JP2005010292A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that copes with a demand for high quality and a demand for various kinds of recording media and, at the same time, minimizes productivity decrease resulting from change of processing speed. <P>SOLUTION: Upon receiving a plurality of image forming instructions including specification of a plurality of processing speeds, the image forming apparatus 1 sequentially forms a plurality of images based upon the image forming instructions. In the image forming apparatus 1, every time that one image formation corresponding to one image forming instruction proceeds, an image forming time estimation means 60 estimates the time. A mode determination means 50 employs the estimated time as a determination reference. On the basis of this, an image formation order alteration means 40 alters order in which image formation is carried out to order that is different from order in which the image forming instructions are received. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus that has a plurality of process speeds, receives a plurality of image formation instructions accompanied by a process speed specification, and sequentially forms a plurality of images based on the plurality of image formation instructions on a recording medium. .
[0002]
[Prior art]
In recent years, in electrophotographic image forming apparatuses such as copiers and printers, colorization has progressed from black-and-white as functions have become more intense, and in order to differentiate from other models, high-quality images in color, high productivity, etc. The demand for is getting stronger. In addition, along with demands for high image quality and paper diversification, image forming apparatuses having a plurality of process speeds are becoming popular in order to meet such demands with limited ability image forming apparatuses. In such an image forming apparatus, for example, when images are continuously formed (printed) on a plurality of types of recording media (paper), it is necessary to change the process speed according to the type of the paper. When changing the process speed, it is necessary to change various conditions such as charging, exposure, transfer, and fixing suitable for the paper conditions. It is also necessary to ensure the running stability of the image carrier belt, the transfer medium conveyance belt, and the like. Although the process speed is preferably as fast as possible from the viewpoint of productivity, it is necessary to change the process speed depending on the type of paper, the quality of the image to be formed, and the image mode such as black and white or color.
[0003]
Here, a technique has been proposed in which the image density of a document is detected and the process speed is changed based on the detection result (see Patent Document 1). The image density of the original is the average value of the output signal from the solid-state image sensor (CCD), the average value of the output signal from the image density detecting means provided in the original feeder, or the potential sensor that measures the surface potential of the photoconductor. Can be obtained on the basis of the average value of the output signals from. According to this technique, since the process speed is automatically set, it is possible to obtain an image with improved image forming ability and excellent fixability as compared with the case where the process speed is set by the user's judgment.
[0004]
In addition, when performing only color printing and only monochrome printing, when forming an image at a process speed suitable for each of these color printing and monochrome printing, and continuously performing color printing and monochrome printing. A technique for forming an image at a process speed at the time of color printing slower than a process speed at the time of monochrome printing has been proposed (see Patent Document 2).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 06-003914
[Patent Document 2]
JP 2002-139878 A
[0006]
[Problems to be solved by the invention]
In the technique proposed in Patent Document 1, the process speed is changed every time the image density of the document is different. Each time the process speed is changed, it takes time to change the conditions for charging, exposure, transfer, fixing, etc., and to secure the running stability of the image carrier belt, transfer medium transport belt, etc. Needed. Therefore, productivity may be reduced.
[0007]
Further, in the technique proposed in Patent Document 2, when color printing and monochrome printing are mixed, image formation is performed at a process speed at the time of color printing slower than the process speed at the time of monochrome printing. There is a problem that productivity decreases.
[0008]
SUMMARY OF THE INVENTION In view of the circumstances described above, an object of the present invention is to provide an image forming apparatus in which a decrease in productivity due to a change in process speed is suppressed to a small size while meeting high image quality requirements and requests for diversifying types of recording media. And
[0009]
[Means for Solving the Problems]
An image forming apparatus of the present invention that achieves the above object has a plurality of process speeds, receives a plurality of image forming instructions accompanied by designation of process speeds, and receives a plurality of image forming instructions on a recording medium based on the plurality of image forming instructions. In an image forming apparatus that sequentially forms images,
Image forming order changing means is provided for changing the order of image formation to an order different from the acceptance order of image format instructions when there are a plurality of image forming instructions with different process speed designations. And
[0010]
In the conventional image forming apparatus, when there are a plurality of image forming instructions accompanied by designation of different process speeds, image formation is performed in the instructed order. For this reason, the process speed is changed each time. When changing the process speed, it takes time to change the charging, exposure, transfer, fixing, and other conditions, and to secure the running stability of the image carrier belt, transfer medium transport belt, etc. Therefore, changing the process speed requires a relatively long time, which may lead to a decrease in productivity.
[0011]
The image forming apparatus according to the present invention changes the order of image formation to an order different from the order of accepting image format instructions when there are a plurality of image formation instructions with different process speed designations. Therefore, image formation with the same process speed can be performed collectively. Therefore, the time required for changing the process speed can be shortened as compared with the conventional technique for forming an image in the instructed order while responding to the demand for high image quality and the diversification of the types of recording media.
[0012]
Here, when there are a plurality of image formation instructions with different process speed designations, a first mode for changing the order of image formation to an order different from the acceptance order of image format instructions, image formation instruction In the second mode in which image formation is performed at the lowest process speed among the plurality of image formation instructions, or in the order in which the image formation instructions are received and designated in each image formation instruction Mode determining means for determining a mode to be employed for image formation from among the third modes in which image formation is performed while changing to a process speed according to each process speed,
It is preferable that the image forming order changing unit operates upon receiving a determination that the first mode is adopted by the mode determining unit.
