Image formation device and image formation program

Abstract

To provide an image formation device capable of saving and reducing consumption of toner in refresh processing according to situations, and an image formation program.SOLUTION: The image formation device comprises a calculation processing part and a setting processing part. The calculation processing part calculates, based on preset operation expressions, a first calculated amount which is an amount of toner to be discharged from an image development part in first refresh processing, a second calculated amount which is an amount of toner to be discharged from the image development part in second refresh processing, and a third calculated amount which is an amount of toner to be discharged from the image development part in refresh processing. When a calculation result obtained by the calculation processing part satisfies preset specific conditions, the setting processing part is set such that a first discharge amount and a second discharge amount in the first refresh processing and the second refresh processing executed by a refresh processing part are values for reaching the third calculated amount obtained by summing the first discharge amount and the second discharge amount.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] In electrophotographic image forming devices that form images using a developer containing toner, a refresh process may be performed when image formation based on print data is not being performed (see, for example, Patent Document 1). In the refresh process, a toner layer is formed on the photosensitive element and intermediate transfer element, and the toner layer is then scraped off from the photosensitive element and intermediate transfer element by a cleaning member. In addition, in the refresh process, old toner is discharged from the developing unit. This improves the quality of images formed in the image formation process in the image forming device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-194652 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when the refresh process is performed, toner is consumed.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and an image forming program that can reduce or eliminate the amount of toner consumed in a refresh process depending on the situation. [Means for solving the problem]

[0006] An image forming apparatus according to one aspect of the present invention includes an image forming unit, a first cleaning member, a second cleaning agent, a print processing unit, a refresh processing unit, a calculation processing unit, and a setting processing unit. The image forming unit includes an image forming unit including a photosensitive drum and a development unit that develops an electrostatic latent image formed on the photosensitive drum with toner, and an intermediate transfer member that transfers a toner image transferred from the photosensitive drum to a sheet. The first cleaning member contacts the surface of the photosensitive drum to remove toner from the surface of the photosensitive drum. The second cleaning agent contacts the surface of the intermediate transfer member to remove toner from the surface of the intermediate transfer member. The print processing unit controls the image forming unit to perform image formation processing that forms an image based on image data to be printed. When a predetermined execution condition is satisfied, the refresh processing unit controls the image forming unit at a timing different from that of the image forming process executed by the print processing unit, and executes refresh processes including a first refresh process in which a predetermined first discharge amount of toner is discharged from the developing unit to form a toner layer on the photosensitive drum, and a second refresh process in which a predetermined second discharge amount of toner is discharged from the developing unit to form a toner layer on the intermediate transfer body. The calculation processing unit calculates a first calculated amount that is the amount of toner to be discharged from the developing unit in the first refresh process, a second calculated amount that is the amount of toner to be discharged from the developing unit in the second refresh process, and a third calculated amount that is the amount of toner to be discharged from the developing unit in the refresh process, each based on a predetermined arithmetic expression. When a calculation result by the calculation processing unit satisfies a predetermined specific condition, the setting processing unit sets the first discharge amount and the second discharge amount in the first refresh process and the second refresh process executed by the refresh processing unit to values ​​such that the sum of the first discharge amount and the second discharge amount is the third calculated amount.

[0007] An image forming program according to another aspect of the present invention is a program for causing a control unit of an image forming apparatus to execute a printing step, a refreshing step, a calculating step, and a setting step. The image forming apparatus includes an image forming unit, a first cleaning agent, and a second cleaning agent. The image forming unit includes an image forming unit including a photosensitive drum and a developing unit that develops an electrostatic latent image formed on the photosensitive drum with toner, and an intermediate transfer body that transfers a toner image transferred from the photosensitive drum to a sheet. The first cleaning agent contacts the surface of the photosensitive drum to remove toner from the surface of the photosensitive drum. The second cleaning agent contacts the surface of the intermediate transfer body to remove toner from the surface of the intermediate transfer body. The printing step controls the image forming unit to perform an image formation process that forms an image based on image data to be printed. The refreshing step, when a predetermined execution condition is satisfied, controls the image forming unit at a timing different from that of the image forming process executed by the printing step, and executes a refreshing process including a first refreshing process in which a predetermined first discharge amount of toner is discharged from the developing unit to form a toner layer on the photosensitive drum, and a second refreshing process in which a predetermined second discharge amount of toner is discharged from the developing unit to form a toner layer on the intermediate transfer body. The calculating step calculates a first calculated amount that is the amount of toner to be discharged from the developing unit in the first refreshing process, a second calculated amount that is the amount of toner to be discharged from the developing unit in the second refreshing process, and a third calculated amount that is the amount of toner to be discharged from the developing unit in the refreshing process, each based on a predetermined arithmetic expression. The setting step, when a calculation result by the calculating step satisfies a predetermined specific condition, sets the first discharge amount and the second discharge amount in the first refreshing process and the second refreshing process executed by the refreshing step to values ​​such that the sum of the first discharge amount and the second discharge amount is the third calculated amount. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an image forming apparatus and an image forming program that can reduce or eliminate the amount of toner consumed in a refresh process depending on the situation. [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 a refresh 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 executes a print process that prints an image based on image data corresponding to a print job onto a sheet in accordance with an electrophotographic method.

[0018] The paper feed unit 4 includes a paper feed cassette, a manual feed tray, and a plurality of transport rollers. The paper feed unit 4 supplies the image forming unit 3 with sheets on which images are to be printed.

[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 unit 3 will be described with reference to FIGS.

[0024] 1 and 3, the image forming section 3 includes an image forming unit 20 (21 to 24), 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 FIG. 2, the image forming section 3 includes a first power source 40 (41 to 44) and a second power source 45.

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

[0026] 3, each image forming unit 20 includes a photosensitive drum 31, a charging roller 32, a developing unit 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 based on the image data is formed on the surface of the photosensitive drum 31.

