JP2010210937A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that suppresses the frequency of interruptions of a printing operation due to adjustments and cleaning operations. <P>SOLUTION: When a certain adjustment and cleaning operation among a plurality of kinds of adjustment and cleaning operations is to be performed in a printer, another adjustment and cleaning operation made to correspond to the certain adjustment and cleaning operation is also performed. For example, if a determination is made that the timing of performing an image stabilizing operation in the printer has reached (S101 to S109), an intermediate rotation blade cleaning and secondary transfer roller cleaning are carried out, together with the image stabilizing operation (S113, S119, S123), if their timings fall within a predetermined time (S111, S117), even if the timings differ from the execution timings. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that performs a plurality of types of adjustment / cleaning operations.

  In image forming apparatuses such as MFP (Multi Function Peripheral), image stabilization operation, ATVC (Auto Transfer Voltage Control) operation, intermediate transfer belt blade cleaning, intermediate transfer belt blade wear countermeasure operation, discharge of deteriorated toner Operations such as operation, toner replenishment operation, intermediate transfer belt cleaning, and secondary transfer roller cleaning may be performed. These operations are operations other than the direct printing operation, and correspond to an adjustment operation and a cleaning operation for performing the printing operation. In the following description, such an operation is referred to as an “adjustment / cleaning operation”. These operations are performed by interrupting the printing operation when it is time to execute during the printing operation. Therefore, it becomes a factor that decreases the productivity of the image forming apparatus.

  Japanese Patent Laying-Open No. 2006-110833 (hereinafter, referred to as Patent Document 1) discloses a printing apparatus that notifies the time required for an operation when the adjustment operation is performed during printing. Thereby, the operator can know the time when the printing operation is interrupted before the start of the adjusting operation.

Japanese Patent Laying-Open No. 2008-83253 (hereinafter, Patent Document 2) discloses an image forming apparatus that calculates an idle time during printing for each toner color and performs an adjustment process for that time. Specifically, the apparatus of Patent Document 2 calculates the idle time of the operation system during printing for each color, and executes adjustment processing for the operation system during the idle time. Thereby, the interruption time of the printing operation can be suppressed. For example, when printing is performed by operating the operation system of each color as follows, the C (cyan) operation system is calculated as the idle time for the second to fourth sheets, and the operation system of C is in the meantime. Run the adjustment process:
1st sheet: YMCK
Second piece: K
3rd sheet: YM K
4th: K
5th sheet: YMCK.

JP 2006-110833 A JP 2008-83253 A

  However, there are a plurality of types of adjustment / cleaning operations in the image forming apparatus as described above, and these operations are performed by interrupting the printing operation at the timing when each operation during printing is required.

  For example, the ATVC operation is executed at the start of printing, when the secondary transfer peripheral temperature changes from the start of printing, and when a predetermined number of continuous sheets (for example, 100 sheets) are printed from the previous operation. Further, for example, the secondary transfer roller cleaning is executed because the secondary transfer roller is stained with fog toner when printing is performed on a predetermined sheet (for example, 200 sheets) while the secondary transfer roller is pressed. Further, for example, the monochrome replenishing operation is an operation for rotating the developing rack to supply toner to the developing roller in a four-cycle machine having no stirring spring in the toner cartridge, and a predetermined amount of toner is supplied during monochrome printing. Executed when consumed.

  It is time to execute any adjustment / cleaning operation during printing. After printing is interrupted and the operation is executed, printing is interrupted for a short time, and printing is interrupted for other adjustment / cleaning operations. It can be executed. Since the secondary transfer ambient temperature has changed, the printing operation is interrupted and the ATVC operation is executed. After printing several sheets, the number of printed sheets reaches a predetermined number (for example, 200 sheets) with the secondary transfer roller pressed. Then, the printing is further interrupted, the secondary transfer roller cleaning is executed, and after that, the monochrome replenishing operation is executed after the printing of several sheets because the monochrome toner is reduced. As described above, when the printing operation is interrupted many times at short time intervals for the adjustment / cleaning operation, that is, when the printing operation is frequently interrupted, the productivity of the image forming apparatus is significantly reduced.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that efficiently performs a plurality of types of adjustment / cleaning operations.

  In order to achieve the above object, according to one aspect of the present invention, an image forming apparatus causes a print operation mechanism, an operation mechanism for a plurality of different types of adjustment / cleaning operations, and an adjustment / cleaning operation to be executed. Control means for controlling the operation mechanism, threshold storage means for storing a threshold value for defining the execution timing for each of a plurality of types of adjustment / cleaning operations, adjustment / cleaning operations, etc. Correspondence storage means for storing the correspondence relationship with the adjustment / cleaning operation, and the control means uses the threshold value to determine the execution timing of the first adjustment / cleaning operation. Determination means for determining the execution timing of the second adjustment / cleaning operation associated with the adjustment / cleaning operation.

  Preferably, when the determination unit determines that the first adjustment / cleaning operation is to be performed, the timing associated with the execution of the first adjustment / cleaning operation is a timing at which the second adjustment / cleaning operation is performed. to decide.