[0013]
In this way, the time required for changing the process speed can be shortened, and images can be formed at the minimum process speed, or images can be formed at a process speed that matches the designated process speed.
[0014]
In addition, when each of the first, second, and third modes is employed and image formation is performed, each time required until completion of a plurality of image formations corresponding to the plurality of image formation instructions is predicted. It is also preferable that the image forming time prediction unit includes an image formation time prediction unit, and the mode determination unit uses the time predicted by the image formation time prediction unit as one of determination criteria to determine a mode to be used for image formation. It is an aspect.
[0015]
In this way, it is possible to form an image by adopting a mode capable of forming an image in a short time.
[0016]
Further, it is preferable that the image formation required time prediction means performs time prediction every time one image formation corresponding to one image formation instruction proceeds.
[0017]
In this way, the shortest time required for image formation can be predicted.
[0018]
In addition, when each of the first, second, and third modes is used to form an image, each process speed required to complete the plurality of image formations corresponding to the plurality of image formation instructions is predicted. And determining the mode to be used for image formation by adopting the number of times of switching predicted by the process speed switching frequency prediction unit as one of the determination criteria. Is also preferable.
[0019]
A relatively long time is required to change the process speed. Therefore, when the number of times of process speed switching is adopted as one of the determination criteria, the time required for image formation can be shortened.
[0020]
Further, the process speed switching frequency prediction means may perform switching frequency prediction every time one image formation corresponding to one image formation instruction proceeds.
[0021]
In this way, the time required for image formation can be further shortened.
[0022]
The image forming apparatus may receive an image forming instruction in units of a job including one page or more of recording media.
[0023]
In this way, it is possible to instruct image formation on a plurality of recording media in one job.
[0024]
Further, the image forming apparatus may receive an image forming instruction in units of one page of the recording medium.
[0025]
In this way, for example, when a plurality of process speeds are included in one print job, an image can be formed with different process speeds for each page of the recording medium.
[0026]
Further, a mode switching unit that switches between a mode in which the image formation order changing unit is operated and a mode in which image formation is performed in the order in which the image formation instruction is received may be provided.
[0027]
With such a mode switching unit, for example, when a copy job instruction and a print job instruction are received at the same time, the copy job can be prioritized.
[0028]
Furthermore, the recording medium after image formation may be provided with a medium discharge means for discharging the recording medium in a manner separated for each image formation instruction.
[0029]
Here, the medium discharge means includes a sorter, an offset, and the like. When such a medium discharge means separates the recording medium after image formation for each image formation instruction, the order of the recording medium in a job having the same process speed is distinguished. can do.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0031]
FIG. 1 is a schematic configuration diagram of an embodiment of an image forming apparatus of the present invention.
[0032]
The image forming apparatus 1 shown in FIG. 1 has a plurality of process speeds, receives a plurality of image forming instructions accompanied by the designation of the process speed, and sequentially, on the recording medium, a plurality of images based on the plurality of image forming instructions. A tandem type color electrophotographic copying machine to be formed.
[0033]
In this image forming apparatus 1, light emitted from the light emitting element 11 a and reflected by the original placed on the original glass 11 b is incident on a solid-state image sensor (CCD) 11 e through a mirror 11 c and a lens 11 d. A document reading device 11 that reads a document image and obtains a gradation signal is provided. The obtained gradation signal is digitally processed and converted into image data for each R (red), G (green), and B (blue) color for each pixel, and the image data for each RGB color is Y (yellow). ), M (magenta), C (cyan), and K (black) colors, thereby obtaining image data for each color of YMCK.
[0034]
In addition, the image forming apparatus 1 includes an image forming unit 12 that forms an image based on the image data. The image forming unit 12 is provided with an operation panel 13 (corresponding to an example of a mode switching unit in the present invention) for switching various modes and giving necessary instructions. Further, in this image forming section 12, toner images of Y (yellow), M (magenta), C (cyan), and K (black) colors, which are arranged in series from the right side of FIG. 1, are formed. Four photoconductors 14 are provided. Here, for easy understanding of the drawing, only the photosensitive member 14 (on the right side in FIG. 1) on which a Y (yellow) toner image is formed will be described with reference numerals. Each photoconductor 14 rotates in the direction of arrow A and is uniformly charged by each charger 15. Each of the charged photoreceptors 14 is exposed by an optical signal emitted from a laser unit 16 that converts image data for each color of YMCK into an optical signal of each color, thereby forming an electrostatic latent image. Around each photoconductor 14, each developing unit 17 that stores YMCK color toner is arranged, and the electrostatic latent image formed on each photoconductor 14 is arranged for each photoconductor 14. Each developing device 17 develops the toner image of each color. On the other hand, the intermediate transfer belt 18 that is in contact with the four photoconductors 14 is looped over the opposing rolls 19 and 20 and the primary transfer roll 21 and circulates in the direction of arrow B, and each color formed on each photoconductor 14. The toner images are superimposed and transferred onto the intermediate transfer belt 18 by the primary transfer rolls 21 disposed at the respective transfer positions. Each color toner image superimposed and transferred on the intermediate transfer belt 18 is transported from the paper tray 22 (or the paper trays 23 and 24) by the paper transport roll 25 (or the paper transport rolls 26 and 27). Alternatively, the image is transferred onto the recording medium 101 by a secondary transfer roll 28 that is superimposed on the recording medium 102, 103) and forms a nip portion with the opposing roll 19 and the intermediate transfer belt 18 interposed therebetween. The recording medium 101 to which each color toner image has been transferred is further heated and pressurized by a fixing device 29 composed of a pair of rolls, whereby each color toner image is fixed on the recording medium 101 to form an image.
