JP2023074867A - image forming system - Google Patents

Abstract

To reduce power consumption of an image forming system by reducing power consumption associated with fixing of a toner image formed on a recording paper sheet using a period for an inserter unit to feed an interleaving paper sheet.SOLUTION: In an image forming system Sy provided herein, a control unit 61 makes a feeder unit 14 of an image forming device 10 temporarily halt feeding of a recording paper sheet and, upon completion of fixing of a recording paper sheet by a fixing unit 15 of the image forming device 10, makes an inserter unit 40 feed an interleaving paper sheet to a conveying path and lowers temperature of a fixing unit 15 during a period from the completion of fixing of the recording paper sheet to resumption of fixing of the next recording paper sheet.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image forming system that forms respective toner images on a plurality of recording sheets and inserts interleaf sheets between the recording sheets, and more particularly to a technique for reducing power consumption of the image forming system.

As an image forming system, a charged toner is applied to an electrostatic latent image on an image carrier, the electrostatic latent image is developed into a toner image, and the toner image on the image carrier is transferred to recording paper. Some have an image forming apparatus for fixing, and an inserter apparatus for inserting a slip sheet between recording sheets on which respective toner images are formed.

Further, in the image forming apparatus described in Japanese Patent Application Laid-Open No. 2002-200010, a cassette containing recording paper on which an image of a document is formed and a cassette containing recording paper used as interleaving paper are set. A slip sheet is inserted between a plurality of recording sheets on which images of respective originals are formed by switching supply. Here, an image can also be formed on a slip sheet, and the slip sheet, like the recording paper on which the original image is formed, is the transfer area of the photoreceptor drum and the space between the heating roller and the pressure roller of the fixing means. output to the output tray.

JP-A-2005-106921

Here, power saving of the image forming system is desired. In Patent Document 1, in order to form an image on the interleaving paper, the photoreceptor drum, the fixing means, and the like are used even during the period in which the interleaving paper is supplied. Therefore, it is difficult to use the period during which the interleaving paper is supplied to save the power consumption of the image forming system.

On the other hand, in a configuration including an image forming apparatus and an inserter device, such as the image forming system described above, an image of a document is formed on recording paper by the image forming device, and the recording paper is conveyed from the image forming device through the inserter device. Also, when the recording paper is not conveyed, and the image forming apparatus is not performing image formation and fixing of the recording paper, the interleaving paper is supplied by the inserter device and conveyed, so the period during which the interleaving paper is supplied is Using this, it is possible to perform processing for saving power in the image forming system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. , to save power in an image forming system.

An image forming system according to one aspect of the present invention includes a paper feeding unit that sequentially supplies a plurality of recording papers; an image forming unit that forms a toner image on each of the recording papers supplied by the paper feeding unit; a fixing unit that heats and presses each recording sheet to fix each toner image on each recording sheet; and a conveying path that sequentially conveys each recording sheet on which each toner image is fixed by the fixing section. an inserter device that supplies an interleaf sheet to the transport path downstream of the image forming unit and the fixing unit in the transport direction of the recording paper and transports the interleaf sheet through the transport path; When the interleaving paper is supplied to the conveying path by the device, the supply of the recording paper by the paper feeding unit is temporarily stopped, and the heater of the fixing unit is driven and controlled to stop fixing the recording paper. and a control unit that lowers the fixing temperature of the fixing unit by a predetermined temperature in a period from when fixing is resumed to the next recording paper.

According to the present invention, the power consumption of the image forming system is reduced by reducing the power consumption associated with fixing the toner image formed on the recording paper using the period during which the interleaving paper is supplied by the inserter device. be able to.

1 is a cross-sectional view showing an image forming apparatus, an inserter apparatus, and a post-processing apparatus in an image forming system according to one embodiment of the present invention; FIG. 2 is a functional block diagram showing the main internal configuration of the image forming apparatus of this embodiment; FIG. FIG. 3 is a diagram showing a recording sheet and an interleaving sheet inserted between the recording sheets; 5 is a timing chart schematically showing control of fixing temperature when conveying recording paper and interleaving paper; 5 is a timing chart showing more specific control of the fixing temperature when conveying the recording paper and interleaving paper; 9 is a timing chart showing another more specific control of the fixing temperature when conveying the recording paper and interleaving paper. 5 is a timing chart showing control of fixing temperature when the number of sheets of recording paper per unit time changes. 5 is a flow chart showing a procedure for controlling the fixing temperature when conveying recording paper and interleaving paper.

An image forming system according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an image forming apparatus, an inserter apparatus, and a post-processing apparatus in an image forming system according to one embodiment of the invention.

