JP4323234B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a composite digital copying machine in which an optional device such as a finisher can be mounted.
[0002]
[Prior art]
Conventionally, there are digital copiers that can be equipped with optional equipment such as finishers. 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 sheet required by the finisher side is called sheet processing time.
[0003]
Conventionally, on the main body of the digital copying machine, the sheet processing time is acquired from an optional finisher, and the timing of discharging a sheet 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 of starting paper feeding. 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. In such a digital copying machine, as in the case of a conventional digital copying machine, when the sheet processing time is acquired from the finisher at the timing of starting paper feeding, the timing at which the image-formed paper is discharged to the finisher is controlled. There is a problem that it becomes difficult.
[0005]
[Patent Document 1]
US Pat. No. 6,226,471
[0006]
[Problems to be solved by the invention]
As described above, when the image forming apparatus main body acquires the sheet processing time required by the finisher at the timing of starting the paper feeding, it is difficult to control the paper discharge interval of the paper on which the image is formed to the finisher. Therefore, an object of the present invention is to provide an image forming apparatus capable of discharging a sheet on which an image is formed at a timing corresponding to a sheet processing time required by the finisher to the finisher.
[0007]
[Means for Solving the Problems]
Of this invention Image forming apparatus In the case where a finisher for processing an image forming medium on which an image is formed is connected, an exposure unit that irradiates the image carrier with light based on an image to be formed on the image forming medium, and irradiation by the exposure unit Formed on the image carrier by the emitted light Was developed and transferred to an intermediate transfer member, and the image transferred to the intermediate transfer member was transferred onto an image forming medium. When image forming means for discharging the image forming medium to the finisher and image forming processing on the image forming medium by the image forming means, when the processing content at the finisher for the image forming medium is determined , An acquisition unit that acquires a sheet processing time indicating a discharge interval of the image forming medium required by the finisher, and a sheet processing time acquired by the acquisition unit Is determined to be longer than the discharge interval of the image forming medium by the image forming process in the image forming unit, and the discharge interval by the image forming process in the image forming unit by this determination unit However, when it is determined that the sheet processing time is long, it is prohibited to transfer an image formed on the image forming medium to the intermediate transfer member in a state where the intermediate transfer member holds another image. And control means.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
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 having an automatic document feeder (ADF) 10, a printer unit 12, a finisher 13, and the like.
[0009]
The finisher 13 has a function of selectively performing various processes on the paper 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 stapling process for stapling a plurality of sheets, a punch process for punching holes in a sheet, and a paper discharge Operation such as bin movement is realized.
[0010]
The operation during the image forming process in the printer unit 12 will be schematically described below.
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.
[0011]
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.
[0012]
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.
[0013]
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.
[0014]
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 30. 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.
[0015]
Further, the sheet as the output 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 paper has reached the registration roller 34 is provided.
[0016]
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.
[0017]
FIG. 2 is a block diagram showing the configuration of the control system of the digital copying machine 1.
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.
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.
[0018]
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.
[0019]
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.
[0020]
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.
[0021]
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.
[0022]
The motor driver 91 is a control mechanism that drives the drive motor 30 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.
[0023]
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.
[0024]
The development control unit 95 controls the operation of the black development device 23 or the color development device 24.
[0025]
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.
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.
[0026]
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.
[0027]
As shown in FIG. 2, the finisher 13 includes a finisher CPU 101, a bin moving mechanism 102, a staple mechanism 103, a paper transport unit 104, and the like.
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.
[0028]
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.
[0029]
Next, the operation at the time of image formation (printing) in the digital copying machine 1 will be described.
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.
[0030]
For this reason, in the present embodiment, first to third operation examples will be described as operation examples at the time of image formation applied to the digital copying machine 1 having the finisher 13 as shown in FIGS.
As a first operation example, the optimum discharge interval control is realized by increasing the acquisition timing of the sheet processing time from the finisher 13.
As a second operation example, optimal sheet discharge interval control is realized based on data stored in the main body in advance without acquiring the sheet processing time from the finisher 13.
[0031]
As a third operation example, the two-sided attachment is not performed at the timing when the sheet processing time from the finisher 13 becomes longer than the cycle time of the apparatus main body.
As a fourth operation example, when the two-side pasting is performed at a timing when the sheet processing time from the finisher 13 becomes longer than the cycle time of the apparatus main body, the transfer belt 28 is idled before the registration roller 34, Further, the sheet interval corresponding to the sheet processing time is realized by rotating it once.
[0032]
First, the first operation example will be described.
In the first operation example, the printer unit 12 acquires the sheet processing time from the finisher 13 prior to the sheet feeding operation, and the discharge timing of the sheet on which the image is formed based on the sheet processing time is as follows. The image forming process is controlled to be optimal.
