JP4482294B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a digital copying machine in which optional equipment such as a finisher can be mounted.
[0002]
[Prior art]
In recent years, digital copiers that can be equipped with optional equipment such as finishers have appeared. In such a digital copying machine, the operation of the digital copying machine main body is controlled in accordance with the processing speed of the finisher. In the digital copying machine main body as described above, it is necessary to secure a paper discharge interval for each sheet on which an image is formed in accordance with the operation of the finisher. The paper discharge interval of the image-formed paper required by the finisher side is called sheet processing time.
[0003]
On the main body of the digital copying machine, the sheet processing time is acquired from an optional finisher, and the paper discharge timing is controlled according to the sheet processing time. Further, in the conventional digital copying machine, the sheet processing time is acquired from the finisher at the timing when the paper feeding is started. Further, in a conventional digital copying machine, an image is prepared after feeding is started, and the image is exposed on a photosensitive drum as an image carrier. That is, in the conventional digital copying machine, the sheet discharge time to the finisher of each sheet is controlled by acquiring the sheet processing time at the sheet feeding start timing that is the timing before the image exposure start. Yes.
[0004]
In recent years, some digital copiers that form color images form a color image by transferring a four-color or three-color image on an intermediate transfer member, and transferring the color image onto a sheet. is there. Some digital copiers that form color images in this manner start image exposure at a timing earlier than the start of paper feed in order to shorten the image formation time.
[0005]
  AboveFinisherFor example, a technique related to a sheet material post-processing apparatus is disclosed (see Patent Document 1). This sheet material processing apparatus can appropriately set a period from the end of the current job to the transition to the next job acceptable state according to the processing mode.
[0006]
Also, when printing paper is output by the finisher, if the output designated output bin is already full, the output destination can be output to other bins in the same way as when the output destination is set automatically. In addition, a technique related to a paper discharge destination selection method for notifying a host of output bin information is disclosed (see Patent Document 2).
[0007]
[Patent Document 1]
JP-A-9-73252
[0008]
[Patent Document 2]
JP-A-11-301922
[0009]
[Problems to be solved by the invention]
  As mentioned above, a digital copier that can be equipped with a finisher must beFinisherNotifies the finisher of paper information about the paper to be ejected,FinisherReceive sheet processing time from For this reason, if the paper runs out after starting copying,FinisherThere was a problem that the side could not operate properly in response to this out of paper. This problem cannot be solved even with Patent Documents 1 and 2 described above.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of appropriately responding to a change in a sheet to be discharged for an optional device such as a finisher.
[0011]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, an image forming apparatus of the present invention is configured as follows.
[0012]
  An image forming apparatus to which a finisher for performing a finishing process on an image forming medium can be connected, wherein the image carrier is exposed by a paper feeding unit for feeding the image forming medium and a light beam corresponding to the image. An exposure unit; an image forming unit that forms an image corresponding to a latent image formed on the image carrier by exposure by the exposure unit on an image forming medium fed by the sheet feeding unit; and the image forming unit. A paper discharge means for discharging the image forming medium on which the image is formed by the above-described finisher;Media information indicating the size and number of image forming media scheduled to be ejected to the finisher by the paper ejecting means is transmitted to the finisher, and a predetermined one of the image forming media scheduled to be ejected is transmitted. When there is a change in the size of the number of image forming media, a cancellation request and cancellation information indicating the number of cancellations corresponding to the predetermined number of sheets are transmitted to the finisher. Communication means for receiving completion of the corresponding cancel processing from the finisher and transmitting to the finisher medium information indicating the size and number of alternative image forming media that are to be newly discharged to the finisher. And the paper feeding means receives an alternative image forming medium in response to the reception of the completion of the canceling process. The paper.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0014]
FIG. 1 is a cross-sectional view showing an internal configuration of a digital copying machine 1 using an electrophotographic system according to an image forming apparatus of the present invention. As shown in FIG. 1, the digital copying machine 1 includes a scanner unit 11, a printer unit 12, a finisher 13, and the like. The scanner unit 11 includes an automatic document feeder (ADF) 10.