The image forming system Sy according to the present embodiment includes an image forming apparatus 10 that forms an image on a recording sheet, receives the recording sheet from the image forming apparatus 10, relays it to the post-processing apparatus 20, and uses the interleaving sheet as the recording sheet. Equipped with an inserter device 40 to be inserted between recording sheets, and a post-processing device 20 capable of receiving recording sheets and interleaving sheets from the inserter apparatus 40 and performing post-processing on the recording sheets and interleaving sheets. there is

The image forming apparatus 10 includes an image reading section 11 and an image forming section 12 . In the image reading section 11, when a plurality of manuscripts MS are placed on the manuscript tray 1, the manuscripts MS are successively pulled out from the manuscript tray 1 and conveyed, while the image of each manuscript MS is read by the imaging element, and each manuscript is read. The MSs are sequentially discharged to the discharge tray 2 and stacked. For each image of each document MS, the analog output of the imaging element is converted into a digital signal to generate image data representing the image of the document MS.

The image forming unit 12 sequentially inputs image data representing images of a plurality of originals MS, and forms an image of the originals MS represented by the image data on the recording paper KP each time image data is input. The image forming section 12 includes an image forming unit 3M for magenta, an image forming unit 3C for cyan, an image forming unit 3Y for yellow, and an image forming unit 3Bk for black. In each of the image forming units 3M, 3C, 3Y, and 3Bk, the surface of the photoreceptor drum 4 is uniformly charged, the surface of the photoreceptor drum 4 is exposed, and an electrostatic latent image is formed on the surface of the photoreceptor drum 4. is formed, the electrostatic latent image on the surface of the photosensitive drum 4 is developed into a toner image, and the toner image on the surface of the photosensitive drum 4 is transferred to the intermediate transfer belt 5 . Thereby, a color toner image is formed on the intermediate transfer belt 5 . This color toner image is secondarily transferred onto the recording paper KP conveyed through the conveying path 8 from the paper feeding unit 14 in the nip area N between the intermediate transfer belt 5 and the secondary transfer roller 6 .

After the image of the document MS is formed on the recording paper KP by the image forming unit 12, the recording paper KP is heated and pressurized by the fixing unit 15, and the toner image on the recording paper KP is fixed by thermocompression. Further, the recording paper KP is discharged to the discharge tray 19 through the discharge roller 7 or transported from the transport roller 16 to the post-processing device 20 through the inserter device 40 .

The inserter device 40 receives the recording paper from the image forming apparatus 10, relays it to the post-processing device 20, and inserts the interleaving paper AP between the recording papers KP. The inserter device 40 includes a paper feed tray 41 on which a plurality of interleaving papers AP are placed, a paper feed roller 42 for drawing out each interleaving paper AP from the paper feed tray 41 one by one, and An interleaving paper transport path 43 for transporting interleaving paper AP, and an interleaving paper AP transported from the interleaving paper transport path 43 or a recording paper KP transported by the transport roller 16 of the image forming apparatus 10 are received. , and a relay conveying path 44 for conveying to the post-processing device 20 .

Transport rollers 45 for transporting the interleaving paper AP are provided at various locations on the interleaving paper transport path 43, and transport rollers 46 for transporting the interleaving paper AP or the recording paper KP are provided at various locations on the relay transport path 44. there is

The post-processing device 20 includes a punching unit 21 that punches the recording paper KP or interleaving paper AP conveyed through the relay conveying path 44 of the inserter device 40 as post-processing, and a recording paper KP or interleaving paper. A transport roller 22 that transports the paper AP, a paper tray 23 that temporarily stocks the sequentially transported recording paper KP or the interleaving paper AP as a bundle of recording paper, and a paper tray 23 that is pulled out and transported. Alternatively, a discharge roller 26 for discharging the recording paper KP or interleaving paper AP directly conveyed from the conveying roller 22 to either the main bin 24 or a plurality of sub bins 25, and a discharge roller for either the main bin 24 or each of the sub bins 25. 26, and a transport branch guide 27 that switches the transport direction of the recording paper KP or interleaving paper AP from the transport roller 22 to the paper receiving tray 23 or the discharge roller 26. FIG.

The post-processing device 20 also includes a stapling unit 28 that performs stapling processing as post-processing on a bundle of recording papers or interleaving papers stocked on the paper receptacle 23, A receiving member 29 for receiving and holding the lower end of the sheaf of paper, a transport roller 31 for transporting the sheaf of recording paper downward from the paper receiving base 23, and a recording paper transported from the transport roller 31 or a stack of sheets. A paper folding unit 32 that performs paper folding processing as post-processing on a bundle of paper (folds a bundle of recording paper or interleaving paper at the center), and a bundle of recording paper or interleaving paper that has undergone the paper folding processing. and an ejection tray 33 to be ejected.

The paper receiving tray 23 includes a drive section (not shown) that moves the receiving member 29 in the direction in which the sheaf of recording paper is carried out. This drive unit moves the receiving member 29 in the direction in which the recording paper or the sheaf of interleaving paper is discharged, and the recording paper or the sheaf of interleaving paper held by the receiving member 29 is conveyed to the discharge roller 26, and the recording paper or A bundle of slip sheets is discharged from the discharge roller 26 to either the main bin 24 or each sub bin 25 .

