JP2001220050A - Paper after-processing device, image forming device, image forming system, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper after-processing device, an image forming device, an image forming system, and an image forming image capable of discharging stored paper sheets stored on an intermediate tray together by high throughput without accumulating the paper sheets even under various operation situations. SOLUTION: Two paths, namely, a main path Pm and subpath Ps are provided as paths conveying the part carried into a finisher 2 onto an intermediate tray 21. A paper bundle can be discharged onto the main tray 22 per process unit while carrying the paper sheet P into the finisher 2 continuously by performing automatic discharge operation to obtain high throughout. Moreover, if the number of non-storage paper sheets to be stored on the intermediate tray 21 following the paper bundle is less than n, the paper bundle stored on the intermediate tray 21 is forcedly discharged to prevent remaining of paper sheets in the finisher 2 for many hours.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for temporarily storing an image-formed sheet in an intermediate tray and then discharging the stored sheets stored in the intermediate tray to a main tray at once. It is about.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer, and a facsimile apparatus, an image is formed on a sheet and the sheet is discharged to a standard discharge tray provided in the apparatus. For handling, it has been conventionally proposed to connect a sheet post-processing apparatus to the discharge side of the image forming apparatus or to incorporate the sheet post-processing apparatus in the image forming apparatus.

This paper post-processing apparatus temporarily stores paper discharged from an image forming apparatus in an intermediate tray, and then collectively discharges stored paper stored in the intermediate tray to a main tray. I have. For example, A4 size paper 5
When printing five copies of one sheet (processing unit), the image forming apparatus continuously forms an image on A4 size paper, transports each sheet to an intermediate tray, and temporarily stores the sheets. By repeating the above operation five times, one set of five sheets is temporarily stored in the intermediate tray. Then, when the last sheet, that is, the fifth sheet is conveyed to the intermediate tray, a sheet bundle of five sheets is discharged from the intermediate tray to the main tray. In this manner, the processing for the first copy (processing unit) is completed.
The second to fifth sets are sequentially discharged to the main tray via the intermediate tray in the same manner as the set.

When staple processing is performed on a bundle of sheets constituting each unit, when the last sheet (fifth sheet) is stored in the intermediate tray, the stapling process is performed near the intermediate tray. The stapling process performed by the stapler disposed in the middle is performed on the sheet bundle on the intermediate tray, and then the sheet bundle is discharged from the intermediate tray to the main tray.

[0005]

As described above, in the conventional apparatus, the sheet bundle stored in the intermediate tray is directly used on the condition that the paper corresponding to the last page of the processing unit is stored in the intermediate tray. Or, after staple processing, paper is discharged to the main tray, and the paper stored in the intermediate tray is not necessarily discharged to the main tray at the proper discharge timing, causing the following problems. I have.

In the case where the discharge condition is such that the paper corresponding to the last page of the processing unit is stored in the intermediate tray, the paper stored in the intermediate tray is subjected to staple processing as necessary, and Until the sheet is discharged to the tray, the next sheet cannot be carried into the sheet post-processing device. Therefore, in the image forming apparatus, it is necessary to set an interval between the image formation of the last page of the processing unit and the image formation of the first page of the next processing unit, which causes a decrease in throughput.

Here, in order to prevent a decrease in throughput, a plurality of transport paths are provided as described in, for example, Japanese Patent Laid-Open No. 11-263520, and the next paper to be carried in is temporarily stored in the transport path. It is possible to wait.
That is, in the paper post-processing apparatus described in the publication,
Two paths for transporting sheets are provided in the intermediate tray, and even after the last page of paper is stored in the intermediate tray, the leading sheet of the next processing unit is continuously carried into the transport path and is kept there. When the second sheet is further conveyed into the sheet post-processing device, the second sheet is already on standby instead of discharging the sheet stored in the intermediate tray to the main tray. The leading paper is simultaneously conveyed to the intermediate tray to prevent a decrease in throughput. When the stapling process is required, the stapling process is performed while the leading sheet is carried in and the standby operation is performed.

However, in the paper post-processing apparatus described in the above publication, the next processing unit is constituted by a plurality of sheets.
In addition, the discharge process of the sheet bundle stored in the intermediate tray to the main tray is started on condition that the second sheet in the processing unit is carried into the sheet post-processing device. Therefore, in the following cases, (1) when the next processing unit does not exist; (2) when the next processing unit is one sheet; (3) When the first or second sheet is out of paper (4) When the first or second sheet is not carried into the sheet post-processing apparatus due to a paper jam in the image forming apparatus:
In this case, the discharge condition is not satisfied, and the sheet bundle stored in the intermediate tray is not discharged to the main tray.

As described above, Japanese Patent Application Laid-Open No. 11-263520
In the paper post-processing apparatus described in Japanese Patent Application Laid-Open Publication No. H11-264, if a paper jam or a paper shortage that is to be carried in following the paper bundle stored in the intermediate tray occurs, the paper bundle may remain in the intermediate tray or may be conveyed. A problem that paper remains in the path occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and does not cause paper to stay in the intermediate tray or a path as a transport route to the intermediate tray, and allows the intermediate tray to be transferred to the intermediate tray with high throughput even in various operating situations. It is an object of the present invention to provide a sheet post-processing device, an image forming apparatus, an image forming system, and an image forming method that can collectively discharge stored stored sheets to a main tray.

[0011]

A sheet post-processing apparatus, an image forming apparatus, an image forming system and an image forming method according to the present invention are provided as a transport path for guiding a sheet to an intermediate tray in order to achieve the first object. N different numbers (n ≧
(2) path is provided, and each of the (n-1) sheets which are sequentially carried in is converted into (n-1) different paths by one.
Instead of automatically discharging the sheet bundle temporarily stored in the intermediate tray to the main tray when the nth unstored sheet is carried in while carrying the sheets one by one and making them stand by, n sheets are replaced. At the same time, the non-stored sheets of the eye are conveyed to the intermediate tray through the remaining paths, and the non-storage sheets in the standby state are respectively conveyed to the intermediate tray through the paths in the standby state. As described above, by executing the automatic discharge operation, unloaded sheets can be continuously carried in, and the throughput can be improved.

When the number of unstored sheets to be stored in the intermediate tray following the sheet bundle is less than n, there is a problem that the automatic discharge operation is not executed in the conventional example.
According to the present invention, the sheet bundle stored in the intermediate tray is forcibly ejected, and the sheet is prevented from staying in the sheet post-processing device or means for a long time.

Here, even if the number of sheets to be conveyed to the sheet post-processing device or means after the sheet bundle is n or more, the m-th sheet (m) to be conveyed after the sheet bundle.
= 1, 2,..., N) cannot be conveyed to the sheet post-processing apparatus, for example, a sheet jam occurs in the image forming apparatus or the unit, or the sheet runs out. If the m-th sheet cannot be carried into the post-processing device or means, the sheet remains in the intermediate tray or the path. However,
When it is determined that the m-th sheet cannot be conveyed to the sheet post-processing device or means, the problem is reliably solved by forcibly discharging the sheet bundle from the intermediate tray to the main tray. Can be eliminated.

[0014]

FIG. 1 is a diagram showing an example of an image forming system according to the present invention. The image forming system includes an image forming apparatus 1, a finisher 2 disposed adjacent to the image forming apparatus 1, a multi-bin unit 3 disposed above the image forming apparatus 1, and a lower part of the image forming apparatus 1. Optional paper feed cassette 4 placed in position
It is composed of

This image forming apparatus 1 has yellow (Y),
Printing a full-color image on paper by superimposing four color toners of cyan (C), magenta (M), and black (K), or printing a monochrome image on paper using only black (K) toner And corresponds to the “image forming apparatus” and the “image forming unit” of the present invention. In the image forming apparatus 1, as shown in FIG. 1, an image carrier unit 12, an exposure unit 13, a transfer unit 14, a fixing unit 15, and a paper supply / discharge unit 16 are provided inside a case 11.