[0035]
In addition, the image forming apparatus 1 includes a discharge tray 30, and the recording medium 101 on which the image is formed is discharged to the discharge tray 30 via the discharge roll 31, or the discharge roll 32. And is discharged to a sheet receiving portion 33 provided in the image forming portion 12. On the other hand, when images are formed on both sides, the recording medium 101 on which the image is formed by being heated and pressed by the fixing device 29 is switched back to the secondary transfer roll 28 again via the duplex conveying path 34. Sent. An image is formed on both sides of the recording medium 101 via the secondary transfer roll 28 and the fixing device 29 and is discharged to the discharge tray 30 or the sheet receiving portion 33. A cleaner 35 for removing residual toner on the photoconductor 14 is provided on the upstream side of the charger 15 with respect to the process direction A of each photoconductor 14, and there are four in the circulation movement direction B of the intermediate transfer belt 18. A belt cleaner 36 for removing residual toner on the intermediate transfer belt 18 is provided on the upstream side where the photoreceptors 14 are arranged. Further, each toner cartridge 37 that supplies toner to each developing device 17 is provided above the image forming unit 12.
[0036]
In addition, when there are a plurality of image forming instructions with different process speed designations in the image forming unit 12, the image forming order is changed to an order different from the order of accepting the image format instructions. Order changing means 40 is provided.
[0037]
Further, when there are a plurality of image forming instructions with different process speed designations, the image forming unit 12 changes the order of image formation to an order different from the order of accepting the image format instructions. Mode, the second mode in which image formation is performed at the lowest process speed of the plurality of image formation instructions, or the order in which image formation instructions are received and A mode determination unit 50 is provided for determining a mode to be used for image formation from among the third modes in which image formation is performed while changing the process speed to the process speed specified in the image formation instruction.
[0038]
Here, the image forming order changing unit 40 operates in response to the determination by the mode determining unit 50 that the first mode is adopted.
[0039]
Further, the image forming unit 12 requires the completion of a plurality of image formations corresponding to a plurality of image formation instructions when image formation is performed by employing each of the first, second, and third modes. An image formation required time predicting means 60 for predicting each time is provided.
[0040]
Here, the mode determination unit 50 determines the mode to be used for image formation by adopting the time predicted by the image formation required time prediction unit 60 as one of the determination criteria. The image formation required time predicting means 60 performs time prediction every time one image formation corresponding to one image formation instruction proceeds. The operations of the image forming order changing unit 40, the mode determining unit 50, and the image formation required time predicting unit 60 will be described later with reference to flowcharts. Before that, the process speed needs to be changed in the image forming apparatus 1 of the present embodiment. Will be described. In general, the slower the process speed, the lower the stress on the xerographic process items for image formation (charging, exposure, development, transfer, fixing, etc. of the photoreceptor). On the other hand, if the process speed is high, the charging capability cannot be caught up in the xerographic process, and charging can only be performed to a charging potential level lower than a predetermined potential, charging potential unevenness occurs, and the exposure light quantity per unit area is also exposed. Is insufficient to reduce the potential to a predetermined light potential, the peripheral speed of the developing roll is increased even in the development process, the carrier is scattered due to centrifugal force, etc. The possibility of toner scattering due to the increase or the like increases. Also, in the transfer process, the toner cannot sufficiently move from the photoconductor to the transfer belt, or from the photoconductor to the recording medium, or from the transfer belt to the recording medium. And the toner may not be sufficiently melted and fixed. When the process speed is low, there are almost no obstacles as described above. Under image forming conditions that allow image formation at a high process speed, it is not possible to form a high-quality image at a high process speed or at a low process speed. Is possible.
[0041]
Conditions for changing the process speed include image printing density, image printing saturated toner amount, high gloss image, and output medium type.
[0042]
1) Image printing density
By reducing the density of the image print data, high-definition printing can be performed, and generally the image quality can be improved. However, since the amount of image data becomes enormous, the data processing speed cannot keep up with the production speed of the IOT (printing apparatus main body), and the data processing speed becomes a limiting condition for the total printing productivity. For this reason, it is possible to change the process speed by selecting which of emphasis is given to productivity and image quality, and to perform output corresponding to each purpose.
[0043]
2) Image printing saturated toner amount
In color image printing, various colors are reproduced by superposing toners of a plurality of colors (usually four colors of maximum YMCK). In the dark color portion, a maximum of 400% of toner per unit area (maximum of 100% per color) is transferred to a development / transfer target medium and further subjected to a fixing process. If the toner is more than a certain amount per unit area when fixing with the fixing device, depending on conditions, the toner may not be fixed on the transfer medium and may adhere to the fixing roll, or the transfer medium may be fixed on the fixing roll (or belt, etc.) ). Therefore, in order to restrict the maximum value of the image signal of a portion where a plurality of colors overlap to a predetermined amount, the above-mentioned problem can be prevented from occurring by changing the process speed according to the image density.