The main bin 24 and sub-bins 25 are lifted by the lift mechanism 35 to the position of the discharge roller 26 to receive the recording paper KP or interleaving paper AP transported from the transport roller 22 or the receiving member 29 .

Next, configurations related to control of the image forming apparatus 10, the inserter device 40, and the post-processing device 20 will be described. FIG. 2 is a functional block diagram showing the main internal configuration of the image forming apparatus 10. As shown in FIG. As shown in FIG. 2, the image forming apparatus 10 includes an image reading unit 11, an image forming unit 12, a display unit 51, an operation unit 52, a touch panel 53, a storage unit 56, interfaces 57 and 58, a control unit 59; These components are enabled to send and receive data or signals to and from each other through the bus.

The display unit 51 is configured by a liquid crystal display (LCD) or an organic EL (OLED: Organic Light-Emitting Diode) display.

The operation unit 52 includes physical keys such as a numeric keypad, an enter key, and a start key. An instruction based on the user's operation of the start key or the like is input to the operation unit 52 .

A touch panel 53 is arranged on the screen of the display unit 51 . The touch panel 53 is a touch panel of a so-called resistive film type, capacitive type, or the like, and detects a contact (touch) of a user's finger or the like on the touch panel 53 together with the contact position, and outputs a detection signal indicating the coordinates of the contact position. is output to a control section 61 (described later) of the control unit 59 or the like.

The storage unit 56 is a large-capacity storage device such as an SSD (Solid State Drive) or HDD (Hard Disk Drive), and stores various application programs and various data.

The control unit 59 includes a processor, RAM (Random Access Memory), ROM (Read Only Memory), and the like. The processor is, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an MPU (Micro Processing Unit). The control unit 59 functions as the control section 61 by the control program stored in the ROM or the storage section 56 being executed by the processor.

The control unit 61 controls the image forming apparatus 10 as a whole. The control unit 59 is connected to the image reading section 11, the image forming section 12, the display section 51, the operation section 52, the touch panel 53, the storage section 56, interfaces 57 and 58, and the like. The control unit 61 controls the operation of these components and transmits and receives signals or data to and from these components.

The control unit 61 serves as a processing unit that executes various processes required for image formation by the image forming apparatus 10 .

Further, the control unit 61 receives an operation instruction input by the user based on the detection signal output from the touch panel 53 or the operation of the physical keys of the operation unit 52 . For example, the control unit 61 receives a touch operation on a GUI (Graphical User Interface) or the like displayed on the screen of the display unit 51 through the touch panel 53 . Furthermore, the control section 61 has a function of controlling the display operation of the display section 51 .

Further, the control unit 61 drives and controls each driving source of the inserter device 40 through the interface 57 . For example, the control unit 61 intermittently rotates the drive motor of the paper feed roller 42 to cause the paper feed roller 42 to pull out each interleaving paper AP from the paper feed tray 41 one by one. By rotating the driving motors of the transport rollers 45 , each transport roller 45 transports the interleaving paper AP from the interleaving paper transport path 43 to the intermediate transport path 44 . Alternatively, the control unit 61 rotates the drive motors of the transport rollers 46 of the relay transport path 44 to drive the interleaving paper AP or the recording paper KP from the relay transport path 44 to the post-processing device 20 by the transport rollers 46 . be transported.

Further, the control unit 61 drives and controls each driving source of the post-processing device 20 through the interface 58 . For example, the control unit 61 rotates the driving motor of the transport roller 22 to transport the recording paper KP or the interleaving paper AP by the transport roller 22 . Alternatively, the control unit 61 drives and controls the drive source of the lifting mechanism 35 to lift either the main bin 24 or each sub bin 25 to the position of the discharge roller 26, thereby moving the recording paper KP or the interleaf paper AP to the main bin 24 and each sub bin 25. Discharge to any of the sub-bins 25. Further, the control unit 61 drives and controls the driving source of the punching unit 21, the driving source of the stapling unit 28, the driving source of the paper folding unit 32, etc., and operates the punching unit 21, the stapling unit 28, and the paper folding unit 32. .

In the image forming system Sy having such a configuration, for example, the image forming apparatus 10 reads images of a plurality of originals MS and records them on respective recording sheets KP, and the post-processing apparatus 20 performs post-processing on each recording sheet KP. , the user operates the GUI displayed on the screen of the display unit 51 through the touch panel 53 to input the details of the post-processing, sets a plurality of manuscripts MS on the image reading unit 11, and performs the operation. The start key of the section 52 is operated.

