JP2009282450A - Print job processing device, image forming apparatus, and print system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a print server for suppressing consumption of toner. <P>SOLUTION: The print server is equipped with a communication part 401c dor communicating with each of a plurality of printers 405a to 405d. The print server manages a remaining toner amount of each of the plurality of printers. The print server decides the toner consumption of a print job to be executed. When deciding that the toner consumption of the print job is large, the job is executed by the printer in which the largest amount of toner remains. When deciding that the toner consumption of the print job is small, the job is executed by the printer in which the smallest amount of toner remains. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a print job processing apparatus, an image forming apparatus, and a printing system, and more particularly, to a print job processing apparatus, an image forming apparatus, and a printing system that manage a toner state.

An electrophotographic image forming apparatus (MFP (Multi Function Peripheral), facsimile machine, copier, printer, etc.) is provided with a developing device that performs development with toner.
Patent Document 1 below discloses an image forming apparatus that counts the number of rotations of a developing roller and the number of dots of an image formed on a photosensitive drum in order to suppress deterioration in image quality due to toner deterioration. Has been. When the number of dots of the image at a predetermined number of rotations of the developing roller is smaller than a predetermined threshold value, a process of developing the developer (discharges staying toner) is executed.
Japanese Patent Laid-Open No. 2004-125829

A conventional image forming apparatus cannot select a print image. In addition, when images with low toner consumption are continuously printed, the staying toner increases, so that there is a problem that the toner must be discharged and the toner may be wasted.
The present invention has been made to solve such problems, and an object of the present invention is to provide a print job processing apparatus, an image forming apparatus, and a print system capable of suppressing toner consumption.

  In order to achieve the above object, according to one aspect of the present invention, a print job processing apparatus includes a communication unit capable of communicating with each of a plurality of image forming apparatuses, and a staying toner amount of each of the plurality of image forming apparatuses. Based on the acquisition means to be acquired, the determination means for determining the toner consumption amount of the print job to be executed, the staying toner amount acquired by the acquisition means and the determination result of the determination means, print jobs from a plurality of image forming apparatuses Selecting means for selecting an image forming apparatus to be executed.

  Preferably, the print job processing apparatus further includes a job distribution unit that distributes the print job to the image forming apparatus selected by the selection unit.

  Preferably, each of the plurality of image forming apparatuses discharges toner when the amount of staying toner is larger than a threshold value.

  Preferably, the acquisition unit acquires the difference between the reference toner amount to be consumed with respect to the driving amount of the developing roller and the actually consumed toner amount as the staying toner amount.

  Preferably, each of the plurality of image forming apparatuses includes a plurality of developing units that store toners corresponding to a plurality of colors, and the acquisition unit manages the amount of staying toner in each of the developing units of the plurality of colors.

  According to another aspect of the present invention, the image forming apparatus acquires the amount of staying toner in the developing device by acquiring information regarding the developing device, driving of the developing roller, and information regarding toner consumption of the print job. And a notifying means for notifying the print job processing apparatus of the acquired amount of staying toner.

  Preferably, the printing system includes any one of the print job processing apparatuses described above and an image forming apparatus.

  According to still another aspect of the present invention, a method for controlling a print job processing apparatus having a communication unit capable of communicating with each of a plurality of image forming apparatuses obtains a staying toner amount of each of the plurality of image forming apparatuses. A print job from a plurality of image forming apparatuses based on the acquisition step, the determination step for determining the toner consumption amount of the print job to be executed, and the staying toner amount acquired in the acquisition step and the determination result of the determination step A selection step of selecting an image forming apparatus to be performed.

  According to still another aspect of the present invention, a control method of an image forming apparatus provided with a developing device obtains information relating to driving of a developing roller and information relating to toner consumption of a print job, whereby staying toner in the developing device is obtained. An acquisition step of acquiring the amount, and a notification step of notifying the acquired amount of staying toner to the print job processing apparatus.

  According to still another aspect of the present invention, a control program for a print job processing apparatus having a communication unit capable of communicating with each of a plurality of image forming apparatuses obtains a staying toner amount of each of the plurality of image forming apparatuses. A print job from a plurality of image forming apparatuses based on the acquisition step, the determination step for determining the toner consumption amount of the print job to be executed, and the staying toner amount acquired in the acquisition step and the determination result of the determination step And a selection step of selecting an image forming apparatus to be executed.

  According to still another aspect of the present invention, a control program for an image forming apparatus provided with a developing device obtains information relating to driving of a developing roller and information relating to toner consumption of a print job, so that staying toner in the developing device is obtained. Causing the computer to execute an acquisition step of acquiring the amount and a notification step of notifying the acquired amount of staying toner to the print job processing apparatus.

  According to these inventions, it is possible to provide an image forming apparatus capable of suppressing toner consumption, a method for controlling the image forming apparatus, and a control program for the image forming apparatus.

[First Embodiment]
FIG. 1 is a diagram showing an outline of the central cross section of the image forming apparatus according to the first embodiment of the present invention. Here, it is assumed that the image forming apparatus is a tandem full-color printer.

  First, the configuration of the image forming unit of the image forming apparatus will be described. The image forming apparatus 1 includes cartridges 28a, 28b, 28c, and 28d corresponding to YMCK (yellow, magenta, cyan, and black). Each cartridge 28a, 28b, 28c, 28d includes charging units 5a, 5b, 5c, 5d for charging the photoreceptors 3a, 3b, 3c, 3d, and exposure units 6a, 6b, 6c, 6d for exposing image patterns. The developing devices 4a, 4b, 4c and 4d for developing the toner are incorporated.

  The image forming apparatus includes an intermediate transfer belt 2 that forms an image by superimposing four color toner images formed on the photoreceptors 3a, 3b, 3c, and 3d, and a toner image formed on the intermediate transfer belt 2 as a recording medium. A secondary transfer roller 11 to be transferred onto the medium, an intermediate transfer belt cleaner (blade) 7 for separating the transfer residual toner from the intermediate transfer belt 2, a waste toner box 15 for storing the separated transfer residual toner, and a cartridge 28a. , 28b, 28c, and 28d, toner bottles 25a, 25b, 25c, and 25d that replenish toner by operating the stirring blades 26a, 26b, 26c, and 26d are provided.

