1. Field of the Invention
The present invention relates to a sheet processing apparatus that processes a sheet and an image forming apparatus including the sheet processing apparatus.
2. Description of the Related Art
In the related art, an image forming system in which a common sheet processing apparatus is capable of receiving a sheet from two image forming apparatuses is suggested (see Japanese Patent Laid-Open No. 2004-093984).
The image forming system receives a sheet conveyed from one of the image forming apparatuses through one of inlets of the common sheet processing apparatus and discharges the sheet to a processing tray to be stacked. Further, the image forming system receives a sheet conveyed from the other image forming apparatus through the other inlet of the common sheet processing apparatus and discharges the sheet to the processing tray to be stacked.
Therefore, since a sheet from both image forming apparatuses can be received by the common sheet processing apparatus, one sheet processing apparatus is only required for two image forming apparatuses. Thus, the cost is reduced and the space is saved.
However, in the above-mentioned related art, while the sheet conveyed from one of the image forming apparatuses is discharged and stacked onto the processing tray, the discharging and stacking of the sheet conveyed from the other image forming apparatus to the processing tray need to wait until the sheet processing is completed. Therefore, even though a user has two image forming apparatuses, the sheet processing has a productivity corresponding to one image processing apparatus. Thus, the productivity for entire system is significantly lowered.
As a method for solving the above-mentioned problem, a method for discharging and stacking sheets conveyed from two image forming apparatuses onto a processing tray of a common sheet processing apparatus is suggested. However, if timings to discharge a sheet to the processing tray as illustrated in
It is desirable to improve the productivity of the entire system by enabling sheets from two image forming apparatuses to be simultaneously discharged to a common sheet processing apparatus.
A sheet processing apparatus that stacks sheets received from two image forming apparatuses in a processing tray and selectively processes a sheet bundle having a plurality of stacked sheets includes a first discharging portion that discharges a sheet received from one of the two image forming apparatuses to the processing tray; a second discharging portion that is disposed so as to be opposite to the first discharging portion with respect to the processing tray and discharges a sheet received from the other image forming apparatus of the two image forming apparatuses to the processing tray; and a controller that controls the first discharging portion and the second discharging portion. The first discharging portion and the second discharging portion are disposed opposite each other so that the sheets discharged to the processing tray are stacked on top of each other. When the sheets are continuously discharged by the first discharging portion and the second discharging portion to the processing tray, the controller controls a timing when the sheets are discharged by the first discharging portion and the second discharging portion to the processing tray such that a leading edge of the sheet discharged by one of the discharging portions abuts on a sheet surface of the sheet discharged by the other discharging portion.
According to the present invention, at a timing when leading edges of two sheets which are discharged to be opposite to each other do not interfere with each other, it is possible to discharge the sheets to the common processing tray, prevent the leading edges of the sheets from colliding with each other to be jammed, and improve the productivity of the entire system.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, with reference to accompanying drawings, exemplary embodiments of the present invention will be illustratively described in detail. A size, a material, a shape, or a relative arrangement of components described in the following embodiments may be appropriately varied depending on the configuration of an apparatus to which the present invention is applied or various conditions. Therefore, if not specifically described, a scope of the present invention is not limited thereto.
An image forming system that includes a sheet processing apparatus according to a first embodiment and two image forming apparatuses that supply a sheet to the sheet processing apparatus will be described. Here, a copying machine as an image forming system having a stacker as a common sheet processing apparatus and two image forming apparatuses will be described as an example.
(Image Forming System)
The image forming system operates as follows. The first image forming apparatus and the second image forming apparatus perform the same operation, so that the operation will be described using the first image forming apparatus and the operation of the second image forming apparatus will be omitted.
Sheets set in sheet cassettes 802a to 802e are conveyed to a registration roller 810 by feed rollers 803a to 803e and a pair of conveying rollers 804. On a photosensitive drum 806 that configures the image forming portion, a process in which an electrostatic latent image is changed into a visible image by a primary charger 807, a development device 809, and an exposure portion 808 is performed. Accordingly, a copying toner image corresponding to digital document data is formed on the photosensitive drum 806. Further, the digital document data may be digital original data obtained by reading out an original document sent from the automatic document feeding apparatus 850 in advance by an image reading apparatus 851 or data sent from a computer through an external I/F.