[0033]
In other words, the conventional digital copying machine 1 outputs a size latch signal for requesting the sheet processing time to the finisher 13 at the timing of starting the paper feeding in the printer unit 12, and outputs a response signal to the size latch signal. Accompanying sheet processing time is obtained. On the other hand, in the first operation example, the main control unit 16 determines the finisher 13 when the information (paper size, main body conveyance speed, finishing mode, etc.) of paper fed by the printer unit 12 is determined. A size latch signal is output, and the sheet processing time is acquired from the finisher 13 as a response signal.
[0034]
Thereby, in the first operation example, even if the exposure start by the exposure device 21 precedes the paper feed start, the exposure start interval of the image by the exposure device 21 corresponding to the paper discharge interval is set. Control that allows the sheet processing time or longer is possible.
[0035]
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.
[0036]
FIG. 3 is a timing chart showing the timing of the first operation example. The example shown in FIG. 3 shows an operation example in the case of performing image formation processing (printing) for three sheets.
For example, when receiving a print start request such as 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.
[0037]
That is, when a print job is generated by a copy function, a network printer function, a facsimile function or the like, the main control unit 16 instructs the printer unit 12 to start a print job. In the example shown in FIG. 3, the main control unit 16 notifies the printer unit 12 when the start of the print job is “a”.
[0038]
Subsequently, the main control unit 16 sets print parameters based on the print conditions of the print job. The print parameters indicate 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, for example. 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. In the example shown in FIG. 3, the main control unit 16 notifies the printer unit 12 of the print parameter setting command for the first sheet at the time “b1”.
[0039]
When the print parameter setting command for the print processing for the first sheet is received, the printer CPU 90 of the printer unit 12 transmits a size latch signal to the finisher 13 together with information indicating the sheet size, the finishing mode for the sheet, and the like. . The size latch signal requests the finisher 13 for a sheet processing time until the finisher 13 can receive the paper (a sheet processing time until the printer 12 can discharge the paper to the finisher 13). Signal.
[0040]
The finisher 13 that has received the size latch signal as described above determines the sheet processing time of the sheet based on the finishing mode of the sheet, and the printer unit 12 uses the sheet processing time as a response signal to the size latch signal. Send to. As a result, the printer CPU 90 of the printer unit 12 receives the print parameter setting command from the main control unit 16 (time b1 in the example shown in FIG. 3), and the sheet processing time for the first sheet from the finisher 13 is reached. (First sheet processing time) is acquired. The first sheet processing time is stored in the memory 90a.
[0041]
When the first sheet processing time is acquired, the printer CPU 90 starts exposure (laser exposure) of an image to be printed on the first sheet onto the photosensitive drum (image carrier) 22 by the exposure device 21. Is determined based on the sheet processing time acquired from the finisher 13.
[0042]
The printer CPU 90 of the printer unit 12 drives the paper feed roller 30a or 30b to feed the first sheet based on a print start instruction for the first sheet from the main control unit 16. At the same time, the timer 90b measures the time after receiving the print start instruction.
[0043]
For example, the time from when the exposure device 21 starts exposure until the paper is discharged to the finisher 13 (this time is B) is a predetermined value determined by the paper conveyance speed in the printer unit 12 and the like. It's time. For this reason, the time from when the print start instruction is received until the exposure device 21 starts exposing the image printed on the first sheet (this time is A1) is printed by the printer unit 12. The determination is made based on the relationship between the time B until the first sheet is discharged to the finisher 13 and the first sheet processing time.
[0044]
That is, the printer CPU 90 determines the exposure start timing of the image to be printed on the first sheet by the exposure device 21 so that the sum of the time A1 and the time B is equal to or longer than the first sheet processing time. To control. An image whose exposure is started at such timing is developed on the photosensitive drum 22 and is fed onto the first sheet fed by the registration roller 34 operating at a predetermined timing via the transfer belt 28. The first sheet is transferred and discharged to the finisher 13.
[0045]
Further, in the example shown in FIG. 3, the print parameter setting command for the second sheet is notified from the main control unit 16 to the printer unit 12 at the time of “b2”. When the print parameter setting command for the printing process for the second sheet is received, the printer CPU 90 of the printer unit 12 sends the size latch signal to the finisher 13 together with information indicating the second sheet size, the finishing mode for the sheet, and the like. Send to.
[0046]
In response to such a size latch signal, the finisher 13 determines a sheet processing time for the second sheet (paper discharge interval with respect to the first sheet), and uses the sheet processing time as a response signal for the printer unit. 12 to send. As a result, the printer CPU 90 of the printer unit 12 receives the print parameter setting command for the second sheet from the main control unit 16 (time b2 in the example shown in FIG. 3). The sheet processing time (second sheet processing time) for the second sheet is acquired. The sheet processing time for the second sheet is stored in the memory 90a.