  Next, the configuration of the recording medium transport unit will be described. The image forming apparatus includes a paper feed roller 8 that feeds a recording medium from the recording medium storage unit 16, a timing roller 10 that temporarily stops the fed recording medium, and a toner image that is image-formed on the intermediate transfer belt 2. A secondary transfer roller 11 for transfer onto the recording medium, a fixing roller 12 (consisting of a pressure roller 12a and a heating roller 12b) for fixing the toner image transferred onto the recording medium, and the recording medium after fixing are discharged. Alternatively, a paper discharge roller 13 that conveys to the double-sided conveyance path, and double-sided path conveyance rollers 14 a and 14 b that convey the recording medium to the timing roller 10 via the double-sided conveyance path are provided.

  Whether or not a loop formed on the sheet by the transfer portion adjacent to the secondary transfer roller 11 and the fixing roller 12 between the secondary transfer roller 11 and the fixing roller 12 on the sheet passing path has reached a certain level. A paper detection sensor (fixing loop sensor or loop detection sensor) 27 is provided.

  The paper feed roller 8 is a standard cassette paper feed roller, and a multi-manual paper feed roller 9 is also provided in the paper passing path.

  In the image forming apparatus, as a motor, a color PC motor 17, a main motor 18, a fixing motor 19, a color developing motor 20, a developing motor 21, a double-sided path conveyance motor 22, and a toner replenishing motor (yellow) are provided. , For magenta) 23 and a toner supply motor (for cyan, black) 24 are provided.

  Further, paper detection sensors 29 to 31 and a paper material detection sensor 32 are provided in the paper passing path. The paper material detection sensor 32 may be omitted.

  FIG. 2 is a block diagram illustrating a configuration of the image forming apparatus 1. The image forming apparatus includes an engine unit 200. The engine unit 200 includes a paper feed conveyance control unit 201, a storage medium control unit 203, an I / F control unit 205, a fixing control unit 207, an image formation control unit 209, and a toner supply control unit 211 (these control units). Is constituted by a CPU).

  The paper feeding / conveying control unit 201 is connected to various loads 301 such as a conveying motor and a paper detection sensor 303, and controls paper feeding / conveying.

  The storage medium control unit 203 is connected to an EEPROM (nonvolatile memory) that is a storage medium in each color toner cartridge (toner bottle) 25a to 25d, and can store data measured by the CPU. The storage medium control unit 203 is also connected to the RAM 207 and the ROM 309.

  The I / F control unit 205 is connected to the controller unit 100 and exchanges various information. An operation panel 305 is connected to the controller unit 100. The user can make various settings from the operation panel 305.

  The fixing control unit 207 is connected to a heater, a fixing motor, and the like 311 and controls various devices that perform fixing processing.

  The image forming control unit 209 is connected to members 313 such as a developing device (developing unit), a photoconductor, a polygon motor, various sensors, a pressure contact / separation clutch, and an intermediate conveyance motor, and performs various processes such as development and transfer. Control the device. The image forming control unit 209 is connected to a cooling fan 315 provided for cooling the inside of the apparatus. The image formation control unit 209 controls the cooling fan 315 so that the temperature rise in the apparatus can be suppressed.

  The toner supply control unit 211 is connected to the toner supply motors 23 and 24. The toner replenishment control unit 211 controls various devices so that each color toner can be replenished in accordance with a print instruction.

  The I / F control unit 205 is connected to a communication unit 317 for communicating with an external device through a communication line such as a network.

  FIG. 3 is a cross-sectional view showing a configuration around the photoreceptor 3. The photoreceptor 3 is one of the photoreceptors 3a, 3b, 3c, and 3d. Around the photoreceptor 3, a charging unit 5, a developing device (developing unit) 4, an eraser 51, and a cleaner 53 are arranged.

  The toner in the developing device 4 is consumed by being developed, and the consumed amount is replenished from the toner bottles (toner cartridges) 25a, 25b, 25c, and 25d. By outputting the image, the toner in the developing device is replaced. When images that consume less toner are continuously output, the toner is only slightly replaced. As a result, the time during which the same toner exists in the developing device 4 becomes longer.

  The toner staying for a long time is deteriorated by rubbing against the photoreceptor 3 and the developing blade. The deteriorated toner has reduced chargeability and fluidity. When the deteriorated toner is used for development, it leads to a decrease in image density and various image quality.

  In order to prevent this, in the image forming apparatus of the present embodiment, when printing of an image that consumes less toner (an image with a low CW ratio) continues and the amount of toner staying in the developing device increases, the toner Is forcibly developed (discharged). Then, new toner is supplied from the toner bottle. In this way, the amount of staying toner in the developing device is kept below a certain level.

  The CW ratio is the Color / White ratio, which is the ratio of the image area to the sheet area.

The amount of staying toner is determined as follows.
Residual toner amount = (cumulative rotation amount of developing roller / reference rotation amount) × 3%
-Integrated CW ratio% (Formula 1)

  The reference rotation amount is the rotation amount of the developing roller when one page of A4 paper is printed. In the image forming apparatus according to the present embodiment, when the CW ratio per page of A4 paper is 3% or more, calculation is performed on the assumption that toner retention (deterioration) that leads to deterioration of image quality does not occur. . Therefore, the difference from 3% is the staying toner.

  That is, the difference between the reference toner amount to be consumed ((cumulative rotation amount of developing roller / reference rotation amount) × 3%) with respect to a constant development drive amount and the actually consumed toner amount (integrated CW ratio) is obtained. An amount that is less than the reference toner amount to be consumed is measured as the amount of staying toner.

  The CW ratio is the ratio of the image area to the paper area. For example, in the case of A4 (297 × 210 mm) and 600 dpi (1 inch = 25.4 mm), the paper area is

(297 × 210) / (25.4 / 600) dot
And in an image with 3% CW ratio

{(297 × 210) / (25.4 / 600)} × 0.03 dot
Is the image area.