  Preferably, when the determination unit determines that the timing for executing the first adjustment / cleaning operation is the timing for executing the second adjustment / cleaning operation, the first adjustment / cleaning is performed when the timing for executing the second adjustment / cleaning operation is within a predetermined range. The timing related to the execution of the operation is determined as the timing for executing the second adjustment / cleaning operation.

  More preferably, the first adjustment / cleaning operation and the second adjustment / cleaning operation are related to each other, and the timing of executing the second adjustment / cleaning operation related to the execution of the first adjustment / cleaning operation. Is immediately before or after the first adjustment / cleaning operation.

  Alternatively, the first adjustment / cleaning operation and the second adjustment / cleaning operation do not interfere with each other, and the timing of executing the second adjustment / cleaning operation related to the execution of the first adjustment / cleaning operation. Is a timing in parallel with the first adjustment / cleaning operation.

  More preferably, the combination of the first adjustment / cleaning operation and the second adjustment / cleaning operation is a combination including image stabilization operation and intermediate transfer blade cleaning, and ATVC (Auto Transfer Voltage Control) operation. And a combination including intermediate transfer blade cleaning, a combination including ATVC operation and secondary transfer roller cleaning, and a combination including secondary transfer roller cleaning and ATVC operation.

  According to the present invention, in the image forming apparatus that performs a plurality of types of adjustment / cleaning operations, the frequency of interruption of the printing operation can be suppressed.

It is a figure which shows the specific example of the outline of the cross section of the printer concerning embodiment. FIG. 3 is a block diagram illustrating a specific example of a controller configuration of the printer according to the embodiment. FIG. 3 is a block diagram illustrating a specific example of a functional configuration of the printer according to the embodiment. It is a figure which shows the specific example of the sequence of ATVC operation | movement. FIG. 4 is a diagram illustrating a mechanism for pressing and separating an intermediate transfer belt blade from an intermediate transfer belt. FIG. 10 is a diagram illustrating a specific example of a sequence of intermediate transfer belt blade cleaning. It is a figure for demonstrating toner supply operation | movement (monochrome supply rotation operation). It is a figure which shows the specific example of the sequence of a secondary transfer roller cleaning. It is a flowchart which shows the specific example of the flow of a process at the time of an image stabilization operation | movement. It is a flowchart which shows the specific example of the flow of a process at the time of ATVC operation | movement. 10 is a flowchart showing a specific example of a processing flow during an intermediate transfer belt blade wear countermeasure operation. 6 is a flowchart illustrating a specific example of a flow of processing during intermediate transfer belt blade cleaning. It is a flowchart which shows the specific example of the flow of a process at the time of monochrome supply operation | movement. 10 is a flowchart illustrating a specific example of a processing flow during secondary transfer roller cleaning.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

  In the following description, an example in which the image forming apparatus is a color printer (hereinafter, abbreviated as a printer) called a so-called four-cycle machine without a stirring spring in the toner cartridge is shown. A printer having another configuration may be used. Further, the image forming apparatus is not limited to a printer, and is an apparatus that performs an image forming operation and a plurality of types of adjustment / cleaning operations, such as a copying machine, a facsimile machine, and an MFP (Multi Function Peripheral) that is a device combining these functions. Any other device may be used.

  Referring to FIG. 1, a printer 1 according to the present embodiment includes an image forming unit and a paper conveyance unit that is a print medium.

  The image forming unit includes an annular intermediate transfer belt 2 that is an intermediate transfer member and is suspended from the inside by a plurality of rollers, which is disposed at a substantially central portion inside the printer 1. A photosensitive member 3 is disposed in contact with the intermediate transfer belt 2, and a developing rack 20 that rotates is disposed in contact with the photosensitive member 3.

  The developing rack 20 includes cartridges 15Y, 15M, 15C, and 15K corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), and black (K), which are arranged around the rotation axis. The cartridges 15Y, 15M, 15C, and 15K are also referred to as cartridges 15 as representatives. As the developing rack 20 rotates about the axis, the cartridges 15Y, 15M, 15C, and 15K move to the developing position facing the photoconductor 3 in the order in which they are arranged. Each of the cartridges 15 includes a storage unit (hopper) that stores toner, a holding unit (buffer) that holds toner supplied from the hopper, and a developing unit that develops toner in the buffer (see FIG. 7). The developing units are provided with developing rollers 19Y, 19M, 19C, and 19K, respectively. The developing rollers 19Y, 19M, 19C, and 19K are also referred to as the developing roller 19 as a representative. When the cartridge 15 is in the developing position, the developing roller 19 contacts the photoreceptor 3.

  Around the photoreceptor 3, a charging unit 16, an exposure unit 6, and a primary transfer roller 8 are arranged. The charging unit 16 uniformly charges the surface of the photoreceptor 3. The exposure unit 6 exposes an image pattern of each color on the charged photoreceptor 3. The corresponding color developing roller 19 in contact with the photosensitive member 3 supplies toner to the photosensitive member 3 to develop a toner image on the photosensitive member 3. The primary transfer roller 8 is disposed at a position facing the photoconductor 3 with the intermediate transfer belt 2 interposed therebetween. The toner image developed on the photoreceptor 3 is transferred (primary transfer) to the intermediate transfer belt 2 by the primary transfer roller 8. In monochrome printing, a toner image of one color is transferred to the intermediate transfer belt 2, and in color printing, toner images of up to four colors are transferred to the intermediate transfer belt 2 and superimposed.

