Image forming device and image forming method

Abstract

To provide an image forming device and an image forming method.SOLUTION: An image forming device (100) is provided with an image forming part (3) and a dividing / adjusting part (53). The dividing / adjusting part (53) executes a plurality of image forming processes corresponding to a plurality of pages included in one printing job while dividing the processes among a plurality of sheets. When a preliminarily set continuous execution condition is satisfied, after an image forming process for detection is interrupted due to completion of the image forming process corresponding to the one printing job, the dividing / adjusting part (53) resumes the image forming process for detection from the middle thereof in the image forming process corresponding to the other printing job to be executed subsequently; and unless the continuous execution condition is satisfied, re-executes the image forming processing for detection from the beginning, in the image forming process corresponding to the other printing job.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus and an image forming method. [Background technology]

[0002] An electrophotographic image forming apparatus includes an image forming unit that performs an image forming process to form an image on an intermediate transfer belt or a sheet based on image data included in a print job to be printed. In this type of image forming apparatus, image forming conditions may be adjusted to maintain image quality (see, for example, Patent Document 1). Furthermore, a detection image forming process that forms a detection toner image used to adjust the image forming conditions may be divided into multiple separate image forming operations. Specifically, each of the separate image forming operations may be performed between multiple image forming processes corresponding to multiple sheets (hereinafter referred to as "sheet intervals"). In this case, after the detection toner images formed in all of the separate image forming operations have been detected, the image forming conditions are adjusted based on the detection results. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-318266 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the number of prints in a print job is small, the detection image formation process may be interrupted when the print job ends. In this case, when the next print job is executed, the detection image formation process may be executed from the beginning, but the detection image formation process already executed in the previous print job will be wasted. On the other hand, when the next print job is executed, the interrupted detection image formation process may be resumed from where it was interrupted. However, if multiple divided formation operations are executed in different execution environments, the stabilization of image quality through the adjustment of the image formation conditions may be hindered.

[0005] An object of the present invention is to provide an image forming apparatus and an image forming method that can achieve a good balance between the efficiency of the detection image formation process and the stabilization of image quality. [Means for solving the problem]

[0006] According to one aspect of the present invention, an image forming apparatus includes an image forming unit and a division adjustment processing unit. The image forming unit executes an image formation process that forms an image on a transfer medium based on image data of a print job to be printed. The division adjustment processing unit executes a detection image formation process that forms a detection image on the transfer medium, the detection image used in the image adjustment processing that adjusts image formation conditions in the image forming unit, across multiple sheets in multiple image formation processes corresponding to multiple pages included in one print job. After the detection image formation process is interrupted due to completion of the image formation process corresponding to the one print job, the division adjustment processing unit resumes the detection image formation process from the middle in the image formation process corresponding to another print job to be executed next if a preset continuation condition is satisfied. If the continuation condition is not satisfied, the division adjustment processing unit restarts the detection image formation process from the beginning in the image formation process corresponding to the other print job.

[0007] In another aspect of the present invention, a processor of an image forming apparatus includes an image forming unit that executes an image formation process that forms a print image on a transfer medium based on image data, and the processor executes a division adjustment step. The division adjustment step divides the detection image formation process, which forms a detection image on the transfer medium to be used in an image adjustment process that adjusts image formation conditions in the image forming unit, among multiple sheets in multiple image formation processes corresponding to multiple pages included in one print job. After the detection image formation process is interrupted due to completion of the image formation process corresponding to the one print job, the division adjustment step resumes the detection image formation process from the middle in the image formation process corresponding to another print job to be executed next if a preset continuation condition is satisfied, and, if the continuation condition is not satisfied, restarts the detection image formation process from the beginning in the image formation process corresponding to the other print job. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an image forming apparatus and an image forming method that can achieve a good balance between improving the efficiency of the detection image formation process and stabilizing the image quality. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing the configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the system configuration of the image forming apparatus according to the embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram showing the configuration of the image forming unit of the image forming apparatus according to the embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing an example of the adjustment control process executed in the image forming apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the following embodiment is an example of a specific embodiment of the present invention and does not limit the technical scope of the present invention.

[0011] First, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS.

[0012] For ease of explanation, the vertical direction in the installation state where image forming apparatus 100 is usable (the state shown in FIG. 1) is defined as the up-down direction D1. Also, the front-to-back direction D2 is defined with the left side of image forming apparatus 100 on the paper surface shown in FIG. 1 as the front (front face). Also, the left-to-right direction D3 is defined with the front face of image forming apparatus 100 in the installation state as the reference point.

[0013] Image forming apparatus 100 is a multifunction peripheral that has multiple functions, such as a scanning function for reading an image from an original document, a printing function for forming an image based on image data, a fax function, and a copy function. Note that the present invention may also be applied to image forming apparatuses such as printers, fax machines, and copy machines that are capable of forming images using an electrophotographic method.

[0014] As shown in FIGS. 1 and 2, the image forming apparatus 100 includes an ADF (Auto Document Feeder) 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, an operation display unit 5, a storage unit 6, and a control unit .