[0044]
3) High gloss image
The toner image on the transfer medium is fused by applying a high temperature (or normal temperature) and pressure by a fixing device. At this time, the toner is well melted and fixed by prolonging the time during which the toner is kept under high temperature and high pressure. As a result, the gloss is increased and the color reproduction range is widened. Can do. When outputting an image giving priority to high gloss and high color reproducibility over productivity, it is possible to reduce the process speed and output for this purpose.
[0045]
4) Output medium type
When the heat capacity of the medium to be transferred is large (thickness, high heat capacity material, etc.), there may be a case where only a fixing performance which is not sufficient at the fixing speed for the transfer medium is usually obtained. When forming an image on such a transfer medium, good fixing performance can be obtained by slowing the speed of passing through the fixing device.
[0046]
In the image forming apparatus 1 of the present embodiment, based on the above-described conditions, as described below, the productivity reduction associated with the change of the process speed while responding to the demand for high image quality and the demand for diversifying the type of recording medium. It is devised so that it can be kept small.
[0047]
FIG. 2 is a flowchart of the main routine when priority is given to reducing the processing time in setting the image forming conditions of the image forming apparatus shown in FIG.
[0048]
The routine shown in FIG. 2 is executed by the image forming order changing unit 40, the mode determining unit 50, and the image formation required time predicting unit 60 shown in FIG.
[0049]
First, a job is received in step S1. Next, in step S2, it is determined whether or not the accepted job is a copy job. If it is determined that the job is a copy job, the process proceeds to step S3. In step S3, the copy job is prioritized and executed, and this routine is terminated. In the case of a copy job, since there is a high possibility that the user is waiting for output from the copy job, the copy job processing is performed immediately without applying the productivity priority processing.
[0050]
On the other hand, if it is determined that the job is not a copy job, the process proceeds to step S4.
[0051]
In step S4, an acceptance job processing speed determination process is performed. Although details of step S4 will be described later, the accepted job is a low-speed image forming job for forming an image at a low process speed, a medium-speed image forming job for forming an image at a medium-speed process speed, and an image formation at a high-speed process speed. Judgment processing is performed as to which of the high-speed image forming jobs is to be performed. Thereafter, the process proceeds to step S5.
[0052]
In step S5, an image formation required time calculation flow is performed. Although details of step S5 will be described later, in step S5, the time required to complete image formation is calculated, and the process proceeds to step S6.
[0053]
In step S6, it is determined whether or not the job reception order highest priority mode is set. If it is determined that the job reception order highest priority mode is selected, the process proceeds to step S7. In step S7, the specified minimum process speed among all received jobs is set for all jobs (all received jobs), and the process proceeds to step S8. In step S8, the same image formation required time calculation flow as described above is executed, and the flow proceeds to step S9.
[0054]
In step S9, it is determined whether or not all jobs can be processed in a shorter time if they are executed at the latest specified process speed (the above-mentioned minimum process speed) in the job reception order. If it is determined that processing cannot be performed in a short time, the process proceeds to step S10.
[0055]
In step S10, the setting is returned to the designated process speed for each job, the image forming process is performed, and this routine is terminated. On the other hand, if it is determined that processing can be performed in a short time, the process proceeds to step S11, and all jobs set to the latest process speed among the accepted jobs are subjected to image formation processing at the same process speed, and this routine is executed. Exit.
[0056]
If it is determined in step S6 described above that the job reception order highest priority mode is not set, the process proceeds to step S12.
[0057]
In step S12, it is determined whether or not there is a job whose order of outputting N jobs (hereinafter abbreviated as N jobs) or more has been reduced (waited) among unprocessed jobs. If it is determined that there is a job whose output order has been reduced by N jobs or more, the process proceeds to step S13. In step S13, among the received unprocessed jobs, the priority of the job whose output order has been lowered among the jobs that have been lowered in order of N or more jobs is set to the highest priority, and the process proceeds to step S14. In step S14, the order of jobs having the same processing speed as that of the highest priority job has been lowered in order of N or more jobs, and priorities are assigned in order of the highest priority job in order of acceptance, and this routine ends. To do.
[0058]
If it is determined in step S12 that there is no job whose output order has been reduced by N jobs or more, the process proceeds to step S15. In step S15, job priority determination processing is performed. Although details will be described later, the job with the highest priority among the jobs whose priority has not been determined is set as the job of interest, and the priority is designated for the job of interest.
[0059]
Next, in step S16, the job priority is determined and the execution flow is executed. Although the details of this execution flow will be described later, the processing order of the accepted jobs is determined on the assumption that the job is currently being executed, and settings are made so as to execute from the job with the highest priority.
[0060]
Furthermore, in step S17, the same image formation required time calculation (calculation of time required for completion of image formation) flow as in step S5 described above is performed, and the flow proceeds to step S18.
[0061]
In step S18, it is determined whether or not there is a job whose priority determination has not been completed since the end of the previous job. If it is determined that there is a priority determination incomplete job, the process returns to step S15. On the other hand, if it is determined that there is no priority determination incomplete job, the process proceeds to step S19.