The sheet which is conveyed to the registration roller 810 is conveyed to a transferring portion by the registration roller 810 at a timing when a leading edge of the sheet and a leading edge of a toner image of the photosensitive drum 806 are matched with each other. A transfer bias is applied to the sheet that is conveyed to the transferring portion by a transfer separating charger 805 so that a toner image on the photosensitive drum 806 is transferred onto the sheet.
The sheet onto which the toner image is transferred is conveyed to a fixing device 812 by a conveyance belt 811 and sandwiched between a heating roller and a pressure roller so that the toner image is heat-fixed. In this case, extraneous substances such as remaining toner which is not transferred onto the sheet and attached onto the photosensitive drum 806 are scraped off by a blade of a cleaning device 813 and the surface of the photosensitive drum 806 is cleaned to be prepared for a next image forming process.
The sheet on which the toner image is fixed is discharged to a stacker 100 as a sheet processing apparatus by a discharge roller 814 as it is or conveyed to the two-sided reversing apparatus 801 by a switching member 815 to perform image forming again.
<System Block Diagram>
Next, a configuration of a controller that controls the entire image forming system will be described with reference to
The controller, as illustrated in
A DF (document feeding) controller 202 controls to drive the automatic document feeding apparatuses 850 and 950 based on an instruction from the CPU circuit 206. An image reader controller 203 controls to drive a scanner portion and an image sensor in image reading apparatuses 851 and 951 and transmits an analog image signal which is output from the image sensor to an image signal controller 204.
The image signal controller 204 converts an analog image signal from the image sensor into a digital signal and then performs the processings and converts the digital signal into a video signal to output the video signal to a printer controller 205. Further, the image signal controller 204 performs various processings on a digital image signal which is input from a computer 200 through an external I/F 201 and converts the digital image signal into a video signal to output the video signal to the printer controller 205. The processing operation by the image signal controller 204 is controlled by the CPU circuit 206. The printer controller 205 drives an exposure controlling portion based on the input video signal.
An operation portion 209 includes a plurality of keys that set various functions for forming an image and a display that displays information indicating a setting state. The operation portion 209 outputs a key signal corresponding to the manipulation of the key to the CPU circuit 206 and displays corresponding information on the display based on the signal from the CPU circuit 206.
A stacker controller 210 is mounted in the stacker 100 and exchanges information with the CPU circuit 206 to control to drive the entire stacker. Further, like the above-described controller, the stacker controller 210, which will be described below, has a CPU 52, a ROM 51, and a RAM 53 (see
<Stacker>
A configuration of the stacker 100 will be described with reference to
The stacker 100 discharges the sheet received from each image forming apparatus to a common processing tray 130 by inlet rollers 110 and 120, conveying rollers 111 and 121, and discharge rollers 112 and 122. A sheet bundle having a plurality of sheets discharged and stacked into the processing tray 130 is selectively processed. The sheet which is sent to the processing tray 130 is aligned by an aligning belt 132, an abutting plate 133, and an aligning plate 134, and a staple processing is performed thereon by a stapler 131. The sheet is discharged and stacked onto a stack tray 143 by bundle discharging rollers 141a, 141b, and 141c.
The stacker 100 includes a first discharging portion 100A that discharges the sheet received from the first image forming apparatus 800 to the processing tray 130 and a second discharging portion 100B that discharges the sheet received from the second image forming apparatus 900 to the processing tray 130. The first discharging portion 100A and the second discharging portion 100B are controlled by the stacker controller 210 as a controller. The first discharging portion 100A and the second discharging portion 100B are disposed opposite each other so that the sheets discharged to the processing tray 130 are stacked on top of each other. Here, the first discharging portion 100A discharges a sheet received by the inlet roller 110 to the processing tray 130 by a conveying roller 111 and a discharge roller 112. The second discharging portion 100B discharges a sheet received by the inlet roller 120 to the processing tray 130 by a conveying roller 121 and a discharge roller 122.