[0015] The ADF 1 transports documents to be scanned by the scanning function, and includes a document setting section, a plurality of transport rollers, a document holder, and a paper ejection section.

[0016] The image reading unit 2 realizes the scanning function and includes a document table, a light source, a plurality of mirrors, an optical lens, and a CCD (Charge Coupled Device).

[0017] The image forming unit 3 realizes the print function. Specifically, the image forming unit 3 performs image formation processing in which, according to an electrophotographic method, an image is formed on the intermediate transfer belt 26 based on image data of a print job to be printed, and the image is transferred onto a sheet.

[0018] The paper feed unit 4 supplies sheets to the image forming unit 3. The paper feed unit 4 includes multiple paper feed cassettes 4A, a manual feed tray, and multiple transport rollers. The control unit 7 can preset the sheet type of the sheets stored in each paper feed cassette 4A in response to a user operation. Specifically, the sheet types include multiple types of sheet types such as plain paper, medium-weight paper, and thick paper. The control unit 7 may automatically detect the sheet type of the sheets stored in each paper feed cassette 4A based on the detection results of a detection unit such as an optical sensor or weight sensor (not shown).

[0019] The operation display unit 5 is a user interface of the image forming apparatus 100. The operation display unit 5 has a display unit such as a liquid crystal display that displays various information in response to control instructions from the control unit 7, and an operation unit such as operation keys or a touch panel that inputs various information to the control unit 7 in response to user operations.

[0020] The storage unit 6 is a nonvolatile storage device. For example, the storage unit 6 is a nonvolatile memory such as a flash memory. The storage unit 6 may be an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

[0021] The control unit 7 performs overall control of the image forming apparatus 100. As shown in FIG. 2, the control unit 7 includes a CPU 11, a ROM 12, and a RAM 13. The CPU 11 includes one or more processors that execute various types of arithmetic processing. The ROM 12 is a non-volatile storage device that stores in advance information such as control programs for causing the CPU 11 to execute various types of processing. The RAM 13 is a volatile or non-volatile storage device that is used as a temporary storage memory (work area) for the various types of processing executed by the CPU 11. The CPU 11 performs overall control of the image forming apparatus 100 by executing the various control programs that are stored in advance in the ROM 12.

[0022] The control unit 7 may be a control unit provided separately from a main control unit that performs overall control of the image forming apparatus 100. The control unit 7 may also be configured with an electronic circuit such as an integrated circuit (ASIC).

[0023] [Configuration of image forming unit 3] Next, the configuration of the image forming section 3 will be described with reference to Figures 1 to 3. Here, Figure 3 is a schematic diagram showing the configurations of the image forming unit 20, intermediate transfer belt 26, and secondary transfer roller 27. Figure 3 is also a bottom view showing the configurations of the photosensitive drum 31, intermediate transfer belt 26, drive roller 26A, and secondary transfer roller 27 of the image forming unit 24.

[0024] 1, the image forming section 3 includes four image forming units 20, an optical scanning device 25, an intermediate transfer belt 26, a secondary transfer roller 27, a fixing device 28, and a paper discharge tray 29. Also, as shown in FIGS. 2 and 3, the image forming section 3 includes four first power sources 40, a second power source 45, and a detection section 46.

[0025] The four image forming units 20 include image forming units 21 to 24 corresponding to multiple colors. Image forming unit 21 (see FIG. 3) forms a Y (yellow) toner image. Image forming unit 22 (see FIG. 3) forms a C (cyan) toner image. Image forming unit 23 (see FIG. 3) forms an M (magenta) toner image. Image forming unit 24 (see FIG. 3) forms a K (black) toner image. As shown in FIGS. 1 and 3, the four image forming units 20 are arranged side by side in the order of yellow, cyan, magenta, and black from the front side of image forming apparatus 100 along the front-rear direction D2. Of the image forming units 20, image forming unit 24 is used for monochrome printing, and image forming units 21 to 24 are used for color printing.

[0026] 3, each image forming unit 20 includes a photosensitive drum 31, a charging roller 32, a developing device 33, a primary transfer roller 34, and a drum cleaning unit 35. Each image forming unit 20 also includes a toner container 36 shown in FIG.

[0027] An electrostatic latent image is formed on the surface of the photosensitive drum 31. For example, the photosensitive drum 31 has a photosensitive layer made of amorphous silicon. The photosensitive drum 31 receives a rotational driving force supplied from a motor (not shown) and rotates in a drum rotation direction D4 shown in FIG. 3. As a result, the photosensitive drum 31 transports the electrostatic latent image formed on its surface.

[0028] A preset charging voltage is applied to the charging roller 32, which charges the surface of the photosensitive drum 31. For example, the charging roller 32 charges the surface of the photosensitive drum 31 to a positive polarity. The surface of the photosensitive drum 31 charged by the charging roller 32 is irradiated with light based on image data emitted from the optical scanning device 25. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 31.