The image carrier unit 12 includes a photosensitive member 121 rotatable in a counterclockwise direction in FIG. 1 and a charging roller as charging means around the photosensitive member 121 along the rotating direction. 122, developing devices 123Y, 123C, 123M, 123K as developing means,
And a cleaning unit 124 are provided. Then, the exposure unit 13 irradiates the outer peripheral surface of the photoconductor 121 charged by the charging roller 122 with a laser beam to form an electrostatic latent image.

The electrostatic latent image thus formed is developed by a developing unit with toner. That is, in this embodiment, as the developing units, a yellow developing unit 123Y, a cyan developing unit 123C, a magenta developing unit 123M, and a black developing unit 123K are arranged in this order.
Are arranged along. These developing devices 123Y, 1
23C, 123M, and 123K are photosensitive members 121, respectively.
The four developing devices 1 are configured so as to be freely movable toward and away from the developing device 1 in accordance with a command from a sub-controller described later in detail.
One of the developing units 23Y, 123M, 123C, and 123B selectively comes into contact with the photoconductor 121 to make the electrostatic latent image on the photoconductor 121 visible.

The toner image developed by the developing unit is transferred to the intermediate transfer belt 1 of the transfer unit 14 in a primary transfer area located between the black developing unit 123K and the cleaning unit 124.
The primary transfer is performed on the reference numeral 41.

The transfer unit 14 includes a plurality of rollers and an intermediate transfer belt 141 stretched over these rollers.
And a secondary transfer roller 142 for secondary-transferring the intermediate toner image transferred to the intermediate transfer belt 141 onto paper. In this embodiment, the intermediate transfer belt 14
It is configured to be able to transfer a toner image of a maximum size of A3 on 1 sheet, 2 sheets of A4 size, or 4 sheets of postcard size.
The sheets can be transferred simultaneously.

When a color image is to be transferred to a sheet, a color image is formed by superimposing toner images of respective colors formed on the photoreceptor 121 on the intermediate transfer belt 141, and the paper supply / discharge unit 16 The paper is taken out from the cassette 162, the manual feed tray 163 or the optional paper feed cassette 4 by the paper feed unit 161, and is conveyed to the secondary transfer area. Then, a color image is secondarily transferred to this sheet to obtain a full-color image. When a monochrome image is to be transferred to a sheet, only a black toner image is formed on the photoreceptor 121 on the intermediate transfer belt 141, and the sheet conveyed to the secondary transfer area in the same manner as in the case of a color image. To obtain a monochrome image.

The paper on which the toner image has been transferred by the transfer unit 14 is fed to a paper feed unit 16 of a paper feed / discharge unit 16.
1, the toner image is conveyed to a fixing unit 15 disposed downstream of the secondary transfer area along a predetermined paper feed path (two-dot chain line), and the toner image on the conveyed paper is fixed on the paper. Then, the paper is further conveyed to the paper discharge unit 164 along the paper supply path.

The paper discharge section 164 has two paper discharge paths 164.
a, 164b, one discharge path 164a extends from the fixing unit 15 to the standard discharge tray, and the other discharge path 164b is substantially parallel to the discharge path 164a. It extends between the bin unit 3. Three pairs of rollers are provided along these paper discharge paths 164a and 164b, and the fixed paper is discharged toward the standard discharge tray, finisher 2 or multi-bin unit 3, or the other side. The sheet is also conveyed to the re-feed section 165 to form an image.

As shown in FIG. 1, the re-feeding section 165 feeds the sheet reversely conveyed from the discharging section 164 as described above along the re-feeding path (two-dot chain line). , And is constituted by three pairs of re-feed rollers arranged along the re-feed path. As described above, the sheet conveyed from the sheet discharging unit 164 is returned to the gate roller pair 166 along the re-feeding path, so that the non-image forming surface of the sheet faces the intermediate transfer belt 141 in the sheet feeding unit 161. The image can be secondarily transferred to the surface.

FIG. 2 is a view showing a finisher constituting the image forming system of FIG. This finisher 2
Functions as the "sheet post-processing device" and "sheet post-processing means" of the present invention, and is configured as follows.

As shown in FIG. 2, the finisher 2 has an intermediate tray 21 capable of storing a plurality of sheets, and the sheets conveyed from the image forming apparatus 1 to the finisher 2 are temporarily stored in the intermediate tray 21. After that, the paper stored in the intermediate tray 21 is discharged to the main tray 22. Hereafter, Finisher 2
The configuration of each section will be described in more detail with reference to FIG.

On the side surface of the finisher 2, a paper feed port 201 for receiving the paper discharged from the image forming apparatus 1 is provided. In addition, a punch portion 23 for punching a punch hole in a sheet is provided in the vicinity of the sheet feeding port 201, and a carry-in detection sensor S21 for detecting the carry-in of the sheet to the finisher 2 is supplied as described later. It is located immediately downstream of the paper slot 201. Here, as the carry-in detection sensor S21, for example, a reflection type optical sensor can be used. When a sheet is carried into the finisher 2 through the paper feed port 201, the light from the carry-in detection sensor S21 is transmitted by the sheet. Is reflected, and by detecting this, a paper detection signal indicating that the paper is loaded is output from the carry-in detection sensor S21. For example, by detecting a change in the output level of the sheet detection signal, it is possible to detect the leading edge and the trailing edge of the sheet.

The paper conveyed to the finisher 2 is conveyed to the branch claw 202 along the path P1. This branch claw 2
Numeral 02 is swingable, and the paper conveyed along the path P1 is conveyed to the non-sorting tray 24 by being located at the broken line position in the figure, while being positioned at the solid line position in the figure. It is transported to the transport mechanism 25 side.

In the transport mechanism 25, a pair of rollers 251 for feeding the sheet passing through the branch claw 202 toward the intermediate tray 21 is disposed immediately downstream of the branch claw 202. Further, in the transport mechanism 25, the paper is transferred to the intermediate tray 21.
Two paths are provided in parallel to each other as paths to be guided to the side, that is, a main path Pm and a sub path Ps,
By swinging the branch claw 252 between the two positions, the transport path to the intermediate tray 21 can be selectively switched. That is, the branch claw 252
When the sheet is positioned at the solid line position in FIG. 2, the sheet is conveyed to the intermediate tray 21 via the main path Pm, while when the sheet is positioned at the broken line position in FIG. 2, the sheet is conveyed to the intermediate tray 21 via the sub path Ps. .

The transport mechanism 25 includes four sets of branch rollers 253 (253a, 253a, 253a,
253b, 253c, 253d) and three branch claws 25
4 (254a, 254b, 254c) are arranged. Each of the branch claws 254 swings according to the sheet size, and conveys the sheet to the intermediate tray 21 from any one of the arrows Da, Db, Dc, and Dd. The swing position of each branch claw 254 is set in accordance with the length of the sheet in the transport direction at the time of mode standby immediately after the start of the operation. For example, the direction of arrow Dd for A4 paper and the arrow Da for A3 paper It is carried into the intermediate tray 21 from the direction.

The four sets of branch rollers 253 (253a, 25
3b, 253c and 253d), the driving force of the main motor is directly transmitted to the two branch rollers 253c and 253d on the downstream side, and the rollers are constantly rotated. On the contrary,
The remaining branch rollers 253a and 253b are connected via a clutch that opens and closes in response to a control command from a finisher controller 29, which will be described later. , The sheet that has been waiting on the main path Pm can be conveyed to the intermediate tray 21 together with the sheet conveyed along the sub path Ps.