[0047]
When the sheet processing time for the second sheet is acquired from the finisher 13, the printer CPU 90 performs exposure (laser exposure) of an image to be printed on the second sheet onto the photosensitive drum 22 by the exposure device 21. The start timing is determined based on the sheet processing time acquired from the finisher 13.
[0048]
That is, the time from when the exposure of the image printed on the first sheet starts until the exposure device 21 starts the exposure of the image printed on the second sheet (this time is A2) is: This determination is made based on the relationship between the time B until the second sheet printed by the printer 12 is discharged to the finisher 13 and the second sheet processing time. When the time B from the start of exposure to the discharge in the printer unit 12 is constant, the time A2 is the discharge interval between the first sheet and the second sheet, so the time A2 is two sheets. What is necessary is just to control so that it may become the sheet processing time with respect to the paper of eyes.
[0049]
Therefore, the printer CPU 90 controls the exposure start timing of the image printed on the second sheet by the exposure device 21 so that the time A2 is equal to or longer than the second sheet processing time. An image whose exposure is started at such a timing is developed on the photosensitive drum 22 and is applied to a second sheet fed by a registration roller 34 that operates at a predetermined timing via the transfer belt 28. The second sheet is transferred to the finisher 13.
[0050]
If the time B1 from the start of exposure to the discharge of the first print in the printer unit 12 is different from the time B2 from the start of exposure to the discharge of the second print, the time B1 and the time B2 The time A2 from the start of exposure of the first image to the start of exposure of the second image is determined in consideration of the difference between the times B1 and B2. Is done.
[0051]
Further, the printing operation control for the third sheet is the same as the printing operation control for the second sheet. That is, in the example shown in FIG. 3, the main control unit 16 notifies the printer unit 12 of the print parameter setting command for the third sheet at the time of “b3”. Therefore, at the time point b3 when the print parameter setting command for the print processing for the third sheet is received, the printer CPU 90 outputs a size latch signal together with information indicating the size of the third sheet, the finishing mode for the sheet, and the like. 13 to send.
[0052]
In response to such a size latch signal, the finisher 13 determines the sheet processing time for the third sheet (paper discharge interval with respect to the second sheet), and uses the sheet processing time as a response signal for the printer unit. 12 to send. As a result, the printer CPU 90 receives the print parameter setting command for the second sheet from the main control unit 16 (time b3 in the example shown in FIG. 3), and the sheet for the third sheet from the finisher 13. The processing time (third sheet processing time) is acquired. The sheet processing time for the third sheet is stored in the memory 90a.
[0053]
When the sheet processing time for the third sheet is acquired from the finisher 13, the printer CPU 90 performs exposure (laser exposure) of an image to be printed on the third sheet on the photosensitive drum 22 by the exposure device 21. The start timing is determined based on the sheet processing time acquired from the finisher 13.
[0054]
In other words, the time from when the exposure of the image printed on the second sheet starts until the exposure device 21 starts the exposure of the image printed on the third sheet (this time is A3) is: The determination is made based on the relationship between the time B until the third sheet printed by the printer 12 is discharged to the finisher 13 and the third sheet processing time. When the time B from the start of exposure to the paper discharge in the printer unit 12 is constant, the time A3 is the paper discharge interval between the second paper and the third paper, so the time A3 is 3 sheets. What is necessary is just to control so that it may become the sheet processing time with respect to the paper of the eye.
[0055]
When the time B2 from the start of exposure to the discharge of the second print in the printer unit 12 is different from the time B3 from the start of exposure to the discharge of the third print, the time B2 and the time B3 The time A3 from the start of exposure of the second image to the start of exposure of the third image is determined in consideration of the difference between the time B2 and the time B3. Is done.
[0056]
Therefore, the printer CPU 90 controls the exposure start timing of the image printed on the third sheet by the exposure device 21 so that the time A3 becomes equal to or longer than the third sheet processing time. The image whose exposure is started at such timing is developed on the photosensitive drum 22 and is applied to a third sheet fed by the registration roller 34 operating at a predetermined timing via the transfer belt 28. The third sheet is transferred and discharged to the finisher 13.
[0057]
As described above, according to the first operation example, the printer unit 12 acquires the sheet processing time for the paper from the finisher 13 at the timing when the information (paper size, finishing mode, etc.) regarding the paper to be printed is determined. In addition, the timing of the print processing for the paper is controlled so as to secure the paper discharge interval for the sheet processing time.