Next, an outline of a configuration and an operation of the stacker 100 will be described with reference to block diagrams of
First, an operation of discharging and aligning a sheet P1 on which an image is formed by the first image forming apparatus 800 onto the processing tray 130 of the stacker 100 will be described.
Based on information of a sheet received from the image forming apparatus, the stacker controller 210 controls a switching member 113, the abutting plate 133, the aligning plate 134, a bundle moving member 135, and a stopper 144 to be moved to a predetermined position and performs an initializing operation (S11 in
The sheet P1 on which an image is formed by the first image forming apparatus 800 is received from the first inlet roller 110. Thereafter, the sheet P1 passes through a first conveyance path 114 by the first conveying roller 111, a conveyance route of the sheet P1 is switched by the switching member 113 that switches a conveyance path, and then the sheet P1 is discharged to the processing tray 130 by the discharge roller 112 (S12 to S14 of
An aligning operation in the discharging direction of the sheet P1 discharged to the processing tray will be described with reference to
An operation of aligning a width direction that is perpendicular to the discharging direction which is performed after aligning the discharging direction as described above will be described with reference to
As described above, the sheet P1 conveyed from the first image forming apparatus 800 is discharged onto the processing tray 130 to be aligned in the discharging direction and the width direction.
Next, an operation for discharging and aligning a sheet P2 on which an image is formed by the second image forming apparatus 900 to the processing tray 130 of the stacker 100 will be described.
The sheet P2 on which an image is formed by the second image forming apparatus 900 is received by a second inlet roller 120. Thereafter, the sheet P2 passes through a second conveyance path 124 by the second conveying roller 121 and then the sheet P2 is discharged to the processing tray 130 by the discharge roller 122 (S12 to S14 of
The sheet P2 which is discharged by the discharge roller 122 to the processing tray 130 is led into a nip portion of the aligning belt 132 by declining the processing tray 130. Thereafter, the sheet P2 is conveyed and aligned by the aligning belt 132 (S15 and S16 of
As described above, the sheet P1 from the first image forming apparatus 800 and the sheet P2 from the second image forming apparatus 900 are sent to the common stacker 100 and alternately and sequentially laminated on the processing tray 130 to be aligned. If a last sheet of the sheet bundle is discharged and aligned into the processing tray 130 (S17 of
Thereafter, as illustrated in
The stacker controller 210 discharges and stacks the sheet bundle P into the stack box 142 and then checks whether there is a job for a next sheet bundle (S23 of
In the stack box 142, a stack tray 143 and a stopper 144 are disposed. The stack tray 143 is disposed so as to be lifted and lowered vertically (in an arrow Z direction of
Continuously, an operation that continuously and alternately stacks the sheets P1 and P2 conveyed from the first image forming apparatus 800 and the second image forming apparatus 900 to the processing tray 130 will be described in detail with reference to drawings of
The stacker 100 includes sensors Sa1 and Sa2 as a first detecting portion that detects a position of the sheet P1 from the first image forming apparatus 800 and sensors Sb1 and Sb2 as a second detecting portion that detects a position of the sheet P2 from the second image forming apparatus 900. The stacker controller 210 controls as follows based on information on the positions of the sheets detected by the sensors Sa1, Sa2, Sb1, and Sb2.
First, the stacker 100 receives the sheet P1 conveyed from the first image forming apparatus 800 (S31 of
As illustrated in
As illustrated in
In this manner, by temporally stopping one of discharging portions (here, the first discharging portion), a leading edge of the sheet P1 discharged from the first discharging portion abuts with a sheet surface of the sheet P2 discharged from the second discharging portion. Accordingly, discharging timings of the sheets by the discharging portions are shifted from each other (see
If the conveyance is performed with the positional relationship of the sheets P1 and P2 illustrated in
As described above, the sheet P1 is controlled so as to be temporally stopped to be discharged to the processing tray 130 in a state shifted from the sheet P2 by a distance ΔL=V×T. In this case, the distances of the sensors Sa2 and Sb2 from a conflict point of the sheet P1 and the sheet P2 illustrated in
The reason for the above-mentioned arrangement is as follows.