[0029] The developing device 33 develops the electrostatic latent image formed on the surface of the photosensitive drum 31. The developing device 33 includes a pair of stirring members, a magnet roller, and a developing roller. The pair of stirring members stir the developer, which contains toner and a carrier, contained within the developing device 33. For example, the toner contained in the developer is positively charged due to friction with the carrier contained in the developer. The magnet roller draws up the developer stirred by the pair of stirring members and supplies the toner contained in the developer to the developing roller. The developing roller transports the toner supplied from the magnet roller to a position facing the photosensitive drum 31. Furthermore, the developing roller receives a preset development bias voltage and supplies the toner transported to the facing position to the photosensitive drum 31. As a result, toner is selectively supplied to an exposure area of ​​the photosensitive drum 31 irradiated with light emitted from the optical scanning device 25, thereby developing the electrostatic latent image formed on the surface of the photosensitive drum 31. The developing device 33 is supplied with toner from a toner container 36 .

[0030] The primary transfer roller 34 receives a supply of a preset primary transfer current and transfers the toner image formed on the surface of the photosensitive drum 31 onto the outer circumferential surface of the intermediate transfer belt 26. As shown in Fig. 3, the primary transfer roller 34 is disposed opposite the photosensitive drum 31 with the intermediate transfer belt 26 sandwiched therebetween.

[0031] The drum cleaning unit 35 removes the toner remaining on the surface of the photosensitive drum 31 after the toner image has been transferred by the primary transfer roller 34 .

[0032] The optical scanning device 25 emits light based on image data toward the surface of the photosensitive drum 31 of each image forming unit 20.

[0033] The intermediate transfer belt 26 is an endless belt member onto which the toner images formed on the surfaces of the photosensitive drums 31 of each image forming unit 20 are transferred. For example, the intermediate transfer belt 26 is made of a resin material such as polyimide. The intermediate transfer belt 26 is stretched with a predetermined tension by a drive roller 26A (see FIG. 3) and a tension roller 26B (see FIG. 3). The intermediate transfer belt 26 rotates in a belt rotation direction D5 shown in FIG. 3 when the drive roller 26A rotates due to a rotational driving force supplied from a motor (not shown). As a result, the intermediate transfer belt 26 transports the toner images transferred from each photosensitive drum 31 to a transfer position onto a sheet by a secondary transfer roller 27. After the toner images are transferred by the secondary transfer roller 27, the outer peripheral surface of the intermediate transfer belt 26 is cleaned by a belt cleaning unit 26C (see FIG. 3).

[0034] The secondary transfer roller 27 receives a preset secondary transfer current and transfers the toner image transferred onto the outer peripheral surface of the intermediate transfer belt 26 onto a sheet supplied from the paper feed unit 4. As shown in FIG. 3, the secondary transfer roller 27 is disposed opposite the drive roller 26A with the intermediate transfer belt 26 sandwiched therebetween.

[0035] The fixing device 28 fixes the toner image transferred onto the sheet by the secondary transfer roller 27 onto the sheet.

[0036] The sheet on which the toner image has been fixed by the fixing device 28 is discharged onto the paper discharge tray 29.

[0037] Of the four first power sources 40, first power source 41 (see FIG. 2) is a constant current power source that supplies the primary transfer current to the primary transfer roller 34 of the image forming unit 21. Of the four first power sources 40, first power source 42 (see FIG. 2) is a constant current power source that supplies the primary transfer current to the primary transfer roller 34 of the image forming unit 22. Of the four first power sources 40, first power source 43 (see FIG. 2) is a constant current power source that supplies the primary transfer current to the primary transfer roller 34 of the image forming unit 23. Of the four first power sources 40, first power source 44 (see FIG. 2) is a constant current power source that supplies the primary transfer current to the primary transfer roller 34 of the image forming unit 24. Each of the first power sources 40 supplies the primary transfer current set by the control unit 7 to the primary transfer roller 34. For example, the primary transfer current is a negative current.

[0038] The second power supply 45 is a constant current power supply that supplies the secondary transfer current to the secondary transfer roller 27. The second power supply 45 supplies the secondary transfer current set by the control unit 7 to the secondary transfer roller 27. For example, the secondary transfer current is a negative current.

[0039] The detection unit 46 is used to detect the density of the toner image transferred onto the outer peripheral surface of the intermediate transfer belt 26. For example, the detection unit 46 is a reflective photosensor that includes a light-emitting unit that emits light toward the intermediate transfer belt 26 and a light-receiving unit that receives the light emitted from the light-emitting unit and reflected by the intermediate transfer belt 26. The detection unit 46 then inputs an electrical signal to the control unit 7 that corresponds to the density of the toner image to be detected.

[0040] 3, the detection unit 46 is disposed downstream in the belt rotation direction D5 of the photosensitive drum 31 of the image forming unit 24 and upstream in the belt rotation direction D5 of the position where the toner image is transferred by the secondary transfer roller 27. Furthermore, when a detection toner image, which will be described later, is formed on the intermediate transfer belt 26 outside the area where a print image based on the image data of the print target is formed, the detection unit 46 may be disposed downstream in the belt rotation direction D5 of the position where the toner image is transferred by the secondary transfer roller 27 and upstream in the belt rotation direction D5 of the position where the belt cleaning unit 26C cleans the outer circumferential surface of the intermediate transfer belt 26.