The intermediate tray 21 is composed of a pair of tray members separated in a direction (width direction X) perpendicular to the paper surface of FIG. 2, and the front side of the pair of tray members (right side in FIG. 2). ) Supports and stores the entire paper surface.
The lower end of the sheet is supported by sheet receivers 261 and 261 of the stapler 26 described below.

The stapler 26 is arranged below the intermediate tray 21 and performs a stapling process on the sheets stored in the intermediate tray 21 as necessary.
As shown in FIG. 3, the stapler 26 includes two paper receivers 261 and 261. The lower end of the paper P conveyed toward the intermediate tray 21 by the conveyance mechanism 25 is locked, and the paper P is It prevents sliding down from the intermediate tray 21. In this embodiment, the stapler body 262 of the stapler 26 is fixedly arranged. And
The intermediate tray 21 is moved by the position adjusting mechanism 27 described below.
After the staple position is determined by shifting the paper P stored in the intermediate tray 21 in the width direction X, the stapler body 262 collectively staples the paper P stored in the intermediate tray 21. Of course, stapler body 2
62 is configured to be movable in the width direction X of the intermediate tray 21,
The stapler body 262 may be configured to collectively stap the sheets P stored in the intermediate tray 21 at a desired position.

A position adjusting mechanism 27 is provided on both sides of the intermediate tray 21. This position adjusting mechanism 27
Is for aligning or shifting the sheets P stored in the intermediate tray 21 in the width direction X, and a pair of joggers 271 and 272 arranged movably in the width direction X on the front side of the intermediate tray 21. And the jogger 271 in the width direction X
First jogger drive control section (see reference numeral 27 in FIG. 5)
3) and a second jogger drive control unit (reference numeral 274 in FIG. 5) that drives the jogger 272 in the width direction X. Therefore, by controlling the amount of movement of the joggers 271 and 272, the sheets P can be aligned in the intermediate tray 21,
The sheet P can be shifted in the width direction X at a time. In addition, since the sheet alignment and the sheet shift in the intermediate tray 21 are known per se in the related art, a detailed description thereof will be omitted.

Further, the finisher 2 is provided with a discharge mechanism 28 for discharging the paper P stored in the intermediate tray 21 to the main tray 22. In the discharge mechanism 28, an endless belt 281 is stretched between the tray members, that is, along a separation portion of the intermediate tray 21 extending in the discharge direction Y. The endless belt 281 is a belt roller 28
2, 282, which run in the discharge direction Y and are fixed to the surface of the endless belt 281.
Move 3 As shown in FIG. 3, the paper receiver 283 is configured to store the paper
61, and moves in the discharge direction Y to replace the sheet trays 261 and 261.
After supporting the lower end portion of the paper P stored in the main tray 22, the paper P is further moved from the intermediate tray 21 to the main tray 22 side. A discharge roller pair 284 is provided on the main tray side (upper side in FIG. 2) of the intermediate tray 21 to reliably discharge the sheet P carried out from the intermediate tray 21 to the main tray 22.

In the finisher 2 configured as described above, in addition to the carry-in detection sensor S21 for detecting the sheet P, a conveyance confirmation sensor S22 for detecting sheet conveyance to the intermediate tray 21, and an intermediate tray 21 Storage detection sensor S23 for detecting the paper stored in the
A discharge detection sensor S24 for detecting paper discharge is provided.

FIG. 4 is a diagram showing an electrical configuration of the image forming system of FIG. In this image forming system, a main controller 17 and a sub-controller 18 are provided in the image forming apparatus 1 as shown in FIG. The main controller 17 includes a CPU, an image memory, a communication interface, and the like, and receives an image formation command (a signal indicating the content of a print request) from the host computer 5 to send an operation instruction to each unit of the image forming apparatus 1. Converts to job data (print information) in a suitable format,
This is given to the sub-controller 18. The sub-controller 18 receiving the information includes a CPU, a ROM, a RAM, a communication interface, and the like, and controls each unit of the image forming apparatus 1 according to the job data (print information).

In response to this, the sub-controller 18 gives a control signal such as a discharge request to be described later to the finisher controller 29 through serial communication,
By providing various control signals to the multi-bin unit controller 31 and various control signals to the optional paper cassette controller 41, the finisher 2, the multi-bin unit 3 and the optional paper cassette 4 are controlled. The printing process corresponding to the image forming command is executed. In particular, the sub-controller 18 determines the timing of discharging the stored sheets from the intermediate tray 21 as described later, and instructs the finisher 2 to request the discharge at the discharge timing. The specific operation will be described later in detail.

FIG. 5 is a diagram showing an electrical configuration of a finisher controller provided in the finisher main body for controlling the finisher shown in FIG. The finisher controller 29 is configured such that various information is provided to the CPU 290 from the sub-controller 18 of the image forming apparatus 1 via the communication interface 294 together with detection signals from the sensor groups S21 to S24 provided in the finisher 2. I have. The CPU 290 controls each component of the finisher based on these signals and information according to a program stored in the ROM 292 in advance, and functions as “control means” of the present invention.

The following control units are electrically connected to the CPU 290 to control each unit of the finisher 2.

(A) Punch drive control section 231: punch section 2
3 is driven to form a punch hole in the sheet.

(B) Main-sub path switching control section 256:
The branch pawl 252 is driven to swing to switch the paper transport path between the main path Pm and the sub path Ps.

(C) Conveyance path switching control section 257: branch roller 253 (253a, 253b, 25
3c, 253d) and branch claws 254 (254a, 25
4b, 254c) to drive the paper to the arrows Da, D
The sheet is conveyed to the intermediate tray 21 from one of the directions b, Dc, and Dd.

(D) First jogger drive control section 273: The jogger 271 is driven in the width direction X.

(E) Second jogger drive control section 274: drives the jogger 272 in the width direction X.

(F) Stapler drive controller 263: Moves and positions the stapler body 262 in the width direction X, and staples the sheets P stored in the intermediate tray 21 at a desired position.

(G) Main motor drive control section 291: Drive control of a main motor (not shown) which is a drive source of each section of the finisher 2.

(H) Main tray drive controller 221: The main tray 22, which is movable in the vertical direction, is moved up and down in accordance with the amount of discharged paper.

Further, the AC power supplied through the AC input unit 296 is changed to a DC voltage of a predetermined voltage by the power supply unit 295, and the finisher controller 29 is supplied to the finisher controller 29.
Power source within. In particular, in this embodiment, the power supply unit 29 is controlled based on a relay control signal from the image forming apparatus 1.
The power supply from the AC input unit 296 can be remotely controlled by the image forming apparatus 1 by controlling the conduction / non-conduction of the AC relay 295a provided in the image forming apparatus 5.

Reference numeral 293 in the figure denotes control data for controlling each part of the finisher 2 and the CPU 2.
90 for temporarily storing the operation result and the like at 90
AM.

Next, the operation of the finisher 2 configured as described above will be described, and then the operation of the image processing system will be described.

The finisher 2 executes the automatic discharge operation shown in FIG. 6 when continuously discharging sheets P of a specific size, for example, A4 size to the main tray 22 in units of a plurality of sheets. In such a case, the forced discharge operation shown in FIG. 7 is executed.