When a copy operation instruction is input to the operation unit 52 by the above operation by the user, the control unit 61 accepts the copy operation instruction. In accordance with the copy operation instruction, the control section 61 causes the image reading section 11 to sequentially read the image of each document MS, and causes the image forming section 12 to form the image of each document MS on each recording paper KP. Further, the control unit 61 sequentially conveys these recording sheets KP to the post-processing device 20 through the inserter device 40, and at the same time, drives the post-processing device 20 through the interface 58 based on the input post-processing content. Then, the post-processing device 20 performs various post-processing on each recording sheet KP.

Here, when the image of each document MS is read and recorded on each recording paper KP, and the interleaving paper AP is inserted between the recording papers KP, the user can display the image on the screen of the display unit 51 through the touch panel 53, for example. A copy operation instruction including the number of originals MS, the number of copies to be printed, the insertion timing of the interleaving paper AP, and the number of inserted sheets J is input by operating the GUI.

At this time, when a copy operation instruction is input to the operation unit 52 by the above operation by the user, the control unit 61 accepts the copy operation instruction, and first, based on the number of sheets of each document MS and the number of copies to be printed, the current copy operation is performed. Calculate the number of sheets S of each recording paper KP used in .

Then, the control unit 61 executes a job based on the copy operation instruction, causes the image reading unit 11 to read the original document MS, causes the paper supply unit 14 to supply the recording paper KP, and causes the image forming apparatus 10 to print the recording paper KP. An image of the document MS is formed, and the recording paper KP is conveyed to the post-processing device 20 through the inserter device 40 . The control unit 61 counts the number s of the recording papers KP each time the paper feed unit 14 supplies the recording papers KP. When the number of sheets reaches S, reading of the document MS by the image reading unit 11, feeding of the recording paper KP by the paper feeding unit 14, and image formation on the recording paper KP by the image forming apparatus 10 are temporarily stopped.

Subsequently, the control unit 61 causes the inserter device 40 to convey and supply the specified number of insertion sheets J of the interleaving paper AP from the paper feed tray 41 through the interleaving paper conveying path 43 to the intermediate conveying path 44. Document reading, feeding, and image formation are resumed, and the recording paper KP on which the image of the document MS is formed is conveyed from the image forming apparatus 10 to the post-processing apparatus 20 through the relay conveying path 44 of the inserter apparatus 40 .

Further, based on the detection timing of the recording paper KP by the paper sensors provided at various places on the transport path 8 and the relay transport path 44, the control unit 61 starts supplying the recording paper KP from the paper feeding unit 14, and the registration roller 9 (Fig. 1) and the start of feeding the interleaving paper AP by the paper feed roller 42 of the inserter device 40 are controlled to provide a substantially constant interval between the recording paper KP and the interleaving paper AP. transported sequentially. For example, as shown in FIG. 3, every time five sheets (S=5) of recording paper KP are conveyed from the image forming apparatus 10 to the post-processing apparatus 20 through the inserter device 40, two sheets (J=2) are printed. The interleaving paper AP is inserted, and at this time, each recording paper KP and each interleaving paper AP are sequentially conveyed with a substantially constant space between them.

Note that if the post-processing device 20 does not perform post-processing while the inserter device 40 is supplying the interleaving paper AP, the post-processing device 20 receives the recording paper KP and the interleaving paper AP from the inserter device 40. Discharge to the main bin 24 .

If the post-processing by the post-processing device 20 is not performed while the inserter device 40 is feeding the interleaving paper AP, the control unit 61 controls the document reading, paper feeding, and transfer to the recording paper KP by the image forming device 10. to temporarily stop the image formation of the

Therefore, in the present embodiment, while the formation of the image of the document MS on the recording paper KP is temporarily stopped in order to insert the interleaving paper AP, it is not necessary to perform fixing by the fixing unit 15. The fixing temperature F of the fixing unit 15 is lowered from the target temperature FH suitable for fixing the toner image on the recording paper KP to the prescribed power saving temperature FL, thereby reducing the power consumption of the fixing unit 15 .

For example, if the fixing unit 15 has a configuration in which the recording paper KP is sandwiched between a heating roller and a pressure roller to fix the toner image on the recording paper KP, the control unit 61 controls the heating roller is driven and controlled to lower the temperature of the heater, thereby lowering the fixing temperature F of the fixing unit 15 from the target temperature FH to the power saving temperature FL. Further, when the fixing unit 15 has a configuration in which the recording paper KP is sandwiched between the fixing belt and the pressure roller to fix the toner image on the recording paper KP, the control unit 61 The fixing temperature F of the fixing section 15 is lowered from the target temperature FH to the power saving temperature FL by lowering the temperature of the heater that heats the belt or the temperature of the fixing belt that generates heat due to electromagnetic induction. As a result, the power consumption of the fixing section 15 is reduced.

