JP2001215858A - Printer and image forming method in the printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a throughput of a printer constructed so that a paper sheet with a formed image can be transported to a paper sheet posttreatment means which performs a prescribed posttreatment to a plurality of paper sheets having an image formed. SOLUTION: A main controller judges whether the posttreatment by a finisher is performed and further whether the exchange condition of the finisher is satisfied, on the basis of the content of a printing request included in an image forming command, changes then a spacing for forming an image in an intermediate transfer belt 141 according to the judgment result, and controls an image forming mode in an image forming means. For example, when not performing the posttreatment, an image is formed continuously on the intermediate transfer belt 141, and in the posttreatment under the condition where exchange conditions are not satisfied, an image is formed on the intermediate transfer belt 141 at intervals of α corresponding to the time necessary for the posttreatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for forming an image on a sheet by an image forming means in accordance with an image forming command given from the outside of the apparatus, and then performing the post-processing on the sheet on which the image has been formed. The present invention relates to a printer for conveying to a processing unit and an image forming method in the printer.

[0002]

2. Description of the Related Art In a printer, an image is formed on a sheet in accordance with an image forming command (a signal indicating the content of a print request) from an external device such as a host computer, and then the sheet is discharged to a standard discharge tray of the printer. However, when handling a relatively large amount of paper, it has been conventionally proposed to connect paper post-processing means to the discharge side of the printer or to incorporate paper post-processing means in the printer.

The paper post-processing means temporarily stores the paper discharged from the printer in an intermediate tray and then collectively discharges the stored paper stored in the intermediate tray to a main tray. For example, when five copies of A4 size paper are printed as one copy (processing unit), and each copy is discharged to the main tray of the sheet post-processing means, images are continuously formed on A4 size paper by a printer. Meanwhile, a series of operations of transporting each sheet to the intermediate tray and temporarily storing each sheet is repeated five times, so that one sheet 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, and subsequently, the second to fifth copies are sequentially transferred to the main tray via the intermediate tray in the same manner as the first copy. Is discharged.

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.

As described above, in the sheet post-processing means, after a plurality of sheets on which images have been formed are temporarily stored in the intermediate tray, the stored sheets stored in the intermediate tray are collectively stored. Then, predetermined post-processing such as discharging to the main tray or performing staple processing on the sheet bundle stored in the intermediate tray as necessary is executed.

[0006]

When post-processing is performed by the sheet post-processing means, the sheets stored in the intermediate tray are subjected to stapling as necessary, and are then discharged to the main tray. Then, the next sheet cannot be carried into the sheet post-processing means. Therefore, in the printer, an interval corresponding to the time required for post-processing (hereinafter, referred to as a “processing unit switching 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. Need to be taken.

Therefore, in the conventional printer, when the paper post-processing means is connected to the printer, or when the paper post-processing means is incorporated, the processing unit switching interval is set regardless of whether or not the paper post-processing is executed. It is set uniformly. As a result, even when the post-processing is not performed, that is, even when the paper on which the image is formed is discharged to the standard discharge tray, the paper cannot be continuously discharged to the discharge tray, which lowers the throughput. It is a factor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a printer configured to be able to convey an image-formed sheet to a sheet post-processing means for performing a predetermined post-process on a plurality of sheets on which images have been formed. And to improve the throughput.

[0009]

According to the present invention, after an image is formed on a sheet by an image forming means in accordance with an image forming command given from outside the apparatus, the sheet on which the image has been formed is subjected to post-processing. What is claimed is: 1. A printer for conveying to a sheet post-processing unit and an image forming method in the printer, the image forming method comprising: ing. For this reason, compared with the case where the image forming mode is set uniformly regardless of the presence or absence of post-processing as in the conventional example,
The image forming mode can be optimized according to the presence or absence of post-processing, and the throughput is improved.