[0058]
As a result, the image forming apparatus whose exposure by the exposure device precedes the start of paper feeding as the image forming medium (that is, the time required to generate an image to be transferred onto the paper than the time required for paper feeding). Even with a long image forming apparatus), it is possible to realize print processing for discharging each sheet to the finisher at an optimal timing according to the sheet processing time of each sheet.
[0059]
In the first operation example, when the printer unit 12 receives from the main control unit 16 a print parameter setting command indicating information related to the paper to be printed from the main control unit 16, the printer unit 12 sends the paper to the finisher. The size latch signal is transmitted together with the information on the sheet, and the sheet processing time for the sheet is acquired from the finisher as a response to the size latch signal, and is sequentially stored in the memory. The printer unit 12 storing the sheet processing time of each sheet in the memory determines the timing for starting the exposure processing of the image to be printed on each sheet by the exposure device based on the sheet processing time of each sheet stored in the memory. Then, print processing is executed. As a result, the printing process can be executed so that the paper discharge interval of the paper discharged to the finisher is optimized according to the sheet processing time of each paper.
[0060]
Next, a second operation example will be described.
In the second operation example, the sheet discharge interval time (or sheet processing time) corresponding to various finishing modes in the finisher 13 is stored in the memory 90a in advance, and the sheet processing time stored in the memory 90a is stored in the memory 90a. Is used to control the paper discharge interval of the printed paper.
[0061]
In the digital copying machine 1 as in the present embodiment, the sheet discharge interval must be controlled based on the sheet processing time in the finisher 13 in practice. This is only when the paper discharge interval (hereinafter referred to as the main body cycle time) by the image forming process becomes longer. The sheet processing time that is longer than the main body cycle time is, for example, the sheet processing time for the first sheet after the stapling process by the finisher 13 (the discharge interval between the stapling sheet and the first sheet after the stapling process). The sheet processing time for the first sheet after movement of the discharge bin in the finisher 13 (discharge interval between the final sheet before movement of the discharge bin and the first sheet after movement of the discharge bin), and the like.
[0062]
Therefore, in the second operation example, the sheet processing time longer than the main body cycle time is stored in the memory 90a in the printer unit 12 in advance, and the printing of each sheet received by the printer CPU 90 from the main control unit 16 is performed. Based on the parameter setting, it is determined whether or not the sheet processing time is longer than the main body cycle time. If it is determined that the sheet processing time is longer than the main body cycle time, the sheet processing time stored in the memory 90a is set. Based on this, the paper discharge interval is controlled.
[0063]
FIG. 4 is a flowchart for explaining the second operation example. Hereinafter, the second operation example will be described in detail with reference to the flowchart shown in FIG.
That is, it is assumed that all finishing modes in which the sheet processing time is longer than the main body cycle time and the sheet processing times corresponding to these finishing modes are stored in the memory 90a in advance.
[0064]
For example, when the sheet processing time for the first sheet after stapling is longer than the main body cycle time, the memory 90a stores the stapling process as a finishing mode in which the sheet processing time is longer than the main body cycle time. At the same time, the sheet processing time corresponding to the stapling by the finisher 13 is stored in the memory 90a. The memory 90a may store the sheet processing time, or may store a standby time obtained by subtracting the main body cycle time from the sheet processing time.
[0065]
In this state, when a print parameter setting command is received from the main control unit 16, the printer CPU 90 of the printer unit 12 stores paper information (paper size, finishing mode, etc.) relating to the paper from the print parameter setting command in the memory 90a. It is determined whether or not it is necessary to secure a paper discharge interval for the paper discharged to the finisher 13 (step S11).
[0066]
In this determination, the printer CPU 90 needs to ensure the discharge interval by comparing information on the paper printed last time (previous paper information) and information on paper printed this time (paper information on the paper). Determine whether or not.
[0067]
For example, when the previous paper is staple and the paper is not stapled (that is, when the paper is the first paper after stapling), the printer CPU 90 sets the paper discharge interval. Judge that it is necessary to secure. Further, when the paper discharge bin of the previous paper is different from the paper discharge bin of the paper, or when it is necessary to move the paper discharge bin before discharging the paper (that is, the paper is 1 after the bin movement). The printer CPU 90 determines that it is necessary to secure a paper discharge interval.
[0068]
If it is determined from the above determination that it is not necessary to secure the paper discharge interval (step S12, paper space is not required), the printer CPU 90 waits for the main body cycle time to elapse (timing at which print processing can be performed on the paper). (Step S13), the exposure apparatus 21 is allowed to start exposure processing of an image to be printed on the paper (Step S14).