[0029] The developing unit 33 develops the electrostatic latent image formed on the surface of the photosensitive drum 31. The developing unit 33 includes a developing roller 331, a magnet roller 332, and a pair of stirring members 333. The pair of stirring members 333 stir the developer, which contains toner and magnetic carriers, contained inside the developing unit 33. In this embodiment, the toner contained in the developer is positively charged due to friction with the magnetic carriers contained in the developer. The toner in the developer also contains an abrasive. The magnet roller 332 scoops up the developer stirred by the pair of stirring members 333 and supplies the toner contained in the developer to the developing roller 331. The developing roller 331 transports the toner supplied from the magnet roller 332 to a position facing the photosensitive drum 31. The developing roller 331 receives a preset development bias voltage and supplies the toner transported to the opposing position to the photosensitive drum 31. As a result, toner is selectively supplied to the exposure area of ​​the photosensitive drum 31 that is 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. Note that toner is supplied to the developing unit 33 from a toner container 36.

[0030] Upon receiving a supply of a preset primary transfer current, the primary transfer roller 34 transfers the toner image formed on the surface of the photosensitive drum 31 toward the primary transfer roller 34. As a result, the toner image formed on the surface of the photosensitive drum 31 is transferred to the surface (outer peripheral 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 toner remaining on the surface of the photosensitive drum 31 after the toner image has been transferred by the primary transfer roller 34. Specifically, the drum cleaning unit 35 includes a first cleaning member 351 such as a blade or roller that comes into contact with the surface of the photosensitive drum 31 and removes toner from the surface of the photosensitive drum 31.

[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 the image forming units 20 are transferred. The intermediate transfer belt 26 is an example of an intermediate transfer body. For example, the intermediate transfer belt 26 is made of a resin material such as polyimide. The intermediate transfer belt 26 is stretched at 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 the photosensitive drums 31 to a transfer position onto a sheet by the secondary transfer rollers 27. After the toner images are transferred by the secondary transfer rollers 27, the surface of the intermediate transfer belt 26 is cleaned by a belt cleaning unit 26C (see FIG. 3). Specifically, the belt cleaning unit 26C includes a second cleaning member 261 such as a blade or roller that comes into contact with the surface of the intermediate transfer belt 26 and removes toner from the surface of the intermediate transfer belt 26.

[0034] The secondary transfer roller 27 receives a supply of a preset secondary transfer current and moves the toner image transferred onto the surface of the intermediate transfer belt 26 toward the secondary transfer roller 27. As a result, the toner image transferred onto the surface of the intermediate transfer belt 26 is transferred 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] The first power source 40 is a power supply circuit that supplies power to the image forming units 20. Specifically, the first power source 40 includes first power sources 41-44 corresponding to the image forming units 21-24.

[0038] The first power source 41 (see FIG. 2) supplies the charging voltage to the charging roller 32 of the image forming unit 21. The first power source 41 also supplies the developing bias voltage to the developing roller 331 of the image forming unit 21. Furthermore, the first power source 41 is a constant current power source that supplies the primary transfer current to the primary transfer roller 34 of the image forming unit 21. In this embodiment, the primary transfer current is a negative current.

[0039] Similarly, first power supply 42 supplies the charging voltage, the developing bias voltage, and the primary transfer current to charging roller 32, developing roller 331, and primary transfer roller 34 of image forming unit 22. First power supply 43 supplies the charging voltage, the developing bias voltage, and the primary transfer current to charging roller 32, developing roller 331, and primary transfer roller 34 of image forming unit 23. First power supply 44 supplies the charging voltage, the developing bias voltage, and the primary transfer current to charging roller 32, developing roller 331, and primary transfer roller 34 of image forming unit 24.

[0040] The second power source 45 supplies the secondary transfer current to the secondary transfer roller 27. The second power source 45 supplies the secondary transfer current set by the control unit 7 to the secondary transfer roller 27. In this embodiment, the secondary transfer current is a current of negative polarity. Note that in other embodiments, the charge polarity of the toner may be negative, and the primary transfer current and the secondary transfer current may be currents of positive polarity.

[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 refresh processing unit 52, a calculation processing unit 53, a setting processing unit 54, etc. Specifically, an image forming 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 image forming program stored in the ROM 12 to function as each of the above-mentioned processing units.

[0043] The image forming 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. Some or all of the print processing unit 50, count processing unit 51, refresh processing unit 52, calculation processing unit 53, and setting processing unit 54 may be configured using electronic circuits such as an application specific integrated circuit (ASIC).

[0044] The print processing unit 50 controls the image forming unit 3 to perform printing processes such as a monochrome printing process for forming a monochrome image on a sheet or a color printing process for forming a color image on a sheet based on image data included in a print job to be printed. Specifically, in the monochrome printing process, the print processing unit 50 controls the optical scanning device 25 and the image forming unit 24 corresponding to black to perform a monochrome image formation process for forming a black toner image on the intermediate transfer belt 26 based on the image data. In the color printing process, the print processing unit 50 controls the optical scanning device 25 and the image forming units 21-24 corresponding to each color to perform a color image formation process for forming color toner images on the intermediate transfer belt 26 based on the image data. Thereafter, the toner images formed on the intermediate transfer belt 26 by the monochrome image formation process and the color image formation process are transferred to a sheet by the secondary transfer roller 27. Note that, hereinafter, the monochrome image formation process and the color image formation process may be collectively referred to simply as image formation process.

[0045] Furthermore, in the image forming apparatus 100, a preset inter-sheet process is executed between the image forming process for forming an image based on one page of image data on the intermediate transfer belt 26 and the image forming process for forming the next image based on the image data of one page on the intermediate transfer belt 26. In the inter-sheet process, preset processes such as a refresh process described below are executed as needed.

[0046] The count processing unit 51 counts a monochrome execution count BK1 indicating the cumulative number of times the monochrome image formation process has been executed in the image forming apparatus 100. The monochrome execution count BK1 is used to determine whether or not a refresh process, which will be described later, needs to be executed, and to calculate the amount of toner discharged in the refresh process.

[0047] The count processing unit 51 also counts a color execution count C1 indicating the cumulative number of executions of the color image forming process in the image forming apparatus 100. The color execution count C1 is used to calculate the amount of toner discharged in the refresh process.

[0048] Furthermore, the count processing unit 51 counts the cumulative printing rate of each color in the image forming units 21 to 24 after the refresh process described below has been executed for the last time. Specifically, the count processing unit 51 counts the cumulative printing rate corresponding to each color based on image data included in a print job executed by the image forming apparatus 100. The cumulative printing rate is used to calculate the amount of toner discharged in the refresh process.

[0049] When the preset execution conditions are met, the refresh processing unit 52 controls the image forming unit 3 at a timing different from the image forming process executed by the print processing unit 50, and executes the preset refresh processing.

