Patent Application
20190161313
The present disclosure relates to a sheet processing apparatus and an image forming apparatus which execute stapling processing on sheets.
A sheet processing apparatus that executes stapling processing on sheets has heretofore been known as an example of a sheet processing apparatus which is used by being connected to an image forming apparatus such as a copying machine or a printer.
Japanese Patent Application Laid-Open No. 2006-151570 discusses a sheet processing apparatus that executes stapling processing on sheets after the sheets conveyed to an intermediate tray are aligned in a width direction. A sheet bundle on which the stapling processing is executed is discharged from the intermediate tray to a discharge tray, and then the stapling processing is executed on newly conveyed sheets in the intermediate tray.
In this case, an abnormal state relating to a sheet being conveyed may occur while the sheet is conveyed to the intermediate tray so as to execute stapling processing. Such an abnormal state may occur, for example, when a sheet having a size different from a size which is notified in advance is conveyed. If the abnormal sheet is directly conveyed to the intermediate tray, the stapling processing is executed on the abnormal sheet together with the other sheets stacked on the intermediate tray. Japanese Patent Application Laid-Open No. 2015-225158 discusses a control operation for switching a discharge destination of an abnormal sheet to a tray which is different from the discharge destination of the other sheets. However, there are issues that a structure including a plurality of sheet discharge destinations leads to an increase in the size of the apparatus and the control operation as described above cannot be applied to a structure including only one sheet discharge destination.
Aside from a demand for excluding an abnormal sheet from sheets to be subjected to stapling processing, there is a demand for inserting an index sheet into a sheet bundle on which the stapling processing is executed. If this demand is met, for example, an operation for inserting a questionnaire between materials on which the stapling processing is executed can be automatically performed, which leads to a drastic reduction in operation time. However, there is an issue that a known apparatus which is exclusively used for inserting an index sheet between sheets is expensive and the apparatus increases in size.
The present disclosure works towards providing a sheet processing apparatus and an image forming apparatus that are capable of executing stapling processing on sheets except a specific sheet, which is not subjected to stapling processing, with a simple structure, while stacking the specific sheet on a tray on which the other sheets are stacked.
According to an aspect of the present disclosure, a sheet processing apparatus includes an intermediate tray on which a sheet is to be stacked, a stapler configured to execute stapling processing on the sheet stacked on the intermediate tray, a discharge tray on which the sheet subjected to the stapling processing by the stapler and discharged from the intermediate tray is to be stacked, a control unit configured to control the stapler, and a shift unit configured to shift the sheet to a position on the intermediate tray, wherein the position is outside of a range in which the stapling processing is to be executed, and wherein, in a state where a first sheet and a second sheet are stacked on the intermediate tray and the second sheet is subject to the stapling processing, the control unit causes the shift unit to shift the first sheet on which the stapling processing is not executed, and causes the stapler to execute the stapling processing on the second sheet.
Further features of the present disclosure will become apparent from the following description of embodiments with reference to the attached drawings.
Referring to
The image forming unit 101 includes a photosensitive drum 111, a charge roller 112, and an exposure apparatus 113. The photosensitive drum 111 rotates clockwise in
The feed unit 102 includes a cassette 105 on which a plurality of sheets S is stacked, and a pickup roller 106 that picks up the sheets S stacked on the cassette 105. The feed unit 102 also includes feed rollers 107 that feed each sheet S picked up by the pickup roller 106 to a conveyance guide 109. The feed unit 102 also includes registration rollers 110 that convey the sheet S, which has passed through the conveyance guide 109, to a transfer nip portion that is formed by the photosensitive drum 111 and the transfer roller 115.
The discharge unit 104 includes a flapper 120, conveyance rollers 119, discharge rollers 123, a discharge tray 124, and a fully stacked state detection lever 125. The flapper 120 guides the sheet S having an image fixed thereon by the fixing unit 103 to the discharge tray 124 or the post-processing apparatus 200. In the case of guiding the sheet S to the discharge tray 124, the flapper 120 moves to a position indicated by a solid line in
Next, the post-processing apparatus 200 will be described with reference to
An inlet roller pair 201 receives each sheet S from the printer 100. A sheet detecting sensor 213 is disposed immediately before the inlet roller pair 201, and detects a leading edge and a trailing edge of the received sheet S. The leading edge refers to a downstream end of the sheet S in a conveyance direction. The trailing edge refers to an upstream end of the sheet S in the conveyance direction. The sheet S conveyed to the post-processing apparatus 200 passes through a conveyance guide 202 and is sent to conveyance rollers 203 (conveyance member). An intermediate tray 207 that temporarily stores the sheet S is disposed downstream of the conveyance rollers 203. On the downstream side of the intermediate tray 207 is provided a jogger 206 that supports both ends of the sheet S in a width direction thereof and aligns the position of the sheet S. The width direction of the sheet S is a direction that is parallel to a stacking surface of the intermediate tray 207 and is orthogonal to the conveyance direction of the sheet S. As illustrated in
A process flow in which the sheet S is conveyed from the printer 100 to the post-processing apparatus 200 and stapling processing is executed on the sheet S by the stapler 208 will be described in detail. First, the inlet roller pair 201 conveys the sheet S, which has been conveyed from the printer 100, to the conveyance rollers 203 through the conveyance guide 202. The conveyance rollers 203 convey the sheet S to the intermediate tray 207. At this point, the discharge roller 205 is located at a position spaced apart from the sheet S to be stacked on the intermediate tray 207. The jogger 206 moves to a position where the jogger 206 can receive the sheet S before the sheet S is conveyed to the intermediate tray 207 by the conveyance rollers 203. This state is illustrated in
The jogger 206 supports the both ends in the width direction of the sheet S stacked in such a manner that the sheet S extends over the jogger 206 and the intermediate tray 207. Specifically, the first alignment member 206a contacts one end of the sheet S in the width direction, and the second alignment member 206b contacts the other end of the sheet S in the width direction. Then, the jogger 206 moves along the width direction to align the position of the sheet S in the width direction. This state is illustrated in
In the present embodiment, the second alignment member 206b is stopped by a mechanical stopper (not illustrated) so as to serve as a reference position for alignment, and only the first alignment member 206a moves in the width direction. Specifically, the sheet S is aligned so as to contact the second alignment member 206b. However, the present disclosure is not limited to this structure. Only the second alignment member 206b may be configured to be movable, or both the first alignment member 206a and the second alignment member 206b may be configured to be movable.