FIG. 6 is a flowchart showing the automatic discharging operation of the finisher shown in FIG. The finisher 2 conveys the paper P carried into the finisher 2 to the intermediate tray 21 via the main path Pm and temporarily stores the paper P, except when executing the subsequent steps ST7 to ST11 (step ST1). . This sheet storage process is continuously performed until it is confirmed in step ST2 that the last sheet in the processing unit is stored in the intermediate tray 21, and sheets P on which images are formed are stacked on the intermediate tray 21. In this specification, the sheets stored in the intermediate tray 21 in this manner are referred to as “stored sheets”, while the sheets to be carried into the finisher 2 are referred to as “unstored sheets”.

When "YES" is determined in the step ST2, that is, when it is confirmed that the storage of the last sheet in the intermediate tray 21 is completed, a storage completion signal is transmitted to the sub controller 18 of the image forming apparatus 1, and And the A4 size first sheet P constituting the next processing unit is carried into the main path Pm, and immediately before the leading end of the sheet reaches the branch roller 253c, the branch rollers 253a, 253a
By switching the clutch connected to 3b to the OFF state, the rotation of the branch rollers 253a and 253b is stopped.
Thus, the paper P is made to wait in the main path Pm. At the same time, steps ST5 and ST6 are executed to staple the sheet bundle temporarily stored in the intermediate tray 21 as necessary.

Next, the standby for carrying the first sheet (first sheet) P into the main path Pm is completed (step ST4).
Then, the second uncontained sheet P is carried into the finisher 2 following the first sheet, and is guided by the branching claw 252 switched to the position indicated by the broken line in FIG. 2 to be conveyed to the sub path Ps. Further, it is determined whether it is necessary to shift the sheet bundle stored in the intermediate tray 21 in the width direction X (step ST7). Here, only when it is determined that the shift movement is to be performed, the joggers 271 and 272 are moved in parallel in the width direction X and shifted with respect to the sheet bundle aligned and discharged to the main tray 22 (step ST8). The reason for the shift movement is to clarify the processing unit in the main tray 22 by alternately discharging the sheet bundle for each processing unit.

When the leading edge of the second sheet P is detected by the carry-in detection sensor S21 (step ST9), the sheet bundle is discharged (step S10). In this step ST10, the sheet bundle 283 is moved in the discharge direction Y by running the endless belt 281 in the discharge direction Y to support the lower end portion of the sheet bundle stored in the intermediate tray 21 while discharging the sheet bundle in the discharge direction. Then, it is moved to Y and discharged from the intermediate tray 21 to the main tray 22 (step ST10).
Further, instead of this, the branch rollers 253a, 253
The clutch connected to b is switched to the ON state. In response to this, the branch rollers 253c and 25 that are constantly rotating
In addition to 3d, the branch rollers 253a and 253b also start to rotate, and the second sheet P conveyed to the sub path Ps and the first sheet P waiting on the main path Pm are simultaneously conveyed to the intermediate tray 21. (Step ST11). Then, returning to step ST1, the above series of processing is repeated.

As described above, in this embodiment, the main tray 22 is continuously provided with a plurality of sheets of A4 size paper P.
If the paper P is continuously discharged to the finisher 2
The paper bundle is transferred to the main tray 2
2 and a high throughput can be obtained.

FIG. 7 is a flowchart showing the forcible discharge operation of the finisher shown in FIG. The finisher 2 receives a discharge request signal from the sub-controller 18 of the image forming apparatus 1 as shown in FIG.
1) and whether or not stapling is designated in step ST22, and executes stapling only when stapling is designated (step ST22).
23).

Further, it is determined whether it is necessary to shift the bundle of sheets stored in the intermediate tray 21 in the width direction X (step ST24). Only when it is determined that the shift movement is to be performed, the joggers 271 and 27
2 is moved in parallel in the width direction X to shift the bundle of sheets aligned and discharged on the main tray 22 (step ST25).

Subsequently, the paper receiver 283 is moved in the discharge direction Y by running the endless belt 281 in the discharge direction Y.
, While supporting the lower end portion of the sheet bundle stored in the intermediate tray 21, the sheet bundle is moved in the discharge direction Y and discharged from the intermediate tray 21 to the main tray 22 (step ST26).

As described above, in this finisher 2,
In response to a discharge request signal from the sub-controller 18, the sheet bundle stored in the intermediate tray 21 is transferred to the main tray 22.
, It is possible to prevent the sheet bundle from being discharged to the main tray 22 at an appropriate timing and to prevent the sheet from staying in the intermediate tray 21 or the like for a long time. More specifically, the size of the unstored paper P to be conveyed to the finisher 2 after the stored paper P stored in the intermediate tray 21 is different from the stored paper P, and the image forming apparatus 1 side The middle tray 2 may be out of order due to paper out, paper jam, etc.
There is a possibility that discharge of the stored paper P in the tray 1 to the main tray 22 may be restricted. Therefore, in this embodiment, as described below, the sub-controller 18 of the image forming apparatus 1 detects such a phenomenon, transmits a discharge request signal to the finisher 2, and forcibly forms a sheet bundle at an appropriate timing. It is discharged to the main tray 22.

FIGS. 8 to 10 are flowcharts showing the operation of the image forming apparatus shown in FIG. The image forming apparatus 1 forms an image following the stored paper P stored in the intermediate tray 21, and controls the discharge timing in the finisher 2 based on the information regarding the unstored paper P to be carried into the finisher 2.

More specifically, in the image forming apparatus 1, when the main controller 17 receives an image forming command (a signal indicating the content of a print request) from the host computer 5,
The data is converted into one or a plurality of job data (print information) and sequentially provided to the sub controller 18. For example, when an image forming command to print a mixed size document composed of four A4 size documents and two A3 size documents is transmitted from the host computer to the main controller 17, an image according to the present embodiment is transmitted. In the forming apparatus 1, the main controller 17 converts the image forming instruction into the following five job data so as to be in a format suitable for the operation instruction of each unit of the apparatus.

(1) A job for printing two pages of A4 size document; (2) A job for printing two pages of A4 size document; (3) A job for widening the paper interval by performing idle processing; (4) A3 (5) Job to print one page of A3 size document; These jobs include various information indicating print contents, such as paper size, single-sided / double-sided mode, and continuous printing. The last sheet designation indicating the last sheet at the time of performing the job is included, and job data indicating each job is sequentially provided to the sub controller 18. Then, the sub controller 18 that has received the job data
Outputs the discharge request to the finisher 2 at an appropriate timing while controlling the respective units of the apparatus as follows, so as to optimize the discharge timing in the finisher 2. Hereinafter, the control operation will be described in detail with reference to FIGS.

The sub-controller 18 determines whether or not the given job includes the last sheet designation (step ST31). As long as the last sheet designation is not included, image formation is continuously performed according to the job data. The processing is performed, and the paper P on which an image is formed is sequentially loaded into the finisher 2. On the other hand, the finisher 2 receiving this also stores the incoming sheets P one after another in the intermediate tray 21.

When it is confirmed in step ST31 that the last sheet designation is included, whether or not there is a next job (step ST32) and whether or not the next print size is the same as the previous print size (step ST32) ST33) and determine whether or not the number of printed sheets is two or more (step ST34). If all three requirements are satisfied, the second discharge processing is executed (step ST36). Performs a first discharge process (step ST35).

In the first discharge process, it is detected that the last sheet has been stored in the intermediate tray 21 based on the storage completion signal transmitted from the finisher 2 (step ST35).
1), and transmits a discharge request signal to the finisher 2 (step ST352). As a result, the finisher 2 executes the forced ejection operation shown in FIG.
1 is temporarily stored in the main tray 22.
To be discharged. Then, when the finisher 2 transmits to the sub-controller 18 that the discharge of the sheet bundle to the main tray 22 is completed (step ST353), the first discharge processing is completed, and the process returns to step ST31 in FIG.