  The image forming unit further includes an intermediate transfer belt blade 5 and a secondary transfer roller 12 that can be pressed against and separated from the intermediate transfer belt 2 and a fixing roller 13. The secondary transfer roller 12 and the intermediate transfer belt 2 constitute a secondary transfer unit. The toner image on the intermediate transfer belt 2 is transferred (secondary transfer) to the sheet conveyed to the secondary transfer portion by the secondary transfer roller 12. The fixing roller 13 includes a pair of rollers, and forms a fixing unit therebetween. The sheet on which the toner image conveyed to the fixing unit is transferred by the fixing roller 13 is heated to fix the toner image. While the intermediate transfer belt blade 5 is in pressure contact with the intermediate transfer belt 2, the residual toner after the secondary transfer on the intermediate transfer belt 2 is scraped off from the intermediate transfer belt 2 to a waste toner collecting unit (not shown). This mechanism will be described later.

  While the four color toner images are superimposed on the intermediate transfer belt 2 during color printing, the secondary transfer roller 12 and the intermediate transfer belt blade 5 are separated from the intermediate transfer belt 2. The secondary transfer roller 12 is pressed against the intermediate transfer belt 2 until the leading end of the superimposed toner image reaches the secondary transfer portion. After the trailing edge of the superimposed toner image passes through the intermediate transfer belt blade 5, the intermediate transfer belt blade 5 is pressed against the intermediate transfer belt 2.

  The conveyance unit includes a conveyance roller 11, a secondary transfer roller 12, a fixing roller 13, and a paper discharge roller 14 along the conveyance path. The conveyance path is indicated by a dotted line in FIG. The transport roller 11 feeds the sheet 9 in the cassette 10 that is fed by the sheet feed roller and disposed in the lower part of the printer 1 to the secondary transfer composed of the secondary transfer roller 12 and the intermediate transfer belt 2. To the part. The secondary transfer roller 12 conveys the sheet secondarily transferred by the secondary transfer unit to a fixing unit constituted by a pair of fixing rollers 13. The fixing roller 13 conveys the paper on which the toner image is fixed by the fixing unit to the paper discharge roller 14. The paper discharge roller 14 discharges the fixed paper.

  In the vicinity of the secondary transfer roller 12, an environmental sensor 17 for measuring the environmental value of the secondary transfer portion is disposed. The environmental value is an environmental value related to the printing operation, and corresponds to, for example, temperature, humidity, atmospheric pressure, and the like. The environmental sensor 17 measures either of these or a combination thereof. In the following examples, temperature is assumed to be measured.

  A density sensor 18 for measuring the density of the surface of the intermediate transfer belt 2 is disposed near the intermediate transfer belt 2. A preferred example of the density sensor 18 includes a light emitting unit (for example, an LED (Light Emitting Diode)) and a light receiving unit. The light reflected from the light emitting unit to the surface of the intermediate transfer belt 2 is detected by the light receiving unit. Based on the light, the toner concealment rate on the surface of the intermediate transfer belt 2 is measured and detected as the toner density on the intermediate transfer belt 2.

  The printer 1 further includes a controller 100 that controls the entire apparatus. Referring to FIG. 2, a controller 100 includes a CPU (Central Processing Unit) 50, a ROM (Read Only Memory) 51 as a storage device, a RAM (Random Access Memory) 52, and an EEPROM (a type of nonvolatile memory). Electronically Erasable and Programmable Read Only Memory) 53, a density sensor communication unit 54 that is electrically connected to and communicates with the concentration sensor 18, and an environment sensor 17 that is electrically connected to communicate with the sensor. An environmental sensor communication unit 55 for controlling the primary transfer, a primary transfer control unit 56 for controlling primary transfer, a secondary transfer control unit 57 for controlling secondary transfer, and the operation of the intermediate transfer belt blade 5. An intermediate transfer blade controller 58 that controls the operation of the developing rack 20, and a developing rack controller 59 that controls the operation of the developing rack 20. The ROM 51 stores a program executed by the CPU 50. The RAM 52 and the EEPROM 53 store image data to be printed and values necessary for executing the program. The density sensor communication unit 54, the environment sensor communication unit 55, the primary transfer control unit 56, the secondary transfer control unit 57, the intermediate transfer blade control unit 58, and the development rack control unit 59 may all be configured by hardware. However, the CPU 50 may be configured by the CPU 50 executing the program.

  In the printer 1, in addition to the printing operation, as an adjustment operation and a cleaning operation for performing the printing operation, an image stabilization operation, an ATVC (Auto Transfer Voltage Control) operation, and an intermediate transfer belt blade wear countermeasure A plurality of types of operations including an operation, an intermediate transfer belt blade cleaning, a toner supply operation, and a secondary transfer roller cleaning are performed. In the following description, an operation corresponding to an adjustment operation or a cleaning operation for performing such a printing operation is referred to as an “adjustment / cleaning operation”. The adjustment / cleaning operation is not limited to the above operation, and may include other operations such as a deteriorated toner discharging operation, for example. In addition, all the operations above are not necessarily included. The printer 1 only needs to include at least two types of adjustment / cleaning operations.