[0050] The execution conditions include a first execution condition and a second execution condition, which will be described later.

[0051] The first execution condition is a condition for determining whether or not to execute the refresh process after the image formation process based on all the image data included in one print job is completed. Specifically, the first execution condition is that the monochrome execution count BK1 reaches a preset first threshold N1 at the end of the print job. Then, when the first execution condition is satisfied, the refresh processing unit 52 executes the refresh process at a timing after the execution of the print job. In this embodiment, the first threshold N1 is set to "50."

[0052] The second execution condition is a condition for determining whether to execute the refresh process at the inter-sheet interval between the image forming processes based on the image data of different pages included in the print job. Specifically, the second execution condition is that the monochrome execution count BK1 during execution of the print job reaches a preset second threshold N2. When the second execution condition is satisfied, the refresh processing unit 52 executes the refresh process as part of the inter-sheet processing at the timing of the inter-sheet interval during execution of the print job. In this embodiment, the second threshold N2 is set to "10."

[0053] The refresh processing unit 52 executes the refresh processing after the execution of the print job when the first execution condition is satisfied, and executes the refresh processing between sheets during the execution of the print job when the second execution condition is satisfied. The refresh processing includes a first refresh processing and a second refresh processing, which will be described later. Note that in the refresh processing, the old toner contained in the developing unit 33 is forcibly consumed by the first refresh processing or the second refresh processing.

[0054] In the first refresh process, in the image forming units 21 to 24 of each color used in the color image formation process, a predetermined first discharge amount of toner α0 is discharged from the developing unit 33, and a toner layer is formed on the photosensitive drum 31. Specifically, in the first refresh process, the photosensitive drum 31 is driven, and the developing bias voltage is applied to the developing roller 331. Meanwhile, in the first refresh process, the charging voltage is not applied to the charging roller 32 until a toner layer of the toner of the first discharge amount α0 is formed on the photosensitive drum 31, and after that period has elapsed, the charging voltage is applied to the charging roller 32. As a result, in the first refresh process, the toner of the first discharge amount α0 is supplied from the developing unit 33 to the photosensitive drum 31, and a toner layer is formed over the entire image formation target area on the surface of the photosensitive drum 31. In addition, in the first refresh process, a reverse bias voltage of the same polarity as the charging polarity of the toner is applied to the primary transfer roller 34. As a result, in the first refreshing process, the toner layer does not transfer from the photosensitive drum 31 to the intermediate transfer belt 26, but remains on the surface of the photosensitive drum 31. The toner layer is then scraped off from the photosensitive drum 31 by the first cleaning member 351 of the drum cleaning unit 35. The first refreshing process reduces, for example, contact noise between the drum cleaning unit 35 and the photosensitive drum 31, and suppresses uneven abrasion of the photosensitive drum 31 and variations in the surface potential.

[0055] In the second refresh process, only in the black image forming unit 24 used in the monochrome image formation process, a preset second discharge amount β0 of toner is discharged from the developing unit 33, and a toner layer is formed on the intermediate transfer drum 26. Specifically, in the second refresh process, the photosensitive drum 31 and the intermediate transfer belt 26 are driven, and the developing bias voltage is applied to the developing roller 331. On the other hand, in the first refresh process, the charging voltage is not applied to the charging roller 32 until a toner layer of the second discharge amount β0 of toner is formed on the photosensitive drum 31, and after that period has elapsed, the charging voltage is applied to the charging roller 32. As a result, in the second refresh process, the toner of the second discharge amount β0 is supplied from the developing unit 33 to the photosensitive drum 31, and a toner layer is formed over the entire image formation target area on the surface of the photosensitive drum 31. Also, in the second refresh process, the primary transfer current is supplied to the primary transfer roller 34. As a result, in the second refreshing process, the toner layer is transferred from the photosensitive drum 31 to the surface of the intermediate transfer belt 26. Also, in the second refreshing process, a reverse bias voltage of the same polarity as the charge polarity of the toner is applied to the secondary transfer roller 27. As a result, the toner layer does not transfer from the intermediate transfer belt 26 to the secondary transfer roller 27, but remains on the surface of the intermediate transfer belt 26. Thereafter, the toner layer is scraped off from the intermediate transfer belt 26 by the second cleaning member 261 of the belt cleaning unit 26C. Furthermore, the second refreshing process can reduce, for example, contact noise between the belt cleaning unit 26C and the intermediate transfer belt 26, deformation of the belt cleaning unit 26C, and slippage of the intermediate transfer belt 26.

[0056] The first refresh process is not limited to the method described here, as long as it is possible to form a toner layer of toner supplied from the developing unit 33 at a first discharge amount α0 on the photosensitive drum 31. Similarly, the second refresh process is not limited to the method described here, as long as it is possible to form a toner layer of toner supplied from the developing unit 33 at a second discharge amount β0 on the intermediate transfer belt 26. For example, in another embodiment, in the first refresh process and the second refresh process, the developing bias voltage may be applied to the developing roller 331, and laser light based on a preset refresh image may be irradiated from the optical scanning device 25 onto the photosensitive drum 31. As a result, an electrostatic latent image based on the refresh image formed on the photosensitive drum 31 is developed with toner, and a toner layer based on the refresh image is formed on the photosensitive drum 31 or the intermediate transfer belt 26.

[0057] The calculation processing unit 53 calculates a first calculated amount x, which is the amount of toner to be discharged from the developing unit 33 in the image forming units 21 to 24 in the first refresh process, based on the following formula (1), which is a preset first arithmetic formula.

[0058] In this embodiment, in the first refresh process and the second refresh process, a toner layer having a width equal to the image formation target area on the surface of the photosensitive drum 31 is formed on the photosensitive drum 31. Therefore, the amount of toner consumed in the first refresh process and the second refresh process is determined by the circumferential length of the photosensitive drum 31. Therefore, in this embodiment, the amount of toner discharged from the developing unit 33 is expressed in "mm," which indicates the circumferential length of the photosensitive drum 31. In other embodiments, the amount of toner discharged from the developing unit 33 may be expressed in "ms," which indicates the driving time of the photosensitive drum 31.