[0015]
The finisher 13 has a function of selectively performing various finishing processes (sheet processes) on a sheet on which an image is formed by the printer unit 12. The finisher 13 is an optional device connected to the digital copying machine 1 and operates by transmitting / receiving commands to / from the digital copying machine 1 main body. For example, in the finisher 13, in accordance with a command from the printer unit 12, a sheet shift process for shifting sheets one by one, a staple process for stapling a plurality of sheets, a punch process for punching holes in a sheet, a final tray The operation such as moving is realized.
[0016]
Hereinafter, an outline of the operation during the image forming process in the printer unit 12 will be described.
[0017]
First, in the printer unit 12, exposure light (laser light) based on image data is irradiated from the exposure device 21 to the photosensitive drum 22. As a result, a latent image corresponding to the intensity of the exposure light irradiated by the exposure device 21 is formed on the photosensitive drum 22.
[0018]
The latent image formed on the photosensitive drum 22 is a black developing device 23 for developing a single black color, that is, a black image, or a single color image of three colors cyan, magenta, and yellow constituting a color image. The corresponding color toner is selectively supplied from any one of the color developing devices 24 to be visualized (developed) as a toner image.
[0019]
The toner image on the photosensitive drum 22 is conveyed to a predetermined intermediate transfer position by rotating the photosensitive drum 22 in the direction a. The intermediate transfer position is a position where the transfer belt (intermediate transfer member) 28 and the photosensitive drum 22 face each other. At the intermediate transfer position, the surface of the photosensitive drum 22 and the transfer belt 28 are in contact with each other by the intermediate transfer roller 29.
[0020]
The toner image on the photosensitive drum 22 conveyed to the intermediate transfer position is transferred from the photosensitive drum 22 onto the transfer belt 28 by an intermediate transfer voltage provided from the intermediate transfer roller 29 side. On the transfer belt 28, for example, there is an area where two A4 size images can be transferred. That is, when a plurality of images are continuously formed, the transfer belt 28 is configured to be able to hold two images at the same time. Such simultaneous transfer of two images to the transfer belt 28 is referred to as two-sided pasting.
[0021]
The toner image transferred to the transfer belt 28 is conveyed to a predetermined transfer position when the transfer belt 28 is moved in the direction b by the drive motor 20. The transfer position is a position where a toner image is transferred from the transfer belt 28 to a sheet as an output medium, and is an area where the transfer roller 31 and the transfer belt 28 face each other. At the transfer position, the surface of the transfer belt 28 onto which the toner image is transferred and the transfer roller 31 are in contact with each other by a driving roller 32 that drives the transfer belt 28.
[0022]
Further, the sheet as the image forming medium is conveyed so as to pass between the transfer roller 31 and the transfer belt 28 at the transfer position. That is, the paper taken out from the paper feed cassette 33a or 33b at a predetermined timing is conveyed by the registration roller 34 to the transfer position with the timing of the toner image transferred onto the transfer belt 28 aligned with the toner. The image is transferred. In front of the registration roller 34, a pre-registration sensor 34a for detecting that the sheet has reached the registration roller 34 is provided.
[0023]
  The sheet on which the toner image is transferred at the transfer position is further conveyed to the fixing device 35. The fixing device 35 melts and fixes the toner constituting the toner image on the paper by supplying and applying a predetermined heat to the paper on which the toner image has been transferred. As a result, the toner image is fixed on the paper. The sheet on which the toner image is fixed passes through conveyance paths 37 and 38 that function as sheet discharge means,FinisherThe paper is discharged to 13.
[0024]
  Finisher13 includes an intermediate tray 50, a stapler 51, final trays 52 and 53, a conveyance path 54, and the like. The intermediate tray (first tray) 50 temporarily holds a sheet for performing a finishing process on the sheet discharged from the digital copying machine 1. The stapler 51 performs stapling on a predetermined position of the paper held on the intermediate tray 50. The final trays (second trays) 52 and 53 finally hold the paper discharged from the intermediate tray 50. The conveyance path 54 conveys paper from the intermediate tray 50 to the final tray 52 or 53.