When the sheet post-processing means is configured as described below, a plurality of sheets temporarily stored in the intermediate tray are collectively transferred while the sheets are continuously conveyed to the sheet post-processing means. Then, a post-process of discharging to the main tray can be executed. That is, the paper post-processing means
When a predetermined replacement condition is satisfied, at least one sheet carried into the sheet post-processing means is temporarily stored in the intermediate tray while temporarily waiting on the transport path. Instead of discharging the stored stored papers to the main tray, the non-stored papers waiting in the transport path are transported to the intermediate tray. When the post-processing is performed by such a sheet post-processing unit, the same image forming mode as that when the post-processing is not performed can be adopted by satisfying the replacement condition.
In addition to whether or not to perform post-processing, determine whether or not the replacement condition is satisfied based on the image forming command,
It is desirable to control the image forming mode in the image forming means according to the result of the determination.

[0011]

FIG. 1 is a diagram showing a first embodiment of a printer according to the present invention. The printer 1 includes a finisher 2 disposed adjacent to the printer 1 and a multi-bin unit 3 disposed above the printer 1.
Are mechanically connected to an optional paper feed cassette 4 arranged below the printer 1 and play a central role in the printer system shown in FIG.

This printer 1 prints a full-color image on paper by superimposing four color toners of yellow (Y), cyan (C), magenta (M), and black (K), or prints a black (K) image. A monochrome image is printed on paper using only toner, and as shown in FIG.
3, a transfer unit 14, a fixing unit 15, and a paper supply / discharge unit 16 are provided.

The photoreceptor unit 12 includes a photoreceptor 121 rotatable in a counterclockwise direction in FIG. 1 and a charging roller 122 as a charging unit around the photoreceptor 121 along the rotation direction. Developing units 123Y, 123C, 123M, 123K as developing means;
And a cleaning unit 124 are provided. Then, laser light is emitted from the exposure unit 13 toward the outer peripheral surface of the photoconductor 121 charged by the charging roller 122, and an electrostatic latent image corresponding to an image forming command given from outside the apparatus is formed as described later. You.

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. Thus, the photoconductor unit 1
Reference numeral 2 denotes a toner image corresponding to the image forming command.
Form on top.

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. As described above, in this embodiment, the intermediate transfer belt 141 functions as the “image carrier” of the present invention, and an image forming unit that forms an image on a sheet by the photosensitive unit 12, the exposure unit 13, and the transfer unit 14 is configured. Have been.

The sheet on which the toner image has been transferred by the transfer unit 14 is secondary-transformed along a predetermined sheet feeding path (two-dot chain line) by the sheet feeding section 161 of the sheet feeding / discharging unit 16 serving as the conveying means of the present invention. The sheet is conveyed to the fixing unit 15 disposed downstream of the transfer area, and the toner image on the conveyed sheet is fixed on the sheet. Then, the paper is further conveyed to the paper discharge unit 164 along the paper supply path.

This 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 a fixed paper discharge tray, a finisher (paper post-processing means)
2 or multi-bin unit 3
Re-feed unit 1 for forming an image on the other side
Or to the 65 side.

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 an example of a finisher which can be connected to the printer shown in FIG. The finisher 2 functions as the "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. The intermediate tray 21 temporarily stores the sheet carried in from the printer 1 to the finisher 2. After that, the paper stored in the intermediate tray 21 is discharged to the main tray 22. Hereinafter, the configuration of each part of the finisher 2 will be described in more detail with reference to FIG.

A paper feed port 20 for receiving paper discharged from the printer 1 is provided on a side surface of the finisher 2.
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. Paper mouth 2
01 is located immediately downstream. 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 further to the intermediate tray 21 side 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 has 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 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 needed.
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 printer system of FIG. In this printer system, as shown in FIG.
And a sub-controller 18 are provided. The main controller 17 includes a CPU, an image memory, a communication interface, and the like. Upon receiving an image formation command (a signal indicating a print request content) from the host computer 5, the main controller 17 is suitable for an operation instruction of each unit of the printer 1. The job data is converted into job data (print information) in a format and provided to the sub controller 18. In particular, the main controller 17
Determines whether or not post-processing by the finisher 2 is to be performed as described later, and whether or not the replacement condition of the finisher 2 is satisfied, creates job data according to the determination result, and Has given to.
Thus, the main controller 17 functions as the “control means” of the present invention.