The control unit 61 temporarily stops the supply of the recording paper KP by the paper feeding unit 14 to stop the image formation of the document MS, and as shown in FIG. During the period T1 from 1 to tb1 when the fixing of the next recording paper KP is restarted, the inserter device 40 supplies the interleaving paper AP to the relay conveying path 44, and the fixing temperature F of the fixing unit 15 is lowered to the power saving temperature FL. Lower. As a result, the power consumption of the fixing section 15 is reduced. Here, the point at which fixing of the next recording paper KP is restarted means, for example, the timing at which the leading edge of the next recording paper KP reaches the nip area N of the fixing section 15 while being transported by the transport path 8 . do. Alternatively, the timing of restarting fixing of the next recording paper KP may be, for example, the timing when the next recording paper KP is started to be transported by the transport path 8 .

However, when the fixing temperature F of the fixing unit 15 is raised and returned to the target temperature FH, if the fixing unit 15 starts fixing the recording paper KP before the fixing temperature F reaches the target temperature FH, fixing failure occurs. If the time from when the fixing temperature F reaches the target temperature FH to when the fixing unit 15 starts fixing becomes longer, the power consumption reduction effect becomes smaller.

Therefore, a temperature sensor 55 (shown in FIG. 2) for detecting the fixing temperature F of the fixing section 15 is provided. As shown in FIG. 5, the control unit 61 lowers the fixing temperature F of the fixing unit 15 to the power-saving temperature FL from the fixing end time ta1 of the recording paper KP, and the fixing temperature F is lower than the fixing restart time tb1 of the next recording paper KP. The fixing temperature F of the fixing section 15 is increased before a preset fixed time tt. Subsequently, the control unit 61 measures a temperature rise time Δt11 from the start time tc of the rise of the fixing temperature F to the arrival time td at which the fixing temperature F detected by the temperature sensor 55 reaches the target temperature FH. A waiting time Δt2 from the arrival time td to the fixing restart time tb1 of the next recording paper KP is measured. When the control unit 61 finishes counting the waiting time Δt2, the control unit 61 causes the paper supply unit 14 to start supplying the next recording paper KP, and the image forming apparatus 10 restarts the formation of the toner image on the next recording paper KP. Let

After that, the control unit 61 again temporarily stops the supply of the recording paper KP by the paper feeding unit 14 in order to insert the interleaving paper AP, and prevents the image forming apparatus 10 from forming the image of the document MS on the recording paper KP. When stopped, the fixing unit 15 is driven and controlled to lower the fixing temperature F to the power saving temperature FL from time ta2 when fixing of the recording paper KP is completed. Then, when resuming the fixing of the next recording paper KP, the control unit 61 drives the fixing unit 15 from before the temperature rise time Δt11 before the resuming time tb2 of the fixing of the next different recording paper KP. to raise the fixing temperature F. As a result, the fixing temperature F of the fixing unit 15 reaches the target temperature FH at the restart time tb2. As a result, fixing failure does not occur on the next recording sheet KP, and the standby time .DELTA.t2 is omitted, so power consumption can be reduced.

Note that the timed temperature rise time Δt11 may change gradually due to changes in the internal environment (internal temperature, etc.) of the image forming apparatus 10 .

Therefore, as shown in FIG. 6, the control unit 61 lowers the fixing temperature F of the fixing unit 15 to the power saving temperature FL from the time point tan (n=2, 3, . The fixing temperature F is increased from a time point before the temperature rise time Δt1(n−1) from the fixing restart time point tbn of the paper KP. Then, the control unit 61 counts the temperature rise time Δt1n from the time tc when the fixing temperature F starts rising to the time td when the fixing temperature F detected by the temperature sensor 55 reaches the target temperature FH. Further, the control unit 61 again lowers the fixing temperature F to the power saving temperature FL from the fixing end time ta(n+1) of the recording paper KP, and when restarting the fixing of the next recording paper KP, the next recording paper The fixing temperature F of the fixing unit 15 is increased from before the temperature rise time Δt1n from the KP fixing restart time tb(n+1). As a result, the fixing temperature F of the fixing unit 15 reaches the target temperature FH at the restart time tb(n+1). Therefore, when each toner image is sequentially formed on each recording paper KP, fixing failure does not occur on any of the recording papers KP, and the standby time Δt2 is omitted, thereby reducing power consumption. .

On the other hand, in the image forming apparatus 10, the number of sheets of recording paper KP processed per unit time (ppm) may change due to the influence of changes in the printing rate for the recording paper KP, changes in the power supply voltage of the image forming apparatus 10, and the like. be. When the number of sheets of recording paper KP processed per unit time is changed, the amount of heat taken away from the fixing section 15 by the recording paper KP changes. The temperature rise time Δt1 until the arrival time td at which the fixing temperature F reaches the target temperature FH fluctuates greatly.