[0025]
FIG. 2 is a block diagram showing the configuration of the control system of the digital copying machine 1.
[0026]
As shown in FIG. 2, the control system of the digital copying machine 1 includes a scanner unit 11, a printer unit 12, a finisher 13, a main control unit 16 having a user interface 15, and the like.
[0027]
The user interface 15 is an operation panel for inputting operation instructions from the user and providing various guidance to the user. The user interface 15 is composed of, for example, a liquid crystal display device with a built-in touch panel.
[0028]
The main control unit 16 controls the entire digital copying machine 1. The main control unit 16 includes a main CPU 60, a hard disk drive (HDD) 61, a color / monochrome control unit 62, a copy control unit 63, a printer control unit 64, a FAX control unit 65, a scan data processing unit 66, a network expansion unit 67, a TA. A composer 68, a service utility 69, a network card interface (I / F) 70, a serial I / F 71, a FAX I / F 72, and the like are included.
[0029]
The main CPU 60 controls the entire digital copying machine 1. The main CPU 60 includes, for example, a CPU that performs arithmetic processing, a ROM that stores control programs and control data, and a RAM that stores various parameters and work data. For example, when an image forming process (print job) is performed by a copy function, a printer function, or a FAX function, the main CPU 60 instructs the printer unit 12 to start a print job, set print parameters, start paper feeding, and the like. It comes to direct.
[0030]
The printer unit 12 forms a black image or a color image on a sheet as an output medium. As shown in FIG. 2, the control system of the printer unit 12 includes a printer CPU 90, a motor driver 91, a conveyance control unit 92, an exposure control unit 93, a transfer control unit 94, a development control unit 95, a fixing control unit 96, an automatic duplexing unit. A unit (ADU) 36, a PFP 97, a large-capacity paper feeder (LCF) 98, and the like are included.
[0031]
The printer CPU 90 controls the entire printer unit 12. The printer CPU 90 includes a CPU that performs arithmetic processing, a memory 90a, and the like. The memory 90a includes a ROM in which control programs and control data are stored in advance, and a RAM in which data such as printing conditions and control data are temporarily stored. Further, the printer CPU 90 also has a timer 90b for measuring time.
[0032]
The motor driver 91 is a control mechanism that drives the drive motor 20 and the like in the printer unit 12. The conveyance control unit 92 controls conveyance of sheets from the respective paper feed stages (paper cassettes) 33 a and 33 b to the finisher 13 in the printer unit 12. The conveyance control unit 92 controls operations of the paper feed rollers 30a and 30b, the transfer roller 31, the registration roller 34, and the like based on an operation command of the printer CPU 90.
[0033]
The exposure control unit 93 controls the operation of the exposure apparatus 21. Under the control of the exposure controller 93, the exposure device 21 irradiates the outer peripheral surface of the photosensitive drum 22 as an image carrier with laser light to form an electrostatic latent image.
[0034]
The development control unit 95 controls the operation of the black development device 23 or the color development device 24.
[0035]
The transfer control unit 94 controls the transfer of the toner image formed on the photosensitive drum 22 onto the transfer belt 28, and further transfers the toner image on the transfer belt 28 to a sheet.
[0036]
For example, when printing a black image, the transfer control unit 94 transfers the black toner image formed on the photosensitive drum 22 onto the transfer belt 28, and further transfers the black toner image on the transfer belt 28. The toner image is transferred to a sheet at a predetermined transfer position.
[0037]
When printing a color image, the transfer controller 94 superimposes a cyan toner image, a magenta toner image, and a yellow toner image formed on the photosensitive drum 22 on the transfer belt 28. Transcript. As a result, a color toner image of cyan, magenta, and yellow is formed on the transfer belt 28, and the transfer control unit 94 applies the color toner image on the transfer belt 28 to a sheet at a predetermined transfer position. Transcript.