[0059] The value A1 in the following formula (1) is a value that is predetermined for each model of image forming apparatus 100. In this embodiment, the value A1 is 0.9 [mm]. As described above, the monochrome execution count BK1 is a value that is counted by count processing unit 51 as a value that indicates the cumulative number of executions of the monochrome image formation process.

[0060] x [mm] = A1 × BK1 (1)

[0061] Furthermore, the calculation processing unit 53 calculates a second calculated amount y, which is the amount of toner to be discharged from the developing unit 33 in the image forming unit 24 in the second refresh process, based on a preset second arithmetic expression. In particular, when the second refresh process is performed between sheets during execution of the print job, the calculation processing unit 53 uses the following equation (2) as the second arithmetic expression. In addition, when the second refresh process is performed after execution of the print job, the calculation processing unit 53 uses the following equation (3) as the second arithmetic expression. Note that in this embodiment, the black image forming unit 24 is used in the second refresh process, but in other embodiments, any one or more of the image forming units 21 to 24 may be used in the second refresh process.

[0062] The values ​​A2 and A3 in the following formulas (2) and (3) are values ​​that are predetermined for each model of the image forming apparatus 100. In particular, in this embodiment, the value A2 is 0.9 [mm] and the value A3 is 0.3 [mm]. The values ​​A2 and A3 are expressed as absolute moisture amounts H [g / m 3 ] may be corrected based on the above.

[0063] y [mm] = A2 × BK1 (2) y [mm] = A3 × BK1 (3)

[0064] Furthermore, the calculation processing unit 53 calculates third calculation amounts z1 to z4, which are the amounts of toner to be discharged from the developing unit 33 in the image forming units 21 to 24 in the refresh process, based on a third predetermined arithmetic expression. In particular, the calculation processing unit 53 calculates the third calculation amounts z1, z2, z3, and z4 corresponding to yellow, cyan, magenta, and black based on the following expressions (4) to (7).

[0065] In the following formulas (4) to (7), the cumulative printing rate counted by the count processing unit 51 and corresponding to the yellow image forming unit 21 is defined as C21. Similarly, the cumulative printing rates counted by the count processing unit 51 and corresponding to the cyan and magenta image forming units 22 and 23 are defined as C22 and C23, respectively. Furthermore, the cumulative printing rate counted by the count processing unit 51 and corresponding to the black image forming unit 24 is defined as BK24. The values ​​A4 and A5 in the following formulas (4) to (7) are values ​​that are predetermined for each model of the image forming apparatus 100, for example. In particular, in this embodiment, the value A4 is 0.4 [mm] and the value A5 is 3 [mm]. As described above, the color execution count C1 is a value counted by the count processing unit 51 as a value indicating the cumulative execution count of the color image formation process. z1[mm]=(A4×C1) -(C21×A5) ···(4) z2[mm]=(A4×C1) -(C22×A5) ···(5) z3[mm]=(A4×C1) -(C23×A5) ···(6) z4[mm]=(A4×BK1)-(BK2×A5) ···(7)

[0066] The setting processing unit 54 sets the toner discharge amount α0 in the first refresh process and the toner discharge amount β0 in the second refresh process of the refresh process executed by the refresh processing unit 52 based on the first calculation amount x, the second calculation amount y, and the third calculation amounts z1 to z4 calculated by the calculation processing unit 53.

[0067] Specifically, the setting processing unit 54 determines whether the calculation result by the calculation processing unit 53 satisfies a predetermined specific condition. The specific condition is that the third calculated amount z4 is greater than the first calculated amount x, the second calculated amount y is greater than the first calculated amount x, and the third calculated amount z4 is greater than or equal to the sum of the first calculated amount x and the second calculated amount y. That is, the specific condition is that the third calculated amount z4 > the first calculated amount x > the second calculated amount y, and the third calculated amount z4 > the first calculated amount x + the second calculated amount y. If the specific condition is satisfied, the setting processing unit 54 sets the first discharge amount α0 or the second discharge amount β0 so that the sum of the first discharge amount α0 and the second discharge amount β0 becomes the third calculated amount z4. Specifically, when the specific condition is satisfied, the setting processing unit 54 sets the first toner discharge amount α0 in the first refresh process to a value obtained by subtracting the second calculated amount y from the third calculated amount z4, and sets the second toner discharge amount β0 in the second refresh process to the second calculated amount y. Note that in another embodiment, the specific condition may be that the third calculated amount is greater than the first calculated amount, and the first calculated amount is greater than the second calculated amount.

[0068] However, when the refresh process is performed, toner is consumed. In contrast, in the image forming apparatus 100 according to the present embodiment, the amount of toner consumed in the refresh process can be reduced or increased depending on the situation.

[0069] [Refresh control process] An example of the procedure of the refresh control process executed by the control unit 7 will be described below with reference to Fig. 4. The control unit 7 executes the refresh control process when starting print processing by the print processing unit 50. Note that steps S10, S11, etc. represent the numbers of the processing procedures (steps) executed by the control unit 7.

[0070] <Step S10> In step S10, the refresh processing unit 52 of the control unit 7 determines whether or not the image formation process for one page has been completed in the printing process based on the image data included in the print job to be printed. If it is determined that the image formation process for one page has been completed (S10: Yes), the process proceeds to step S11, and the process waits in step S10 until the image formation process for one page has been completed (S10: No).

[0071] <Step S11> In step S11, the count processing unit 51 of the control unit 7 counts the cumulative execution count corresponding to the type of image formation process determined to have ended in step S10, and proceeds to step S12. Specifically, if the type of image formation process is monochrome image formation process, the count processing unit 51 increments the monochrome execution count BK1 by 1, and if the type of image formation process is color image formation process, the count processing unit 51 increments each of the monochrome execution count BK1 and the color execution count C1 by 1. The monochrome execution count BK1 and the color execution count C1 are stored in the memory unit 6.

[0072] <Step S12> In step S12, the refresh processing unit 52 of the control unit 7 determines whether the print job is finished. That is, it determines whether the image formation process based on all image data included in the print job is finished. For example, if it is the timing of the inter-page interval in the print job, it is determined that the print job is not finished. Here, if it is determined that the print job is finished (S12: Yes), the process proceeds to step S121, and if it is determined that the print job is not finished (S12: No), the process proceeds to step S13.