As described above, in this embodiment, when there is no unstored paper P to be loaded into the finisher 2 following the stored paper P stored in the intermediate tray 21 ("NO" in step ST32). If determined),
As described in later-described first to third embodiments (FIGS. 11 to 13), the sheet bundle is discharged to the main tray 22 simultaneously with the completion of the storage of the final sheet in the intermediate tray 21. Therefore, it is possible to prevent the paper from staying in the finisher 2 for a long time.

When the size of the non-stored paper P to be carried in after the stored paper P is different from the size of the stored paper P (when judged “NO” in step ST 33), Prior to the transfer to the intermediate tray 21, the first discharge process (step ST35) is executed, the stored paper P is discharged from the intermediate tray 21 to the main tray 22, the intermediate tray 21 becomes empty, and the next another The preparation for storing the paper P of the size in the intermediate tray 21 is performed. Therefore, even when a plurality of paper sizes are included in a processing unit (one copy) as described in a first embodiment (FIG. 11) described later, all the papers can be reliably transferred to the main tray 22.
Can be discharged. Further, paper jams in the finisher 2 can be prevented from occurring without paper of different sizes being mixed in the intermediate tray 21.

Further, the finisher 2 executes the automatic discharge operation shown in FIG. 6 when continuously discharging a plurality of sheets of A4 size paper P to the main tray 22, but the processing unit to be executed later is one sheet. In this case, if the automatic discharge operation is performed as it is, a problem occurs that a sheet bundle remains on the intermediate tray 21 and unstored sheets P remain on the main path Pm. However, in this embodiment, when the number of prints of the next job is less than the number of transport paths (n = 2) ("N" in step ST34).
O), the sheet bundle is discharged to the main tray 22 at the same time when the storage of the last sheet in the intermediate tray 21 is completed, and the unstored sheet P constituting the next processing unit is carried into the finisher 2. Is delayed to prevent interference with the discharge processing. Therefore, if the paper is
For a long time can be prevented.

Next, the second discharging process will be described with reference to FIG. In the second discharge process, it is detected that the last sheet is stored in the intermediate tray 21 based on the storage completion signal transmitted from the finisher 2 (step ST3).
61), when executing the first print processing in the next processing unit, it is determined whether or not the paper has run out or a paper jam has occurred in the image forming apparatus 1 (step ST362). Here, when the paper exhaustion or the paper jam is detected, the process proceeds to step ST363 to transmit a discharge request signal to the finisher 2. Thus, the finisher 2 executes the forced ejection operation shown in FIG. 7 and ejects the sheet bundle temporarily stored in the intermediate tray 21 to the main tray 22.

On the other hand, if it is determined in step ST362 that the paper has not run out, an image is formed on the first paper P, and the paper P is carried into the finisher 2. The paper P is carried on standby in the main path Pm.

In the next step ST364, in executing the printing process for the second sheet, it is determined whether or not the paper has run out or a paper jam has occurred in the image forming apparatus 1. Here, when the sheet is out of paper or the paper jam is detected, the process proceeds to step ST363 to transmit a discharge request signal to the finisher 2, and executes the forced discharge operation shown in FIG. The bundle of papers stored in the main tray 22 is discharged to the main tray 22.

On the other hand, if it is determined in step ST364 that the paper has not run out, an image is formed on the second sheet P, and the sheet P is carried into the finisher 2. At this time, the finisher 2 executes the automatic ejection operation shown in FIG. That is, the sheet bundle stored in the intermediate tray 21 is discharged to the main tray 22, and the second sheet P conveyed to the sub-path Ps in place of the sheet bundle and the main path Pm
Simultaneously with the first sheet of paper P that has been waiting at
Transport to

When the finisher 2 sends a notification to the sub-controller 18 that the sheet bundle has been discharged to the main tray 22 (step ST365), the second discharge process is completed, and the process proceeds to step ST31 in FIG. Return.

As described above, in this embodiment, a processing unit consisting of A4 size paper is followed by a plurality of A
To execute a processing unit consisting of 4 size paper,
By executing the second discharge process, it is possible to prevent the paper from staying in the finisher 2 for a long time. The details will be described below.

For example, when there is no m-th (m = 1, 2) unstored sheet to be carried into the finisher 2 following the stored sheets, the following problem occurs.
First, when the first sheet is out of paper or a paper jam occurs, a problem occurs in which a bundle of sheets remains on the intermediate tray 21 until such a device status is eliminated. Further, when the second sheet is out of paper or a paper jam occurs, a sheet bundle remains in the intermediate tray 21 until such a device status is resolved, and
A problem that unstored paper P remains in the main path Pm occurs.

On the other hand, in this embodiment, when the paper or paper jam occurs in the first sheet or the second sheet, the sheet bundle is moved to the main tray 2 simultaneously with the detection of the paper out.
It is discharged to 2. It is possible to prevent the paper from staying inside the finisher 2 for a long time.

If no paper shortage or the like has occurred, the discharge request signal is not output from the sub-controller 18 and the discharge timing of the stored paper stored in the intermediate tray 21 is determined by the finisher controller 29. Is done.

In the above embodiment, the finisher 2 is provided with two paths Pm and Ps as a transport path for transporting unstored paper to the intermediate tray 21, but the number of passes is not limited to this. Alternatively, three or more paths may be provided. In other words, n different (n ≧ 2) paths are provided as a transport path for guiding the unstored paper carried in from the image forming apparatus 1 to the intermediate tray 21 and are sequentially carried in from the image forming apparatus 1 (n− 1) While each sheet of paper is carried one by one into (n-1) paths different from each other and kept in a standby state, the sheet is temporarily stored in the intermediate tray 21 when the nth unstored sheet is carried in. The present invention can be applied to a finisher that conveys the non-stored paper in each pass to the intermediate tray 21 instead of automatically discharging the stored paper P that has been stored to the main tray 22.

In the above embodiment, the finisher 2
Controls the automatic paper ejection timing according to the flowchart shown in FIG. 6, and the forced ejection timing is controlled according to an ejection request signal given from the sub-controller 18. However, the finisher 2 is sent from the image forming apparatus 1 to the finisher controller 29.
May be provided so that the finisher controller 29 controls the discharge timing based on this information.

On the contrary, from the finisher 2 to the sensors S21 to S21.
The output signal of S24 and the like may be transmitted to the image forming apparatus 1, and the sub-controller 18 of the image forming apparatus 1 may control the automatic ejection timing and the forced ejection timing in the finisher 2 collectively.

In the above embodiment, the image forming apparatus 1
Although the image forming system in which the image forming apparatus 1 is connected to the finisher 2 has been described, the present invention can also be applied to an image forming system in which the finisher is incorporated in the image forming apparatus 1, and the same as the above embodiment by applying the present invention. The operation and effect of the invention can be obtained. In this image forming system,
The image forming system may be configured to be controlled by a sub-controller without providing a finisher controller.

In the above embodiment, the automatic discharge operation is performed only when the A4 size paper P is continuously discharged to the main tray 22 in units of a plurality of sheets. It is not limited to the size. If the main path Pm is configured so that another size, for example, a letter size sheet can be made to stand by, the letter size sheet is continuously put on the main tray 22 in plural units. Also in the case of discharging, an automatic discharging operation can be executed. In the main path Pm, another size other than the A4 size, for example, a letter size, an A3 size,
If a sheet of B4 size or B5 size can be put on standby, a sheet having a size different from the size of the sheet temporarily stored in the intermediate tray 21 is put on standby in the main path Pm to execute an automatic discharge operation. can do. For example, instead of discharging a sheet bundle including a plurality of sheets of A4 size paper to the main tray 22,
Intermediate tray 2 with two empty sheets of B5 size simultaneously
1 can also be stored.