[0041] [Configuration of control unit 7] Next, the configuration of the control unit 7 will be described with reference to FIG.

[0042] 2, the control unit 7 includes a print processing unit 50, a count processing unit 51, a collective adjustment processing unit 52, and a split adjustment processing unit 53. Specifically, an adjustment program for causing the CPU 11 to function as each of the above-mentioned processing units is stored in advance in the ROM 12 of the control unit 7. The CPU 11 then executes the adjustment program stored in the ROM 12 to function as each of the above-mentioned processing units.

[0043] The adjustment program may be recorded on a computer-readable recording medium such as a CD, DVD, or flash memory, and may be read from the recording medium and stored in a storage device such as the memory unit 6. In addition, some or all of the print processing unit 50, count processing unit 51, collective adjustment processing unit 52, and division adjustment processing unit 53 may be configured using electronic circuits such as an integrated circuit (ASIC).

[0044] The print processing unit 50 controls the image forming unit 3 and performs printing processes such as monochrome printing, which forms a monochrome image on a sheet, or color printing, which forms a color image on a sheet, based on image data included in the print job to be printed. Specifically, the print processing unit 50 controls the optical scanning device 25 based on image data included in the print job to form electrostatic latent images corresponding to each color on the photosensitive drum 31 of each image forming unit 20 at a predetermined timing. As a result, in each image forming unit 20, the electrostatic latent image formed on the photosensitive drum 31 is developed into a toner image, and the toner images are sequentially transferred to the intermediate transfer belt 26. Thereafter, the color image or monochrome image formed on the intermediate transfer belt 26 is transferred to a sheet by the secondary transfer roller 27, and the intermediate transfer belt 26 is cleaned by the belt cleaning unit 26C.

[0045] The print processing unit 50 outputs the output data corresponding to the image data to the optical scanning device 25 based on input / output characteristics that indicate the relationship between the image data input to the image forming apparatus 100 and the output data to the image forming unit 3. The print processing unit 50 also controls the amount of laser light emitted from the optical scanning device 25 by controlling the current value input to the optical scanning device 25. During the print processing, the print processing unit 50 also controls the development bias voltage in each image forming unit 20 to a value that is set in advance for that image forming unit 20. During the print processing, the print processing unit 50 also controls the charging voltage, the primary transfer current, and the secondary transfer current of the secondary transfer roller 27 in each image forming unit 20.

[0046] Furthermore, the print processing unit 50 can change the linear speed in the image forming unit 3 depending on the type of sheet used in the printing process (plain paper, medium-weight paper, thick paper, etc.) and the type of printing process (monochrome printing, color printing). The linear speed is the running speed (surface movement speed) of a transfer medium such as the intermediate transfer belt 26, and the print processing unit 50 changes the linear speed by controlling the rotation speed of the drive roller 26A that drives the intermediate transfer belt 26. Note that, for example, if the image forming unit 3 does not have an intermediate transfer belt 26 and a toner image is transferred from each photosensitive drum 31 to a sheet, the linear speed may be the sheet transport speed.

[0047] Furthermore, in the printing process, the print processing unit 50 executes a preset inter-sheet process between an image forming process for forming an image based on one page of image data on the intermediate transfer belt 26 and an image forming process for forming an image based on the next page of image data on the intermediate transfer belt 26. For example, the inter-sheet process executes a preset process such as cleaning the photosensitive drum 31 by the drum cleaning unit 35 or various image processes for the image data corresponding to the next sheet. In the present embodiment, a division formation process, which will be described later, may be executed as part of the inter-sheet process.

[0048] The count processing unit 51 counts the cumulative number of printed sheets or the cumulative operating time of the image forming apparatus 100. The count processing unit 51 also counts the number of printed sheets in a job, which indicates the number of printed sheets in one print job, or the operating time in a job, which indicates the operating time of one print job.

[0049] When a preset first execution condition is satisfied, the collective adjustment processing unit 52 executes a collective adjustment process for adjusting the image formation conditions of the image forming unit 3. For example, the first execution condition is that a request for execution of the collective adjustment process is made by a user operation, or that the printing type of the printing process executed by the print processing unit 50 is changed from one of monochrome printing and color printing to the other, thereby changing the linear speed, etc.

[0050] In the collective adjustment process, a detection image forming process, a toner image detection process, and an image adjustment process are executed in this order. In the detection image forming process, the collective adjustment processing unit 52 controls the image forming unit 3 to collectively form detection toner images based on preset detection image data on the intermediate transfer belt 26 using each of the image forming units 21 to 24. Next, in the toner image detection process, the collective adjustment processing unit 52 uses the detection unit 46 to detect the density of each of the detection toner images formed on the intermediate transfer belt 26. Thereafter, in the image adjustment process, the collective adjustment processing unit 52 adjusts the image formation conditions in the image forming unit 3 based on the detection results of the density of the detection toner images.