[0073] <Step S13> In step S13, the refresh processing unit 52 of the control unit 7 determines whether the first execution condition is satisfied. If it is determined that the first execution condition is satisfied (S13: Yes), the process proceeds to step S14. If it is determined that the first execution condition is not satisfied (S13: No), the process returns to step S11.

[0074] <Step S14> In step S14, the calculation processing unit 53 of the control unit 7 executes a calculation step of calculating the first calculation amount x, the second calculation amount y, and the third calculation amounts z1 to z4 based on the above-mentioned equations (1) to (7).

[0075] <Step S15> In step S15, the setting processing unit 54 of the control unit 7 executes a setting step of setting the first discharge amount α0 and the second discharge amount β0 based on the calculation result in step S14. Specifically, the setting processing unit 54 sets the second discharge amount β0 to the second calculated amount y. Meanwhile, the setting processing unit 54 calculates the first discharge amount α0 based on the first calculated amount x, the third calculated amounts z1 to z4, and the specific condition. In addition, hereinafter, the first discharge amount α0 of toner discharged from the developing unit 33 in the image forming units 21 to 24 in the first refresh process of the refresh process will be referred to as first discharge amounts α1 to α4.

[0076] Specifically, when the image formation process is the color image formation process and the calculation result satisfies the specific condition, the setting processing unit 54 sets the first discharge amount α1 to the larger of the first calculated amount x and the third calculated amount z1. Similarly, the setting processing unit 54 sets the first discharge amount α2 to the larger of the first calculated amount x and the third calculated amount z2, and sets the first discharge amount α3 to the larger of the first calculated amount x and the third calculated amount z3. Meanwhile, the setting processing unit 54 sets the first discharge amount α4 to a value obtained by subtracting the second calculated amount y from the third calculated amount z4.

[0077] Furthermore, when the image formation process is the color image formation process and the calculation result does not satisfy the specific condition, the setting processing unit 54 sets the first discharge amount α1 to the larger of the first calculated amount x and the third calculated amount z1. Similarly, the setting processing unit 54 sets the first discharge amount α2 to the larger of the first calculated amount x and the third calculated amount z2, sets the first discharge amount α3 to the larger of the first calculated amount x and the third calculated amount z3, and sets the first discharge amount α4 to the larger of the first calculated amount x and the third calculated amount z4.

[0078] Furthermore, when the image formation process is the monochrome image formation process and the calculation result satisfies the specific condition, the setting processing unit 54 sets the first discharge amounts α1 to α4 to the first calculated amount x. Similarly, when the image formation process is the monochrome image formation process and the calculation result does not satisfy the specific condition, the setting processing unit 54 sets the first discharge amounts α1 to α4 to the first calculated amount x.

[0079] That is, when the image forming process is the monochrome image forming process, even if the third calculated amounts z1 to z4 are greater than the first calculated amount x, the first discharge amounts α1 to α4 are set to the first calculated amount x. As a result, when the image forming process is the monochrome image forming process and the first refresh process is executed between sheets, only the amount of toner corresponding to the first calculated amount x set as the first discharge amounts α1 to α4 is discharged from the developing sections 33 of all the image forming units 21 to 24, and it is possible to shorten the time required for the first refresh process.

[0080] If the image formation process is the monochrome image formation process and the third calculated amount z1 is equal to or less than the first calculated amount x, the third calculated amount z1 of toner is discharged from the developing unit 33 of the image forming unit 21 in the first refresh process. On the other hand, if the image formation process is the monochrome image formation process and the third calculated amount z1 is greater than the first calculated amount x, the third calculated amount z1 of toner is not discharged from the developing unit 33 in the first refresh process. The same applies to the third output amounts z2 and z3 corresponding to the image forming units 22 and 23. Therefore, if any of the third calculated amounts z1 to z3 calculated in step S14 is greater than the first calculated amount x, the setting processing unit 54 changes the shortage flag stored in the storage unit 6 from off to on to execute the refresh process at the end of the print job. As a result, in step S131 described below, it is determined that the shortage flag is on and that the refresh process needs to be executed at the end of the print job.

[0081] In another embodiment, even when the image forming process is the monochrome image forming process, the setting processing unit 54 may set the first discharge amounts α1 to α4 based on whether or not the specific conditions are satisfied, just as when the image forming process is the color image forming process.

[0082] <Step S16> In step S16, the refresh processing unit 52 of the control unit 7 executes the refresh processing between the sheets based on the first discharge amounts α1 to α4 and the second discharge amount β0 set in step S15.

[0083] Specifically, in the first refresh process of the refresh process, the refresh processing unit 52 discharges first discharge amounts α1 to α4 of toner corresponding to the image forming units 21 to 24 from the developing units 33 of the image forming units 21 to 24. For example, in the first refresh process, the refresh processing unit 52 does not apply the charging voltage to the charging rollers 32 of the image forming units 21 to 24 during a period in which a toner layer is formed on the surface of the photosensitive drum 31 of the image forming units 21 to 24 over a distance corresponding to the first discharge amounts α1 to α4. For example, the refresh processing unit 52 does not apply the charging voltage to the charging roller 32 of the image forming unit 21 during a period in which the amount of movement (amount of rotation) of the surface of the photosensitive drum 31 reaches the first discharge amount α1. In addition, the refresh processing unit 52 drives the photosensitive drum 31 in the image forming units 21 to 24 until the toner layer formed on the surface of the photosensitive drum 31 with the toner of the first discharge amounts α1 to α4 is wiped off by the first cleaning member 351 of each of the image forming units 21 to 24.

[0084] Furthermore, in the refresh process, when the first refresh process is completed, the refresh process unit 52 executes the second refresh process. In the second refresh process, the refresh process unit 52 discharges toner of a second discharge amount β0 from the developing unit 33 of the image forming unit 24. For example, in the second refresh process, the refresh process unit 52 does not apply the charging voltage to the charging roller 32 of the image forming unit 24 during a period in which a toner layer is formed on the surface of the photosensitive drum 31 of the image forming unit 24 over a distance corresponding to the second discharge amount β0. For example, the refresh process unit 52 does not apply the charging voltage to the charging roller 32 of the image forming unit 24 during a period in which the amount of movement (amount of rotation) of the surface of the photosensitive drum 31 reaches the second discharge amount β0. Furthermore, the refresh processing unit 52 drives the photosensitive drum 31 and the intermediate transfer belt 26 until a toner layer formed on the surface of the photosensitive drum 31 in the image forming unit 24 with the toner of the second discharge amount β0 is transferred from the photosensitive drum 31 to the intermediate transfer belt 26 and the toner layer is cleaned by the second cleaning member 261. Note that in other embodiments, the order of execution of the first refresh processing and the second refresh processing in the refresh processing may be reversed.