In the above embodiment, the finisher 2
Although the carry-in detection sensor S21 for detecting the carry-in of the paper into the paper feed port 201 is disposed immediately downstream of the paper feed port 201, the arrangement position is not limited to this, and it is determined according to the automatic discharge timing. What is necessary is just to provide on the conveyance path of a paper appropriately.

In the above embodiment, the toner image on the photosensitive member 121 is transferred to the intermediate transfer belt 141.
The present invention is also applied to an image forming apparatus that transfers a toner image to a transfer medium other than the intermediate transfer belt (transfer drum, transfer belt, transfer sheet, intermediate transfer drum, intermediate transfer sheet, reflective recording sheet, transparent storage sheet, etc.). Can be applied. In addition, the present invention can be applied to an image forming apparatus employing a so-called tandem method as an image forming method. Although the image forming apparatus 1 is a printer, the image forming apparatus includes all image forming apparatuses such as a copying machine and a facsimile machine. Further, the present invention can be applied to an image forming apparatus that forms an image by an image forming method other than the electrophotographic method, for example, an ink jet method or a thermal transfer method.

[0086]

EXAMPLES Next, examples of the present invention will be described. However, the present invention is not limited by the following examples, and the present invention can be practiced with appropriate modifications within a range that can conform to the spirit of the preceding and following examples. Of course, it is possible, and all of them are included in the technical scope of the present invention.

<First Embodiment: FIG. 11> In this first embodiment, as shown in FIG. 11 (a), two copies of an A4 size document as a processing unit (one copy) are printed. This is the content of the request. In order to execute such a print content, the host computer 5 sends the main controller 17
Is sent to the main controller 1
7 converts the image forming command into the following four job data so as to be in a format suitable for the operation instruction of each unit of the apparatus.

(1) A job for printing two A4 size documents; (2) A job for printing two A4 size documents; (3) A job for printing two A4 size documents; ) A job for printing two pages of an A4 size document;
In the jobs (2) and (4), the last sheet is designated. To illustrate this, in the same figure (and later FIGS. 12-14)
Indicated by black triangles.

First, the sub-controller 18 controls each part of the apparatus in accordance with the job data (1) and places the toner images I11 and I12 on the intermediate transfer belt 141 as shown in FIG.
Is formed, the toner images I11 and I12 are respectively transferred onto the sheets P11 and P12 conveyed continuously to the secondary transfer area, and conveyed to the finisher 2. Then, in the finisher 2, the sheets P11 and P12 are transported to the intermediate tray 21 via the main path Pm and stored. In this embodiment, the sheet bundle B0 has already been discharged to the main tray 22 at this time.

Next, the sub-controller 18 controls each part of the apparatus in accordance with the job data (2) and places the toner images I13 and I14 on the intermediate transfer belt 141 as shown in FIG.
Is formed, the toner images I13 and I14 are respectively transferred to the papers P13 and P14 continuously conveyed to the secondary transfer area, and are conveyed to the finisher 2. Then, the finisher 2 conveys and stores the sheets P13 and P14 to the intermediate tray 21 via the main path Pm. Thus, the four stored sheets P11 to P14 are stacked in this order on the intermediate tray 21.

Here, since the sheet P14 is designated as the last sheet, the sub-controller 18 determines the discharge timing based on the information regarding the sheet to be formed next and to be conveyed to the finisher 2. In this embodiment, the sheet is an A4 size sheet and a sheet bundle B1 (stored sheet P1).
1 to P14) and more than the number of paths (conveyance paths) (n = 2), the sub-controller 18 controls each unit of the apparatus in accordance with the next job data (3) and performs intermediate transfer. The same figure (b) on the belt 141
The toner images I21 and I22 are transferred to the papers P21 and P22 conveyed continuously to the secondary transfer area while forming the toner images I21 and I22, respectively, and are conveyed to the finisher 2 as shown in FIG.

Then, the finisher 2 executes an automatic ejection process. That is, after the transport of the first sheet P21 on the main path Pm, the second sheet P22
Into the finisher 2. Further, the sheet bundle B1 (sheets P11, P12) stored in the intermediate tray 21 is shifted by the shift amount Δ with respect to the sheet bundle B0 discharged to the main tray 22. When the leading edge of the second sheet P22 is detected by the carry-in detection sensor S21, the shifted sheet bundle B1 is forcibly discharged to the main tray 22. In this embodiment, since the stapling process is not required, the stapling process is not executed at this ejection timing. However, when the stapling process is required, the stapling process is executed prior to the shift movement. Alternatively, the second sheet P22 conveyed to the sub path Ps and the first sheet P2 waiting for the main path Pm are replaced.
1 and are simultaneously conveyed and stored in the intermediate tray 21.

As described above, when the processing unit of A4 size and two or more sheets are continuously executed, the automatic discharging operation can be performed. That is, the stored paper stored in the intermediate tray 21 is transferred to the main tray 2.
2, the image forming apparatus 1 can continuously perform the image forming operation and the carrying-in operation to the finisher 2, so that the throughput can be improved.

Subsequently, the sub-controller 18 controls each unit of the apparatus in accordance with the job data (4) and places the toner image I on the intermediate transfer belt 141 as shown in FIG.
The toner images I23 and I24 are transferred to the papers P23 and P24 conveyed continuously to the secondary transfer area while forming the sheets 23 and I24, respectively, and are conveyed to the finisher 2. Then, the finisher 2 conveys and stores the sheets P23 and P24 to the intermediate tray 21 via the main path Pm. Thus, the four stored sheets P21 to P24 are stacked on the intermediate tray 21 in this order.

Here, since the sheet P24 is designated as the last sheet, the sub-controller 18 determines the discharge timing based on the information regarding the sheet to be formed next and to be carried into the finisher 2. In this embodiment, since there is no next sheet, the sub-controller 18 sends a discharge request signal to the finisher controller 29.
In response to this, on the finisher 2 side, the sheet bundle B1 (sheets P11 to P1) discharged to the main tray 22 is output.
Following the shift of 4) by the shift amount Δ,
The paper is forcibly discharged to the main tray 22. By doing so, the final sheet P24 is stored in the intermediate tray 21 at the same time as the sheet P21.
Since the sheet bundle B2 including the sheets P21 to P24 is discharged, it is possible to prevent the sheets P21 to P24 from staying inside the finisher 2 for a long time.

<Second Embodiment: FIG. 12> The second embodiment differs from the first embodiment in that staple processing is performed on each sheet bundle B1 and B2. Are identical. When the stapling process is performed as described above, the stapling process is performed at each ejection timing, and then the sheet bundle is ejected onto the main tray 22 without being shifted.

After the stapling process is performed, it goes without saying that the process may be shifted for each processing unit as in the first embodiment.

<Third Embodiment: FIG. 13> In this third embodiment, as shown in FIG. 13A, one copy of four A4 size documents is set as a processing unit (one copy), and one A4 size document is processed. The print request content is to print one copy of one document as a processing unit (one copy). When an image forming command is transmitted from the host computer 5 to the main controller 17 to execute such a print content, the main controller 17 converts the image forming command into a format suitable for an operation command of each unit of the apparatus. It is converted into five job data.

(1) A job for printing two pages of A4 size document; (2) A job for printing two pages of A4 size document; (3) A job for widening the paper interval by idling; (4) A4 Job to print one page of size document;
In the job (2), the last sheet is designated.