Sub-controller 1 receiving job data
Reference numeral 8 includes a CPU, a ROM, a RAM, a communication interface, and the like, and controls each unit of the printer 1 according to job data. In response to this, the sub-controller 18 provides a control signal such as a discharge request to be described later to the finisher controller 29 by serial communication, and various control signals to the multi-bin unit controller 31, and further supplies an optional sheet feeder. By giving various control signals to the cassette controller 41, the respective units of the finisher 2, the multi-bin unit 3, and the optional sheet cassette 4 are controlled to execute a printing process corresponding to an image forming command.

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 so that various information is supplied to the CPU 290 from the sub-controller 18 of the printer 1 via the communication interface 294 together with detection signals from the sensor groups S21 to S24 provided in the finisher 2. The CPU 290 controls each part of the finisher according to a program stored in advance in the ROM 292 based on these signals and information.

Further, 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: The jogger 272 is driven in the width direction X.

(F) Stapler drive controller 263: The stapler main body 262 is moved and positioned in the width direction X, and the sheets P stored in the intermediate tray 21 are collectively stapled at a desired position.

(G) Main motor drive control section 291: The main motor drive control section 291 controls the drive of a main motor (not shown) as a drive source of each section of the finisher 2.

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

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

Reference numeral 293 in the figure denotes control data for controlling each part of the finisher 2 or 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 printer system will be described.

The finisher 2 performs the automatic discharge operation shown in FIG. 6 when the replacement condition of continuously discharging a specific size, for example, A4 size paper P to the main tray 22 in units of a plurality of sheets is satisfied. Otherwise, the forced ejection operation shown in FIG. 7 is executed in other cases.

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 step ST2, that is, when it is confirmed that the last sheet has been stored in the intermediate tray 21, the sub controller 18 of the printer 1
A notification of the completion is sent to the A4 size first sheet P constituting the next processing unit.
Is carried into the main path Pm, and immediately before the leading edge of the sheet reaches the branch roller 253c, the branch rollers 253a, 253
By switching the clutch connected to b 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 state for loading 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, when the replacement condition is satisfied, the paper bundle is discharged to the main tray 22 for each processing unit while the paper P is continuously carried into the finisher 2. And 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 printer 1 as shown in the figure (step ST21).
And whether or not stapling is designated in step ST22, and executes stapling only when stapling is designated (step ST2).
3).

Further, it is determined whether or not it is necessary to shift the sheet bundle 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 carried into the finisher 2 after the stored paper P stored in the intermediate tray 21 is different from the stored paper P, There is a possibility that discharge of the stored paper P in the intermediate tray 21 to the main tray 22 may be restricted due to a cause such as a cut or a paper jam. Therefore, in this embodiment, the sub-controller 18 of the printer 1 detects such a phenomenon, transmits a discharge request signal to the finisher 2, and forcibly discharges the sheet bundle to the main tray 22 at an appropriate timing. .

Next, an image forming operation in the printer system configured as described above will be described with reference to FIGS. In the printer 1, the main controller 17 controls the print request content included in the image forming command,
For example, it is determined whether or not post-processing by the finisher 2 is to be performed based on the paper size, the number of sheets, the number of processing units (number of copies), the discharge destination, and the like. The job data corresponding to the result is created and given to the sub-controller 18.

For example, as shown in FIG. 8A, one copy of four A4 size documents is set as a processing unit (one copy).
A case will be described in which an image forming instruction is issued from the host computer 5 to the printer 1 with a print request content of printing one copy of two documents of three sizes as a processing unit (one copy).

Here, as shown in FIG. 9B, when post-processing is not performed, that is, when an image is formed on a sheet P by the image forming means and then the sheet P is sequentially discharged to the standard discharge tray. Since there is no need to consider the interference of the paper P at the finisher 2 at all, image formation can be performed continuously. Therefore, in order to execute such a print content, the main controller 17 converts the image forming instruction 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 one A3 size document; ) A job for printing one page of an A3-size document; the last sheet is designated in jobs (2) and (4). In order to show it, the same figure (and later FIGS. 9 and 11)
Then, it is indicated by a black triangle.