[0069]
If it is determined that it is necessary to secure the paper discharge interval (step S12, paper space needs to be secured), the printer CPU 90 reads the sheet processing time for the paper to the finisher 13 from the memory 90a. (Step S15).
[0070]
For example, if the sheet is the first sheet after stapling, the printer CPU 90 reads the sheet processing time for the first sheet after stapling by the finisher 13 from the memory 90a. If the sheet is the first sheet after the movement of the discharge bin, the printer CPU 90 reads out the sheet processing time for the first sheet after the movement of the discharge bin in the finisher 13 from the memory 90a. .
[0071]
When the sheet processing time for the sheet is read from the memory 90a, the printer CPU 90 waits for the sheet processing time consisting of the main body cycle time and the standby time to elapse (step S16), and the exposure device 21 applies the sheet processing time. The start of the exposure process for the image to be printed is permitted (step S14).
[0072]
As described above, according to the second operation example, it is determined whether or not the sheet processing time required by the finisher can be secured by the time of the paper discharge interval in the image forming process in the normal cycle. When it is determined that the sheet processing time cannot be secured, the timing of the print processing for the paper is controlled based on the discharge interval time (sheet processing time) previously stored in the memory on the printer side. It is.
[0073]
Accordingly, it is possible to determine the timing of the printing process only on the image forming apparatus side, and it is not necessary to acquire the sheet processing time for each sheet from the finisher, and the sheet discharge interval to the finisher is easily optimized. Thus, the image forming process can be controlled.
[0074]
Next, a third operation example will be described.
In the third operation example, when the sheet processing time from the finisher 13 is longer than the main body cycle time in the printer unit 12, the two surfaces are attached to the transfer belt 28 (two images on the transfer belt 28). (Simultaneous transfer) is not performed.
[0075]
In the digital copying machine 1, for example, two images can be transferred on the transfer belt 28 in A4 size. In particular, when printing a color image, it is necessary to transfer toner images of three colors of cyan, magenta, and yellow on the transfer belt 28 in a superimposed manner, so that it takes a long time to form an image. For this reason, when printing a color image, the time required for printing is shortened by transferring two surfaces (two images) to the transfer belt 28.
[0076]
However, when two images are transferred onto the transfer belt 28, the paper discharge interval between the two sheets onto which these images are transferred becomes the main body cycle time, so the printer unit 12 controls the paper discharge interval. It becomes difficult to do. That is, when the sheet processing time required by the finisher 13 is longer than the main body cycle time as the paper discharge interval of two sheets onto which two images transferred simultaneously on the transfer belt 28 are transferred, the printer unit 12, it is difficult to perform control for discharging the two sheets on which the image with the two-side pasting is printed while securing the sheet processing time.
[0077]
In the third operation example, it is determined whether or not the discharge interval of two sheets on which two images to be attached to the transfer belt 28 are attached is longer than the main body cycle time. If it is determined that the paper discharge interval is longer than the main body cycle time, the two-sided attachment is prohibited.
[0078]
Further, the sheet processing time as the paper discharge interval of the two sheets to be attached to the two sides may be acquired from the finisher 13 using the method described in the first operation example. Then, the method described in the second operation example may be used to read from the memory 90a in which the sheet processing time for the paper information is stored in advance. That is, the third operation example can be implemented in combination with the first operation example or the second operation example.
[0079]
For example, when the same method as in the second operation example is used, sheet processing times corresponding to various finishing modes are stored in advance in the memory 90a, and based on the sheet processing times stored in the memory 90a. Thus, it may be determined whether or not the discharge interval of the two sheets on which the two images to be attached to the transfer belt 28 are to be printed is longer than the main body cycle time.
[0080]
FIG. 5 is a flowchart for explaining the third operation example. Hereinafter, the third operation example will be described in detail with reference to the flowchart shown in FIG.
First, upon receiving a print parameter setting command from the main control unit 16, the printer CPU 90 of the printer unit 12 stores paper information (paper size, finishing mode, etc.) relating to the paper in the memory 90a from the print parameter setting command.
[0081]
Further, the printer CPU 90 determines whether or not an image to be printed on a sheet immediately before the sheet and an image to be printed on the sheet are objects to be affixed to the transfer belt 28. If it is determined by this determination that the image printed on the immediately preceding sheet and the image printed on the sheet are not to be attached to the transfer belt 28, the operation shown in FIG. 5 is omitted.
[0082]
If it is determined that the image to be printed on the immediately preceding sheet and the image to be printed on the sheet are to be attached to the transfer belt 28, the printer CPU 90 determines the sheet information about the immediately preceding sheet and the sheet. The paper information is compared with each other, and it is determined whether or not the two-side pasting prohibition condition is satisfied (step S21).