  The CPU 50 included in the controller 100 executes the program stored in the ROM 51 to determine the timing for executing these operations for each operation, and the operations are executed at the determined timing as shown in FIGS. A control signal is output for each component. FIG. 3 shows functions for controlling execution of the adjustment / cleaning operation. These configurations are mainly configured in the CPU 50 when the CPU 50 executes a program stored in the ROM 51.

  Referring to FIG. 3, the above functions are as follows: determination unit 501, threshold storage unit 502, corresponding operation storage unit 503, and various counters as image stabilization execution counter 504, intermediate transfer blade cleaning counter 505, and secondary transfer. A roller cleaning counter 506, a monochrome replenishment rotation counter 507, a monochrome consumption counter 508, a middle blade wear countermeasure counter 509, and an ATVC execution counter 510 are included.

  The determination unit 501 calculates the number of prints from the signals from the control units and counts them using a necessary counter. The threshold value storage unit 502 stores a threshold value used for determining execution of each operation. The threshold value here is a threshold value for determining the timing for executing the corresponding adjustment / cleaning operation alone, and the adjustment / cleaning operation related to the execution of another corresponding adjustment / cleaning operation described later. It refers to both of the threshold value for determining the timing for executing the operation. The corresponding operation storage unit 503 stores a correspondence relationship with other adjustment / cleaning operations related to the execution timing of the adjustment / cleaning operations described later. The determination unit 501 compares the count value of the counter with the threshold value stored in the threshold value storage unit 502 to determine the execution timing for each of the adjustment / cleaning operations. Further, for other corresponding adjustment / cleaning operations stored in the corresponding operation storage unit 503 for each adjustment / cleaning operation, the count value of the counter is compared with the threshold value stored in the threshold storage unit 502. By doing so, it is determined whether or not execution is necessary. Based on the determination in the determination unit 501, the CPU 50 outputs a control signal for causing the corresponding operation system to perform the adjustment / cleaning operation.

Here, each of the plurality of types of adjustment / cleaning operations will be specifically described.
<Image stabilization operation>
The image stabilization operation includes a density adjustment operation, a laser light amount adjustment operation, and a gamma correction operation. Specifically, the density adjustment operation is an operation for adjusting the density when the developing unit develops the toner image on the photosensitive member 3. Specifically, the density adjustment operation includes a plurality of all pixels on the intermediate transfer belt 2. This is an operation in which dots are formed, so-called solid images are formed at a plurality of different densities, read by the density sensor 18, and the applied voltage of the developing unit is adjusted to a voltage that provides an optimum toner adhesion amount. The laser light amount adjustment operation is an operation for adjusting the laser light amount irradiated to the photosensitive member 3 by the exposure unit 6. The streak pattern is formed with a plurality of different laser light amounts, read by the density sensor 18, and the laser light amount of the exposure unit 6 is adjusted to an appropriate laser light amount capable of forming a thin line. The gamma correction operation is an operation for obtaining data to be used for γ correction. Specifically, the gamma correction image is formed on the intermediate transfer belt 2 with a plurality of patterns and is used by the density sensor 18. This refers to an operation of reading and storing the data for γ correction in a predetermined area of the RAM 52 or the like.

  The image stabilization operation is performed when a new cartridge is installed in the developing rack 20, when a change in the environmental value in the printer 1 is detected by a predetermined amount or more, and every time a predetermined number of sheets are printed from the previous image stabilization operation. To be executed. The predetermined number is 1000 in the following examples.

  Therefore, the determination unit 501 uses the image stabilization execution counter 504 to count the number of printed sheets from the previous image stabilization operation. In addition, the threshold storage unit 502 stores the amount of change in the environmental value and the number of continuous prints (1000 sheets) as thresholds for determining the timing for executing the image stabilization operation alone.

<ATVC operation>
The ATVC operation is to measure a secondary transfer voltage flowing in a state where a constant current is applied to the secondary transfer roller 12 in order to suppress a secondary transfer failure caused by a change in the resistance value of the secondary transfer roller 12. This refers to the operation of determining the secondary transfer voltage to be applied to the secondary transfer roller 12 during printing based on the measured value. Specifically, with reference to FIG. 4, a constant current is applied to the secondary transfer roller 12 in a state where the secondary transfer roller 12 is pressed against the intermediate transfer belt 2. In this state, the secondary transfer voltage is measured. From the measured secondary transfer voltage value, a secondary transfer voltage suitable for the medium (plain paper, cardboard, etc.) and the environment is determined.

  Normally, the ATVC operation is executed when printing is started. However, in a small printer, heat generating parts such as polygon heads and motors are densely packed, so that the temperature rises during printing and the resistance value of the secondary transfer roller 12 is likely to change due to temperature changes. As a result, a secondary transfer failure occurs during printing. In order to prevent the occurrence of this secondary transfer failure, the ATVC operation is executed when the temperature in the vicinity of the secondary transfer roller 12 has changed by a predetermined amount since the previous ATVC operation was executed. The predetermined amount is 5 ° C. in the following examples.