First, as in the first embodiment, the job data
According to (1) and (2), the sub-controller 18 controls each unit of the apparatus to form toner images I11 to I14 on the intermediate transfer belt 141 as shown in FIG. Image I on the paper P11-P14 conveyed
11 to I14 are transferred and conveyed to the finisher 2. In the finisher 2, the sheets P11 to P14 are sequentially conveyed to and stored in the intermediate tray 21 via the main path Pm. In this embodiment, the sheet bundle B0 has already been discharged to the main tray 22 at this time.

Here, since the sheet P14 is specified as the last sheet, the sub-controller 18 determines the discharge timing based on the information on the sheet to be formed next and to be carried into the finisher 2. In this embodiment, the sheet is an A4 size sheet, which is the same size as the stored sheets P11 to P14, but the job contains only one sheet and the number of paths as a transport path (n = 2 ), The sub-controller 18 transmits a discharge request signal to the finisher controller 29. In response to this, on the finisher 2 side, the sheet bundle B1 is shifted by the shift amount Δ with respect to the sheet bundle B0 discharged to the main tray 22.
(Sheets P11 to P14) are forcibly discharged to the main tray 22 after the shift. In this way, on the main tray 22, the sheet bundles B0 and B1 are shifted and overlapped with each other, and the processing unit can be clarified. In this embodiment, since the stapling process is not required, the stapling process is not executed at this ejection timing. However, when the stapling process is required, the stapling process is executed prior to the shift movement.

On the other hand, on the image forming apparatus 1 side, the idling process is performed in accordance with the job data (3) in parallel with the above-described series of discharging processes, so that the next sheet P15 is not carried into the finisher 2 and the discharging process is performed. The interference with is prevented.

Then, following the idling process, the sub-controller 18 controls each part of the apparatus according to the job data (4) to form a toner image I21 on the intermediate transfer belt 141 as shown in FIG. Meanwhile, the toner image I21 is transferred onto the sheet P21 conveyed to the secondary transfer area, and is discharged to an appropriate discharge position such as the finisher 2 or a standard discharge tray.

As described above, an image is formed next to the sheet bundle B1 (sheets P11 to P14) stored in the intermediate tray 21.
Although the size of the paper P21 to be carried into the finisher 2 is A4 size like the stored papers P11 to P14, only one sheet is smaller than the number of passes. Is the main path Pm
The paper bundle (stored papers P11 to P14) remains in the intermediate tray 21 while being kept in the carry-in standby state. However, in this embodiment, the sheet bundle B1 is discharged to the main tray 22 simultaneously with the completion of the storage of the final sheet P14 in the intermediate tray 21, so that the sheet bundle B1 is prevented from staying inside the finisher 2 for a long time. can do.

<Fourth Embodiment: FIG. 14> In this fourth embodiment, as shown in FIG. 14 (a), two copies of an A4 size document as a processing unit (one copy) are printed. This is the content of the request. In order to execute such a print content, the host computer 5 sends the main controller 17
Is sent to the main controller 1
7 converts the image forming command into the following five job data so as to be in a format suitable for the operation instruction of each unit of the apparatus.

(1) A job for printing two A4 size documents; (2) A job for printing two A4 size documents; (3) A job for printing two A4 size documents; ) A job for printing two pages of an A4 size document;
In the job (2), the last sheet is designated.

First, as in the first embodiment, the job data
According to (1) and (2), the sub-controller 18 controls each unit of the apparatus to form toner images I11 to I14 on the intermediate transfer belt 141 as shown in FIG. Image I on the paper P11-P14 conveyed
11 to I14 are transferred and conveyed to the finisher 2. In the finisher 2, the sheets P11 to P14 are sequentially conveyed to and stored in the intermediate tray 21 via the main path Pm. In this embodiment, the sheet bundle B0 has already been discharged to the main tray 22 at this time.

Here, since the sheet P14 is designated as the last sheet, the sub-controller 18 determines the discharge timing based on the information on the sheet to be image-formed next and conveyed to the finisher 2. In this embodiment, the sheet is A4 size sheet, the same size as the stored sheets P11 to P14, and four sheets are printed in the next processing unit. ), The respective parts of the apparatus are controlled to form toner images I21 and I22 on the intermediate transfer belt 141 as shown in FIG.
Is formed, the toner images I21 and I22 are respectively transferred to the sheets P21 and P22 which are continuously conveyed to the secondary transfer area, and are to be conveyed to the finisher 2. In the finisher 2, an automatic discharge operation is performed.

Here, if a paper jam or a paper break occurs, the first image cannot be formed, and the image forming apparatus 1 informs the display panel (not shown) that a paper break or a paper jam has occurred. Is displayed, and the image formation is interrupted until the display disappears. Therefore, a problem that a sheet bundle remains in the intermediate tray 21 until such a device status (paper shortage or paper jam) is solved as it is is generated. If the second sheet P22 is out of paper or a paper jam occurs, the first sheet P21
Is already on standby in the main path Pm of the finisher 2, the sheet bundle B1 (sheets P11 to P14) remains in the intermediate tray 21 and is not stored in the main path Pm until such device status is resolved. The problem that the sheet P21 remains remains.

On the other hand, in this embodiment, when the paper runs out or the paper jam occurs on the first or second sheet, the sub-controller 18 sends a discharge request signal to the finisher 2 at the same time as the detection of the paper running out. The sheet bundle B1 (sheets P11 to P14) is output and discharged to the main tray 22. By doing so, it is possible to prevent the paper from staying inside the finisher 2 for a long time.

[0111]

As described above, according to the present invention, n different (n ≧ 2) paths are provided as a conveyance path for guiding a sheet to an intermediate tray, and an automatic discharge operation is performed. Therefore, unloaded sheets can be continuously loaded, and the throughput can be improved.
Further, when the number of unstored sheets to be stored in the intermediate tray following the sheet bundle is less than n, the sheet bundle stored in the intermediate tray is forcibly discharged and the sheets are transferred to the sheet post-processing device or means. Long stay can be prevented.

Even if the number of sheets to be conveyed to the sheet post-processing device or means after the sheet bundle is n or more, the m-th sheet (m =
When it is determined that the sheets (1, 2,..., N) cannot be conveyed to the sheet post-processing device or means, the sheet bundle is forcibly discharged from the intermediate tray to the main tray, whereby the intermediate It is possible to reliably prevent paper from staying in a tray or a path.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an image forming system according to the present invention.

FIG. 2 is a diagram illustrating a finisher included in the image forming system of FIG. 1;

FIG. 3 is a perspective view showing a position adjusting mechanism and a stapler provided in the finisher of FIG. 2;

FIG. 4 is a diagram illustrating an electrical configuration of the image forming system of FIG. 1;

FIG. 5 is a diagram showing an electrical configuration of a finisher controller.

FIG. 6 is a flowchart showing an automatic discharging operation of the finisher shown in FIG. 2;

FIG. 7 is a flowchart showing a forcible discharge operation of the finisher shown in FIG. 2;

FIG. 8 is a flowchart illustrating an operation of the image forming apparatus illustrated in FIG. 1;

FIG. 9 is a flowchart illustrating an operation of the image forming apparatus illustrated in FIG. 1;

FIG. 10 is a flowchart illustrating an operation of the image forming apparatus illustrated in FIG. 1;

FIG. 11 is an operation schematic diagram for explaining the first embodiment.

FIG. 12 is an operation schematic diagram for explaining the second embodiment.

FIG. 13 is an operation schematic diagram for explaining the third embodiment.