[0062]
In step S19, it is determined whether or not the image processing time calculation result including no processing order change has the shortest job processing time (shortest time) during the job processing order change. If it is determined that the job processing order is changed at the shortest time, the process proceeds to step S20. In step S20, the job processing order is set in the processing order of the shortest time, and this routine ends. On the other hand, if it is determined that there is no shortest time among the job processing order changes, the process proceeds to step S21. In step S21, the job processing order is returned to the priority of the receiving order, and this routine is terminated.
[0063]
FIG. 3 is a flowchart of “execution processing of acceptance job processing speed” executed in step S4 shown in FIG.
[0064]
First, in step S4_1, it is determined whether or not the print image density is low. If it is determined that the print image density is not low, the process proceeds to step S4_2.
[0065]
In step S4_2, it is determined whether or not the print image density is medium density. If it is determined that the print image density is not medium density, since the print image density is high, the process proceeds to step S4_3 to set that it is a low-speed image forming job, and this routine is ended.
[0066]
On the other hand, if it is determined in step S4_1 that the print image density is low, the process proceeds to step S4_4. In step S4_4, it is determined whether the image printing saturated toner amount is small. If it is determined that the image printing saturated toner amount is not small, the process proceeds to step S4_5.
[0067]
In step S4_5, it is determined whether or not the image printing saturated toner amount is medium. If it is determined that the image printing saturated toner amount is not medium, since the image printing saturated toner amount is large, in step S4_3 described above, it is set that the job is a low-speed image forming job, and this routine is ended.
[0068]
If it is determined in step S4_4 that the image printing saturated toner amount is small, the process proceeds to step S4_6. In step S4_6, it is determined whether the image designated gloss is low. If it is determined that the image designated gloss is not low, the process proceeds to step S4_7, and it is determined whether or not the image designated gloss is medium. If it is determined that the image designated gloss is not medium, since the image designated gloss is high, in step S4_3 it is set as a low-speed image forming job, and this routine is terminated.
[0069]
If it is determined in step S4_6 that the designated image gloss is low, the process proceeds to step S4_8. In step S4_8, it is determined whether or not the output medium is plain paper. If it is determined that the output medium is not plain paper, the process proceeds to step S4_9, and it is determined whether or not the thickness of the output medium is medium thick paper. If it is determined that the output medium is not medium-thick paper, the output medium is high-thick paper, so in step S4_3 it is set as a low-speed image forming job and this routine is terminated. On the other hand, if it is determined in step S4_9 that the thickness of the output medium is medium thick paper, the process proceeds to step S4_10. In step S4_10, the medium speed image forming job is set and this routine is terminated.
[0070]
Furthermore, when it is determined in step S4_8 that the output medium is plain paper, the process proceeds to step S4_11. In step S4_11, the fact that it is a high-speed image forming job is set, and this routine is ended.
[0071]
FIG. 4 is a flowchart of “image formation required time calculation flow execution” executed in step S5 shown in FIG.
[0072]
First, in step S5_1, among the received jobs, the job with the highest priority among the jobs for which the processing time has not been calculated is set as the job of interest, and the process proceeds to step S5_2.
[0073]
In step S5_2, it is determined whether or not the job of interest needs to be changed in processing speed (process speed) with respect to the job processed and executed immediately before. If it is determined that the processing speed needs to be changed, the process proceeds to step S5_3.
[0074]
In step S5_3, the time required for changing the process speed of the job of interest for the immediately preceding job is calculated, and the calculated job processing time is added to the calculated upper priority job processing time, and the process proceeds to step S5_4. On the other hand, if it is determined in step S5_2 that it is not necessary to change the processing speed, the process proceeds to step S5_3.
[0075]
In step S5_3, the time for executing the attention job process at the designated process speed of the attention job is calculated, and the process proceeds to step S5_5.
[0076]
In step S5_5, the calculated job processing time is added to the calculated upper priority job processing time, and the process proceeds to step S5_6.
[0077]
In step S5_6, it is determined whether or not there is an undecided processing time calculation for the accepted job. If it is determined that there is an undecided processing time, the process returns to step S5_1. On the other hand, if it is determined that there is no processing time calculation undetermined, this routine is terminated. In this way, the time required for image formation is calculated. In this flow, an example of processing in units of jobs has been described, but processing may be performed in units of pages.
[0078]
FIG. 5 is a flowchart of “job priority determination process execution” executed in step S15 shown in FIG.
[0079]
First, in step S15_1, the job having the highest priority among the jobs for which priority has not been determined is set as the job of interest, and the process proceeds to step S15_2.
[0080]
In step S15_2, it is determined whether or not the job of interest is a high processing speed designation. If it is determined that the high processing speed is specified, the process proceeds to step S15_3. In step S15_3, priority is given to the target job in the oldest order in the high processing speed designation job, and this routine is terminated. On the other hand, if it is determined that the job of interest is not a high processing speed designation, the process proceeds to step S15_4.