  Further, when the paper is passed many times between a pair of rollers constituting the secondary transfer roller 12, the resistance value of the secondary transfer roller 12 may change. In order to suppress this change in resistance value, the ATVC operation is executed every time a predetermined number of sheets are printed from the previous ATVC operation. The predetermined number is set to 100 in the following examples.

  Therefore, the determination unit 501 uses the ATVC execution counter 510 to count the number of printed sheets from the previous ATVC operation. In addition, the threshold storage unit 502 stores the amount of change in the environmental value and the number of continuous prints (100 sheets) as thresholds for determining the timing for executing the ATVC operation alone.

<Intermediate transfer belt blade wear countermeasure action (Medium transfer blade wear countermeasure action)>
The intermediate transfer belt blade wear countermeasure operation (hereinafter referred to as the intermediate transfer blade wear countermeasure operation) is an intermediate transfer for removing the waste toner accumulated on the tip of the intermediate transfer belt blade 5 that is in pressure contact with the intermediate transfer belt 2. It refers to the operation of pressing and separating the belt blade 5.

  As described above, in the case of color printing, the operation of pressing and separating the intermediate transfer belt blade 5 from the intermediate transfer belt 2 is performed during printing. However, in the case of monochrome continuous printing, the above operation is not performed. 5 is maintained in pressure contact with the intermediate transfer belt 2. When monochrome printing is continued in a state where the intermediate transfer belt blade 5 is in pressure contact with the intermediate transfer belt 2, as shown in FIG. 5A, an intermediate portion that is a pressure contact portion between the intermediate transfer belt blade 5 and the intermediate transfer belt 2 is obtained. Waste toner accumulates on the tip of the transfer belt blade 5 (dotted circle in FIG. 5A). In this case, the waste toner may slip through the intermediate transfer belt blade 5 due to the pressure of the accumulated waste toner. At the time of slipping, the intermediate transfer belt blade 5 is scraped. Further, when the amount of waste toner that slips through increases, the toner on the intermediate transfer belt 2 still remains. The intermediate rotation blade wear countermeasure operation is an operation for preventing the above phenomenon. Specifically, the intermediate transfer belt blade 5 is pressed against and separated from the intermediate transfer belt 2 and is shown in FIG. In this manner, the waste toner accumulated at the tip is screened off.

  The intermediate rotation blade wear countermeasure operation is executed every time a predetermined number of monochrome prints are performed in which the intermediate transfer belt blade 5 is pressed against the intermediate transfer belt 2 and pressed. The predetermined number is 80 in the following examples.

  Therefore, the determination unit 501 uses the intermediate blade wear countermeasure counter 509 to count the continuous number of monochrome prints. The threshold value storage unit 502 stores the number of continuous prints (80 sheets) as a threshold value for determining the timing for executing the intermediate transfer blade wear countermeasure operation alone.

<Intermediate transfer belt blade cleaning (medium blade cleaning)>
Intermediate transfer belt blade cleaning (hereinafter referred to as intermediate transfer blade cleaning) is a secondary process for removing waste toner adhering to the side surface of the intermediate transfer belt blade 5 by utilizing the fact that the waste toner is charged. This refers to an operation in which a negative voltage and a positive voltage are continuously applied to the transfer roller 12.

  When the color printing in which the intermediate transfer belt blade 5 is pressed against and separated from the intermediate transfer belt 2 is continuously performed, a small amount of waste toner flies by the pressure contact and separation operation of the intermediate transfer belt blade 5 to the side surface of the intermediate transfer belt blade 5. Adhere to. When the amount of adhering toner increases, the adhering toner flies due to the charge state between the intermediate transfer belt blade 5 and the intermediate transfer belt 2 and adheres to the intermediate transfer belt 2, thereby causing a smudge of the printed image. Therefore, an operation for removing the waste toner from the intermediate transfer belt blade 5 is required.

  Specifically, in the intermediate transfer blade cleaning, the secondary transfer roller 12 and the intermediate transfer belt blade 5 are pressed against the intermediate transfer belt 2 in a state where the secondary transfer roller 12 and the intermediate transfer belt blade 5 are pressed against the secondary transfer roller 12 for 200 ms as shown in FIG. The voltage application and the + voltage application for 200 ms are repeated. As a result, a positively charged region and a negatively charged region are alternately formed on the intermediate transfer belt blade 5 in pressure contact with the secondary transfer roller 12. Further, a voltage having the same polarity is applied to the primary transfer roller 8 at the timing when this charged region reaches the intermediate transfer belt blade 5. As a result, the waste toner adhering to the intermediate transfer belt blade 5 that is charged to one of the two is adsorbed to the charging area of the intermediate transfer belt 2. By generating a positively charged region and a positively charged region on the intermediate transfer belt 2, waste toner adhering to the periphery of the intermediate transfer belt blade 5 is positively charged even if it is positively charged. However, it is easy to move to the intermediate transfer belt 2. The charged area of the intermediate transfer belt 2 to which the waste toner has adhered passes through the intermediate transfer belt blade 5 to scrape the waste toner, and the intermediate transfer blade cleaning is completed.