[0083]
Here, the prohibition condition for the two-sided attachment means that the discharge interval of two sheets on which two images to be attached to the transfer belt 28 are printed is longer than the main body cycle time. This is a long condition and is stored in advance in the memory 90a. In addition, the sheet processing time between the two sheets and the main body cycle time are compared, and when the sheet processing time is longer than the main body cycle time, it is determined that the two-side pasting prohibition condition is satisfied. good.
[0084]
If it is determined by this determination that the two-side sticking prohibition condition is not satisfied (step S22, no prohibition condition), the printer CPU 90 executes the two-side sticking process to the transfer belt 28 (step S23). In this case, the image to be printed on the paper is simultaneously formed on the transfer belt 28 together with the previous image. As a result, the two-sided images formed on the transfer belt 28 are sequentially transferred onto two sheets, and these sheets are discharged from the printer unit 12 to the finisher 13 at a discharge interval based on the main body cycle time. Is done.
[0085]
If it is determined by the above determination that the two-surface pasting prohibition condition is satisfied (step S22, there is a prohibition condition), the printer CPU 90 prohibits the two-side pasting process to the transfer belt 28. In this case, the printer CPU 90 executes a pasting process for each surface (one image) on the transfer belt 28 (step S24). Further, the printer CPU 90 stores paper information including information indicating that each surface is attached to the transfer belt 28 in the memory 90a as paper information relating to the paper (step S25).
[0086]
As a result, an image to be printed on the paper is formed on the transfer belt 28 alone. As a result, the printer CPU 90 controls the timing of printing on the sheet, and causes the sheet to be printed on the printer unit so that the discharge interval between the sheet and the immediately preceding sheet is at least the sheet processing time required by the finisher 13. The paper is discharged from 12 to the finisher 13.
[0087]
Note that when the two-sided attachment is prohibited and the one-side attachment is performed on the transfer belt 28, the print timing (control of the discharge interval) for the paper is the first operation example or the first. Similar to the operation example 2, it may be controlled by the exposure timing of the image by the exposure device 21.
[0088]
As described above, according to the third operation example, the main body cycle time as the paper discharge interval between two sheets for transferring two images to be attached to the transfer belt on the two sides is required to have a finisher. If the sheet processing time is longer than the main body cycle time, it is prohibited to attach the two surfaces to the transfer belt, The paper discharge interval is controlled by pasting. Accordingly, it is possible to control the sheet discharge interval to be appropriate even between the two sheets on which the two images to be attached to the transfer belt on the two sides are printed.
[0089]
Next, a fourth operation example will be described.
In the fourth operation example, even when two surfaces are attached to the transfer belt 28, if the sheet processing time from the finisher 13 is longer than the main body cycle time in the printer unit 12, By causing the transfer belt 28 to idle, the paper discharge interval of the two sheets on which the two images pasted on the two sides are printed is controlled to be appropriate.
[0090]
That is, in the fourth operation example, when the sheet processing time for the two sheets on which the second-side image pasted on the transfer belt 28 is printed becomes longer than the main body cycle time, After the image is transferred to the first sheet, the second image is transferred to the second sheet after the transfer belt 28 is idled by one turn without transferring the second sheet image to the second sheet. It is intended to be transferred to a sheet of paper.
[0091]
In this case, the second sheet on which the image on the second side is to be printed waits in front of the registration roller 34 while the transfer belt 28 is idling for one revolution, and is on the transfer belt 28 idling for one revolution. Are conveyed in accordance with the image (the second image). As a result, as the paper discharge interval between the second sheet on which the second-side image is printed and the sheet on which the first-side image is printed, a time period during which the transfer belt 28 is rotated by one round is secured. The
[0092]
FIG. 6 is a flowchart for explaining a fourth operation example. Hereinafter, the fourth operation example will be described in detail with reference to the flowchart shown in FIG.
First, upon receiving a print parameter setting command from the main control unit 16, the printer CPU 90 of the printer unit 12 stores paper information (paper size, finishing mode, etc.) relating to the paper in the memory 90a from the print parameter setting command. Further, the printer CPU 90 determines whether or not an image to be printed on the sheet is attached to the transfer belt 28 on two sides. If it is determined by this determination that the image to be printed on the sheet is not attached to the transfer belt 28, the operation shown in FIG. 6 is omitted.
[0093]
When it is determined that the image to be printed on the paper is pasted on the transfer belt 28 by the judgment, the printer CPU 90 transfers the image to be printed on the paper to the transfer belt 28 as a second image. It is determined whether or not it has been performed (step S31).
[0094]
If it is determined that the image to be printed on the paper is not transferred as the second image on the transfer belt 28, that is, the image to be printed on the paper is transferred to the transfer belt 28 as the first image. If so (NO in step S31), the printer CPU 90 performs a normal print process (step S35). This print processing is realized, for example, by an operation based on the first operation example or the second operation example.