Each time each job data is received, the sub-controller 18 sets the image I11 to I1 corresponding to each document.
4, while continuously forming I21 and I22 on the intermediate transfer belt 41, the image is transferred and fixed to each sheet, and further discharged to a standard discharge tray.

On the other hand, as shown in FIG. 9C, when performing post-processing, it is further determined whether or not the replacement condition is satisfied. In this specific example, the paper constituting the preceding processing unit is A4 size, while the paper constituting the subsequent processing unit is A3 size paper, which is different in size from the stored paper. Is not satisfied. Therefore, the main controller 17 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 an A4 size document for two pages; (2) A job for printing an A4 size document for two pages; (3) A job for widening the paper interval by idling; (4) A3 (5) A job for printing one page of an A3-size document; a job which is largely different from a case where post-processing is not executed is that the job is idle based on job data (3). The processing is being executed, and the gap α between images on the intermediate transfer belt 41 is increased by the idling processing. By doing so, the finisher 2 of the sheet on which the image has been formed is moved by the processing unit switching interval α.
Is stopped.

On the other hand, the sub-controller 18 transmits a discharge request signal to the finisher controller 29 during that time. Then, in response to this, on the finisher 2 side,
After the sheet bundle is shifted by the shift amount with respect to the sheet bundle discharged to the main tray 22, the sheet bundle is forcibly discharged to the main tray 22. By doing so, the sheet bundle is shifted and overlapped on the main tray 22 and the processing unit can be clarified. If staple processing is required, staple processing is performed prior to shift movement.

Then, following the idling process, the sub-controller 18 controls each unit of the apparatus according to the job data (4) to form an image I21 on the intermediate transfer belt 141 as shown in FIG. The image I21 is transferred to a sheet conveyed to the secondary transfer area, and is conveyed to the finisher 2. Then, the finisher 2 conveys the paper to the intermediate tray 21 via the main path Pm and stores it.

Subsequently, the sub-controller 18 controls each unit of the apparatus in accordance with the job data (5) to form the image I22 on the intermediate transfer belt 141 and to copy the image I21 onto the sheet conveyed to the secondary transfer area. The image is transferred and conveyed to the finisher 2. Then, the finisher 2 conveys the paper to the intermediate tray 21 via the main path Pm and stores it. As a result, two stored sheets of A3 size are stacked on the intermediate tray 21 in this order.

In the specific example shown in FIG. 8, a case where the replacement condition is not satisfied has been described. Next, a specific example in which the replacement condition is satisfied, for example, as shown in FIG.
A description will be given of a case where an image forming command is issued from the host computer 5 to the printer 1 with a print request content of printing two copies of four A4 size documents as a processing unit (one copy).

As shown in FIG. 9B, when post-processing is not performed, that is, when an image is formed on a sheet by the image forming means and then the sheet is sequentially discharged to the standard discharge tray, Similarly to the above specific example (FIG. 8), the images I11 to I14 and I21 to I24 corresponding to the respective documents are transferred and fixed on the respective sheets while continuously forming them on the intermediate transfer belt 41.
Further, the paper is discharged to a standard discharge tray.

On the other hand, as shown in FIG. 10C, when performing post-processing, it is further determined whether or not the replacement condition is satisfied. In this specific example, the paper constituting the preceding processing unit is A4 size, and the paper constituting the subsequent processing unit is also A4 size paper, so that the replacement condition is satisfied. Therefore, the main controller 17 creates exactly the same job data as in the case where the post-processing is not performed, and gives it to the sub-controller 18. As a result, the printer 1 continuously transfers and fixes images to each sheet while continuously forming images I11 to I14 and I21 to I24 corresponding to each document on the intermediate transfer belt 41, and further continuously discharges them to the finisher 2.