[0051] When a preset second execution condition is satisfied, the division adjustment processing unit 53 executes a division adjustment process to adjust the image formation conditions of the image forming unit 3. The second execution condition includes that the cumulative number of printed sheets counted by the count processing unit 51 is an integer multiple of a first reference number of sheets, or that the cumulative operating time is an integer multiple of a first reference time. The second execution condition also includes that the number of printed sheets during the job counted by the count processing unit 51 is an integer multiple of a second reference number of sheets, or that the operating time during the job is an integer multiple of the second reference time.

[0052] Specifically, in the division adjustment process, the division adjustment processing unit 53 executes the detection image forming process, the toner image detection process, and the image adjustment process.

[0053] In particular, the division adjustment processing unit 53 divides the detection image formation process into multiple intervals between multiple sheets of the image formation process corresponding to multiple pages corresponding to one print job, and executes the division adjustment process. Note that the intervals between sheets are an example of a division period in the present invention, and the division period is not limited to the intervals between sheets. For example, the division period may be a period that is partially or entirely parallel to the execution periods of the image formation processes corresponding to multiple pages.

[0054] Specifically, the division adjustment processing unit 53 may individually execute the division formation process corresponding to each image forming unit 20 for each sheet interval. In this case, in one print job, the division formation process is executed in the first sheet interval that arrives after the second execution condition is satisfied, in which the detection toner image corresponding to image forming unit 21 is formed on the intermediate transfer belt 26. Thereafter, the division formation process is executed in the second sheet interval, in which the detection toner image corresponding to image forming unit 22 is formed on the intermediate transfer belt 26. Similarly, the division formation process is executed in the third sheet interval, in which the detection toner image corresponding to image forming unit 23 is formed on the intermediate transfer belt 26. Subsequently, the division formation process is executed in the fourth sheet interval, in which the detection toner image corresponding to image forming unit 24 is formed on the intermediate transfer belt 26. Furthermore, the division method for each division formation process is not limited to each color, and the number of divisions for each division formation process is not limited to four. For example, each division formation process may correspond to a predetermined image adjustment process, or may correspond to any predetermined timing depending on the length of the sheet interval. Furthermore, a plurality of the division forming processes may be executed in accordance with the content of one color or one of the image adjustment processes.

[0055] In the division adjustment process, the division adjustment processing unit 53 detects the density of each of the detection toner images formed at positions corresponding to the paper gap on the intermediate transfer belt 26 using the detection unit 46 in the toner image detection process. Specifically, each time a detection toner image is formed by the division formation process, the division adjustment processing unit 53 detects the density of the detection toner image by the toner image detection process.

[0056] Thereafter, in the division adjustment process, when the division adjustment processing unit 53 detects the densities of all the detection toner images, the image adjustment process adjusts the image forming conditions based on the detection results of the densities of the detection toner images. For example, the image forming conditions include the development bias voltage in the image forming units 21 to 24, the light amount of the laser light in the optical scanning device 25, the image forming position (image write timing) on ​​each of the photosensitive drums 31 of the image forming units 21 to 24 by the optical scanning device 25, and input / output characteristics (gamma characteristics). Note that the image forming conditions may also include the charging voltage, the primary transfer current, and the secondary transfer current.

[0057] However, if the number of prints in a print job is small, the detection image formation process may be interrupted when the print job ends. In this case, when the next print job is executed, the detection image formation process may be executed from the beginning, but the detection image formation process already executed in the previous print job will be wasted. On the other hand, when the next print job is executed, the interrupted detection image formation process may be resumed from where it left off. However, if multiple divided formation operations are executed in different execution environments, this may hinder the stabilization of image quality through the adjustment of the image formation conditions. In contrast, the image forming apparatus 100 according to this embodiment can achieve a good balance between the efficiency of the detection image formation process and the stabilization of image quality.

[0058] [Adjustment control processing] An example of the procedure of the adjustment control process (image forming method) executed by the control unit 7 will be described below with reference to Fig. 5. The control unit 7 executes the adjustment control process when the print processing unit 50 starts print processing based on image data included in the print job to be printed. Note that steps S10, S11, etc. represent the numbers of the processing procedures (steps) executed by the control unit 7.

[0059] <Step S10> In step S10, the division adjustment processing unit 53 of the control unit 7 determines whether the timing between sheets in the printing process has arrived. If it is determined that the timing between sheets has arrived (S10: Yes), the process proceeds to step S11, and the process waits in step S10 until it is determined that the timing between sheets has arrived (S10: No). Note that if the print job ends while the process is waiting in step S10, the adjustment control process also ends.

[0060] <Step S11> In step S11, the division adjustment processing unit 53 of the control unit 7 determines whether or not it is necessary to re-execute the division adjustment process. Specifically, the division adjustment processing unit 53 determines that it is necessary to re-execute the division adjustment process when re-execution information M1, which will be described later, is set to 1. Here, if it is determined that it is necessary to re-execute the division adjustment process (S11: Yes), the process proceeds to step S13, and if it is determined that it is not necessary to re-execute the division adjustment process (S11: No), the process proceeds to step S12.