  The image forming apparatus does not calculate the CW ratio based on the cumulative total of all pixels (dots) that form an image, but corrects the CW ratio according to the density of the pixel and the distribution status of pixels around the pixel. I'm calculating.

  The CW ratio in the present embodiment is not the CW ratio with respect to the image size to be printed, but the CW ratio with respect to the paper size (A4 size) (the number of dots forming the image / the number of dots of the A4 size).

  Further, the cumulative CW ratio in the above (Equation 1) is a cumulative value of the CW ratio of each print image.

  Since the amount of staying toner does not become negative, when the value obtained by (Equation 1) is 0 or less, the amount of staying toner is set to “0”.

  Prior to the print instruction to the engine unit, the controller unit counts the CW ratio of the image. When receiving a print instruction from the controller unit, the engine unit starts a printing operation and counts the rotation amount of the developing roller. Thus, the “cumulative rotation amount of the developing roller” in the above (Equation 1) is calculated.

  Further, the engine unit cumulatively adds the CW ratios notified from the controller unit to obtain the “integrated CW ratio” in the above (Equation 1). The engine unit obtains the amount of staying toner according to the above (Equation 1) every time one print is completed. When the amount of staying toner exceeds the first threshold, the engine unit interrupts printing and discharges staying toner.

  Further, when the amount of staying toner exceeds the second threshold value at the end of the print job (Job), staying toner is discharged.

  The first threshold value is a threshold value at which the image quality does not deteriorate. The second threshold value is a threshold value about 1/5 of the first threshold value. The second threshold value is a threshold value for discharging the staying toner when a certain amount of staying toner is accumulated at the end of the job so that the printing is not interrupted by the first threshold value.

  When the staying toner is discharged, the “cumulative rotation amount of the developing roller” and the “cumulative CW ratio” are cleared.

  The amount of staying toner increases or decreases according to the CW ratio of the image to be printed. Since the amount of staying toner does not become “0” or less, in this embodiment, the amount of staying toner is suppressed by changing the order of print jobs.

  FIG. 4 is a diagram illustrating the transition of the staying toner amount when a plurality of jobs are printed from the state where the staying toner amount is “0”.

  Here, a change in the amount of staying toner when two jobs (low CW ratio job and high CW ratio job) are continuously executed will be described. The horizontal axis represents time, and the vertical axis represents the amount of staying toner. Here, the low CW ratio job is a job having a CW ratio of less than 3%, and the high CW ratio job is a job having a CW ratio of 3% or more. When the low CW ratio job is executed, the amount of staying toner increases because the toner consumption is small, and conversely, when the high CW ratio job is executed, the amount of toner consumption is high and the staying toner amount decreases.

  The solid line in (1) shows the change in the amount of staying toner when the high CW ratio job is executed after executing the low CW ratio job, and the dotted line in (2) shows the low CW ratio job after executing the high CW ratio job. Is a change in the amount of staying toner when the operation is executed.

  Whether the process (1) is performed or the process (2) is performed, the accumulation of the CW ratio itself is the same.

  When the process (2) is performed, since the high CW ratio job is printed in a state where the amount of staying toner is 0, the amount of staying toner does not increase at first and remains 0. The amount of staying toner increases in the latter half of the print of a low CW ratio job.

  When the process (1) is performed, the amount of staying toner increases because a low CW ratio job is printed first. The amount of staying toner decreases in the latter half of the print of a high CW ratio job.

  As a result, it is possible to reduce the final amount of staying toner by performing the process (1) than by performing the process (2). Therefore, in this embodiment, even if the total CW ratio of a plurality of jobs is the same, the image forming apparatus is controlled so as to reduce the final staying toner amount by changing the printing order.

  More specifically, the controller unit obtains an integrated CW ratio of the entire job prior to printing, and changes the job order according to the amount of staying toner.

  Assume that the job to be executed next is a high CW ratio job in a state where the amount of staying toner is small. When the job is printed, if the amount of staying toner becomes 0 or less, printing of another low CW ratio job is preferentially executed.

  Conversely, assume that the job to be executed next is a low CW ratio job in a state where the amount of staying toner is large. When the job is printed, the staying toner exceeds the second threshold value, and when the staying toner is discharged, printing of another high CW ratio job is preferentially executed.

  In the example of FIG. 4, the amount of staying toner is zero at first. If a high CW ratio job is executed here, the amount of staying toner will be 0 or less in calculation (the actual amount of staying toner will not be 0 or less, so if it is 0 or less in calculation, it will be recorded as 0). Therefore, the execution of the high CW ratio job temporarily enters a standby state, and another low CW ratio job is executed. Thereafter, the high CW ratio job that was in the standby state is executed. That is, in the image forming apparatus according to the present embodiment, the process indicated by the solid line (1) is executed instead of the process indicated by the dotted line (2). Thereby, the final amount of staying toner can be reduced.

  FIG. 5 is a diagram illustrating a job management table managed by the image forming apparatus.

  Job numbers are assigned from old jobs to new jobs. Here, job 1 is the oldest and job 5 is the newest (the job registered last). In principle, the job is executed from the oldest one. That is, job 1 is a candidate job for execution.

  Before executing job 1, which is a candidate job, an expected value of the amount of staying toner after executing job 1 is calculated from the current amount of staying toner and the CW ratio of job 1. At this time, if the expected value of the staying toner is 0 or less or exceeds the second threshold value, the execution of the job 1 is temporarily reserved, and the candidate job is the job 2 as the next job. Regarding job 2, the same processing as that of job 1 is performed.

  In addition, when the expected value of the amount of staying toner after the job 1 is executed is 0 or more and less than or equal to the second threshold value, the job 1 is executed.

  FIG. 6 is a flowchart illustrating a staying toner amount calculation process performed by the image forming apparatus when one image is printed.

  Referring to the figure, in step S101, the driving amount (rotation amount) of the developing roller is calculated. As the driving amount of the developing roller increases, the toner deteriorates. In step S101, the amount of such deterioration is measured.