[0081]
In step S15_4, it is determined whether or not the job of interest is designated for a medium processing speed. If it is determined that the medium processing speed is specified, the process proceeds to step S15_5. In step S15_5, priority is given to the job of interest in the oldest order in the medium processing speed designation job, and this routine ends. On the other hand, if it is determined that the job of interest is not the medium processing speed designation, the process proceeds to step S15_6. In step S15_6, priority is given to the job of interest in the oldest order in the low processing speed designation job, and this routine is terminated.
[0082]
FIG. 6 is a flowchart of “job priority determination & execution flow execution” executed in step S16 shown in FIG.
[0083]
First, in step S16_1, it is determined whether a high-speed job is currently being executed. If it is determined that the high-speed job is not currently being executed, the process proceeds to step S16_7, which will be described later, and if it is determined that the high-speed job is currently being executed, the process proceeds to step S16_2.
[0084]
In step S16_2, it is determined whether or not the received job includes a high-speed designated job. If it is determined that there is a high-speed designated job, the process proceeds to step S16_3. In step S16_3, execution is set from the highest priority among the accepted high-speed jobs, and this routine is terminated. On the other hand, if it is determined that there is no high-speed designated job, the process proceeds to step S16_4.
[0085]
In step S16_4, it is determined whether or not the currently accepted job includes a medium speed designation job. If it is determined that there is a medium speed designated job, the process proceeds to step S16_5, the process speed is changed from high speed to medium speed, the medium speed job is set to be executed from the highest priority, and this routine is terminated. On the other hand, if it is determined that there is no medium speed designation job, the process proceeds to step S16_6. In step S16_6, the process speed is changed from the medium speed to the low speed, the low speed job is set to be executed from the highest priority, and this routine is ended.
[0086]
If it is determined in step S16_1 that the high-speed job is not currently being executed and the process proceeds to step S16_7, it is determined in step S16_7 whether the medium-speed job is currently being executed. If it is determined that the medium-speed job is not currently being executed, the process proceeds to step S16_13 described later. If it is determined that the medium-speed job is currently being executed, the process proceeds to step S16_8.
[0087]
In step S16_8, it is determined whether the currently accepted job includes a medium speed designation job. If it is determined that there is a medium-speed designated job, the process proceeds to step S16_9, and it is set to execute from the medium-priority job having the highest priority among the accepted medium-speed jobs, and this routine is terminated. On the other hand, if it is determined that there is no medium speed designation job, the process proceeds to step S16_10.
[0088]
In step S16_10, it is determined whether or not the job having the oldest acceptance order among the currently accepted jobs is designated at high speed. When it is determined that the high speed is designated, the process proceeds to step S16_11. In step S16_11, the process speed is changed from the medium speed to the high speed, the high speed job is set to be executed from the highest priority, and this routine is terminated. On the other hand, if it is determined that the old job is not designated at high speed, the process proceeds to step S16_12. In step S16_12, the process speed is changed from the medium speed to the low speed, the low speed job is set to be executed from the highest priority, and this routine is ended.
[0089]
On the other hand, if it is determined in step S16_7 that the medium-speed job is not currently being executed and the process proceeds to step S16_13, it is determined in step S16_13 whether the currently accepted job includes a low-speed designated job. If it is determined that there is a low-speed designated job, the process proceeds to step S16_14, and execution is started from the highest priority among the accepted low-speed jobs, and this routine is terminated. On the other hand, if it is determined that there is no low-speed designated job, the process proceeds to step S16_15.
[0090]
In step S16_15, it is determined whether or not the job having the oldest acceptance order among the currently accepted jobs is designated at high speed. If it is determined that the high speed is designated, the process proceeds to step S16_16. In step S16_16, the process speed is changed from low speed to high speed, the high speed job is set to be executed from the highest priority, and this routine is terminated. On the other hand, if it is determined that the old job is not designated at high speed, the process proceeds to step S16_17. In step S16_17, the process speed is changed from the low speed to the medium speed, the medium speed job is set to be executed from the highest priority, and this routine is ended.
[0091]
The above-described routine shown in FIG. 2 is an example in the case where priority is given to reducing the processing time based on the image formation required time prediction unit 60 in the image forming condition setting of the image forming apparatus 1 shown in FIG. A process speed switching number predicting unit that predicts each process speed required to complete a plurality of image formations corresponding to a plurality of image forming instructions, and the mode determination unit 50 performs the switching predicted by the process speed switching number predicting unit. The number of times may be adopted as one of determination criteria to determine a mode to be used for image formation. Here, the process speed switching frequency predicting means predicts the switching frequency every time one image formation corresponding to one image formation instruction proceeds. Hereinafter, a description will be given with reference to FIG.
[0092]
FIG. 7 is a flowchart of a main routine in the case where priority is given to reducing the number of process speed changes in setting the image forming conditions of the image forming apparatus.
[0093]
The same steps as those in the flowchart shown in FIG. 2 described above are denoted by the same reference numerals, and only different steps will be described.
[0094]
The flowchart shown in FIG. 7 differs from the flowchart shown in FIG. 2 in steps S31, 32, and 33. In step S31, a process speed change count counting flow is performed. First, the process speed change count counting flow will be described with reference to FIG.
[0095]
FIG. 8 is a flowchart of “Process speed change count counting flow execution” executed in step S31 shown in FIG.