Then, in the finisher 2, after the paper on which the images I11 to I14 are formed is conveyed and stored in the intermediate tray 21 via the main path Pm, the automatic discharge process is executed.
That is, after the first sheet (the sheet on which the image I21 is formed) of the next processing unit is transported on standby in the main path Pm, the second sheet (the sheet on which the image I22 is formed) is finished. Carry in 2 Then, the carry-in detection sensor S
When the leading end of the second sheet 22 is detected by 21, the sheet bundle stored in the intermediate tray 21 is shifted by a predetermined shift amount with respect to the sheet bundle discharged to the main tray 22. The paper is forcibly discharged to the main tray 22. If staple processing is required here, staple processing is executed prior to shift movement. Alternatively, the second sheet conveyed to the sub-path Ps and the first sheet conveyed on the main path Pm are simultaneously conveyed and stored in the intermediate tray 21. afterwards,
The sheets on which the images I23 and I24 are formed are sequentially transferred to the main path Pm.
Through the intermediate tray 21.

As described above, according to this embodiment, whether the main controller 17 executes the post-processing by the finisher 2 based on the print request content included in the image forming command, and furthermore, the condition for replacing the finisher 2 is determined. It is determined whether or not the condition is satisfied, and the image forming interval on the intermediate transfer belt 141 is changed according to the result of the determination to control the image forming mode of the image forming unit. More specifically,
When post-processing is not performed (FIGS. 8B and 9B),
Alternatively, when the post-processing is executed but the replacement condition is satisfied (FIG. 9C), the image is continuously formed on the intermediate transfer belt 141, and the post-processing is performed in a state where the replacement condition is not satisfied. When the process is executed (FIG. 8C), an image is formed on the intermediate transfer belt 141 at an interval α corresponding to the time required for post-processing. Therefore, the throughput of the printer 1 can be improved as compared with the related art in which the image forming interval on the intermediate transfer belt 141 is fixed uniformly.

In the above embodiment, the finisher 2
Is configured to be able to execute an automatic discharge process. Therefore, even when the post-process is executed, the intermediate transfer belt 1 is controlled depending on whether or not the replacement condition is satisfied.
Although the image forming interval on the image transfer belt 41 is changed, an image may be formed on the intermediate transfer belt 141 at a uniform interval α when performing post-processing.
In this case, control by the main controller 17 can be simplified.

In the above embodiment, the printer 1 is connected to the finisher 2 which can execute the automatic discharge process. However, the finisher which can be connected to the printer 1 is connected to the intermediate tray 21 as shown in FIG. There is a finisher 2 'which has a single transfer path and cannot execute the automatic discharge process. Also in this case, the throughput of the printer 1 can be improved by applying the present invention. Hereinafter, a second embodiment of the present invention will be described with reference to FIG.

FIG. 11 is a diagram showing the operation of the second embodiment of the printer according to the present invention. The second embodiment is largely different from the first embodiment only in that it is determined whether or not post-processing is performed without determining the replacement condition, and the intermediate transfer belt is determined in accordance with the determination result. 141
The point is that the image forming position is changed.

Here, as shown in FIG.
An image forming command is issued from the host computer 5 to the printer 1 with a print request content of printing two copies of a document having four sizes and four sheets as a processing unit (one copy).

Here, as shown in FIG. 11B, when post-processing is not performed, that is, when an image is formed on a sheet by the image forming means and then the sheet is sequentially discharged to the standard discharge tray, Since there is no need to consider any paper interference at the finisher 2 ', image formation can be performed continuously. Therefore, in order to execute such print contents,
The main controller 17 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) a job for printing two pages of an A4 size document; and each time the job data is received, the sub-controller 18 causes the images I11 to I14 and I21 to I24 corresponding to each document to be printed.
While being continuously formed on the intermediate transfer belt 41, is transferred and fixed to each sheet, and is further discharged to a standard discharge tray.