  In step S103, the CW ratio of the printed image is counted. When an image having a large CW ratio is printed, the toner is discharged as much and new toner is introduced into the developing device, so that the degree of deterioration of the toner in the developing device becomes small. In step S103, such a toner discharge amount is measured.

  In step S105, the amount of staying toner is calculated by the above (Equation 1) based on the driving amount of the developing roller and the CW ratio of the image. Note that if the print job is a plurality of print jobs, the processes of steps S101 to S105 are repeated.

  FIG. 7 is a flowchart showing the staying toner discharging process.

  Referring to the figure, in step S201, it is determined whether it is a predetermined timing. The predetermined timing is when one image is printed or when one job is finished.

  If “YES” in the step S201, it is determined whether or not the staying toner amount calculated in the process of FIG. 6 is larger than a predetermined value in a step S203. Here, as the “predetermined value”, the first threshold is used when printing of one image is completed. Further, the second threshold value is used at the end of the print job.

  If “YES” in the step S203, the staying toner is discharged in a step S205. Further, the amount of staying toner is cleared. Thereafter, the process ends.

  If NO in step S203, the processing from step S201 is executed.

  FIG. 8 is a flowchart showing job order change processing.

  As described with reference to FIG. 5, it is assumed that the first (oldest) print job is registered as a print candidate job.

  In step S301, an average CW ratio (CW_ave) of candidate jobs is obtained. The average CW ratio of a job is the CW ratio of the image if there is one image printed in the job, and the average CW ratio of those images if there are multiple images printed in the job. Is the ratio.

In step S303, it is determined whether the candidate job is a job with a low CW ratio. Specifically, it is determined whether CW_ave of the candidate job is less than 3%. If YES (CW_ave is less than 3%), the amount of staying toner basically increases after the candidate job ends. In step S315, it is determined whether the staying toner is discharged after the candidate job is completed. In particular,
It is determined whether the relationship of (3% −CW_ave) × number of job pages + current staying toner amount> second threshold value is satisfied.

  That is, the amount of staying toner after the candidate job ends is predicted from the current amount of staying toner and CW_ave. If the amount of staying toner after the completion of the candidate job exceeds the second threshold and it is predicted that the staying toner will be discharged (YES in S315), the printing of this candidate job is suspended in step S307.

  On the other hand, if the amount of staying toner after the completion of the candidate job falls below the second threshold and it is predicted that the staying toner will not be discharged (NO in S315), the candidate job is printed in step S313. To do.

If NO in step S303 (CW_ave is 3% or more), the amount of staying toner basically decreases after the candidate job ends. In step S305, it is determined whether the amount of staying toner becomes 0 or less after the candidate job is completed. In particular,
It is determined whether (CW_ave−3%) × number of job pages> current amount of staying toner is satisfied.

  That is, the amount of staying toner after the candidate job ends is predicted from the current amount of staying toner and CW_ave. If the amount of staying toner after the completion of the candidate job becomes 0 or less (YES in S305), printing of this candidate job is suspended in step S307.

  On the other hand, if it is predicted that the amount of staying toner after completion of the candidate job is 0 or more (NO in S305), printing of this candidate job is executed in step S313.

  If the candidate job is suspended in step S307, it is determined in step S309 whether the current candidate job is the final job. The final job is the latest job as shown in FIG. If it is not the final job (NO in S309), the next job in the order is registered as a print candidate job in step S317, and the processing from step S301 is executed.

  If the job held in step S307 is the final job (YES in S309), the oldest held job is selected as a candidate job in step S311, and the job is printed in step S313.

  The fact that the last job has been held means that all jobs have been held. In this case, the final staying toner amount does not change even if the job order is changed. For this reason, the order is not changed.

  When a subsequent job is printed without being held after the job is held, the amount of staying toner changes. Therefore, there is a possibility that the previously held job can be printed next. In order not to change the order of jobs as much as possible, when another job is printed after the job is held, it is desirable to determine whether the held job can be printed again. Specifically, after printing is performed in step S313 in FIG. 8, it is desirable to perform the processing from step S301 with the oldest job as a candidate job.

  As described above, according to the present embodiment, the image forming apparatus changes the order of images to be printed according to the amount of staying toner. More specifically, when a plurality of print jobs are stagnant and the amount of staying toner is large (NO in S305 of FIG. 8), priority is given to printing of a high CW ratio image, and the amount of staying toner is small (FIG. 8). NO in S305 gives priority to the printing of the low CW ratio image.

  When the amount of staying toner is large, priority is given to the processing of a high CW ratio image, so the amount of staying toner is temporarily reduced, and staying toner discharge is suppressed (postponed). Subsequent printing of the low CW ratio image may meet the staying toner discharge conditions, but staying toner discharge due to a temporary increase in staying toner amount is suppressed.

  When the amount of staying toner is small, priority is given to the processing of the low CW ratio image. Therefore, the amount of staying toner temporarily increases, but the amount of staying toner may decrease in the subsequent printing of the high CW ratio image. . Since the amount of staying toner never becomes 0 or less, there is a possibility that the amount of staying toner can be reduced as compared with the case where a high CW ratio image is printed first or the order is not changed. Get higher.

[Modification 1]
In FIG. 8, candidate jobs are sequentially set from the old job to the new job, and it is determined whether the candidate job satisfies the condition. For example, in the determination in step S305, jobs that meet the conditions (jobs determined to be NO in S305) are executed from the oldest one. Instead, it is determined whether or not all registered jobs meet the conditions, and among the jobs that meet the conditions, the job that can reduce the stagnant toner is executed with priority. Also good. In other words, among jobs whose staying toner amount does not become 0 or less after the end of the job, priority is given to a job having the largest CW ratio. Thereby, the amount of staying toner in the developing device can be reduced, and the image quality can be improved.

[Modification 2]
The staying toner amount may be recorded for each developing device of each color, and the toner may be discharged in the developing device in which the staying toner amount has increased.

[Modification 3]
In the above embodiment, the rotation amount of the developing motor (developing roller drive amount) is acquired, and the amount of staying toner is obtained from the CW ratio with respect to the rotation amount. However, other information is acquired as information regarding the toner state of the developing device. May be. For example, information proportional to the rotation amount of the developing roller such as the rotation amount of the photosensitive member may be acquired, or the staying toner amount may be obtained by acquiring the CW ratio with respect to the number of prints.