[0096]
First, in step S31_1, it is determined whether or not the process speed to be processed differs between the job of interest at the time of job processing and the next processing order job in accordance with the current processing order of the accepted job. If it is determined that the process speed is different, the process proceeds to step S31_2, the speed change count is incremented (+1), and the process proceeds to step S31_3. On the other hand, if it is determined that the process speed is the same, the process proceeds to step S31_3 as it is.
[0097]
In step S31_3, it is determined whether there is an accepted job that has not yet been subjected to the speed change count determination. If it is determined that there is a speed change count determination incomplete, the process proceeds to step S31_4. In step S31_4, the next processing order attention job currently determined is changed to the attention job, and the process returns to step S31_1. On the other hand, if it is determined that there is no speed change count determination incomplete, this routine is terminated. In this flow, an example of processing in units of jobs has been described, but processing may be performed in units of pages.
[0098]
The description will be continued with reference to FIG. After executing step S31 described above, the process proceeds to step S18. In step S18, it is determined whether or not there is a job whose priority determination has not been completed since the end of the previous job. If it is determined that there is a priority determination incomplete job, the process returns to step S15. On the other hand, if it is determined that there is no priority determination incomplete job, the process proceeds to step S32.
[0099]
In step S32, it is determined whether or not the image processing time calculation result including the case where there is no change in the processing order is the one with the smallest number of process speed changes is being changed in the job processing order. When it is determined that there is a process speed change number that is the smallest in the job processing order change, the process proceeds to step S33. In step S33, the job processing order is set in the processing order with the smallest number of process speed changes, and this routine is terminated. On the other hand, if it is determined that there is no change in the number of process speed changes at the time of changing the job processing order, the process proceeds to step S21. In step S21, the job processing order is returned to the priority of the receiving order, and this routine is terminated. In this way, priority may be given to reducing the number of times the process speed is changed in setting the image forming conditions of the image forming apparatus.
[0100]
FIG. 9 is a flowchart of a process speed change routine in the image forming apparatus shown in FIG.
[0101]
To change the process speed, first, in step S41, it is determined whether or not the current image forming mode is a multi-engine drive mode for forming a multi-color image. If it is determined that the multi-engine drive mode is selected, the process proceeds to step S43.
[0102]
In step S43, the charging voltage, the developing bias voltage, and the primary transfer voltage are arranged in order so that the timing is adjusted on the image superposition medium (recording medium) after completion of image formation for each image forming engine that sequentially performs image formation. To turn it off. Further, in parallel, the secondary transfer voltage, the developing device driving voltage, and the main driving voltage are turned off in order in accordance with the timing when the charging off area passes. Thereafter, the process proceeds to step S44.
[0103]
On the other hand, if it is determined that the multi-engine drive mode is not selected, the process proceeds to step S42. In step S42, the driving (K color) engine is turned off in the order of the charging voltage, the developing bias voltage, and the primary transfer voltage so that the timing is adjusted on the image superposition medium after completion of image formation. Further, in parallel, the secondary transfer voltage, the developing device driving voltage, and the main driving voltage are turned off in order in accordance with the timing when the charging off area passes. Thereafter, the process proceeds to step S44.
[0104]
In step S44, it is determined whether or not the next image forming mode is a multiple engine drive mode. If it is determined that the engine is in the multiple engine drive mode, the process proceeds to step S46.
[0105]
In step S46, application of the main drive voltage is started at the process speed for forming the next image, and the timing of the start of charging for each engine matches the timing on the image overlay medium under conditions suitable for the process speed. Start charging. Further, each engine is turned on in the order of the developing bias voltage, the developing device driving voltage, and the main driving voltage in accordance with the timing when the charging on area passes. Further, the primary transfer voltage, the secondary transfer voltage, and the fixing device temperature are set in accordance with a timing at which sufficient ability is exhibited at the timing at which the image forming area passes, and this routine is terminated.
[0106]
On the other hand, if it is determined in step S44 that the multi-engine drive mode is not set, the process proceeds to step S45. In step S45, application of the main drive voltage to the drive (K color) engine is started at a process speed for forming the next image, and charging is started under conditions suitable for the process speed. Further, in accordance with the timing when the charging on area passes, the developing bias and the developing device driving voltage are turned on in this order. Further, the primary transfer voltage, the secondary transfer voltage, and the fixing device temperature are set in accordance with a timing at which sufficient ability is exhibited at the timing at which the image forming area passes, and this routine is terminated.
[0107]
FIG. 10 is a diagram showing a state in which the recording medium after image formation is discharged in a form separated for each image formation instruction to a discharge tray without a sorter.
[0108]
The left side of FIG. 10 shows a perspective view of the discharge tray in a state in which the recording media after image formation are stacked, as viewed obliquely from the front. Further, the right side of FIG. 10 shows a front view of the discharge tray in a state in which the recording media after image formation are stacked as viewed from the discharge direction.