  The intermediate transfer blade cleaning is performed every time a predetermined number of color prints are performed in which the intermediate transfer belt blade 5 is pressed against and separated from the intermediate transfer belt 2. The predetermined number is set to 100 in the following examples.

  Therefore, the determination unit 501 counts the continuous number of color prints using the intermediate transfer blade cleaning counter 505. In addition, the threshold storage unit 502 stores the number of continuous prints (100 sheets) as a threshold for determining the timing for performing the intermediate transfer blade cleaning alone.

<Toner supply operation (monochrome supply rotation operation)>
The toner replenishing operation (hereinafter referred to as “monochrome replenishing rotation operation”) refers to an operation of rotating the developing rack 20 once to replenish toner from the toner hopper in the cartridge 15 to the buffer.

  Specifically, referring to FIG. 7, the hatched portion in FIG. 7 of the cartridge 15 corresponds to the hopper, and the other portion corresponds to the buffer. As described above, the printer 1 is not provided with a stirring mechanism for supplying toner from the hopper to the buffer. At the time of color printing, since the developing rack 20 is rotated, the toner moves from the hopper to the buffer, and the toner is supplied to the buffer. However, if monochrome printing without rotation of the developing rack 20 continues, toner is not supplied from the hopper to the buffer, and the toner in the buffer of the cartridge 15K for monochrome printing is insufficient. Insufficient toner in the buffer leads to blurring of the image. Therefore, a monochrome replenishment rotation operation is required.

  The monochrome replenishment rotation operation is necessary when the toner in the buffer of the cartridge 15K is insufficient, and is therefore executed when a predetermined amount of toner is consumed in monochrome continuous printing. The predetermined amount is 4 g in the following examples.

  The toner consumption amount is calculated based on the dot count of the image data. However, there are cases where an error occurs due to an inaccurate calculation of the amount of consumption from the dot count calculated from the image data. Therefore, the monochrome replenishment rotation operation is executed even when a predetermined number of monochrome prints are continuously performed. The predetermined number is 200 in the following examples.

  The determination unit 501 counts the toner consumption using the monochrome consumption counter 508. In addition, the monochrome replenishment rotation counter 507 is used to count the continuous number of monochrome prints. In addition, the threshold storage unit 502 stores toner consumption (4 g) and the number of continuous prints (200) as thresholds for determining the timing for executing the monochrome replenishment rotation operation alone.

<Secondary transfer roller cleaning>
In the secondary transfer roller cleaning, a negative voltage and a positive voltage are applied to the secondary transfer roller 12 in order to remove the toner adhered to the secondary transfer roller 12 by the fog toner using the fact that the toner is charged. It refers to the operation of applying continuously.

  During monochrome printing, the state where the secondary transfer roller 12 is pressed against the intermediate transfer belt 2 is maintained. Therefore, when monochrome printing continues, fog toner adheres to the secondary transfer roller 12 and the backside of the printing paper is generated. . Therefore, secondary transfer roller cleaning is required.

  Specifically, in the secondary transfer roller cleaning, as shown in FIG. 8, with the secondary transfer roller 12 being in pressure contact with the intermediate transfer belt 2, application of a voltage to the secondary transfer roller 12 for 200 ms, The application of + voltage for 200 ms is repeated. As a result, a positively charged region and a negatively charged region are alternately formed on the intermediate transfer belt blade 5 in pressure contact with the secondary transfer roller 12. Toner adhering to the secondary transfer roller 12 that is charged to either is adsorbed to the charging area of the intermediate transfer belt 2. The charged area of the intermediate transfer belt 2 to which the toner has adhered passes further through the intermediate transfer belt blade 5 to scrape off the toner, and the secondary transfer roller cleaning is completed.

  The application of the voltage to the secondary transfer roller 12 in the secondary transfer roller cleaning is the same as the application in the intermediate transfer blade cleaning. Therefore, when the intermediate transfer blade cleaning is executed, there is an effect of the secondary transfer roller cleaning. However, the intermediate transfer blade cleaning is an operation required during color printing. Further, when the intermediate transfer blade cleaning and the operation are combined, it takes a long time to control the application of voltage to the primary transfer roller 8. During continuous printing, secondary transfer roller cleaning different from the intermediate transfer blade cleaning is performed. The secondary transfer roller cleaning is executed every time a predetermined number of monochrome prints are continuously performed. The predetermined number is 200 in the following examples.

  For this reason, the determination unit 501 uses the secondary transfer roller cleaning counter 506 to count the continuous number of monochrome prints. In addition, the threshold storage unit 502 stores the continuous print number (200 sheets) as a threshold value for determining the timing of performing the secondary transfer roller cleaning alone.

  The determination unit 501 determines the execution timing of each operation described above using the counter value in the corresponding counter and the threshold value stored in the threshold value storage unit 502. Furthermore, the execution timing of other adjustment / cleaning operations that are stored in the corresponding operation storage unit 503 and that determine the execution timing in relation to each other is also determined. For example, when a condition for executing a certain adjustment / cleaning operation is satisfied (for example, when the count value reaches a threshold value) and the execution timing is determined, the determination unit 501 relates to the adjustment / cleaning operation. Advance the timing for cleaning the location. Specifically, if the location related to the adjustment / cleaning function is dirty, correct adjustment cannot be performed. Therefore, the timing for executing the cleaning of the location is advanced so that the contamination can be surely removed. In this example, the correspondence operation storage unit 503 stores a correspondence relationship between the adjustment operation and the above-described cleaning operation as an adjustment / cleaning operation related to the operation content.