[Second Embodiment]
Since the basic configuration of the image forming apparatus according to the second embodiment of the present invention is the same as that of the image forming apparatus according to the first embodiment, description thereof will not be repeated. Here, the difference between the image forming apparatus in the second embodiment and the image forming apparatus in the first embodiment will be described.

  In the image forming apparatus according to the second embodiment, determination of staying toner discharge for each print using the first threshold value is performed according to the flowchart of FIG. Determination of staying toner discharge at a job break using the second threshold value is performed according to the flowchart of FIG.

  FIG. 9 is a flowchart illustrating a process for determining staying toner discharge at a job break, which is executed by the image forming apparatus according to the second embodiment.

  In step S401, after one job is executed (that is, at a break between jobs), it is determined in step S403 whether the staying toner discharge condition is satisfied. That is, it is determined whether the staying toner at that time exceeds the second threshold value.

  If YES in step S403, in step S405, the CW ratio of the job to be executed next and the amount of staying toner generated in the job are calculated. In step S407, it is determined whether the next job to be executed is a job with a low CW ratio. If NO (that is, if the job has a high CW ratio), the remaining toner can be reduced by executing the job. In step S409, it is determined whether the toner amount obtained by adding the amount of staying toner generated in the next job to the current amount of staying toner exceeds the second threshold value. Here, since the next job is a job with a high CW ratio, the value of the staying toner amount generated in the next job is negative.

  If “YES” in the step S409, it indicates that the staying toner amount exceeds the second threshold value even if the next job is executed. Therefore, the staying toner is discharged at the current time in a step S411. Also, the amount of staying toner is cleared.

  If NO in step S409, the amount of staying toner can be made equal to or less than the second threshold value by executing the next job, so that the process ends without discharging staying toner at the present time.

  If “NO” in the step S403, since the staying toner does not exceed the second threshold value at the present time, the staying toner is not discharged and the process is finished.

  If YES in step S407, the next job to be executed is a job with a low CW ratio, and even if the job is executed, the staying toner cannot be reduced. Toner is discharged. Also, the amount of staying toner is cleared.

  As described above, according to the second embodiment, when the amount of staying toner exceeds the second threshold at the end of the job, the image forming apparatus performs the next job to be executed with a high CW ratio. If the staying toner amount does not exceed the second threshold due to the execution of the job, the staying toner discharge can be suppressed.

[Third Embodiment]
Since the basic configuration of the image forming apparatus according to the third embodiment of the present invention is the same as that of the image forming apparatus according to the first embodiment, description thereof will not be repeated here. Here, differences between the image forming apparatus according to the third embodiment and the image forming apparatus according to the first embodiment will be described.

  The image forming apparatus according to the present embodiment counts the CW ratio of the entire job remaining at the break of the job. If the amount of staying toner is predicted to be less than or equal to the second threshold at the end of all jobs, control is performed so that staying toner is not discharged according to the second threshold at job breaks. . This is because the amount of staying toner can be reduced to the second threshold value or less by executing all jobs, so that it is less necessary to discharge staying toner at the break of the job.

  FIG. 10 is a flowchart illustrating a process for determining staying toner discharge at job breaks, which is executed by the image forming apparatus according to the third embodiment.

  In step S701, after one job is executed (that is, at a break between jobs), it is determined in step S703 whether the staying toner discharge condition is satisfied. That is, it is determined whether the staying toner at that time exceeds the second threshold value.

  If YES in step S703, in step S705, the average CW ratio of all jobs registered at that time and the amount of staying toner that is finally generated by executing all jobs are calculated. In step S707, it is determined whether the amount of toner obtained by adding the amount of staying toner generated in all jobs to the current amount of staying toner exceeds a second threshold value.

  If “YES” in the step S707, it indicates that the staying toner amount exceeds the second threshold value even if all the jobs are executed, and thus the staying toner is discharged at the current time in a step S709. Also, the amount of staying toner is cleared.

  If “NO” in the step S707, the final staying toner amount can be set to be equal to or less than the second threshold value by executing all the jobs. Therefore, the processing is not performed at this time without discharging the staying toner. finish.

  If “NO” in the step S703, since the staying toner does not exceed the second threshold value at the present time, the staying toner is not discharged and the process is finished.

  As described above, according to the third embodiment, when the amount of staying toner exceeds the second threshold at the end of the job, the image forming apparatus executes the first job by executing all jobs registered at that time. When the threshold value of 2 is not exceeded, the final staying toner amount can be suppressed. Further, it is possible to suppress toner consumption due to discharge of staying toner.

[Fourth Embodiment]
Since the basic configuration of the image forming apparatus according to the fourth embodiment of the present invention is the same as that of the image forming apparatus according to the first embodiment, description thereof will not be repeated. Here, the difference between the image forming apparatus in the fourth embodiment and the image forming apparatus in the first embodiment will be described.

  In step S201 in the flowchart of FIG. 7, the image forming apparatus according to the present embodiment has a predetermined timing at the end of the image stabilization process or the end of the print job (YES in S201). In step S203, a plurality of predetermined values (threshold toner amount threshold values) for determining whether or not the staying toner is discharged are used.

  That is, the staying toner discharge condition at the end of the print job is different from the staying toner discharge condition at the end of the image stabilization process. The threshold value (third threshold value) used at the end of the image stabilization process is larger than the threshold value (second threshold value) used at the end of the print job.

  This makes it difficult for the staying toner to be discharged at the end of image stabilization, and suppresses (postpones) staying toner discharge. In the subsequent printing, there is a possibility that the condition for discharging the staying toner may be met, but the staying toner discharge due to a temporary increase in the staying toner amount accompanying image stabilization is suppressed.

  Note that the threshold value (third threshold value) used at the end of image stabilization is greater than the threshold value (first threshold value) used at the end of printing one image during print job execution. It may be enlarged. The first and third threshold values may be the same value.