[0038]
As shown in FIG. 2, the finisher 13 includes a finisher CPU 101, a tray moving mechanism 102, a staple mechanism 103, a paper transport unit 104, and the like.
[0039]
The finisher CPU 101 controls the entire finisher 13. The finisher CPU 101 includes a CPU that performs arithmetic processing, a ROM that stores control programs and control data in advance, a RAM that temporarily stores data such as processing mode (finishing mode) and control data, and the like. It has a memory 101a.
[0040]
The finisher CPU 101 has a function of performing bidirectional communication with the printer CPU 90. For example, when the printer unit 12 executes an image forming process, the finisher CPU 101 notifies the printer CPU 90 of the time required for the finisher to operate in response to a size latch signal (described later) from the printer unit 12. It has become.
[0041]
Next, information exchange between the digital copying machine 1 and the finisher 13 will be described.
[0042]
As described above, in the digital copying machine 1, an image (toner image) is transferred to the transfer belt 28 as an intermediate transfer member, and further, the image (toner image) is transferred from the transfer belt 28 to a sheet as an image forming medium. Is to be transferred. For this reason, in this digital copying machine 1, it takes a long time from the start of exposure by the exposure device 21 to the transfer of the image onto the paper. In particular, when printing a color image, the digital copying machine 1 needs to transfer images of four colors. Therefore, it takes a long time from the start of exposure until the color image is transferred onto a sheet.
[0043]
Therefore, the digital copying machine 1 realizes the optimum sheet discharge interval control by increasing the acquisition timing of the sheet processing time from the finisher 13. That is, the printer unit 12 acquires the sheet processing time from the finisher 13 prior to the paper feeding operation, and the image is output so that the discharge timing of the paper on which the image is formed based on the sheet processing time is optimal. Control the forming process.
[0044]
That is, in the conventional digital copying machine, a size latch signal for requesting the sheet processing time is output to the finisher 13 at the timing of starting paper feeding in the printer unit 12, and a response signal to the size latch signal is attached. And get the sheet processing time. On the other hand, the main control unit 16 of the digital copying machine 1 sends the size to the finisher 13 when information on the paper to be fed by the printer unit 12 (paper size, main body conveyance speed, finishing mode, etc.) is determined. A latch signal is output, and the sheet processing time is acquired from the finisher 13 as a response signal.
[0045]
As a result, even when the exposure start by the exposure device 21 precedes the start of paper feed, control is performed so that the exposure start interval of the image by the exposure device 21 corresponding to the paper discharge interval is longer than the sheet processing time. It is possible.
[0046]
In the printer unit 12, the discharge timing of the paper on which the image is printed is determined by the timing at which the exposure device 21 starts exposure of the image. In other words, the printer unit 12 discharges the paper on which the image is printed to the finisher 13 a predetermined time after the exposure device 21 starts exposure of the image.
[0047]
Next, the cancellation process will be described.
[0048]
  This digital copying machine 1 (printer CPU 90) performs cancel processing when the image forming operation originally planned such as auto cassette change, paper feed retry, and LCF transfer is changed and the image forming operation is further continued. Execute. Cancel processing is a change in image forming operation, for exampleFinisher13 when the image forming medium scheduled to be discharged is changed.Finisher13 to cancel information, cancel part or all of the previously transmitted paper information,Finisher13 is a process for canceling a part or all of the sheet processing time obtained in advance from 13.
[0049]
  As explained above,FinisherThe sheet information (sheet size, sheet attribute, finishing mode, etc.) relating to the sheet discharged to 13 is preliminarily obtained from the digital copying machine 1 (printer CPU 90) before image formation is started.Finisher13 (FinisherCPU 101).Finisher13 (FinisherThe CPU 101) receives the paper information transmitted from the digital copying machine 1 (printer CPU 90), and returns the finishing processing time, that is, the sheet processing time to the digital copying machine 1 (printer CPU 90) based on the paper information. To do. The digital copying machine 1 (printer CPU 90) controls the image formation start timing, that is, by controlling the exposure start timing.Finisher13 at the paper discharge interval corresponding to the sheet processing time returned fromFinisherThe paper is discharged to 13. That is, the sheet processing time is acquired prior to the start of image formation.