When the sheet P2 goes ahead and then the sheet P1 is conveyed, similar control is performed. As illustrated in
As described above, the positions of the sheets P1 and P2 are detected by the sensors Sa1, Sa2, Sb1, and Sb2 that are disposed at the upper stream of the processing tray 130 in which the sheets P1 and P2 intersect each other and conveyance stop/continuance is controlled by the stacker controller 210. By doing this, the sheets P1 and P2 are discharged in a state where the leading edges are appropriately shifted on the processing tray 130. Thus, the conflict of the leading edges of the sheets P1 and P2 can be avoided.
Further, even though a job that performs the staple processing has been described, sheets received from the first and second image forming apparatuses may be stacked on the stack tray 143 without performing the staple processing. This method is allowed by an operation that the stapler 131, the abutting plate 133, the aligning plate 134, and the bundle moving member 135 continuously wait in a retracted state (a state illustrated in
As described above, at a timing when the leading edges of two opposite sheets P1 and P2 do not interfere with each other, the sheets P1 and P2 can be discharged to the common processing tray and simultaneously conveyed from two image forming apparatuses to the common sheet processing apparatus, which can improve the productivity of the entire system.
An image forming system that includes a sheet processing apparatus according to a second embodiment and two image forming apparatuses that supply a sheet to the sheet processing apparatus will be described. Here, a copying machine as an image forming system having a stacker as a common sheet processing apparatus and two image forming apparatuses will be described as an example.
First, difference of the second embodiment from the first embodiment will be described. In the first embodiment, the stacker 100 detects the positions of the sheets P1 and P2 and controls to stop conveying and re-convey the sheets so as to prevent conflict of the sheets on the processing tray. The present invention is not limited thereto. In the second embodiment, the image forming apparatus detects the positions of the sheets P1 and P2 and controls a feeding timing (temporally stop/re-convey) of the sheets from the image forming apparatus to the stacker so as to prevent conflict of the leading edges of the sheets on the processing tray of the stacker.
Sheet conveying speeds V of the first image forming apparatus 800 and the second image forming apparatus 900 are the same. Further, the distances from feeding portions 802 and 902 to an inlet of the common stacker 100 are the same. Furthermore, as illustrated in
Accordingly, if the feeding portions of the image forming apparatuses 800 and 900 start the feeding at the same timing, the sheets may arrive at the processing tray 130 at the same timing, which causes the conflict as illustrated in
In order to prevent the above problem, that is, as illustrated in
As illustrated in
If the same control is performed when the image forming apparatus 900 feeds the sheet, without causing conflict of the leading edges of the sheets P1 and P2 on the processing tray 130, the sheets P1 and P2 can be alternately discharged and stacked in a state where the leading edges of the sheets P1 and P2 are shifted by a required distance Lx or more.
Further, as described above, since the image forming apparatus is controlled by the CPU circuit 206, the feed starting/waiting controls to drive the printer controller 205 of the image forming apparatuses 800 and 900 based on the instruction of the CPU circuit 206.
As described above, the sheets can be discharged to the common processing tray at a timing when the leading edges of two opposite sheets P1 and P2 do not interfere with each other and the sheets can be simultaneously discharged from the two mage forming apparatuses to the common sheet processing apparatus, which can improve the productivity of the entire system.
Further, in the above-mentioned embodiment, even though the copying machine is described as an example of an image forming apparatus, the present invention is not limited thereto. For example, the image forming apparatus may be other image forming apparatus such as a printer or a facsimile or other image forming apparatus such as a complex machine that combines the functions. By applying the invention to the image forming system including the image forming apparatus and the sheet processing apparatus, the same advantageous effect can be obtained.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2012-032392, filed Feb. 17, 2012, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2012-032392 | Feb 2012 | JP | national |
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