On the other hand, as shown in FIG. 11C, when performing post-processing, the main controller 17 sets the following five job data in order to make the image forming command a format suitable for the operation command of each section of the apparatus. Convert to

(1) A job for printing two pages of an A4 size document; (2) a job for printing two pages of an A4 size document; (3) a job for widening the paper interval by idling; (4) A4 (5) A job for printing A4 size document for two pages; a job which is greatly different from a case where post-processing is not performed is that the job is idle based on job data (3). The processing is being executed, and the gap α between images on the intermediate transfer belt 41 is increased by the idling processing. In this manner, the conveyance of the sheet on which the image is formed to the finisher 2 'is interrupted by the processing unit switching interval α.

Meanwhile, the sub-controller 18 transmits a discharge request signal to the finisher controller 29 during that time. Then, in response to this, the finisher 2 ′ shifts the sheet bundle by the shift amount with respect to the sheet bundle discharged to the main tray 22 and then forcibly discharges the sheet bundle to the main tray 22. By doing so, the sheet bundle is shifted and overlapped on the main tray 22 and the processing unit can be clarified. If staple processing is required, staple processing is performed prior to shift movement.

As described above, according to the second embodiment, the main controller 17 determines whether or not to execute the post-processing by the finisher 2 'based on the print request content included in the image forming command, and the determination is made. The image forming interval on the intermediate transfer belt 141 is changed according to the result, and the image forming mode of the image forming unit is controlled. More specifically, when the post-processing is not performed (FIG. 11B), while the image is continuously formed on the intermediate transfer belt 141,
When the post-processing is performed (FIG. 11C), an image is formed on the intermediate transfer belt 141 at a processing unit switching interval α corresponding to the time required for the post-processing. Therefore,
The throughput of the printer 1 can be improved as compared with the conventional example in which the image forming interval on the intermediate transfer belt 141 is fixed uniformly.

The present invention is not limited to the above embodiment, and various changes other than those described above can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the printer 1 connected and connected to the finishers 2 and 2 '(sheet post-processing means) provided separately and independently has been described. However, the present invention is also applicable to a printer with a finisher incorporating a finisher. The present invention can be applied, and the same operation and effect as those of the above embodiment can be obtained by applying the present invention. Further, a printer with a finisher may be configured so that the entire printer is controlled by a sub-controller without providing a finisher controller.

In the above embodiment, the automatic discharge operation is executed only when the A4 size paper P is continuously discharged to the main tray 22 in units of a plurality of sheets. The present invention is not limited to the size, and the automatic discharge operation may be performed when another size, for example, letter size paper is continuously discharged to the main tray 22 in units of a plurality of sheets.

In the above embodiment, the image forming mode of the image forming means is controlled by executing the idling process and changing the image forming interval on the intermediate transfer belt 141. The image forming position on the image forming unit 141 may be changed to control the image forming mode of the image forming unit.

In the above embodiment, the intermediate transfer belt 141 is used as the image carrier of the present invention, and
The image forming mode is controlled by changing the image forming interval and the forming position on the photoconductor 41. However, the image forming mode is changed by changing the image forming interval and the forming position on the photoconductor 121. You may make it control. In particular, in a printer that directly transfers an image on a photoreceptor to paper without using an intermediate transfer medium, it is necessary to control an image forming mode by changing a forming interval and a forming position of an image on a photoreceptor. .

Further, in the above embodiment, the photosensitive member 121
Although the upper toner image is transferred to the intermediate transfer belt 141, a transfer medium other than the intermediate transfer belt (a transfer drum, a transfer belt, a transfer sheet, an intermediate transfer drum, an intermediate transfer sheet, a reflective recording sheet, or a transparent storage sheet) Such)
The present invention can be applied to a printer that transfers a toner image to a printer. Further, the present invention can be applied to a printer employing a so-called tandem method as an image forming method.

[0088]

As described above, according to the present invention, according to whether or not post-processing is executed in the sheet post-processing means,
Since the image forming mode is controlled by the image forming unit, the presence / absence of post-processing is compared with the case where the image forming mode is uniformly set regardless of the presence / absence of post-processing as in the conventional example. The image forming mode can be optimized in accordance with the above, and the throughput can be improved.