After completion of the alignment of the sheet S in the width direction by the jogger 206, the position of the sheet S in the conveyance direction is aligned by the alignment paddle 204. The alignment paddle 204 causes the sheet S stacked on the intermediate tray 207 to move to a side where the stapler 208 is disposed, and aligns the sheet S in such a manner that an end of the sheet S contacts the stapler 208. In the manner described above, the alignment processing executed in a case where one sheet S is conveyed to the intermediate tray 207 is completed. In a case where two or more sheets S are subjected to stapling processing in a job, the conveyance rollers 203 convey the next sheet S to the intermediate tray 207. Then, the above-described alignment processing is repeated.
In a case where a plurality of sheets S to be subjected to stapling processing is stacked on the intermediate tray 207 and the alignment processing is performed by the jogger 206 and the alignment paddle 204, the stapler 208 executes stapling processing on the plurality of sheets S. Then, the discharge roller 205 moves to a position in contact with the sheets S stacked on the intermediate tray 207, and discharges the sheets S subjected to stapling processing onto the discharge tray 209. At this point, the jogger 206 moves to the retracted position. This state is illustrated in
In a case where a plurality of sheets S is subjected to stapling processing, the alignment processing is executed on each sheet S by the jogger 206 and the alignment paddle 204 in the embodiment described above. However, the alignment processing may be controlled to be executed only when the last sheet S to be subjected to stapling processing is conveyed. The alignment processing to be executed on each sheet S may be different from the alignment processing to be executed when the last sheet S is conveyed. Specifically, in the alignment processing to be executed on each sheet S, each of the interval A and the interval B is set to a wider interval and a rough alignment is performed. When the last sheet S is conveyed, each of the interval A and the interval B is set to be narrower than that when the alignment processing is executed on each sheet S, and a fine alignment is performed so as to align the positions of the plurality of sheets S. Alternatively, the number of times of alignment processing to be executed by the jogger 206 may be changed.
The controller 300 communicates with an external apparatus (not illustrated), such as a computer, to receive information about a print job and transmit the received information to the control unit 301. The information about a print job indicates, for example, the size of the sheet S which has an image formed thereon by the printer 100 and is conveyed to the post-processing apparatus 200, a conveyance speed of the sheet S, and whether to execute stapling processing. In the case of executing stapling processing, the information about a print job also includes information indicating whether the conveyed sheet S is the end of one set of sheets S to be subjected to stapling processing. Based on these pieces of information, the control unit 301 controls the stapler 208, the conveyance rollers 203, the alignment paddle 204, the jogger 206, and the discharge roller 205.
The index sheet determination unit 304 determines whether the sheet S being conveyed is an index sheet, i.e., a sheet to be subjected to stapling processing, based on the information sent from the controller 300. The size mismatch determination unit 305 obtains the length in the conveyance direction of the sheet S being conveyed based on the timings when the leading edge and the trailing edge of the sheet S are detected by the sheet detecting sensor 213 and the conveyance speed of the sheet S. Then, the size mismatch determination unit 305 compares the obtained length with the length corresponding to the size of the sheet S indicated in the information sent from the controller 300, and in a case where the difference between the lengths is greater than a predetermined threshold, the size mismatch determination unit 305 determines that an abnormal state due to a size mismatch has occurred. In this case, the size mismatch determination unit 305 treats the sheet S being conveyed as the sheet on which stapling processing is not to be executed, even when the sheet S being conveyed is originally set as the sheet to be subjected to stapling processing.