For example, as shown in FIG. 7, when the number of sheets of recording paper KP processed per unit time (ppm) is changed from large (large) to small (small), the next fixing restart time point tb ( n+1), even if the fixing temperature F of the fixing unit 15 is increased from the temperature rise time .DELTA.t1n before the restart time tb(n+1), the rising speed of the fixing temperature F becomes faster, and the fixing unit The fixing temperature F of No. 15 reaches the target temperature FH, resulting in wasteful power consumption. Conversely, even at the restart time tb(n+1), the fixing temperature F of the fixing unit 15 may not reach the target temperature FH, and fixing failure may occur.

Therefore, the control unit 61 counts the number of sheets of recording paper KP processed per unit time (ppm), and when the counted ppm changes, invalidates the temperature rise time Δt1n, and then adjusts the temperature as shown in FIG. As shown, the temperature rise time Δt11 and the standby time Δt2 are measured again. Then, the control unit 61 lowers the fixing temperature F of the fixing unit 15 to the power saving temperature FL from time ta2 when fixing of the recording paper KP is completed. Then, when restarting fixing of the next recording paper KP, the control unit 61 raises the fixing temperature F of the fixing unit 15 from before the temperature rise time Δt11 from the fixing restart time tb2 of the next recording paper KP. As a result, the fixing temperature F of the fixing unit 15 reaches the target temperature FH at the restart time tb2, and the standby time Δt2 can be omitted. This makes it possible to avoid poor fixing and reduce power consumption without being affected by ppm changes.

Next, when the formation of the image of the document MS on the recording paper KP is temporarily stopped in order to insert the interleaving paper AP as described above, the fixing temperature F of the fixing unit 15 is lowered to A control procedure for reducing the power consumption of No. 15 will be organized and explained with reference to the flowchart shown in FIG.

The user operates the GUI displayed on the screen of the display unit 51 through the touch panel 53, for example, and for the print job to be executed this time, the number of sheets of each document MS, the number of copies, the insertion timing of the interleaving paper AP, and the insertion timing of the interleaving paper AP. Enter the number of inserts J.

The control unit 61 receives the input number of sheets of each document MS, the number of copies to be printed, the insertion timing of the interleaving paper AP, and the number J of the interleaving paper AP to be inserted. Then, the control unit 61 causes the paper feed unit 14 to start feeding the recording paper KP, and causes the image forming apparatus 10 to start forming images of each document MS (S101). At this time, it is assumed that the fixing temperature F of the fixing section 15 is adjusted to the target temperature FH.

When the recording paper KP is supplied by the paper feeding unit 14, the control unit 61 counts the number s of the recording papers KP step by step (S102), and the counted number s is used as the insertion timing of the interleaving paper AP. (S103), and if the counted number s has not reached the number S (S103 "No"), S102 is repeated.

When the controller 61 determines that the counted number of sheets s has reached the number of sheets S (S103 "Yes"), it calculates the number of sheets of recording paper KP processed per unit time (ppm) (S104).

The control unit 61 stops the feeding of the recording paper KP by the paper feeding unit 14 (S105), and after the fixing operation for the recording paper KP last fed by the paper feeding unit 14 is completed, the recording paper KP (most recent (S106), and the heater of the fixing unit 15 is driven and controlled from the fixing end time ta1 of the recording paper KP to The heating capacity is lowered to lower the fixing temperature F of the fixing section 15 to the power saving temperature FL (S107). It should be noted that the reduction in heating capacity due to drive control of the heater of the fixing section 15 here includes temporary suspension of the heating capacity of the heater by the control section 61 . When the heating capacity of the heater is lowered, the control unit 61 controls the rotational driving of the heating roller and the pressure roller of the fixing unit 15 to either maintain the rotational driving or stop the rotational driving. good. However, from the viewpoint of power consumption reduction, it is preferable that the control section 61 stop the rotational driving of the heating roller and the pressure roller of the fixing section 15 when the heating capacity of the heater is lowered.

The control unit 61 controls, for example, the start time of the recording paper KP transported by the registration rollers 9 (shown in FIG. 1), the length of the recording paper KP in the transport direction, the length of the recording paper KP from the registration rollers 9 through the nip region N to the fixing unit 15 Based on the conveying distance of KP and the conveying speed of the recording paper KP, the end time ta1 of the fixing of the recording paper KP by the fixing unit 15 is calculated.

The control unit 61 causes the recording paper KP for which the fixing end time ta1 has been determined in S105 to be conveyed to the post-processing device 20 through the inserter device 40, and the inserter device 40 relays and conveys the interleaving paper AP of the inserted number J. The interleaving paper AP is fed to the path 44 and conveyed to the post-processing device 20 (S108).

After receiving the recording paper KP and the interleaving paper AP, the post-processing device 20 discharges the recording paper KP and the interleaving paper AP to the main bin 24 through the transport rollers 22, for example.