FIG. 14 is an operation schematic diagram for explaining the fourth embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image forming apparatus (image forming means) 2 finisher (sheet post-processing device, sheet post-processing means) 17 main controller (control means) 18 sub-controller (control means) 21 intermediate tray 22 main tray 26 Stapler (stapling means) 29 finisher controller (control means) 262 stapler body 290 CPU (control means) B0-B2 sheet bundle I11-I14, I21-I24 toner image P11-P14, P21-P24 sheet Pm … Main path Ps… Sub path

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F053 EA02 EA04 EA05 EC02 ED14 LA02 LA05 LA07 LB01 3F054 AA01 AB01 AC02 AC03 AC05 BA04 BB07 BJ11 DA01 DA14

Claims (10)

[Claims] 1. A paper post-processing apparatus for temporarily storing a plurality of sheets in an intermediate tray and then discharging a bundle of sheets of the plurality of stored sheets to a main tray at a time. N (n ≧ 2) paths different from each other are provided as a transport path for guiding the unstored sheets to the intermediate tray, and each of the (n−1) sheets successively carried in from the outside of the apparatus is different from each other. At the time when the n-th unstored sheet is carried in, the sheet bundle temporarily stored in the intermediate tray is automatically transferred to the (n-1) paths one by one while waiting. Instead of being discharged to the main tray, the n-th unstored sheet is conveyed to the intermediate tray via the remaining path, and the waiting unstored sheet is transferred via the respective waiting path. Intermediate tray The sheet bundle forcibly ejecting the sheet bundle stored in the intermediate tray when the number of uncontained sheets conveyed from the outside of the apparatus subsequent to the sheet bundle is less than n while being conveyed; Post-processing device. 2. An image is formed on a sheet according to an image forming instruction, and the sheet is loaded into the sheet post-processing device while
An image for outputting a discharge request when it is determined that the number of sheets to be conveyed to the sheet post-processing device subsequent to the sheet bundle stored in the intermediate tray is less than n based on the image forming command. 2. The sheet according to claim 1, further comprising: a control unit connected to the forming apparatus, the control unit configured to control to forcibly discharge the sheet bundle from the intermediate tray to the main tray in response to a discharge request output from the image forming apparatus. Post-processing device. 3. The image forming apparatus according to claim 1, wherein the number of sheets to be conveyed to the sheet post-processing apparatus subsequent to the sheet bundle stored in the intermediate tray is n or more.
The m-th sheet (m =
When it is determined that the sheet (1, 2,..., N) cannot be conveyed to the sheet post-processing apparatus, the control unit of the sheet post-processing apparatus is configured to output a discharge request. 3. The sheet post-processing apparatus according to claim 2, further comprising control means for controlling to forcibly discharge the sheet bundle from the intermediate tray to the main tray in response to a discharge request. 4. An image is formed on a sheet according to an image forming instruction, and the sheet is loaded into the sheet post-processing device while
The image forming apparatus is connected to an image forming apparatus that outputs information related to the image forming command, and is loaded into the apparatus after the sheet bundle stored in the intermediate tray based on the information output from the image forming apparatus. 2. The sheet post-processing apparatus according to claim 1, further comprising control means for controlling to forcibly discharge the sheet bundle from the intermediate tray to the main tray when it is determined that the number of sheets to be printed is less than n. 5. An intermediate tray for temporarily storing a plurality of sheets, and n different transport paths for guiding uncontained sheets carried in from outside the apparatus to the intermediate tray.
.Gtoreq.2), and each of the (n-1) sheets sequentially carried in from the outside of the apparatus is different from each other (n-
1) The sheet bundle temporarily stored in the intermediate tray is automatically discharged to the main tray at the time when the n-th sheet has not been stored while the sheets are carried one by one into each path and made to stand by. Instead, the n-th unstored sheet is conveyed to the intermediate tray via the remaining path, and the waiting non-stored sheet is conveyed to the intermediate tray via each of the waiting paths. An image forming apparatus that is connected to a sheet post-processing device to form an image on a sheet according to an image forming command, and conveys the sheet to the intermediate tray based on the image forming command. When it is determined that the number of sheets to be conveyed to the sheet post-processing device subsequent to the sheet bundle is smaller than n, the sheet bundle is forcibly discharged from the intermediate tray to the main tray. An image forming apparatus comprising a control unit for causing the image forming apparatus to output the image. 6. The image forming apparatus according to claim 1, wherein the control unit of the image forming apparatus is configured such that the number of sheets to be conveyed to the sheet post-processing apparatus after the sheet bundle stored in the intermediate tray is n or more. If it is determined that the m-th sheet (m = 1, 2,..., N) to be carried in after the sheet bundle cannot be conveyed to the sheet post-processing device, the discharge request is also issued. The image forming apparatus according to claim 5, wherein the image forming apparatus outputs the sheet bundle from the intermediate tray to the main tray forcibly. 7. An image forming means for forming an image on a sheet in accordance with an image forming command inputted from outside, an intermediate tray for temporarily storing a plurality of sheets, and an image carried in from said image forming means. N different conveyance paths (n ≧ n) as a conveyance path for guiding the formed sheet to the intermediate tray.
2), each of the (n-1) sheets successively carried in from the image forming unit is carried one by one into (n-1) different paths, and is put on standby. Instead of automatically discharging the sheet bundle temporarily stored in the intermediate tray to the main tray at the time when the sheet of uncontained paper is carried in, the n-th sheet of non-contained paper is replaced with the remaining sheet. A sheet post-processing unit that conveys the non-stored sheets in a standby state to the intermediate tray through a path in a standby state at the same time as conveying the sheet to the intermediate tray via a path, the image forming unit and the sheet post-processing unit The control unit should carry in the sheet post-processing unit following the sheet bundle stored in the intermediate tray based on the image forming command. When the number of the paper is determined to be smaller than n sheets, the image forming system characterized by forcibly discharged from the intermediate tray the sheet bundle to the main tray. 8. The control unit according to claim 1, wherein the number of sheets to be conveyed to the sheet post-processing unit following the sheet bundle stored in the intermediate tray is n or more. Subsequently, the m-th sheet (m = 1,
8. The image forming system according to claim 7, wherein when it is determined that the sheet of (2,..., N) cannot be transported to the sheet post-processing means, the sheet bundle is forcibly discharged from the intermediate tray to the main tray. . 9. After a plurality of sheets are temporarily stored in the intermediate tray, the following automatic discharge operation is executed to collectively discharge the sheet bundle including the plurality of stored sheets to the main tray. In the image forming method, when the number of sheets to be stored in the intermediate tray subsequent to the sheet bundle is less than n, a forced discharge operation is performed instead of the automatic discharge operation, and the sheets are stored in the intermediate tray. An image forming method, wherein the sheet bundle is forcibly discharged. In the automatic discharge operation, the sheet bundle temporarily stored in the intermediate tray is discharged to the main tray, and the image-formed sheets are emptied through n different (n ≧ 2) paths. Stored in the intermediate tray,
Each of the (n-1) sheets following the sheet bundle temporarily stored in the intermediate tray is different from each other (n-
1) Instead of automatically discharging the bundle of sheets in the intermediate tray to the main tray when the n-th unstored sheet is carried in while carrying the sheets one by one into each path and making them stand by, In this operation, the n-th unstored sheet is conveyed to the intermediate tray via the remaining path, and simultaneously, the non-stored sheet in the standby state is conveyed to the intermediate tray through the respective waiting path. 10. Even if the number of sheets to be stored in the intermediate tray subsequent to the sheet bundle is n or more, the m-th sheet (m = 1, 2,
10. The image forming method according to claim 9, wherein the sheet bundle is forcibly discharged from the intermediate tray to the main tray when the sheets of..., N) cannot be carried into the corresponding path.