheet entrance path 81, a stopper 81a is provided. The first fold of a sheet S which has entered (retracted to) the sheet entrance path 81 strikes the stopper 81a.
The second folding device 90 performs second folding process on a sheet S on which first folding process has been applied and which has struck the stopper 81a.
Specifically, the second folding device 90 has a second folding roller pair 91. The second folding roller pair 91 performs second folding process on a sheet S on which first folding process has been applied. The second folding roller pair 91 is composed of the first roller 76 mentioned above and a third roller 92 located above the first roller 76. The first roller 76 is a common roller shared between the first and second folding roller pairs 75 and 91. The third roller 92 is, via a driving force transmission mechanism, driven to rotate by a motor (neither of these are illustrated).
Between the first and third rollers 76 and 92, there is formed a second nip portion N2. As shown in
As shown in
Next, with reference to
First, twofold folding process will be described. Twofold folding process is applied when a user selects a twofold mode using the operation panel 12 (see
A sheet S conveyed in through the sheet inlet passage 61 is stacked on the upstream-side and downstream-side sheet stacking portions 63a and 63b and is aligned by the aligning member 65. The aligning member 65 arranges the sheet S at a predetermined position so that the folding position of the sheet S faces the tip end of the folding blade 72. Next, the folding blade 72 of the push-out mechanism 71 is thrust out to raise the sheet S upward (in the direction perpendicular to the sheet S). Here, the folding blade 72 makes contact with the folding position of the sheet S. The sheet S raised by the folding blade 72 enters, while being bent, the first nip portion N1 of the first folding roller pair 75. In the sheet S which has passed through the first nip portion N1, the first fold is formed. The sheet S in which the first fold has been formed is, via the first discharge conveying passage 88, discharged from the lower discharge port 85 to the lower discharge tray 87 (see
Next, threefold folding process will be described. Threefold folding process is applied when a user selects a threefold mode using the operation panel 12 (see
After the first fold of the sheet S strikes the stopper 81a, the first folding roller pair 75 continues to be driven to rotate. Thus, as shown in
The bend S1 formed in the sheet S enters the second nip portion N2 of the second folding roller pair 91. On the sheet S which has passed the second nip portion N2, the second fold is formed. The sheet S on which the second fold has been formed is conveyed through the second discharge conveying passage 89 while winding around the circumferential face of the third roller 92 and is discharged by the discharge roller pair 86 from the lower discharge port 85 to the lower discharge tray 87.
Next, the structure of and around the sheet inlet passage 61 will be described in detail.
As shown in
Specifically, the blowing device 110 has a blowing fan 111 and a duct 112. The blowing fan 111 generates a flow of air. The duct 112 is connected to the blowing fan 111 and discharges air from the blowing fan 111. The duct 112 is provided so as to discharge air parallel to the sheet tray 63.
In a part, facing the duct 112, of a curved guide face 611b on the right side of the inlet guide 611 in
Below the inlet guide 611, a guide member 615 for guiding a sheet S to the inlet roller pair 612 is provided. The inlet guide 611 and the guide member 615 form the sheet inlet passage 61. The inlet guide 611 and the guide member 615 are curved in such directions that their respective upstream parts in the sheet conveying direction recede from each other. The guide member 615 has also a function of guiding air which has been discharged from the duct 112 and has not flowed into the air inflow port 611a to the bottom face of a sheet S.
The inlet roller pair 612 is composed of a driving roller 613 and a driven roller 614 which is in pressed contact with the driving roller 613. The driving roller 613, as shown in
To the rotary shaft 613a of the driving roller 613, a plurality of resin pressing members 616 are fitted which can rotate idly about the rotary shaft 613a. When the pressing members 616 make contact with a sheet S being conveyed by the inlet roller pair 612, they pivot to a position indicated by solid lines in
As shown in
The third conveying passage 44, the blowing device 110, and the sheet detection sensor 120 are provided in the postprocessing device main body 31. On the other hand, as mentioned above, the inlet guide 611, the sheet tray 63, the stapling device 67, the first folding device 70, the second folding device 90, the lower discharge port 85, and the lower discharge tray 87 are provided in the sheet folding unit 60. Thus, when a sheet jam occurs in the sheet tray 63, the stapling device 67, the first folding device 70, the second folding device 90, or the like, the sheet folding unit 60 can be drawn out, as shown in
As shown in
The ROM stores data and the like that are not changed during the use of the sheet postprocessing device 30, such as a control program for the sheet postprocessing device 30 and values needed for control. The RAM stores necessary data generated while the sheet postprocessing device 30 is controlled, data temporarily needed to control the sheet postprocessing device 30, and the like.
The postprocessing controller 101 can control the stapling device 67, the first folding device 70, the second folding device 90, the upstream-side driving pulley 654a, the downstream-side driving pulley 656a, the conveyance destination switching member 83, and the like. The postprocessing controller 101 controls the whole sheet postprocessing device 30.
Here, in this embodiment, when performing postprocessing on a sheet S by the sheet folding unit 60, the postprocessing controller 101 makes the blowing device 110 start to blow air when the sheet detection sensor 120 senses the first sheet S.
The postprocessing controller 101, when applying binding process on a sheet S by the stapling device 67, makes the aligning member 65 align a predetermined number of sheets S and then move them to the binding process position. Here, the postprocessing controller 101 makes the aligning member 65 move the sheets S to the binding process position and, substantially at the same time, makes the blowing device 110 stop blowing air.