  The controller unit of the image forming apparatus according to the present embodiment counts the CW ratio of an image to be printed prior to a print instruction to the engine unit. When there is a print instruction from the controller unit, the engine unit starts the printing operation and counts the rotation amount of the developing roller. Thereby, the cumulative rotation amount of the developing roller of the above (Equation 1) is calculated.

  Further, the engine unit cumulatively adds the CW ratios notified from the controller unit to obtain an integrated CW ratio. The engine unit obtains the amount of staying toner according to the above (Equation 1) every time one print is completed. If the amount of staying toner exceeds the second threshold value at the end of the print job, the engine unit discharges staying toner. Here, the second threshold value is 40%, but is not limited thereto. Note that “40%” is “40%” when “the amount of residual toner in an amount that makes one page of A4 paper a solid image” is 100%.

  During the image stabilization process, a pattern is drawn on the intermediate transfer belt. Since the CW ratio of the pattern to be drawn is 3% or less, the amount of staying toner increases when the image stabilization process is performed. The amount of staying toner is obtained not only at the end of the printing operation but also after the end of the image stabilization process. When the amount of staying toner exceeds the third threshold value, the staying toner is discharged. Here, the third threshold value is assumed to be 200%, but is not limited thereto. Note that “200%” is “200%” when “the amount of residual toner in an amount that makes one page of A4 paper a solid image” is 100%.

  Since the pattern drawn on the intermediate transfer belt at the time of image stabilization is determined in advance, the CW ratio may be stored as a fixed value in the engine. In this case, the CW ratio is not notified from the controller.

  When the staying toner is discharged, the cumulative rotation amount of the developing roller and the cumulative CW ratio are cleared.

  The third threshold value is a value equal to or less than the amount of staying toner that causes a reduction in image quality, and is larger than the second threshold value. Further, the third threshold value is larger than the amount of staying toner accumulated in one image stabilization process.

  FIG. 11 is a diagram illustrating a transition of the staying toner amount when the print job is executed after the image stabilization process is executed.

  Here, a change in the amount of staying toner when a print job with a high CW ratio is executed after the image stabilization process is executed will be described. The horizontal axis represents time, and the vertical axis represents the amount of staying toner. The case where the processing according to the prior art is performed by the one-dot chain line, and the case where the processing according to the present embodiment is performed by the solid line are shown.

  The amount of staying toner accumulated by the image stabilization process is equal to or greater than the second threshold value. In the prior art, the staying toner is discharged at the end of the image stabilization process (A).

  However, when the amount of staying toner exceeds the second threshold value, the image quality does not immediately decrease. At the end of the image stabilization process (A), the staying toner exceeding the second threshold value is accumulated, but it is also assumed that an image with a high CW ratio is printed in the subsequent printing. In this embodiment, at the end of the image stabilization process, the staying toner is not discharged according to the second threshold value. Thereby, useless toner consumption can be suppressed.

  When a print job with a high CW ratio that consumes a large amount of toner is executed after the image stabilization process, according to the prior art, the amount of staying toner at the end of the job (B) Since the toner is discharged at the time point A), it remains 0. On the other hand, in the present embodiment, the amount of staying toner may be set to be equal to or less than the second threshold value at the end of the job (B) without discharging the toner at the end of the image stabilization process (A). There is a possibility.

  Thereafter, when a plurality of print jobs having a low CW ratio are executed, in the conventional technique, the staying toner is discharged when the staying toner amount reaches the second threshold value (D) at the end of the job. Thereafter, the amount of staying toner remains zero even when a print job with a high CW ratio is executed.

  According to the present embodiment, when a plurality of low CW ratio print jobs are executed following the end of job (B), the amount of staying toner becomes the second threshold value at the end of those jobs. At time (C), the staying toner is discharged. Thereafter, when a low CW ratio print job is executed, the staying toner amount increases, and when a high CW ratio print job is executed, the staying toner amount decreases.

  The reason why the toner is not discharged by the second threshold value after the image stabilization process is completed will be further described.

  The image stabilization process is performed when the power is turned on. Thereafter, it is assumed that only monochrome printing is performed and the power is turned off. Since monochrome toner does not consume color toner, if toner is discharged at the second threshold value, color toner is consumed even though color printing is not performed. Therefore, the staying toner is not discharged as much as possible only by the image stabilization process.

  Since the amount of staying toner is large after the image stabilization processing is completed, a print job with a high CW ratio is preferentially output when there are a plurality of jobs according to the flowchart of FIG. Further, by executing the processing in the flowcharts of FIGS. 9 and 10, when the staying toner decreases in the future, the toner discharge can be suspended.

  As described above, for example, when power ON, monochrome printing, and power OFF are repeated, the amount of staying toner in the color toner increases and eventually exceeds the third threshold value. In this case, since the subsequent image quality is deteriorated, the staying toner is discharged.

  FIG. 12 is a flowchart illustrating a staying toner discharge control process according to the fourth embodiment.

  In step S501, it is determined whether the image stabilization process is finished or the print job is finished. If the print job is finished, a second threshold value is set as a threshold value for discharging the staying toner in step S503. On the other hand, if the image stabilization process is finished, a third threshold value is set as a threshold value for discharging the staying toner in step S509.

  If it is determined in step S505 that the amount of staying toner exceeds the threshold for discharging staying toner (YES in step S505), staying toner is discharged in step S507 if YES.

[Effects of the fourth embodiment]
As described above, according to the fourth embodiment, by changing the staying toner discharge condition at the end of the print job and the staying toner discharge condition at the end of the image stabilization process, the image stabilization process with a low CW ratio can be performed. There is an effect that toner consumption due to the staying toner discharge accompanying execution can be minimized.

[Fifth Embodiment]
A print system according to the fifth embodiment of the present invention includes a plurality of image forming apparatuses connected to a network and a print server. The image forming apparatus may be the image forming apparatus in the first to fourth embodiments, or may be a conventional image forming apparatus.

  When a print server inputs a job from a client PC, the print server determines an image output destination (that is, an image forming apparatus that prints the image). At this time, the output destination is determined so that the amount of staying toner in each image forming apparatus is uniform.