[0050]
  In color copying or the like, the image formation start timing is much earlier than the paper feed timing. If the sheet processing time is acquired at the paper feed start timing, appropriate control cannot be performed. In other words, when the type of paper on which the image is formed is known, the paper information isFinisher13 toFinisher13 to obtain the sheet processing time in advance.
[0051]
  As described above, at the time when the image forming operation is started in the digital copying machine 1, the sheet information has already been preceded.Finisher13 is notified. After the image forming operation is started, for example, when an event that requires changing the paper type occurs and the paper type is changed, the paper information corresponding to the paper that does not actually exist is displayed.Finisher13 has been transmitted. In addition, the sheet processing time corresponding to the non-paper is obtained.
[0052]
  The digital copying machine 1 (printer CPU 90) executes the above-described canceling process in response to the occurrence of an event that requires part or all of the transmitted paper information to be canceled. That is, the digital copying machine 1 (printer CPU 90)Finisher13 (FinisherThe CPU 101) cancels part or all of the sheet information that has been transmitted to the CPU 101) and cancels the sheet processing time corresponding to a sheet that does not exist. An event in which all the transmitted paper information must be canceled is, for example, a case where there is no designated paper. An event that requires canceling part of the transmitted paper information is, for example, a case where a designated paper is insufficient.
[0053]
A specific example of the cancellation process will be described with reference to FIG. For example, an example of cancel processing corresponding to the vertical and horizontal alternating auto cassette change function of A4 paper and A4-R paper will be described.
[0054]
For example, when receiving a print start request such as a copy button press, a printer print request, or a facsimile print request, the main control unit 16 generates a print job. That is, when a print job is generated by a copy function, a network printer function, or a facsimile function, the main control unit 16 (main CPU 60) instructs the printer unit 12 (print CPU 90) to start the print job. For example, it is assumed that a print job for 10 A4 sheets is instructed. Further, at this time, it is assumed that three A4 sheets are contained in the sheet feeding cassette 33a functioning as the sheet feeding means, and seven or more A4-R sheets are contained in the sheet feeding cassette 33b also functioning as the sheet feeding means.
[0055]
Subsequently, the main control unit 16 sets print parameters based on the print conditions of the print job. For example, information such as the size of the printing paper, the paper conveyance speed in the printer unit 12, and the finishing mode in the finisher 13 are set. Such print parameters are notified from the main control unit 16 to the printer unit 12 for each sheet as a print parameter setting command.
[0056]
When a print parameter setting command for print processing for the first sheet is received, the printer CPU 90 functioning as a communication unit transmits sheet information indicating the sheet size, sheet attribute, finishing mode, and the like, that is, a size latch signal to the finisher 13. To do. Similarly, the printer CPU 90 performs a size latch signal corresponding to the second sheet print process, a size latch signal corresponding to the third sheet print process, a size latch signal corresponding to the fourth sheet print process, and the fifth sheet. A size latch signal corresponding to the print processing is transmitted to the finisher 13. The size latch signal is a signal that requests the finisher 13 for a sheet processing time until the finisher 13 can receive the sheet (a sheet processing time until the printer unit 12 can discharge the sheet to the finisher 13).