[0061] <Step S12> In step S12, the division adjustment processing unit 53 of the control unit 7 determines whether the second execution condition is satisfied. If it is determined that the second execution condition is satisfied (S12: Yes), the process proceeds to step S13. If it is determined that the second execution condition is not satisfied (S12: No), the process proceeds to step S17.

[0062] <Step S13> In step S13, the division adjustment processing unit 53 of the control unit 7 executes the division formation process corresponding to the division formation number N among the detection image formation processes. In this embodiment, the division formation number N has an initial value of 1. The division formation number N is identification information for identifying multiple division formation processes in the detection image formation process, and is incremented by 1 in step S15 described below, and reset to 1 in step S125 or S153 described below. Thereafter, when the division formation process is completed, the process proceeds to step S14.

[0063] <Step S14> In step S14, the division adjustment processing unit 53 of the control unit 7 determines whether the detection image formation process has ended. For example, if the detection image formation process is divided into four division formation operations, the division adjustment processing unit 53 determines that the detection image formation process has ended when the division formation number N is 4.

[0064] <Step S15> In step S15, the division adjustment processing unit 53 of the control unit 7 increments the division formation number N by 1 (N=N+1). As a result, in step S13, the division formation processes are executed in order as the division formation number N is incremented.

[0065] <Step S16> In step S16, the division adjustment processing unit 53 of the control unit 7 determines whether the print job being executed has finished. If it is determined that the print job has not finished (S16: No), the process proceeds to step S17, and if it is determined that the print job has finished (S16: Yes), the process proceeds to step S18.

[0066] <Step S17> In step S17, the division adjustment processing unit 53 of the control unit 7 determines whether the timing between sheets in the printing process has arrived, similar to step S10. If it is determined that the timing between sheets in the printing process has arrived (S17: Yes), the process returns to step S13. Furthermore, the process waits in step S17 until it is determined that the timing between sheets in the printing process has not arrived (S17: No).

[0067] <Step S18> In step S18, the division adjustment processing unit 53 of the control unit 7 starts measuring the elapsed time T, which indicates the elapsed time since the print job during the detection image formation process was completed. If the division adjustment processing unit 53 had already started measuring the elapsed time T before step S18 was executed, i.e., if the elapsed time T is not 0 in step S18, the division adjustment processing unit 53 continues measuring the elapsed time T without resetting the elapsed time T to 0. As a result, the elapsed time T indicates the elapsed time since the print job that was being executed when the first division formation process was executed in the interrupted detection image formation process was completed. The elapsed time T is used in step S122 (described later) to determine whether a predetermined period has elapsed since the print job during the interrupted detection image formation process was completed. Hereinafter, the print job during the interrupted detection image formation process during the first division formation process is sometimes referred to as the interrupted print job.

[0068] The division adjustment processing unit 53 may store the current date and time as the end date and time of the print job in the storage unit 7 instead of the elapsed time T. In this case, in step S122 described below, it is possible to determine whether the specified period has elapsed based on the difference between the current date and time and the end date and time.

[0069] <Step S151> If it is determined in step S14 that the detection image formation process has ended, the process proceeds to step S151. In step S151, the division adjustment processing unit 53 of the control unit 7 determines whether all of the detection toner images formed in the detection image formation process have been detected by the detection unit 46. If it is determined that all of the detection toner images have been detected (S151: Yes), the process proceeds to step S152, and remains on standby at step S151 until all of the detection toner images have been detected (S151: No).

[0070] <Step S152> In step S152, the division adjustment processing unit 53 of the control unit 7 executes the image adjustment processing based on the density of each of the detection toner images detected by the detection unit 46 and the like.

[0071] <Step S153> In step S153, the division adjustment processing unit 53 of the control unit 7 resets the re-execution information M to 0, the division formation number N to 1, and the elapsed time T to 0.

[0072] <Step S121> On the other hand, if it is determined in step S12 that it is not time to perform the division adjustment process, the process proceeds to step S121. Then, in step S121, the division adjustment processing unit 53 of the control unit 7 determines whether the detection image formation process has been interrupted during the execution of the previous print job.

[0073] Specifically, if the division formation number N is 2 or greater, the division adjustment processing unit 53 determines that the detection image formation process has been interrupted during execution of the previous print job. Furthermore, if the division formation number N is 1, the division adjustment processing unit 53 determines that the detection image formation process has not been interrupted during execution of the previous print job. If it is determined that the detection image formation process has not been interrupted (S121: No), the process returns to step S10. If it is determined that the detection image formation process has been interrupted (S121: Yes), the process proceeds to step S122. Thereafter, in steps S122 to S124, it is determined whether a preset continuation execution condition is met.

[0074] <Step S122> In step S122, the split adjustment processing unit 53 of the control unit 7 executes a determination process to confirm, as one of the conditions for continued execution, that a predetermined specific period has not elapsed since the end of the interrupted print job. Specifically, in step S122, the split adjustment processing unit 53 determines that the specific period has not elapsed if the elapsed time T, the measurement of which was started in step S18, has not reached a specific time corresponding to the specific period. The specific period is a period set to determine that the difference in the execution environment of the multiple split formation processes is within an acceptable range. For example, the specific period is 60 minutes or 120 minutes.