[0085] After that, when the refresh process is completed, the control unit 7 shifts the process to step S17. When the sheet-to-sheet process including the refresh process is executed, the print processing unit 50 of the control unit 7 executes the image forming process based on the image data of the next page after the sheet-to-sheet process is completed.

[0086] <Step S17> In step S17, the refresh processing unit 52 of the control unit 7 resets the monochrome execution count BK1 and the color execution count C1 to "0".

[0087] <Step S121> If it is determined in step S12 that the print job has ended (S12: Yes), the refresh processing unit 52 of the control unit 7 determines in the following step S121 whether the second execution condition is satisfied. If it is determined that the second execution condition is satisfied (S121: Yes), the process proceeds to step S122, and if it is determined that the second execution condition is not satisfied (S121: No), the process proceeds to step S131.

[0088] <Step S131> In step S131, the refresh processing unit 52 of the control unit 7 determines whether the shortage flag is set to ON, i.e., whether the refresh processing needs to be executed at the end of the print job. If it is determined that the shortage flag is ON (S131: Yes), the process proceeds to step S132, and if it is determined that the shortage flag is not ON (S131: No), the refresh control process ends.

[0089] <Step S132> In step S132, the setting processing unit 54 of the control unit 7 executes a setting step of setting first discharge amounts α1 to α4 and second discharge amount β0 in the refresh process executed in step S124, which will be described later, based on the first calculated amount x and the third calculated amounts z1 to z3 in the refresh process executed in step S16. Note that in step S132, the setting processing unit 54 sets the first discharge amount α4 to 0.

[0090] Specifically, the setting processing unit 54 sets the first discharge amounts α1 to α3 corresponding to the image forming units 21 to 23 to values ​​obtained by subtracting the first calculated amount x from the third calculated amounts z1 to z3 in the refresh process. For example, the first discharge amount α1 corresponding to the image forming unit 21 is the value obtained by subtracting the first calculated amount x from the third calculated amount z1. After executing the setting step, the setting processing unit 54 transitions the process to step S124. As a result, when the refresh process is executed in step S124 (described later), the amount of toner that was insufficient with respect to the third calculated amounts z1 to z3 in the refresh process executed in step S16 is discharged from the image forming units 21 to 23.

[0091] <Step S122> In step S122, the calculation processing unit 53 of the control unit 7 executes a calculation step of calculating the first calculation amount x, the second calculation amount y, and the third calculation amounts z1 to z4 based on the above-mentioned equations (1) to (7).

[0092] <Step S123> In step S123, the setting processing unit 54 of the control unit 7 executes a setting step of setting the first discharge amount α0 and the second discharge amount β0 based on the calculation result in step S122. Specifically, the setting processing unit 54 sets the second discharge amount β0 to the second calculated amount y.

[0093] Meanwhile, the setting processing unit 54 calculates the first discharge amount α0 based on the first calculated amount x, the third calculated amounts z1 to z4, and the specific conditions. In step S123, the first discharge amounts α1 to α4 are set using the same setting method whether the image formation process is the color image formation process or the monochrome image formation process. In other embodiments, in step S123 as well, the first discharge amounts α1 to α4 may be set using different setting methods depending on the type of the image formation process, as in step S15.

[0094] Specifically, when the calculation result does not satisfy the specific condition, the setting processing unit 54 sets the first discharge amount α1 to the larger of the first calculated amount x and the third calculated amount z1. Similarly, the setting processing unit 54 sets the first discharge amount α2 to the larger of the first calculated amount x and the third calculated amount z2, sets the first discharge amount α3 to the larger of the first calculated amount x and the third calculated amount z3, and sets the first discharge amount α4 to the larger of the first calculated amount x and the third calculated amount z4.

[0095] Furthermore, when the calculation result satisfies the specific condition, the setting processing unit 54 sets the first discharge amount α1 to the larger of the first calculated amount x and the third calculated amount z1. Similarly, the setting processing unit 54 sets the first discharge amount α2 to the larger of the first calculated amount x and the third calculated amount z2, and sets the first discharge amount α3 to the larger of the first calculated amount x and the third calculated amount z3. Meanwhile, the first discharge amount α4 is set to the larger of the first calculated amount x and the value obtained by subtracting the second calculated amount y from the third calculated amount z4.

[0096] In the above formula (1), if the value A1 is 0.9 [mm] and the number of monochrome runs BK1 at the end of the print job is 15, the first calculated amount x is calculated as 13.5 [mm] by 0.9 × 15. In the above formula (3), if the value A3 is 0.3 [mm] and the number of monochrome runs BK1 at the end of the print job is 15, the second calculated amount y is calculated as 4.5 [mm] by 0.3 × 15. Furthermore, in the above formulas (4) to (7), if the value A4 is 3 [mm] and the cumulative printing rate BK2 is 5 [mm], the third calculated amount z4 is calculated as 30 [mm] by (3 × 15) - (5 × 3). In this case, the setting processing unit 54 sets the first discharge amount α4 to 24.5 [mm], which is the larger of 13.5 [mm], which is the first calculated amount x, and 24.5 [mm], which is the value obtained by subtracting the second calculated amount y from the third calculated amount z4.

[0097] On the other hand, for example, as another method, if the setting processing unit 54 sets the first discharge amount α4 to the third calculated amount z4 and the second discharge amount β0 to the second calculated amount y, the amount of toner consumed in the refresh process will be the sum of the third calculated amount z4 and the second calculated amount y.

[0098] Therefore, when the specific condition is satisfied and the value obtained by subtracting the second calculated amount y from the third calculated amount z4 is equal to or greater than the first calculated amount x, the amount of toner consumed in the refresh process will be reduced by the second calculated amount y depending on the situation compared to the other methods.

[0099] <Step S124> In step S124, similar to step S16, the refresh processing unit 52 of the control unit 7 executes the refresh process based on the first discharge amount α0 and the second discharge amount β0 set in step S123 or step S132. That is, in step S124, the refresh processing unit 52 executes the refresh process at the timing after the print job is completed. After that, when the refresh process is completed, the control unit 7 shifts the process to step S125.