[0057]
  As described above, in this example, the digital copying machine 1 (printer CPU 90)Finisher13, sheet information (size latch signal) for five A4 sheets is transmitted. In response,Finisher13 (FinisherThe CPU 101) transmits a sheet processing time (size latch response signal) for five A4 sheets to the digital copying machine 1 (printer CPU 90). An exposure control unit 93 that functions as a discharge interval control unit controls the exposure start timing based on the sheet processing time. As a result of this exposure start timing control,Finisher13 is controlled. The conveyance control unit 92 functioning as a sheet feeding unit outputs a registration signal corresponding to the exposure start timing (registration on), and starts conveying A4 sheets by the sheet feeding roller 30a and the registration roller 34 functioning as a sheet feeding unit. To do. At this time, the digital copying machine 1 (printer CPU 90)Finisher13 (FinisherA registration signal (registration on) is also output to the CPU 101). In response,Finisher13 (FinisherThe CPU 101) transmits a registration-on response to the digital copying machine 1 (printer CPU 90).
[0058]
  On the other hand, an electrostatic latent image is formed by irradiating the outer peripheral surface of the photosensitive drum 22 functioning as an image forming unit with laser light based on exposure start timing control. The toner image is visualized (developed) by at least one developing device of the device 24. The toner image is transferred to the conveyed A4 paper by the transfer belt 28, and the toner image transferred to the A4 paper is fixed by the fixing device 35. The sheet on which the toner image is fixed, that is, the sheet on which the image is formed is conveyed by a conveyance control unit 92 that functions as a sheet discharge unit and conveyance paths 37 and 38.FinisherThe paper is discharged to 13.
[0059]
  Along with the above-described feeding operation, when three A4 sheets are fed, an A4 sheet runs out, that is, a phenomenon that a part of the sheet information has to be canceled occurs. In response to this, the digital copying machine 1 (printer CPU 90)Finisher13, a cancel request and the number of sheet information to be canceled (= number of size latches to cancel) are transmitted. In this case, the number of sheet information to be canceled is two. As a result, the size latch signal corresponding to the print processing for the fourth sheet (print processing on A4 paper) and the size latch signal corresponding to the print processing for the fifth sheet (print processing on A4 paper) are cancelled.
[0060]
  Finisher13 (FinisherThe CPU 101) receives the cancel request and the number of pieces of paper information to be canceled, and executes a cancel process. For example,FinisherWhen sheets remain in the thirteen paper transporting sections 104, the remaining sheets are discharged, and the finishing process for the fourth and fifth A4 sheets is cancelled. furtherFinisher13 (printer CPU 101) receives a third A4 sheet.FinisherThe digital copying machine 1 is notified of a cancel response, that is, the completion of the cancellation, using as a trigger a sorter discharge signal indicating discharge to the 13 sorters.
[0061]
  When the digital copier 1 (printer CPU 90) receives the cancel response, the digital copying machine 1 (printer CPU 90) stops sending the cancel request and the number of paper information to be canceled, and substitute paper information, that is, the fourth print process (printing on A4-R paper) Size latch signal corresponding to the finisher 13 (FinisherThe size latch signal corresponding to the fifth printing process (printing process on A4-R paper) is transmitted to the finisher 13 (CPU 101).FinisherCPU101).
[0062]
  In response,Finisher13 (FinisherThe CPU 101) performs the sheet processing time (size latch response signal) for the fourth A4-R sheet with respect to the digital copying machine 1 (printer CPU 90), and further the sheet processing time for the A4-R sheet as the fifth sheet ( Size latch response signal). An exposure control unit 93 that functions as a discharge interval control unit controls the exposure start timing based on the sheet processing time. As a result of this exposure start timing control,Finisher13 is controlled. The conveyance control unit 92 functioning as a sheet feeding unit outputs a registration signal corresponding to the exposure start timing (registration on), and the A4-R sheet is conveyed by the sheet feeding roller 30b and the registration roller 34 functioning as a sheet feeding unit. To start. At this time, the digital copying machine 1 (printer CPU 90)Finisher13 (FinisherA registration signal (registration on) is also output to the CPU 101). In response,Finisher13 (FinisherThe CPU 101) transmits a registration-on response to the digital copying machine 1 (printer CPU 90).