  Specifically, the correspondence operation storage unit 503 stores the correspondence between the image stabilization operation and the intermediate blade cleaning as the adjustment / cleaning operation related to the operation content, and the threshold storage unit 502 stores the correspondence relationship between the image stabilization operation and the intermediate transfer blade cleaning. Stores a threshold for associating these operations and determining the execution timing. The determination unit 501 refers to these storage units, and when performing the image stabilization operation, if the interval for performing the intermediate transfer blade cleaning is normally 80 sheets, and if color printing is continuously performed on 50 sheets or more, It is determined that the image stabilization is executed after the intermediate transfer blade cleaning is executed.

  In addition, the correspondence operation storage unit 503 stores the correspondence between the ATVC operation and the intermediate transfer blade cleaning as the adjustment / cleaning operation related to the operation content, and the threshold storage unit 502 stores these operations. A threshold value for determining the execution timing in association with each other is stored. When the determination unit 501 refers to these storage units and executes the ATVC operation, similarly, when the interval of executing the intermediate blade cleaning is set to the interval of 80 sheets, and 50 or more color prints are continuously performed, Then, it is determined that the ATVC operation is performed after executing the intermediate blade cleaning.

  Further, the correspondence operation storage unit 503 stores the correspondence between the ATVC operation and the secondary transfer roller cleaning as the adjustment / cleaning operation related to the operation content, and the threshold storage unit 502 stores these operations. Is stored as a threshold for determining the execution timing. The determination unit 501 refers to these storage units, and when executing the ATVC operation, if the interval for executing the secondary transfer roller cleaning is usually 200 sheets, and monochrome printing is continuously performed 100 sheets, the secondary transfer roller cleaning is performed. It is determined that the ATVC operation is performed after the roller cleaning is performed. On the contrary, the determination unit 501 may change the resistance value of the secondary transfer roller 12 when the secondary transfer roller cleaning is performed. Therefore, the secondary transfer roller cleaning is performed regardless of the interval from when the ATVC operation is performed. It is determined that the ATVC operation is executed after executing the above.

  In addition, the correspondence operation storage unit 503 stores a correspondence relationship between a plurality of adjustment / cleaning operations as an adjustment / cleaning operation that is not related to the operation content but can be executed in association with the operation content. Reference numeral 502 stores a threshold value for determining the execution timing in association with these adjustment / cleaning operations. The determination unit 501 refers to these storage units and associates execution timings, thereby preventing a plurality of adjustment / cleaning operations from being executed in a short time. This is because the operation contents are not related to other adjustment / cleaning operations, and other adjustments / cleaning operations are performed at the time of executing an adjustment / cleaning operation even if the adjustment / cleaning operations do not need to be executed simultaneously or sequentially. Since the execution timing of the operation is approaching, and other adjustment / cleaning operations are executed in a short period after the adjustment / cleaning operation is finished, the print job is frequently interrupted. is there. For this reason, the determination unit 501 refers to these storage units and determines that, when executing a certain adjustment / cleaning operation, if the execution timings of other corresponding adjustment / cleaning operations are approaching, they are executed simultaneously or sequentially. In this case, the threshold value storage unit 502 may store a threshold value at which a predetermined number of sheets (for example, 30 sheets) can be continuously printed after a certain adjustment / cleaning operation is completed.

  In this case, the threshold value storage unit 502 may store a print mode (high image quality mode, low image quality mode, etc.) as a threshold value for determining the execution timing. In this case, the determination unit 501 refers to these storage units, and when the timing for executing a certain adjustment / cleaning operation is reached, the timing defined by the number of prints for performing another corresponding adjustment / cleaning operation continues. Even if the threshold value (for example, within 30 sheets) when it is determined to be executed is reached, if the low image quality mode is selected as the print mode, other adjustment / Do not perform the cleaning operation. For example, when the low image quality mode is selected and the timing for executing the image stabilization operation is reached, the timing until the execution of the secondary transfer roller cleaning is stored in relation to the image stabilization operation and the secondary transfer roller cleaning. When the set threshold value (for example, 10 printed sheets) has been reached, the determination unit 501 performs the secondary transfer roller cleaning and the image stabilization operation after printing the remaining 10 sheets.

  The adjustment / cleaning operation may include other adjustment / cleaning operations. In that case, the adjustment / cleaning operation included in the adjustment / cleaning operation for a certain adjustment / cleaning operation is stored in the corresponding operation storage unit 503 as the adjustment / cleaning operation included. When the determination unit 501 refers to the corresponding operation storage unit 503 and determines that it is the timing to execute a certain adjustment / cleaning operation, another adjustment / cleaning operation is stored as an operation included in the adjustment / cleaning operation. Then, it is determined that another adjustment / cleaning operation has been performed at that timing, and the next timing of execution of the other adjustment / cleaning operation is determined.