[0100] <Step S125> In step S125, the refresh processing unit 52 of the control unit 7 resets the monochrome execution count BK1 and the color execution count C1 to "0".

[0101] <Step S126> In step S126, if the shortage flag is on, the refresh processing unit 52 of the control unit 7 sets the shortage flag to off, and ends the refresh control process.

[0102] As described above, in the refresh control process, when the specific condition is satisfied, the toner discharge amounts in the first refresh process and the second refresh process are set so that the sum of the first discharge amount α0 and the second discharge amount β0 becomes the third calculated amount z4. That is, the toner discharge amount in the refresh process when the specific condition is satisfied becomes the third calculated amount z4. Therefore, in the image forming apparatus 100 according to this embodiment, the amount of toner consumed in the refresh process can be reduced or increased depending on the situation, compared to when, for example, the first discharge amount α0 is set to the larger of the first calculated amount x and the third calculated amount z4, and the second discharge amount β0 is set to the second calculated amount y.

[0103] [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.

[0104] <Appendix 1> an image forming unit including a photosensitive drum and a developing unit that develops an electrostatic latent image formed on the photosensitive drum with toner, and an image forming unit that includes an intermediate transfer member that transfers the toner image transferred from the photosensitive drum onto a sheet; a first cleaning member that comes into contact with the surface of the photosensitive drum to remove toner from the surface of the photosensitive drum; a second cleaning member that contacts the surface of the intermediate transfer body to remove toner from the surface of the intermediate transfer body; a print processing unit that controls the image forming unit to perform image forming processing to form an image based on image data to be printed; a refresh processing unit that, when a preset execution condition is satisfied, controls the image forming unit at a timing different from that of the image forming process executed by the print processing unit, and executes refresh processing including a first refresh processing in which a preset first discharge amount of toner is discharged from the developing unit to form a toner layer on the photosensitive drum, and a second refresh processing in which a preset second discharge amount of toner is discharged from the developing unit to form a toner layer on the intermediate transfer body; a calculation processing unit that calculates a first calculated amount, which is the amount of toner to be discharged from the developing unit in the first refresh process, a second calculated amount, which is the amount of toner to be discharged from the developing unit in the second refresh process, and a third calculated amount, which is the amount of toner to be discharged from the developing unit in the refresh process, based on a preset calculation formula, respectively; a setting processing unit that, when a calculation result by the calculation processing unit satisfies a predetermined specific condition, sets the first discharge amount and the second discharge amount in the first refresh process and the second refresh process executed by the refresh processing unit to values ​​such that the sum of the first discharge amount and the second discharge amount becomes the third calculated amount; An image forming apparatus comprising:

[0105] <Appendix 2> the specific condition is that the third calculated amount is greater than the first calculated amount, the first calculated amount is greater than the second calculated amount, and the third calculated amount is greater than or equal to the sum of the first calculated amount and the second calculated amount. 2. The image forming apparatus according to claim 1.

[0106] <Appendix 3> When the specific condition is satisfied, the setting processing unit sets the first discharge amount to an amount obtained by subtracting the second calculated amount from the third calculated amount, and sets the second discharge amount to the second calculated amount. 3. The image forming apparatus according to claim 1 or 2.

[0107] <Appendix 4> the image forming section includes a plurality of image forming units corresponding to a plurality of colors, the print processing unit is capable of executing a monochrome image forming process for forming a monochrome image based on the image data, and a color image forming process for forming a color image based on the image data; the execution conditions include a first execution condition for determining whether or not to execute the refresh process after completion of the image forming process based on all the image data included in one print job, and a second execution condition for determining whether or not to execute the refresh process between sheets of paper between the image forming processes based on the image data of different pages included in the print job; the refresh processing unit executes the refresh processing after execution of the print job when the first execution condition is satisfied, and executes the refresh processing between sheets when the second execution condition is satisfied, the refresh processing unit performs the first refresh processing for the plurality of colors in the first refresh processing, and performs the second refresh processing for only the colors used in the monochrome image forming processing in the second refresh processing; the calculation processing unit calculates the first calculation amount and the second calculation amount corresponding to colors used in the monochrome image formation process, the setting processing unit sets the first discharge amount corresponding to a color not used in the monochrome image formation process to the first calculated amount corresponding to a color used in the monochrome image formation process. 4. The image forming apparatus according to claim 1.

[0108] <Appendix 5> the calculation processing unit calculates the third calculation amounts corresponding to the plurality of colors; When the refresh process is executed between the sheets and the third calculated amount corresponding to a color not used in the monochrome image forming process is greater than the first discharge amount, the refresh process is executed after the print job is executed, and in the refresh process, at least an amount of toner obtained by subtracting the first calculated amount from the third calculated amount is discharged from the developing unit. 5. The image forming apparatus according to claim 4.

[0109] <Appendix 6> the first execution condition is that the cumulative number of executions of the image forming process reaches a preset first threshold value when the print job is completed; the second execution condition is that the cumulative number of executions of the image forming process reaches a second threshold value set in advance, the second threshold value being greater than the first threshold value, during execution of the print job; 6. The image forming apparatus according to any one of claims 1 to 5.

[0110] <Appendix 7> a control unit of an image forming apparatus including an image forming unit including a photosensitive drum and a developing unit that develops an electrostatic latent image formed on the photosensitive drum with toner, an image forming unit including an intermediate transfer body that transfers the toner image transferred from the photosensitive drum onto a sheet, a first cleaning member that contacts the surface of the photosensitive drum to remove toner from the surface of the photosensitive drum, and a second cleaning member that contacts the surface of the intermediate transfer body to remove toner from the surface of the intermediate transfer body; a printing step of controlling the image forming unit to perform an image forming process of forming an image based on image data to be printed; a refresh step for executing refresh processes, when a preset execution condition is satisfied, by controlling the image forming unit at a timing different from that of the image forming process executed by the printing step, the refresh process including a first refresh process in which a preset first discharge amount of toner is discharged from the developing unit to form a toner layer on the photosensitive drum, and a second refresh process in which a preset second discharge amount of toner is discharged from the developing unit to form a toner layer on the intermediate transfer body; a calculation step of calculating a first calculated amount, which is the amount of toner to be discharged from the developing unit in the first refresh process, a second calculated amount, which is the amount of toner to be discharged from the developing unit in the second refresh process, and a third calculated amount, which is the amount of toner to be discharged from the developing unit in the refresh process, based on a predetermined calculation formula, respectively; a setting step of setting the first discharge amount and the second discharge amount in the first refresh process and the second refresh process executed in the refresh step to values ​​such that the sum of the first discharge amount and the second discharge amount becomes the third calculated amount when a calculation result in the calculation step satisfies a predetermined specific condition; An image forming program for executing the above. [Explanation of symbols]