  That is, an image forming apparatus with a large amount of staying toner compared to other image forming apparatuses is made to print a high CW ratio image, and an image forming apparatus with a small amount of staying toner prints a low CW ratio image. Do it.

  FIG. 13 is a diagram illustrating a network to which the image forming apparatus is connected.

  The printers 405a to 405d, which are image forming apparatuses, are connected to a network. The print server 401 distributes the print job from the client PC 403 to each of the printers 405a to 405d.

  The print server 401 includes a CPU 401a, a storage unit 401b, and a communication unit 401c. The print server 401 manages the amount of staying toner in each printer.

  The print server 401 obtains an average CW ratio of the entire job prior to printing. When the average CW ratio is 3% or more, a print instruction is issued to the printer with the largest amount of staying toner. When the average CW ratio is less than 3%, a print instruction is issued to the printer with the least amount of staying toner.

  In each printer, the engine unit starts a printing operation and counts the rotation amount of the developing roller when a printing instruction is issued from a controller (print server). Thereby, the cumulative rotation amount of the developing roller of the above (Equation 1) is calculated.

  The engine unit cumulatively adds the CW ratios notified from the controller (print server) to obtain an integrated CW ratio. The engine unit obtains the amount of staying toner according to the above (Equation 1) every time one print is completed. When the amount of staying toner exceeds the first threshold value when printing of one sheet is completed, printing is interrupted and staying toner is discharged.

  The staying toner is also discharged when the amount of staying toner exceeds the second threshold at the end of the print job.

  The first threshold value is a threshold value that does not deteriorate the image quality. The second threshold value is about 1/5 of the first threshold value, and some amount of staying toner is present at the end of the job so as not to interrupt printing due to the first threshold value. It is for discharging if it is accumulated.

  When the staying toner is discharged, the cumulative rotation amount of the developing roller and the cumulative CW ratio are cleared. At the end of the job, the printer notifies the print server 401 of the current staying toner amount.

  FIG. 14 is a flowchart illustrating job distribution processing executed by the print server.

  Referring to the figure, when a print job is received from the client PC, the average CW ratio value of the job is calculated in step S601. If the average CW ratio value is 3% or more in step S603, the job is transmitted to the printer having the largest amount of staying toner in step S605, and printing is executed. On the other hand, if the average CW ratio value is less than 3% in step S603, the job is transmitted to the printer with the least amount of staying toner in step S607, and printing is executed.

[Effects of Fifth Embodiment]
As described above, according to the fifth embodiment, in an image forming apparatus having a large amount of staying toner, printing of a high CW ratio image is performed with priority, so the amount of staying toner decreases. In an image forming apparatus with a small amount of staying toner, printing of a low CW ratio image is performed with priority, so the amount of staying toner increases. However, as a result, the discharge frequency of staying toner in each image forming apparatus decreases, and wasteful toner consumption is suppressed.

[Sixth Embodiment]
Since the basic configuration of the printing system in the sixth embodiment of the present invention is the same as that of the printing system in the fifth embodiment, the description thereof will not be repeated here. Here, the difference between the print system in the sixth embodiment and the print system in the fifth embodiment will be described.

  In the sixth embodiment, the print server manages the amount of staying toner for each color (Y, M, C, K) of each printer. Based on the toner consumption amount of each color in the print job, it is determined in which printer the print job is executed.

  More specifically, prior to execution of a print job, the print server obtains the amount of staying toner generated by executing the entire job for each color of YMCK by the following equation.

Amount of staying toner = (3% −CW_ave) × number of pages of job (when the average CW ratio exceeds 3%, the amount of staying toner becomes negative)

  Next, the amount of staying toner for the entire job (each color) obtained above is added to the current amount of staying toner (for each color) of each printer. Thus, the amount of staying toner after the job is printed by each printer is obtained.

  At this time, the amount of staying toner of all the printers at the time when printing of the job is completed is stored. Since there are four colors of staying toner amount per printer, the maximum value is stored.

  For example, assume a case where three printers are targets for job distribution (each printer is referred to as No. 1, No. 2, and No. 3).

  FIG. 15 shows the amount of staying toner generated by executing a certain job, 1-No. 3 is a diagram illustrating a current staying toner amount in each of the three printers.

  As shown in (A), it is assumed that the amount of staying toner varies by 10 for Y, 3 for M, -5 for C, and 2 for K by executing a certain job. No. In the printer 1, it is assumed that the current amount of staying toner for each of YMCK is 3, 0, 0, and 6. No. In the second printer, it is assumed that the current amount of staying toner for each of YMCK is 0, 5, 5, and 9. No. In the printer No. 3, the current amount of staying toner of YMCK is assumed to be 2, 8, 8, 4. The amount of staying toner indicates the ratio of staying toner when “the amount of remaining toner that makes one page of A4 paper a solid image” is 100%, and the unit is “%”.

  FIG. 16 shows the job of FIG. It is a figure which shows the change of the residual toner amount of each printer at the time of performing with each printer of 1-3.

  As shown in FIG. 16A, the job in FIG. No. 1 is printed. In the printer 1, the amount of staying toner for each of YMCK is 13, 3, 0, 8 (C is −5, but if it is negative, it is calculated as 0).

  At this time, the amount of staying toner becomes the largest. Y of 1 (the amount is A% (= 13%)).

  As shown in FIG. 16B, the job of FIG. No. 2 is printed. In the printer No. 2, the amount of staying toner for YMCK is 10, 8, 0, and 11, respectively.

  At this time, the amount of staying toner becomes the largest. K of 2 (the amount is B% (= 11%)).

  As shown in FIG. 16C, the job of FIG. No. 3 is printed. In the printer No. 3, the amount of staying toner of YMCK is 12, 11, 3, and 6, respectively.

  At this time, the amount of staying toner becomes the largest. Y of 3 (the amount is C% (= 12%)).

  For all printers, the maximum staying toner amount (A%, B%, C%) after printing is determined, and then the maximum staying toner amount (A%, B%, C%) is compared. A job print instruction is issued to the printer having the smallest maximum amount of staying toner.