[0075] Then, in step S122, if it is determined that the specific period has not elapsed (S122: Yes), the process proceeds to step S123, and if it is determined that the specific period has elapsed (S122: No), the process proceeds to step S125.

[0076] <Step S123> In step S123, the divided adjustment processing unit 53 of the control unit 7 determines, as one of the continuation conditions, whether the collective adjustment processing is being performed by the collective adjustment processing unit 52 after the interrupted print job is completed. If it is determined that the collective adjustment processing is not being performed (S123: Yes), the process proceeds to step S124, and if it is determined that the collective adjustment processing is being performed (S123: No), the process proceeds to step S125.

[0077] <Step S124> In step S123, the split adjustment processing unit 53 of the control unit 7 determines, as one of the continuation conditions, whether or not the collective adjustment processing is being performed by the collective adjustment processing unit 52 after the interrupted print job is completed. If it is determined that the specific event has not occurred (S124: Yes), the process proceeds to step S123, and if it is determined that the specific event has occurred (S124: No), the process proceeds to step S125.

[0078] For example, the specific event may be the replacement of a component such as the photosensitive drum 31 or the developing roller of the image forming unit 3 of the image forming apparatus 100. Alternatively, the specific event may be the execution of an aging process in which the developing device 33 is driven for a predetermined time in order to agitate the toner in the developing device 33 or stabilize the charge amount. Note that the specific event is not limited to those described here, and may be other events such as the effects of other components, changes in temperature, or humidity.

[0079] <Step S125> In step S125, the division adjustment processing unit 53 of the control unit 7 sets the re-execution information M to 1, resets the division formation number N to 1, and resets the elapsed time T to 0. Thereafter, the division adjustment processing unit 53 shifts the process to step S11.

[0080] As described above, in the adjustment control process, if it is determined in steps S122 to S124 that the continuation execution condition is satisfied, the process proceeds to step S13, and the detection image adjustment process that was interrupted in the previous print job is resumed from where it left off. Therefore, the division formation process that was executed in the previous print job is effectively utilized. As a result, toner waste in the division formation process that was executed in the previous print job is reduced.

[0081] On the other hand, if it is determined in any of steps S122 to S124 that the continuation execution condition is not met, the interrupted divisional formation process is not resumed, and the divisional formation number N is reset to 1. Therefore, the next time the detection image formation process is executed, it will be executed from the first divisional formation process. As a result, multiple divisional formation processes in the division adjustment process are executed in a situation where there is little difference in the execution environment of the multiple divisional formation processes, so the accuracy of the adjustment process of the image formation conditions in the division adjustment process is improved, and it is possible to stabilize image quality.

[0082] Furthermore, if it is determined in any of steps S122 to S124 that the continuation execution condition is not satisfied, the interrupted divisional formation process is not resumed, and the re-execution information M is reset to 1. Therefore, even if it is not determined in step S12 that the second execution condition is satisfied, the process in step S11 proceeds to step S13, and the detection image formation process is re-executed from the first divisional formation process. As a result, multiple divisional formation processes in the division adjustment process are executed in a situation where there is little difference in the execution environments of the multiple divisional formation processes, and this improves the accuracy of the adjustment process of the image formation conditions in the division adjustment process, making it possible to stabilize image quality.

[0083] Therefore, the image forming apparatus 100 according to this embodiment can achieve a good balance between the efficiency of the detection image formation process and the stabilization of image quality.

[0084] Furthermore, the continuation execution condition is not limited to the above. For example, the continuation execution condition may include the fact that the image forming apparatus 100 is not turned off and on, or that the image forming apparatus 100 has not entered and returned from sleep mode after the one print job has ended. Furthermore, it is conceivable that the effect of the image forming apparatus 100 being turned off and on, or that the image forming apparatus 100 has entered and returned from sleep mode, is small. Therefore, the image forming apparatus 100 may be configured so that the continuation execution condition does not include the fact that the image forming apparatus 100 has not entered and returned from sleep mode after the one print job has ended.

[0085] In the present embodiment, the split adjustment process executed in the adjustment control process has been described as an example in which the process of adjusting the image formation conditions is executed for the image forming units 21-24 used in color printing. Meanwhile, in other embodiments, the split adjustment process executed in the adjustment control process may be executed as a process of adjusting the image formation conditions for only the image forming unit 24 used in monochrome printing. Furthermore, the adjustment control process for the image forming units 21-24 used in color printing and the adjustment control process for the image forming unit 24 used in monochrome printing may be executed separately.