An operation of the post-processing apparatus 200 in the structure described above will be described with reference to a flowchart illustrated in
First, the control unit 301 receives information about the print job from the controller 300 via a network. The control unit 301 causes the jogger 206 to move to a position where the sheet S is received, before the sheet S is conveyed to the intermediate tray 207. In step S400, the control unit 301 causes the inlet roller pair 201 to convey the sheet S. The control unit 301 sends an inquiry to each of the index sheet determination unit 304 and the size mismatch determination unit 305 about the determination on the sheet S being conveyed. If it is determined that the sheet S being conveyed is an index sheet or a sheet with a mismatched size, in step S401, the control unit 301 determines that the sheet S being conveyed is an excluded sheet (a sheet on which stapling processing is not executed).
If it is determined that the sheet S being conveyed is not the excluded sheet (NO in step S401), the processing proceeds to step 404 and the control unit 301 causes the conveyance rollers 203 to convey the sheet S to the intermediate tray 207. Assume that the conveyance speed of the sheet S by the conveyance rollers 203 at this point is represented by V1. In step S404, the control unit 301 causes the alignment paddle 204 to align the position of the sheet S stacked on the intermediate tray 207. This state is illustrated in
On the other hand, if it is determined that the sheet S being conveyed is the excluded sheet (YES in step S401), as illustrated in
After the sheet S is stacked on the intermediate tray 207, in step S405, the control unit 301 determines whether stacking of a designated number of sheets, which is instructed in a staple instruction from the controller 300, on the intermediate tray 207 is finished. If stacking of all the sheets S is not completed (NO in step S405), the processing returns to step S400 to convey the next sheet S. If stacking of all the sheets S is completed (YES in step S405), the processing proceeds to step S406 and the stapler 208 executes stapling processing. As illustrated in
As described above, according to the present embodiment, it is possible to provide a sheet processing apparatus and an image forming apparatus that are capable of executing stapling processing on sheets except a specific sheet, which is not subjected to stapling processing, with a simple structure, while stacking the specific sheet on a tray on which the other sheets are stacked.
The present embodiment illustrates two processes as processing for shifting the position of the excluded sheet. That is, the first process is executed to increase the conveyance speed of the sheet S, and the second process is executed not to perform alignment processing on the sheet S by the alignment paddle 204. It is not essential to execute both of the two processes. Only one of the two processes may be executed.
In the first embodiment, the position of the excluded sheet is shifted along the conveyance direction of the sheet S, thereby stacking the excluded sheet at a position outside of the range in which stapling processing is executed. The determination as to whether the sheet S being conveyed is the excluded sheet is made based on determination results obtained by the index sheet determination unit 304 and the size mismatch determination unit 305.
In a second embodiment, the position of the excluded sheet is shifted along the width direction (horizontal direction) of the sheet S, thereby stacking the excluded sheet at a position outside of the range in which stapling processing is executed. The conveyance rollers 203 are configured to be movable along the width direction so as to execute shift processing along the width direction. The determination as to whether the sheet S being conveyed is the excluded sheet is made based on a determination result obtained by a remaining sheet presence/absence determination unit 600. Main parts of the second embodiment are similar to those of the first embodiment. Accordingly, only differences between the first embodiment and the second embodiment will be described.
An operation of the post-processing apparatus 200 according to the present embodiment will be described with reference to a flowchart illustrated in
Steps S700 and S701 illustrated in
If it is determined that the sheet S being conveyed is not the excluded sheet (NO in step S701), the processing proceeds to step S703 and the control unit 301 causes the sheet S to be conveyed directly to the intermediate tray 207, without moving the conveyance rollers 203 as illustrated in
On the other hand, if it is determined that the sheet S being conveyed is the excluded sheet (YES in step S701), as illustrated in
As described above, according to the present embodiment, it is possible to provide a sheet processing apparatus and an image forming apparatus that are capable of executing stapling processing on sheets except a specific sheet, which is not subjected to stapling processing, with a simple structure, while stacking the specific sheet on a tray on which the other sheets are stacked.
In the first embodiment described above, the index sheet determination unit 304 and the size mismatch determination unit 305 determine whether the sheet S being conveyed is the excluded sheet. However, like the second embodiment, the remaining sheet presence/absence determination unit 600 may determine whether the sheet S being conveyed is the excluded sheet in the first embodiment. Also, in the second embodiment, the index sheet determination unit 304 and the size mismatch determination unit 305 may determine whether the sheet S being conveyed is the excluded sheet.
The first and second embodiments described above illustrate an example where, as illustrated in
While the first and second embodiments described above illustrate an example of the post-processing apparatus 200 which is fixed to the printer 100, the present disclosure is not limited to this example. The present disclosure can also be applied to an option apparatus that is detachably mounted on the printer 100.
In the first and second embodiments described above, the control unit 301 provided in the post-processing apparatus 200 executes the above-described control operation. Alternatively, a control unit provided in the printer 100 may be configured to control the post-processing apparatus 200.
While the first and second embodiments described above illustrate a laser beam printer as an example of the image forming apparatus, the image forming apparatus to which the present disclosure is applied is not limited to a laser beam printer. The present disclosure can also be applied to an inkjet printer, printers employing other printing methods, and a copying machine.
While the present disclosure has been described with reference to embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2017-229297, filed Nov. 29, 2017, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-229297 | Nov 2017 | JP | national |