The postprocessing controller 101, when applying folding process on a sheet S by the first folding device 70, makes the aligning member 65 align a predetermined number of sheets S and then move them to the folding process position. Here, the postprocessing controller 101 makes the aligning member 65 move the sheets S to the folding process position and, substantially at the same time, makes the blowing device 110 stop blowing air. When further applying folding process on the sheets S on which binding process has been applied, the postprocessing controller 101, while keeping the blowing device 110 from blowing air, has the sheets S moved from the binding process position to the folding process position.
In this embodiment, as described above, the blowing device 110 is provided which blows air between the top face of the top-most sheet S in the sheets S stacked on the sheet tray 63 and the bottom face of a sheet S sent out from the inlet guide 611 to the sheet tray 63. This permits an air layer to be formed between the bottom face of a sheet S sent from the inlet guide 611 into the sheet tray 63 (hereinafter also called a subsequent sheet S) and the top face of the top-most sheet S in the sheets which have already been stacked on the sheet tray 63 (hereinafter also called a top-most sheet S on the sheet tray 63), and thereby it is possible to prevent the subsequent sheet S from making close contact with the top-most sheet S on the sheet tray 63. This helps prevent the occurrence of a sheet jam.
As mentioned above, the blowing device 110 is arranged upstream of the inlet roller pair 612. This allows air to be easily blown between the top face of the top-most sheet S on the sheet tray 63 and the bottom face of the subsequent sheet S.
Also, as mentioned above, the pressing member 616 is provided which is arranged downstream of the inlet guide 611 and presses the upstream-side end part (trailing edge) of a sheet S which has passed the inlet roller pair 612. This helps suppress a rise (curl) at the trailing edge of a sheet S on the sheet tray 63, and thus it is possible to prevent the downstream-side end part (leading edge) of the subsequent sheet S from being caught by the trailing edge of the sheet S on the sheet tray 63. This helps prevent the occurrence of a sheet jam.
As mentioned above, the sheet tray 63 inclines downward toward the downstream side. This helps reduce the angle at which the subsequent sheet S approaches the sheet S on the sheet tray 63. That is, the subsequent sheet S can be conveyed nearly parallel to the sheet S on the sheet tray 63. This make it easier for the air to flow along the top face of the top-most sheet on the sheet tray 63 and the bottom face of the subsequent sheet, and thereby it is possible to prevent the subsequent sheet S from making close contact with the top-most sheet S on the sheet tray 63.
As mentioned above, the duct 112 discharges air substantially parallel to the sheet tray 63, and thus it is possible to pass (send) air smoothly between the top-most sheet S on the sheet tray 63 and the subsequent sheet S.
Also, as mentioned above, the postprocessing controller 101 starts the air blow by the blowing device 110 when the sheet detection sensor 120 senses the sheet S, stops the air blow by the blowing device 110 when, during binding process, making the aligning member 65 move a bundle of sheets on the sheet tray 63 to the binding process position, and stops the air blow when, during folding process, making the aligning member 65 move the sheet S on the sheet tray 63 to the folding process position. This prevents, during binding or folding process, a sheet S from being flipped by the airflow.
Also, as mentioned above, the postprocessing device main body 31 which includes the third conveying passage 44 and the blowing device 110, as well as the sheet folding unit 60 which includes the inlet guide 611, the sheet tray 63, the stapling device 67, the first folding device 70, the second folding device 90, the lower discharge port 85 and the lower discharge tray 87 and which is removable from the postprocessing device main body 31 are provided. Thus, when a sheet jam occurs in the sheet tray 63, stapling device 67, the first folding device 70, or the second folding device 90 and jam handling is performed, the sheet folding unit 60 can be drawn out with the blowing device 110 and the third conveying passage 44 left behind in the postprocessing device main body 31. That is, the sheet tray 63, stapling device 67, the first folding device 70, and the second folding device 90 can separate from the blowing device 110 and the third conveying passage 44. This facilitates jam handling.
The embodiments disclosed above should be understood to be in every aspect illustrative and not restrictive. The scope of the present disclosure is defined not by the description of the embodiments given above but by the appended claims, and should be understood to encompass any modifications made in the sense and scope equivalent to those of the claims.
For example, although the above embodiments deal with an example where the sheet folding unit 60 is provided with the first folding device 70 and the second folding device 90, this is in no way meant to limit the present disclosure. Instead, the sheet folding unit 60 may not be provided with the second folding device 90.
Also, although the above embodiments deal with an example where the pressing member 616 is provided which presses the upstream-side end part (trailing edge) of the sheet S which has passed the inlet roller pair 612, this is in no way meant to limit the present disclosure. Instead, the pressing member 616 may not be provided. In this case, for example, every time a sheet S is stacked on the sheet tray 63, the lower moving member 652 can be moved to the upstream side and, before the subsequent sheet S is conveyed, the lower moving member 652 can be retracted to the original position. In this way, moving the lower moving member 652 upstream allows the upstream-side end part (trailing edge) of the sheet S on the sheet tray 63 to be pressed by the driven roller 614 of the inlet roller pair 612 or by the guide member 615. This helps suppress a rise (curl) at the trailing edge of a sheet S on the sheet tray 63, and thus it is possible to prevent the subsequent sheet S from being caught by the trailing edge of the sheet S on the sheet tray 63.
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|---|---|---|---|
| 2018-102700 | May 2018 | JP | national |
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| Number | Date | Country | |
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| 20190367312 A1 | Dec 2019 | US |