[0086] [Notes on the Invention] The following is a summary of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0087] <Appendix 1> an image forming unit that performs image forming processing to form an image on a transfer medium based on image data of a print job to be printed; a division adjustment processing unit that divides and executes a detection image forming process, in which a detection image used in an image adjustment process that adjusts image formation conditions in the image forming unit is formed on the transfer medium by the image forming unit, into a plurality of division periods in a plurality of the image forming processes corresponding to a plurality of pages included in one print job; Equipped with When a predetermined continuation execution condition is satisfied after the detection image formation process is interrupted due to the completion of the image formation process corresponding to the one print job, the division adjustment processing unit resumes the detection image formation process from the middle in the image formation process corresponding to another print job to be executed next, and when the continuation execution condition is not satisfied, re-executes the detection image formation process from the beginning in the image formation process corresponding to the other print job. Image forming device.

[0088] <Appendix 2> the divided period is a paper interval between the image forming processes corresponding to different pages; 2. The image forming apparatus according to claim 1.

[0089] <Appendix 3> The continuation execution condition includes that a predetermined specific period has not elapsed since the end of the one print job. 3. The image forming apparatus according to claim 1 or 2.

[0090] <Appendix 4> a collective adjustment processing unit that collectively executes the detection image forming process and the image adjustment process under conditions different from those of the divided adjustment processing unit; the continuation execution condition includes that the image adjustment process has not been executed by the collective adjustment processing unit after the one print job has ended. 4. The image forming apparatus according to claim 1.

[0091] <Appendix 5> the continuation execution condition includes that a predetermined event that may change the printing characteristics of the image forming device does not occur after the one print job is completed. 5. The image forming apparatus according to any one of claims 1 to 4.

[0092] <Appendix 6> a processor of an image forming apparatus having an image forming unit that executes image formation processing to form an image on a transfer medium based on image data of a print job to be printed, an image forming method for executing a divided adjustment step in which a detection image forming process for forming a detection image on a transfer medium by an image forming unit, the detection image being used in an image adjustment process for adjusting image formation conditions in the image forming unit, is divided into a plurality of divided periods in a plurality of the image forming processes corresponding to a plurality of pages included in one print job, In the division adjustment step, after the detection image forming process is interrupted due to the completion of the image forming process corresponding to the one print job, if a preset continuation execution condition is satisfied, the detection image forming process is resumed from the middle in the image forming process corresponding to another print job to be executed next, and if the continuation execution condition is not satisfied, the detection image forming process is re-executed from the beginning in the image forming process corresponding to the other print job. Image forming method. [Explanation of symbols]

[0093] 1 ADF 2 Image reading unit 3 Image forming unit 4 Paper feed section 5 Operation display section 6 Memory section 7 Control Unit 20 Image forming unit 25 Optical scanning device 26 Intermediate transfer belt 27 Secondary transfer roller 28 Fixing device 31 Photosensitive drum 32 Charging roller 33 Developing device 34 Primary transfer roller 35 Drum Cleaning Department 36 Toner container 40 1st power supply 45 2nd power supply 46 Detector 100 Image forming device

Claims

1. an image forming unit that performs image forming processing to form an image on a transfer medium based on image data of a print job to be printed; a division adjustment processing unit that divides and executes a detection image forming process, in which a detection image used in an image adjustment process that adjusts image formation conditions in the image forming unit is formed on the transfer medium by the image forming unit, into a plurality of division periods in a plurality of the image forming processes corresponding to a plurality of pages included in one print job; Equipped with When a predetermined continuation execution condition is satisfied after the detection image formation process is interrupted due to the completion of the image formation process corresponding to the one print job, the division adjustment processing unit resumes the detection image formation process from the middle in the image formation process corresponding to another print job to be executed next, and when the continuation execution condition is not satisfied, re-executes the detection image formation process from the beginning in the image formation process corresponding to the other print job. Image forming device.

2. the divided period is a paper interval between the image forming processes corresponding to different pages; The image forming apparatus according to claim 1 .

3. The continuation execution condition includes that a predetermined specific period has not elapsed since the end of the one print job. The image forming apparatus according to claim 1 .

4. a collective adjustment processing unit that collectively executes the detection image forming process and the image adjustment process under conditions different from those of the divided adjustment processing unit; the continuation execution condition includes that the image adjustment process has not been executed by the collective adjustment processing unit after the one print job has ended. The image forming apparatus according to claim 1 .

5. the continuation execution condition includes that a predetermined event that may change the printing characteristics of the image forming device does not occur after the one print job is completed.

5. The image forming apparatus according to claim 1.

6. a processor of an image forming apparatus including an image forming unit that executes image formation processing for forming an image on a transfer medium based on image data of a print job to be printed; an image forming method for executing a divided adjustment step in which a detection image forming process for forming a detection image on a transfer medium by an image forming unit, the detection image being used in an image adjustment process for adjusting image formation conditions in the image forming unit, is divided into a plurality of divided periods in a plurality of the image forming processes corresponding to a plurality of pages included in one print job, In the division adjustment step, after the detection image forming process is interrupted due to the completion of the image forming process corresponding to the one print job, if a preset continuation execution condition is satisfied, the detection image forming process is resumed from the middle in the image forming process corresponding to another print job to be executed next, and if the continuation execution condition is not satisfied, the detection image forming process is re-executed from the beginning in the image forming process corresponding to the other print job. Image forming method.

Images