Subsequently, the control unit 61 drives and controls the heater of the fixing unit 15 to raise the fixing temperature F of the fixing unit 15 from a predetermined time tt before the fixing restart time tb1 for the next recording paper KP. (S109). When the heating capacity of the heater is lowered (S107), if the rotation of the heating roller and the pressure roller of the fixing unit 15 is stopped, the control unit 61 adjusts the fixing temperature F of the fixing unit 15. At the time of raising, the rotation driving of the heating roller and the pressure roller of the fixing section 15 is resumed.

The control unit 61 sets the timing for starting the supply of the next recording paper KP by the paper feeding unit 14 based on the detection timing of the preceding interleaving paper AP or the recording paper KP by the paper sensor, for example, and determines the start timing of the supply of the recording paper KP. A restart point tb1 for fixing the recording paper KP by the fixing unit 15 is calculated based on the timing. Further, the fixed time tt is a time predetermined as a length sufficient for the once-lowered fixing temperature F to rise to and return to a preset target temperature FH suitable for fixing to the recording paper KP. .

The control unit 61 starts measuring the elapsed time tx1 from the start time tc of the rise of the fixing temperature F (S110), and when the fixing temperature F detected by the temperature sensor 55 reaches the target temperature FH, the elapsed time tx1 is measured. (S111), the elapsed time tx1 is obtained as the temperature rise time Δt11 from the start time tc of the fixing temperature F to the arrival time td when the fixing temperature F reaches the target temperature FH (S112).

The control unit 61 causes the paper feed unit 14 to start supplying the recording paper KP, restarts the formation of the toner image on the recording paper KP by the image forming apparatus 10 (S113), and the elapsed time tx2 from the arrival time td. Timing is started (S114), and the timing of the elapsed time tx2 ends at the restart time tb1 at which fixing of the next recording sheet KP by the fixing section 15 is started (S115). Then, the control unit 61 obtains the elapsed time tx2 as the waiting time Δt2 from the arrival time td to the fixing restart time tb1 of the next recording paper KP (S116).

Through S102 to S116, as shown in FIG. 5, the fixing temperature F of the fixing unit 15 is lowered from time ta1 when fixing of the recording paper KP is completed, and is kept constant by a predetermined value after time tb1 when fixing of the next recording paper KP is restarted. The fixing temperature F rises before time tt. The control unit 61 counts the temperature rise time Δt11 from the start time tc of the fixing temperature F rise to the arrival time td at which the fixing temperature F reaches the target temperature FH. A waiting time Δt2 is measured until the fixing restart time tb1.

Further, when the recording paper KP is supplied by the paper feeding unit 14, the control unit 61 counts the number s of the recording papers KP step by step (S117), and the counted number s of the interleaving papers AP is counted. If the number of sheets S, which is the insertion timing, has not been reached (S118 "No"), S117 is repeated.

When the controller 61 determines that the counted number of sheets s has reached the number of sheets S (S118 "Yes"), the controller 61 calculates the number of sheets of recording paper KP processed per unit time (ppm) (S119).

The control unit 61 stops the feeding of the recording paper KP by the paper feeding unit 14 (S120), and after the fixing operation for the recording paper KP last fed by the paper feeding unit 14 is completed, the recording paper KP (most recent (S121), and from the fixing end time ta2 of the recording paper KP, the heater of the fixing unit 15 is driven and controlled to The heating capacity is lowered to lower the fixing temperature F of the fixing section 15 to the power saving temperature FL (S122). It should be noted that the reduction in heating capacity due to drive control of the heater of the fixing section 15 here includes temporary suspension of the heating capacity of the heater by the control section 61 . At this time as well, when the heating capability of the heater is lowered, the control unit 61 controls the rotational driving of the heating roller and the pressure roller of the fixing unit 15 to either maintain the rotational driving or stop the rotational driving. may be performed. However, from the viewpoint of power consumption reduction, it is preferable that the control section 61 stop the rotational driving of the heating roller and the pressure roller of the fixing section 15 when the heating capacity of the heater is lowered.

The control unit 61 causes the recording paper KP for which the fixing end time ta2 has been determined in S121 to be conveyed to the post-processing device 20 through the inserter device 40, and the inserter device 40 relays and conveys the interleaving paper AP of the inserted number J. The interleaving paper AP is fed to the path 44 and conveyed to the post-processing device 20 (S123).

Further, the control unit 61 compares the ppm calculated in S119 and the ppm calculated in S104 to determine whether or not the ppm has changed (S124).

At this time, if the control unit 61 determines that the ppm has not changed ("No" in S124), the control unit 61 causes the paper supply unit 14 to start supplying the next recording paper KP, and (S125), the heater of the fixing unit 15 is driven and controlled, and the fixing is started from before the temperature rise time Δt11 obtained in S112 from the fixing restart time point tb2 of the next recording paper KP. The fixing temperature F of the portion 15 is raised (S126). As a result, the fixing temperature F of the fixing section 15 reaches the target temperature FH at the restart time tb2, so that the next recording paper KP is not defectively fixed, the waiting time Δt2 is omitted, and the power consumption is reduced. When the heating capacity of the heater is lowered (S122), if the rotation of the heating roller and pressure roller of the fixing unit 15 is stopped, the control unit 61 adjusts the fixing temperature F of the fixing unit 15. At the time of raising, the rotation driving of the heating roller and the pressure roller of the fixing section 15 is resumed.