[0063]
  On the other hand, an electrostatic latent image is formed by irradiating the outer peripheral surface of the photosensitive drum 22 functioning as an image forming unit with laser light based on exposure start timing control. The toner image is visualized (developed) by at least one developing device of the device 24. The toner image is transferred to the conveyed A4-R paper by the transfer belt 28, and the toner image transferred to the A4-R paper is fixed by the fixing device 35. The sheet on which the toner image is fixed, that is, the sheet on which the image is formed is conveyed by a conveyance control unit 92 that functions as a sheet discharge unit and conveyance paths 37 and 38.FinisherThe paper is discharged to 13.
[0064]
  Further, the digital copying machine 1 (printer CPU 90) performs the remaining print processing, that is, the size latch signal corresponding to the sixth print processing, the size latch signal corresponding to the seventh print processing, and the eighth print processing. , A size latch signal corresponding to the ninth printing process, and a size latch signal corresponding to the tenth printing process are transmitted to the finisher 13. In this case, the digital copying machine 1 (printer CPU 90)Finisher13, sheet information (size latch signal) for five sheets of A4-R sheets is transmitted. In response,Finisher13 (FinisherThe CPU 101) transmits a sheet processing time (size latch response signal) for five A4-R sheets to the digital copying machine 1 (printer CPU 90). Thereafter, assuming that no sheet runs out, print processing and finishing processing for A4-R sheets are appropriately executed.
[0065]
  As described above, when the digital copying machine 1 (printer CPU 90) has an event in which part or all of the paper information has to be canceled,Finisher13 (FinisherSince the cancel information corresponding to this event is transmitted to the CPU 101),FinisherAn appropriate finishing process can be executed on the 13th side.
[0066]
Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.
[0067]
【The invention's effect】
According to the present invention, it is possible to provide an image forming apparatus capable of appropriately responding to a change in a sheet to be discharged for an optional device such as a finisher.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an internal configuration of a digital copying machine to which a finisher according to an example of the present invention can be attached.
FIG. 2 is a block diagram showing a schematic configuration of a control system of the digital copying machine.
FIG. 3 is a timing chart for explaining cancellation processing;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 12 ... Printer part, 13 ... Finisher, 16 ... Main control part, 21 ... Exposure device, 22 ... Photosensitive drum, 23 ... Black developing device, 24 ... Color developing device, 28 ... Transfer belt, 30a, 30b ... Paper feed roller 31 ... Transfer roller, 33a. 33b: Paper feeding cassette, 34: Registration roller, 34a: Pre-registration sensor, 35 ... Fixing device, 38 ... Paper discharge switch, 50 ... Intermediate tray, 51 ... Stapler, 52, 53 ... Final tray, 60 ... Main CPU, 90 ... Printer CPU, 90a ... Memory, 90b ... Timer, 91 ... Motor driver, 92 ... Conveyance control unit, 93 ... Exposure control unit

Claims (1)

An image forming apparatus to which a finisher for performing a finishing process on an image forming medium can be connected,
Paper feeding means for feeding the image forming medium;
Exposure means for exposing the image carrier with a light beam corresponding to the image;
Image forming means for forming an image corresponding to a latent image formed on an image carrier by exposure by the exposure means on an image forming medium fed by the paper feeding means;
A paper discharge means for discharging the image forming medium on which an image is formed by the image forming means to the finisher;
Media information indicating the size and number of image forming media scheduled to be ejected to the finisher by the paper ejecting means is transmitted to the finisher, and a predetermined one of the image forming media scheduled to be ejected is transmitted. When there is a change in the size of the number of image forming media, a cancellation request and cancellation information indicating the number of cancellations corresponding to the predetermined number of sheets are transmitted to the finisher. Communication means for receiving completion of the corresponding cancel processing from the finisher, and transmitting to the finisher medium information indicating the size and number of alternative image forming media scheduled to be newly discharged to the finisher. And comprising
The image forming apparatus, wherein the sheet feeding unit feeds an alternative image forming medium in response to reception of the completion of the cancel processing.

Images