[0109]
Here, it is assumed that the user 1 forms an image on a recording medium having pages output at a high speed, pages output at a medium speed, and pages output at a low speed. In addition, it is assumed that the user 2 forms an image on a recording medium having only pages that are output at high speed. Further, it is assumed that the user 3 forms an image on a recording medium having only pages output at medium speed. In such a case, the first page output by the user 1 that is output at high speed is image-formed, and the second user 2 that is output at high speed by the user 2 is image-formed. Next, the page that is output at the medium speed of the user 1 is formed on the third image, the page that is output at the medium speed of the user 3 is formed on the fourth image, and the low speed that the user 1 has the fifth image. The page to be output to is imaged. In this way, first, pages that are output at a high speed are collectively imaged, then pages that are output at a medium speed are collectively output, and pages that are output at a lower speed are further imaged. The number of changes in is kept to a minimum. Therefore, the time required for changing the process speed can be shortened, and the productivity of image formation can be improved. Here, since the recording media are stacked on the paper discharge tray for each user, each user 1, 2 and 3 can easily distinguish his / her recording medium from the discharge tray.
[0110]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an image forming apparatus that can cope with the demand for high image quality and the diversification of the types of recording media, while suppressing a decrease in productivity due to a change in process speed. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of an image forming apparatus of the present invention.
FIG. 2 is a flowchart of a main routine when priority is given to reduction of processing time in setting image forming conditions of the image forming apparatus shown in FIG.
FIG. 3 is a flowchart of “execution processing of acceptance job processing speed” executed in step S4 shown in FIG. 2;
FIG. 4 is a flowchart of “image formation required time calculation flow execution” executed in step S5 shown in FIG. 2;
FIG. 5 is a flowchart of “job priority determination process execution” executed in step S15 shown in FIG. 2;
FIG. 6 is a flowchart of “job priority determination & execution flow execution” executed in step S16 shown in FIG. 2;
FIG. 7 is a flowchart of a main routine when priority is given to reducing the number of process speed changes in setting image forming conditions of the image forming apparatus.
FIG. 8 is a flowchart of “process speed change count counting flow” executed in step S31 shown in FIG. 7;
9 is a flowchart of a process speed change routine in the image forming apparatus shown in FIG.
FIG. 10 is a diagram illustrating a state in which a recording medium after image formation is discharged into a discharge tray without a sorter in a manner separated for each image formation instruction.
[Explanation of symbols]
1 Image forming device
11 Document reader
11a Light emitting device
11b Original glass
11c mirror
11d lens
11e Solid-state image sensor (CCD)
12 Image forming unit
13 Operation panel
14 Photoconductor
15 Charger
16 Laser unit
17 Developer
18 Intermediate transfer belt
19, 20 Opposite roll
21 Primary transfer roll
22, 23, 24 Paper tray
25, 26, 27 Paper transport roll
28 Secondary transfer roll
29 Fixing device
30 discharge tray
31, 32 discharge roll
33 Paper receiver
34 Transport path for both sides
35 Cleaner
36 Belt cleaner
37 Toner cartridge
40 Image formation order changing means
50 mode determination means
60 Image formation time prediction means
101, 102, 103 recording medium

Claims (10)

In an image forming apparatus that has a plurality of process speeds, receives a plurality of image formation instructions with a process speed designation, and sequentially forms a plurality of images based on the plurality of image formation instructions on a recording medium.
Image forming order changing means is provided for changing the order of image formation to an order different from the acceptance order of image format instructions when there are a plurality of image forming instructions with different process speed designations. An image forming apparatus. A first mode for changing the order of image formation to an order different from the order of accepting image format instructions when there are a plurality of image formation instructions with different process speed designations, and the order of accepting image formation instructions The second mode in which image formation is performed at the minimum process speed among the plurality of image formation instructions, or the order in which the image formation instructions are received and each specified in each image formation instruction A mode determination unit for determining a mode to be used for image formation from the third mode in which image formation is performed while changing the process speed to the process speed;
The image forming apparatus according to claim 1, wherein the image forming order changing unit operates upon receiving a determination that the mode determining unit adopts the first mode. Image formation for predicting each time required for completion of a plurality of image formations corresponding to the plurality of image formation instructions when image formation is performed using each of the first, second, and third modes A required time predicting means, wherein the mode determining means adopts a time predicted by the image formation required time predicting means as one of determination criteria, and determines a mode to be used for image formation. The image forming apparatus according to claim 2. 4. An image forming apparatus according to claim 3, wherein said image formation required time prediction means performs time prediction each time one image formation corresponding to one image formation instruction proceeds. A process for predicting each process speed required to complete a plurality of image formations corresponding to the plurality of image formation instructions when image formation is performed using each of the first, second, and third modes. A speed switching number predicting unit, wherein the mode determining unit adopts the switching number predicted by the process speed switching number predicting unit as one of determination criteria, and determines a mode to be used for image formation. The image forming apparatus according to claim 2. 4. The image forming apparatus according to claim 3, wherein the process speed switching frequency predicting unit predicts the switching frequency every time one image formation corresponding to one image formation instruction proceeds. The image forming apparatus according to claim 1, wherein the image forming apparatus accepts an image forming instruction in units of a job including one page or more of recording media. The image forming apparatus according to claim 1, wherein the image forming apparatus receives an image forming instruction in units of one page of the recording medium. 2. The image forming apparatus according to claim 1, further comprising a mode switching unit that switches between a mode in which the image forming order changing unit is operated and a mode in which image forming is performed in the order in which the image forming instruction is received. The image forming apparatus according to claim 1, further comprising a medium discharge unit that discharges the recording medium after image formation in a form separated for each image formation instruction.

Images