[0095]
If it is determined that the image to be printed on the paper is transferred to the transfer belt 28 as the second image (YES in step S31), the printer CPU 90 determines that the paper and the paper immediately before the paper. It is determined whether or not it is necessary to secure a paper discharge interval (paper gap) between the paper discharged to the finisher 13 (the paper on which the first image is printed) (step S32).
[0096]
This determination is made, for example, with respect to the sheet processing time for the paper on which the second side-attached image is printed (the first paper on which the first image is printed and the second image on which the second image is printed 2 This is determined by comparing the sheet discharge interval with the first sheet) and the main body cycle time.
[0097]
Further, the sheet processing time for the paper on which the second image is printed may be obtained from the finisher 13 by using the method described in the first operation example, or the second operation. The method described in the example may be used to read from the memory 90a in which the sheet processing time for the paper information is stored in advance. That is, the fourth operation example can be implemented in combination with the first operation example or the second operation example.
[0098]
If it is determined by the above determination that it is not necessary to secure the paper discharge interval, that is, if the sheet processing time for the paper is shorter than the main body cycle time (NO in step S33), the printer CPU 90 performs the normal cycle. A printing process for the paper (printing process for the second side) is performed (step S35).
[0099]
If it is determined by the above determination that it is necessary to secure the paper discharge interval, that is, if the sheet processing time for the paper is longer than the main body cycle time (step S33, YES), the printer CPU 90 removes the paper. In a state of waiting in front of the registration roller 34, the transfer belt 28 is idled by one turn (step S34).
[0100]
As a result, when the transfer belt 28 is idled by one revolution, the printer CPU 90 drives the registration roller 34 in accordance with the image on the second surface of the transfer belt 28 that has been idled by one revolution, and the paper The image on the second side is printed on (Step S35). As a result, the sheet on which the image on the second side is printed is discharged to the finisher 13 after a time corresponding to one cycle of the transfer belt 28 in addition to the main body cycle time after the previous sheet is discharged to the finisher 13. Paper.
[0101]
When the difference between the sheet processing time of the paper for printing the image on the second side and the main body cycle time is longer than the rotation time of one rotation of the transfer belt 28, that is, the main body cycle time and the transfer belt 28 are 1 When it is necessary to secure a paper discharge interval that is equal to or longer than the total time of rotation, after the transfer belt 28 is idled a plurality of times, image transfer from the transfer belt to the paper is started. good. In this case, if the time for one rotation of the transfer belt 28 is stored in the memory 90a in advance, the number of times that the transfer belt 28 should be idled can be determined.
[0102]
As described above, according to the fourth operation example, the sheet that requires the finisher to have a main body cycle time as a paper discharge interval of two sheets onto which two images pasted on the transfer belt are transferred is transferred. When the sheet processing time is longer than the main body cycle time, it is determined whether or not the processing time is longer than the main body cycle time, the sheet on which the second image is printed is waited, the transfer belt is idled, and the sheet processing time is After the image is secured, the image on the second surface on the transfer belt is transferred to a sheet. Thereby, it is possible to control so that the paper discharge interval for two sheets on which two images pasted on the transfer belt are printed is appropriate.
[0103]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide an image forming apparatus capable of discharging a sheet on which an image is formed at a timing corresponding to a sheet processing time required by the finisher to the finisher.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an internal configuration of a digital copying machine equipped with a finisher according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a control system of a digital copying machine equipped with a finisher.
FIG. 3 is a timing chart for explaining operation timing according to a first operation example;
FIG. 4 is a flowchart for explaining the operation of the second operation example;
FIG. 5 is a flowchart for explaining the operation of the third operation example;
FIG. 6 is a flowchart for explaining the operation of the fourth operation example;
[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 feed cassette, 34: Registration roller, 34a: Pre-registration sensor, 35 ... Fixing device, 38 ... Paper discharge switch, 51 ... Stapler, 52.53 ... Paper discharge bin, 60 ... Main CPU, 90 ... Printer CPU, 90a ... memory 90b ... timer 91 ... motor driver 92 ... conveyance control unit 93 ... exposure control unit

Claims (4)

In an image forming apparatus to which a finisher for processing an image forming medium on which an image is formed is connected.