Further, the control unit 61 starts counting the elapsed time tx1 from the start time tc of the rise of the fixing temperature F (S127), and when the fixing temperature F detected by the temperature sensor 55 reaches the target temperature FH, the elapsed time tx1 is reached. is completed (S128), and this elapsed time tx1 is acquired as the temperature rise time Δt1n from the start time tc of the fixing temperature F to the arrival time td at which the fixing temperature F reaches the target temperature FH (S129 ). After that, the process returns to S117.

By repeating S117 to S129, as shown in FIG. 6, the fixing temperature F of the fixing section 15 is lowered from the fixing end time tan of the recording paper KP, and the temperature rise time is longer than the fixing restart time tbn of the recording paper KP. The fixing temperature F is increased before Δt1(n−1), and the temperature rise time Δt1n from the start time tc of the fixing temperature F rising to the arrival time td at which the fixing temperature F reaches the target temperature FH is measured, Further, the fixing temperature F is lowered again to the power-saving temperature FL from the point of time ta(n+1) when fixing of the recording paper KP is completed. The fixing temperature F of the fixing section 15 is increased before the temperature rise time Δt1n from time tb(n+1), and reaches the target temperature FH at the restart time tb(n+1).

Further, when the control unit 61 determines that the ppm has changed (S124 "Yes"), the process returns to S109. As a result, the temperature rise time Δt1n obtained in S128 becomes invalid, and the temperature rise time Δt11 and the waiting time Δt2 shown in FIG. , the waiting time Δt2 is omitted. As a result, even if the ppm changes, the fixing failure does not occur and the power consumption is reduced.

As described above, in this embodiment, the fixing temperature F of the fixing unit 15 is lowered during the period in which the formation of the image of the document MS on the recording paper KP is temporarily stopped for the insertion of the interleaving paper AP. While reducing the power consumption of the unit 15, it is possible to prevent fixing failure by controlling the timing of starting the increase of the fixing temperature F.

It should be noted that the configuration and processing of the above embodiment described with reference to FIGS. 1 to 8 are merely examples of the present invention, and are not intended to limit the present invention to the configuration and processing.

10 Image forming apparatus 11 Image reading section 12 Image forming section 14 Paper feeding section 15 Fixing section 20 Post-processing device 40 Inserter device 51 Display section 52 Operation section 53 Touch panel 56 Storage section 57 Interface 58 Interface 59 Control unit 61 Control section

Claims (3)

a paper feed unit that sequentially supplies a plurality of recording papers;
an image forming unit that forms a toner image on each of the recording paper sheets supplied by the paper feeding unit;
a fixing unit that heats and presses each of the recording papers to fix each toner image on each of the recording papers;
a conveying path for sequentially conveying each of the recording papers on which the respective toner images are fixed by the fixing unit;
an inserter device that supplies an interleaf sheet to the transport path downstream of the image forming unit and the fixing unit in the transport direction of the recording paper and transports the interleaf sheet through the transport path;
When the inserter device is used to supply the interleaving paper to the conveying path between the plurality of recording papers fed by the paper feeding unit, the feeding of the recording papers by the paper feeding unit is temporarily stopped. At the same time, the heater of the fixing section is driven and controlled to lower the fixing temperature of the fixing section by a predetermined temperature during the period from the time when the fixing to the recording paper is stopped until the time when the fixing to the next recording paper is restarted. an image forming system comprising: a control unit that causes a temperature detection unit that detects a fixing temperature of the fixing unit;
The control unit
The fixing temperature is increased from a preset fixed time before the restart of fixing of the next recording sheet, and the fixing temperature detected by the temperature detection unit is set in advance from the start of the fixing temperature rise. The temperature rise time is measured until the temperature reaches the target temperature, and when the temperature rise time is finished, the supply of the next recording paper by the paper feed unit is restarted, and the next recording paper is supplied from the arrival time. measures the waiting time until fixing is restarted on the recording paper of
When the fixing by the fixing section and the feeding of the recording paper by the paper feeding section are temporarily stopped again and the fixing of the next recording paper is restarted, the feeding of the recording paper by the paper feeding section is restarted, 2. The image forming system according to claim 1, wherein the fixing temperature is raised by driving the heater of the fixing section from a time point before the temperature rise time before the fixing restart time for the next different recording paper. When the number of recording sheets per unit time on which the toner images are fixed by the fixing section changes, the control section disables the measured temperature rise time, and counts the temperature rise time. 3. The image forming system according to claim 2, wherein the standby time is measured again.

Images