[0111] 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 41~44 1st power supply 45 2nd power supply 52 Refresh processing unit 53 Calculation processing unit 54 Setting processing section 100 Image forming device

Claims

1. an image forming unit including a photosensitive drum and a developing unit that develops an electrostatic latent image formed on the photosensitive drum with toner, and an image forming unit that includes an intermediate transfer member that transfers the toner image transferred from the photosensitive drum onto a sheet; a first cleaning member that comes into contact with the surface of the photosensitive drum to remove toner from the surface of the photosensitive drum; a second cleaning member that contacts the surface of the intermediate transfer body to remove toner from the surface of the intermediate transfer body; a print processing unit that controls the image forming unit to perform image forming processing to form an image based on image data to be printed; a refresh processing unit that, when a preset execution condition is satisfied, controls the image forming unit at a timing different from that of the image forming process executed by the print processing unit, and executes refresh processing including a first refresh processing in which a preset first discharge amount of toner is discharged from the developing unit to form a toner layer on the photosensitive drum, and a second refresh processing in which a preset second discharge amount of toner is discharged from the developing unit to form a toner layer on the intermediate transfer body; a calculation processing unit that calculates a first calculated amount, which is the amount of toner to be discharged from the developing unit in the first refresh process, a second calculated amount, which is the amount of toner to be discharged from the developing unit in the second refresh process, and a third calculated amount, which is the amount of toner to be discharged from the developing unit in the refresh process, based on a preset arithmetic expression; a setting processing unit that, when a calculation result by the calculation processing unit satisfies a predetermined specific condition, sets the first discharge amount and the second discharge amount in the first refresh process and the second refresh process executed by the refresh processing unit to values ​​such that the sum of the first discharge amount and the second discharge amount becomes the third calculated amount; An image forming apparatus comprising:

2. the specific condition is that the third calculated amount is greater than the first calculated amount, the first calculated amount is greater than the second calculated amount, and the third calculated amount is greater than or equal to the sum of the first calculated amount and the second calculated amount. The image forming apparatus according to claim 1 .

3. When the specific condition is satisfied, the setting processing unit sets the first discharge amount to an amount obtained by subtracting the second calculated amount from the third calculated amount, and sets the second discharge amount to the second calculated amount. The image forming apparatus according to claim 2 .

4. the image forming section includes a plurality of image forming units corresponding to a plurality of colors, the print processing unit is capable of executing a monochrome image forming process for forming a monochrome image based on the image data, and a color image forming process for forming a color image based on the image data; the execution conditions include a first execution condition for determining whether or not to execute the refresh process after completion of the image formation process based on all the image data included in one print job, and a second execution condition for determining whether or not to execute the refresh process between sheets of paper between the image formation processes based on the image data of different pages included in the print job, the refresh processing unit executes the refresh processing after execution of the print job when the first execution condition is satisfied, and executes the refresh processing between sheets when the second execution condition is satisfied, the refresh processing unit performs the first refresh processing for the plurality of colors in the first refresh processing, and performs the second refresh processing for only the colors used in the monochrome image forming processing in the second refresh processing; the calculation processing unit calculates the first calculation amount and the second calculation amount corresponding to colors used in the monochrome image formation process, the setting processing unit sets the first discharge amount corresponding to a color not used in the monochrome image forming process to the first calculated amount corresponding to a color used in the monochrome image forming process.

4. The image forming apparatus according to claim 1.

5. the calculation processing unit calculates the third calculation amounts corresponding to the plurality of colors; the refresh processing unit, when the refresh processing is executed between the sheets and when the third calculated amount corresponding to a color not used in the monochrome image forming processing is greater than the first discharge amount, executes the refresh processing after execution of the print job, and in the refresh processing, discharges from the developing unit at least an amount of toner obtained by subtracting the first calculated amount from the third calculated amount. The image forming apparatus according to claim 4 .

6. the first execution condition is that the cumulative number of executions of the image forming process reaches a predetermined first threshold value when the print job is completed; the second execution condition is that the cumulative number of executions of the image forming process reaches a second threshold value set in advance, the second threshold value being greater than the first threshold value, during execution of the print job; The image forming apparatus according to claim 4 .

7. a control unit of an image forming apparatus including an image forming unit including a photosensitive drum and a developing unit that develops an electrostatic latent image formed on the photosensitive drum with toner, an image forming unit including an intermediate transfer body that transfers the toner image transferred from the photosensitive drum onto a sheet, a first cleaning member that contacts the surface of the photosensitive drum to remove toner from the surface of the photosensitive drum, and a second cleaning member that contacts the surface of the intermediate transfer body to remove toner from the surface of the intermediate transfer body; a printing step of controlling the image forming unit to perform an image forming process of forming an image based on image data to be printed; a refresh step for executing refresh processes, when a preset execution condition is satisfied, by controlling the image forming unit at a timing different from that of the image forming process executed by the printing step, the refresh process including a first refresh process in which a preset first discharge amount of toner is discharged from the developing unit to form a toner layer on the photosensitive drum, and a second refresh process in which a preset second discharge amount of toner is discharged from the developing unit to form a toner layer on the intermediate transfer body; a calculation step of calculating a first calculated amount, which is the amount of toner to be discharged from the developing unit in the first refresh process, a second calculated amount, which is the amount of toner to be discharged from the developing unit in the second refresh process, and a third calculated amount, which is the amount of toner to be discharged from the developing unit in the refresh process, based on a predetermined arithmetic expression; a setting step of setting the first discharge amount and the second discharge amount in the first refresh process and the second refresh process executed in the refresh step to values ​​such that the sum of the first discharge amount and the second discharge amount becomes the third calculated amount when a calculation result in the calculation step satisfies a predetermined specific condition; An image forming program for executing the above.

Images