Further, when the sheet post-processing means for executing the post-processing is configured to be able to sequentially carry in the image-formed sheets from the printer when a predetermined replacement condition is satisfied, the post-processing is executed. Whether or not the replacement condition is satisfied is determined based on the image forming command in addition to whether or not the image forming command is issued, and the image forming mode of the image forming unit is controlled in accordance with the determination result. This makes it possible to further optimize the image forming mode and further improve the throughput.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a printer according to the present invention.

FIG. 2 is a diagram illustrating an example of a finisher configured to be connectable to the printer 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 printer system of FIG. 1;

FIG. 5 is a diagram illustrating an electrical configuration of a finisher controller that controls the finisher illustrated in FIG. 2;

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 diagram illustrating an image forming operation in the printer of FIG. 1;

FIG. 9 is a diagram illustrating an image forming operation in the printer of FIG. 1;

FIG. 10 is a diagram showing a second embodiment of the printer according to the present invention.

11 is a diagram showing an image forming operation in the printer of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printer 2, 2 '... Finisher (paper post-processing means) 12 ... Photoconductor unit (image forming means) 13 ... Exposure unit (image forming means) 14 ... Transfer unit (image forming means) 16 ... Paper supply / discharge unit ( 17: Main controller (control means) 18: Sub-controller 21: Intermediate tray 22: Main tray 26: Stapler 121: Photoconductor 141: Intermediate transfer belt (intermediate transfer medium) 161: Paper supply unit (conveyance means) 164 ... Paper discharge section (transporting means) I11 to I14, I21 to I24... Image Pm... Main path Ps... Subpath P.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/00 534 G03G 21/00 384 5B021 21/00 384 G06F 3/12 P 9A001 G06F 3/12 G03G 21 / 00 372 F term (for reference) 2C061 AQ06 AR01 AS02 CK04 HH05 HK11 HN15 2H027 DA32 ED06 ED16 ED21 ED29 EE01 EE07 EF09 FA23 FA24 FA35 ZA07 2H072 AA01 AA17 AA31 AB15 AB17 GA08 HB07 AC03 BA08 5B021 AA01 KK06 LE08 9A001 HH34 JJ35 KK42

Claims (13)