  In this case, no. No. 2 is printed, because the maximum value in the whole can be minimized. 2 prints the job.

  When there are a plurality of printers having the same maximum staying toner amount, it is desirable to select a printer having the minimum minimum staying toner amount among them.

[Effects of the sixth embodiment]
As described above, according to the sixth embodiment, an image forming apparatus that executes a job is selected based on the amount of staying toner for each color. Thereby, the discharge frequency of the staying toner in each image forming apparatus can be reduced, and wasteful toner consumption is suppressed.

[Others]
The processing in the above-described embodiment may be performed by software or by using a hardware circuit.

  In addition, a program for executing the processing in the above-described embodiment can be provided, and the program is recorded on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, and a memory card and provided to the user. You may decide to do it. The program may be downloaded to the apparatus via a communication line such as the Internet.

  Furthermore, the processes of the above-described embodiments may be performed in combination.

  In addition, it should be thought that the said embodiment is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a diagram showing an outline of a central section of an image forming apparatus according to a first embodiment of the present invention. 1 is a block diagram illustrating a configuration of an image forming apparatus 1. FIG. 2 is a cross-sectional view showing a configuration around a photoconductor 3. FIG. FIG. 10 is a diagram illustrating a transition of a staying toner amount when a plurality of jobs are printed from a state where the staying toner amount is “0”. 3 is a diagram illustrating a job management table managed by the image forming apparatus. FIG. 6 is a flowchart showing a staying toner amount calculation process when one image is printed, which is executed by the image forming apparatus. 10 is a flowchart illustrating a staying toner discharge process. It is a flowchart which shows the order change process of a job. 10 is a flowchart illustrating a stay toner discharge determination process at a job break, which is executed by the image forming apparatus according to the second embodiment. 10 is a flowchart illustrating determination processing for discharging staying toner at a break between jobs, which is executed by the image forming apparatus according to the third embodiment. FIG. 10 is a diagram illustrating a transition of a staying toner amount when a print job is executed after image stabilization is executed. 14 is a flowchart illustrating a staying toner discharge control process according to the fourth embodiment. 1 is a diagram illustrating a network to which an image forming apparatus is connected. 6 is a flowchart illustrating job distribution processing executed by the print server. The amount of staying toner generated by executing a job, 1-No. 3 is a diagram illustrating a current staying toner amount in each of the three printers. The job shown in FIG. It is a figure which shows the change of the residual toner amount of each printer at the time of performing with each printer of 1-3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Full color image forming apparatus 2 Intermediate transfer belt 3a Photoconductor (yellow)
3b Photoconductor (Magenta)
3c photoreceptor (cyan)
3d photoconductor (black)
4a Development section (yellow)
4b Development section (magenta)
4c Development part (cyan)
4d Development section (black)
11 Secondary transfer roller 13 Paper discharge roller 23, 24 Toner supply motor 25a to 25d Toner bottle (toner cartridge)
200 Engine unit 203 Storage medium control unit 307 RAM

Claims (11)

A communication unit capable of communicating with each of a plurality of image forming apparatuses;
Acquisition means for acquiring the amount of staying toner for each of the plurality of image forming apparatuses;
Determining means for determining toner consumption of a print job to be executed;
Print job processing comprising: a selecting unit that selects an image forming apparatus that executes the print job from the plurality of image forming apparatuses based on a staying toner amount acquired by the acquiring unit and a determination result of the determining unit apparatus.   The print job processing apparatus according to claim 1, further comprising a job distribution unit that distributes the print job to the image forming apparatus selected by the selection unit.   The print job processing apparatus according to claim 1, wherein each of the plurality of image forming apparatuses discharges toner when the amount of staying toner is larger than a threshold value.   4. The print according to claim 1, wherein the acquisition unit acquires, as a staying toner amount, a difference between a reference toner amount to be consumed with respect to a driving amount of the developing roller and an actually consumed toner amount. Job processing unit. Each of the plurality of image forming apparatuses includes a plurality of developing units storing toners corresponding to a plurality of colors,
The print job processing apparatus according to claim 1, wherein the acquisition unit manages the amount of staying toner in each of a plurality of color developing devices. A developer,
Obtaining means for obtaining the amount of staying toner in the developing device by obtaining information relating to driving of the developing roller and information relating to toner consumption of the print job;
An image forming apparatus comprising: a notification unit that notifies the print job processing apparatus of the acquired amount of staying toner. A print job processing apparatus according to any one of claims 1 to 5,
A printing system comprising the image forming apparatus according to claim 6. A method for controlling a print job processing apparatus including a communication unit capable of communicating with each of a plurality of image forming apparatuses,
An acquisition step of acquiring the amount of staying toner for each of the plurality of image forming apparatuses;
A determination step for determining a toner consumption amount of a print job to be executed;
A print job process comprising: a selection step of selecting an image forming apparatus that executes the print job from the plurality of image forming apparatuses based on the amount of staying toner acquired in the acquisition step and the determination result of the determination step; Control method of the device. A method for controlling an image forming apparatus including a developing device,
An acquisition step of acquiring the amount of staying toner in the developing device by acquiring information regarding driving of the developing roller and information regarding toner consumption of the print job;
A control method for an image forming apparatus, comprising: a notification step of notifying the acquired amount of staying toner to a print job processing apparatus. A control program for a print job processing apparatus including a communication unit capable of communicating with each of a plurality of image forming apparatuses,
An acquisition step of acquiring the amount of staying toner for each of the plurality of image forming apparatuses;
A determination step for determining a toner consumption amount of a print job to be executed;
A print that causes a computer to execute a selection step of selecting an image forming apparatus that executes the print job from the plurality of image forming apparatuses based on the amount of staying toner acquired in the acquisition step and the determination result of the determination step Control program for job processing unit. A control program for an image forming apparatus including a developing device,
An acquisition step of acquiring the amount of staying toner in the developing device by acquiring information regarding driving of the developing roller and information regarding toner consumption of the print job;
A control program for an image forming apparatus that causes a computer to execute a notification step of notifying the print job processing apparatus of the acquired amount of staying toner.

Images