An exposure means for irradiating the image carrier with light based on an image formed on the image forming medium;
The image formed on the image carrier is developed by the light irradiated by the exposure means and transferred to the intermediate transfer member, and the image transferred to the intermediate transfer member is transferred onto the image forming medium. Image forming means for discharging the image forming medium to the finisher;
When the image forming process is performed on the image forming medium by the image forming unit, the discharge interval of the image forming medium required by the finisher is determined when the processing content of the finisher for the image forming medium is determined. Acquisition means for acquiring the sheet processing time indicating
Determining means for determining whether or not the sheet processing time acquired by the acquiring means is longer than a paper discharge interval of the image forming medium by the image forming processing in the image forming means;
If it is determined by the determining means that the sheet processing time is longer than the paper discharge interval by the image forming process in the image forming means, the image forming process is performed when the intermediate transfer member holds another image. Control means for prohibiting transfer of an image formed on a medium to the intermediate transfer member;
An image forming apparatus comprising: In an image forming apparatus to which a finisher for processing an image forming medium on which an image is formed is connected.
An exposure means for irradiating the image carrier with light based on an image formed on the image forming medium;
The image formed on the image carrier is developed by the light irradiated by the exposure means and transferred to the intermediate transfer member, and the image transferred to the intermediate transfer member is transferred onto the image forming medium. Image forming means for discharging the image forming medium to the finisher;
Processing means for the image forming medium in the finisher, and storage means for preliminarily storing a sheet processing time indicating a paper discharge interval required by the finisher corresponding to each processing content;
When the image forming process is performed on the image forming medium by the image forming unit, the discharge interval of the image forming medium required by the finisher is determined when the processing content of the finisher for the image forming medium is determined. Reading means for reading out the sheet processing time from the storage means ;
Determining means for determining whether or not the sheet processing time read from the storage means by the reading means is longer than a discharge interval of the image forming medium by the image forming processing in the image forming means;
If it is determined by the determining means that the sheet processing time is longer than the paper discharge interval by the image forming process in the image forming means, the image forming process is performed when the intermediate transfer member holds another image. Control means for prohibiting transfer of an image formed on a medium to the intermediate transfer member;
An image forming apparatus comprising: In an image forming apparatus to which a finisher for processing an image forming medium on which an image is formed is connected.
An exposure means for irradiating the image carrier with light based on an image formed on the image forming medium;
The image formed on the image bearing member is developed by the light irradiated by the exposure means and transferred to the intermediate transfer member, and further, the image transferred to the intermediate transfer member is transferred onto the image forming medium. Image forming means for discharging to the finisher;
When image forming processing is performed on a plurality of image forming media by the image forming unit, when the processing content of the finisher for each image forming medium is determined, each image forming medium required by the finisher is discharged. An acquisition means for acquiring a sheet processing time indicating a paper interval;
When two images are simultaneously transferred to the intermediate transfer member, the paper discharge interval between the two image forming media when the two images are continuously formed by the image forming unit is acquired by the acquiring unit. Determining means for determining whether or not the sheet processing time is longer than
If it is determined by this determination means that the sheet processing time is longer than the paper discharge interval when the image forming process is continuously performed by the image forming means, the first image simultaneously transferred to the intermediate transfer member is formed as an image. After transferring to the medium, before transferring the image on the second side to the image forming medium, the intermediate transfer member is operated without transferring the image on the second side to the image forming medium. Processing means for delaying the timing of transferring the image of the surface to the image forming medium;
An image forming apparatus comprising: In an image forming apparatus to which a finisher for processing an image forming medium on which an image is formed is connected.
An exposure means for irradiating the image carrier with light based on an image formed on the image forming medium;
The image formed on the image bearing member is developed by the light irradiated by the exposure means and transferred to the intermediate transfer member, and further, the image transferred to the intermediate transfer member is transferred onto the image forming medium. Image forming means for discharging to the finisher;
Processing means for the image forming medium in the finisher, and storage means for preliminarily storing a sheet processing time indicating a paper discharge interval required by the finisher corresponding to each processing content;
When the image forming process is performed on the plurality of image forming media by the image forming unit, the image forming media required by the finisher are discharged when the processing content of the finisher for each image forming medium is determined. Reading means for reading out the sheet processing time indicating the paper interval from the storage means;
When two images are simultaneously transferred to the intermediate transfer member, the discharge interval between the two image forming media when the two images are successively subjected to image forming processing by the image forming unit is determined by the reading unit. Determination means for determining whether or not the sheet processing time read from the storage means is longer;
If it is determined by this determination means that the sheet processing time is longer than the paper discharge interval when the image forming process is continuously performed by the image forming means, the first image simultaneously transferred to the intermediate transfer member is formed as an image. After transferring to the medium, before transferring the image on the second side to the image forming medium, the intermediate transfer member is operated without transferring the image on the second side to the image forming medium. Processing means for delaying the timing of transferring the image of the surface to the image forming medium;
An image forming apparatus comprising:

Images