[Claims] 1. A sheet post-processing unit for performing predetermined post-processing on a plurality of sheets on which images have been formed is provided separately and independently, and is formed on the sheets by the image forming unit in accordance with an image forming command given from outside the apparatus. After forming an image, when performing post-processing, a printer that conveys an image-formed sheet to the sheet post-processing unit may be configured to perform image processing according to whether the post-processing is performed. A printer comprising control means for controlling a forming mode. 2. A sheet post-processing means for performing predetermined post-processing on a plurality of sheets on which images have been formed, an image forming means for forming an image on a sheet in accordance with an image forming command given from outside the apparatus, Conveying means for conveying the sheet on which the image is formed by the image forming means to the sheet post-processing means,
A printer integrally including a control unit for controlling the sheet post-processing unit, the image forming unit, and the transport unit, wherein the control unit determines whether the image forming unit performs post-processing. A printer that controls an image forming mode in the printer. 3. The sheet post-processing means conveys the image-formed sheet to an intermediate tray via a conveying path as the post-processing, temporarily stores a plurality of sheets in the intermediate tray, The stored sheets stored in the intermediate tray are collectively discharged to the main tray. If a predetermined replacement condition is satisfied, at least one of the sheets that have been conveyed into the sheet post-processing unit is discharged. While temporarily holding more than one sheet of paper on the transport path, instead of discharging stored paper temporarily stored in the intermediate tray to the main tray, the apparatus waits on the transport path. The control unit is configured to convey the non-stored sheets in a standby state to the intermediate tray, and the control unit determines whether the post-processing is performed and whether the replacement condition is satisfied based on the image forming command. Whether according to claim 1 or 2, wherein the printer controls the image forming mode in the image forming unit. 4. The image forming unit is configured to form an image corresponding to the image forming command on an image carrier, and the control unit is configured to form an image on the image carrier. 4. The printer according to claim 1, wherein the image forming mode is controlled by changing an interval. 5. The control means forms an image continuously on the image carrier when no post-processing is performed,
5. The printer according to claim 4, wherein when performing post-processing, images are formed on the image carrier at intervals corresponding to a time required for the post-processing. 6. The image forming unit is configured to form an image corresponding to the image forming command on an image carrier, and the control unit does not execute post-processing, or While performing the processing, if the replacement condition is satisfied, an image is continuously formed on the image carrier, while post-processing is performed if the replacement condition is not satisfied. 4. The printer according to claim 3, wherein images are formed on the image carrier at intervals corresponding to the time required for the image forming. 7. The image forming unit is configured to form an image corresponding to the image forming command on an image carrier, and the control unit is configured to form an image on the image carrier. 4. The printer according to claim 1, wherein the position is changed to control an image forming mode. 8. The image forming apparatus according to claim 4, wherein the image forming unit is configured to form an image corresponding to the image forming command on a photosensitive member functioning as the image carrier. Printer. 9. An image forming unit, comprising: a photoreceptor unit for forming a toner image corresponding to the image formation command on a photoreceptor; and a toner on the photoreceptor on an intermediate transfer medium functioning as the image carrier. The printer according to any one of claims 4 to 7, further comprising: a transfer unit that transfers an image and forms an image corresponding to the image forming command on the intermediate transfer medium. 10. The sheet post-processing means includes a main tray, an intermediate tray for temporarily storing sheets formed by the image forming means, and a staple for stored sheets stored in the intermediate tray. A stapler for performing a process, as the post-processing, after temporarily storing a plurality of sheets in the intermediate tray, performing a stapling process on the plurality of stored sheets, and further collectively storing the stored sheets. The printer according to any one of claims 1 to 9, wherein the printer is configured to discharge the sheet to a main tray. 11. A sheet post-processing means for performing predetermined post-processing on a plurality of sheets on which images have been formed is provided independently of the sheet post-processing means. After forming an image, when performing post-processing based on the image forming command, a determining step of determining whether to execute post-processing in a printer that conveys an image-formed sheet to the sheet post-processing means. And, when it is determined that the post-processing is not to be performed by the determination step, while the image forming unit continuously forms an image corresponding to the image forming command, when it is determined that the post-processing is to be performed, An image forming step of forming an image corresponding to the image forming command by the image forming unit at intervals corresponding to a time required for processing thereafter. . 12. A sheet post-processing means for performing predetermined post-processing on a plurality of sheets on which images are formed, an image forming means for forming an image on a sheet in accordance with an image forming command given from outside the apparatus, And a conveying unit for conveying the sheet on which the image is formed by the image forming unit to the sheet post-processing unit. Execution of predetermined post-processing by the sheet post-processing unit is instructed by an image forming command provided from outside the apparatus. A step of determining whether or not to perform post-processing in a printer that forms an image on a sheet by an image forming unit in accordance with the image forming command and then conveys the sheet to the sheet post-processing unit; When it is determined that the post-processing is not to be performed by the process, the image forming unit continuously forms an image corresponding to the image forming command while executing the post-processing. An image forming step of forming an image corresponding to the image forming command by the image forming unit at an interval corresponding to a time required for the subsequent processing. Method. 13. The sheet post-processing means, as the post-processing, transports an image-formed sheet to an intermediate tray via a transport path, and temporarily stores a plurality of sheets in the intermediate tray. The stored sheets stored in the intermediate tray are collectively discharged to the main tray. If a predetermined replacement condition is satisfied, at least one of the sheets that have been conveyed into the sheet post-processing unit is discharged. While temporarily holding more than one sheet of paper on the transport path, instead of discharging stored paper temporarily stored in the intermediate tray to the main tray, the apparatus waits on the transport path. It is configured to transport the non-stored paper in a standby state to the intermediate tray, and in the determination step, in addition to whether to execute post-processing,
It is determined whether or not the replacement condition is satisfied based on the image forming command, and, even if it is determined that post-processing is to be performed in the image forming process, the replacement condition is satisfied. 13. The image forming method according to claim 11, wherein the image forming unit continuously forms an image corresponding to the image forming command.