  As a specific example, the correspondence operation storage unit 503 stores a correspondence relationship between the image stabilization operation and the intermediate rotation cleaner wear countermeasure operation as the included adjustment / cleaning operation. This is because the intermediate transfer belt blade 5 is pressed and separated from the intermediate transfer belt 2 during the image stabilization operation, so that the intermediate transfer cleaner wear countermeasure operation becomes unnecessary. As another example, the correspondence operation storage unit 503 stores a correspondence relationship between the image stabilization operation and the monochrome replenishment rotation operation as the included adjustment / cleaning operation. This is because monochrome toner is supplied from the hopper of the cartridge 15K to the buffer during the image stabilization operation, so that the monochrome supply rotation operation is unnecessary.

  In the following examples, it is assumed that the correspondence operation storage unit 503 stores associations of a plurality of adjustment / cleaning operations for determining the execution timing in association with each other as described above. Since the operation content is exclusive, association of a plurality of adjustment / cleaning operations that are not executed in association with each other may be stored. In that case, the timing of execution is determined in association with the adjustment / cleaning operation not associated with the corresponding operation storage unit 503. Either case is included in the adjustment / cleaning operation stored in association with a certain adjustment / cleaning operation.

  Hereinafter, control for each of a plurality of types of adjustment / cleaning operations will be described with reference to the drawings.

<Image stabilization operation>
Referring to FIG. 9, every time a printing operation is executed in printer 1 (YES in step S101), determination unit 501 adds image stabilization execution counter 504 (step S103), and counts the number of printed sheets. As long as the count value of the image stabilization execution counter 504 has not reached the threshold value of 1000 sheets stored in the threshold value storage unit 502 (“less than 1000 sheets” in step S105), the determination unit 501 Furthermore, whether or not the environmental value change amount input from the environmental sensor communication unit 55 has reached the environmental value change amount stored in the threshold value storage unit 502 (step S107), and a new cartridge is mounted. It is monitored whether it has been done (step S109). If these conditions are not satisfied, the process ends without performing the image stabilization operation.

  When any one of the conditions is satisfied, the determination unit 501 determines the timing of executing the intermediate blade cleaning stored in the corresponding operation storage unit 503 in association with the image stabilization operation. It is confirmed whether or not the count value of the cleaning counter 505 has reached the threshold value 50 stored in the threshold value storage unit 502 as a threshold value used in connection with the image stabilization operation. If the threshold value has been reached (“50 sheets or more” in step S111), the determination unit 501 performs intermediate transfer blade cleaning even if the threshold value for execution alone (100 sheets) has not been reached. Then, a control signal is output from the CPU 50 to a necessary operation system (step S113). In that case, the determination unit 501 resets the intermediate transfer blade cleaning counter 505 (step S115). If the count value of the intermediate transfer blade cleaning counter 505 has not reached the threshold value (“less than 50 sheets” in step S111), the intermediate transfer blade cleaning is not executed.

  Since the intermediate blade cleaning is performed in association with the image stabilization operation, the waste toner adhering to the side surface of the intermediate transfer belt blade 5 during the image stabilization operation is used in the image stabilization operation on the intermediate transfer belt 2. Can be prevented from adhering to the patches for density adjustment, laser light quantity adjustment, and γ adjustment. Thereby, density measurement is correctly performed and the image can be appropriately tuned. In addition, it is possible to suppress a decrease in productivity without intermittently generating interruption of printing for the image stabilization operation and interruption of printing for intermediate transfer blade cleaning.

  In addition, when any of the above conditions is satisfied, the determination unit 501 further determines the timing for executing the secondary transfer roller cleaning stored in the corresponding operation storage unit 503 in association with the image stabilization operation. Whether the count value of the secondary transfer roller cleaning counter 506 has reached the threshold value 170 stored in the threshold value storage unit 502 as a threshold value used in connection with the image stabilization operation. To check. If the threshold value has been reached (“170 sheets or more” in step S117), the determination unit 501 performs the secondary transfer roller cleaning even if the threshold value for execution alone (200 sheets) has not been reached. It is determined to execute, and a control signal is output from the CPU 50 to a necessary operation system (step S119). In that case, the determination unit 501 resets the secondary transfer roller cleaning counter 506 (step S121). When the count value of the secondary transfer roller cleaning counter 506 has not reached the threshold value (“less than 170 sheets” in step S117), the secondary transfer roller cleaning is not executed.

  During the image stabilization operation, various patch densities on the intermediate transfer belt 2 are measured in a state where the secondary transfer roller 12 is separated from the intermediate transfer belt 2, so that the toner adheres to the secondary transfer roller 12. Does not directly affect the image stabilization operation itself. However, since the secondary transfer roller cleaning is performed in association with the image stabilization operation, the printing interruption for the image stabilization operation and the printing interruption for the intermediate transfer blade cleaning are continuously performed at short intervals. Therefore, it is possible to suppress a decrease in productivity. That is, even after the image stabilization operation is performed, for example, 30 sheets are continuously printed without being interrupted for the intermediate blade cleaning.

  Thereafter, after the image stabilization operation is executed in step S123, in step S125, the determination unit 501 stores the monochrome supply rotation operation and the intermediate rotation blade stored as operations included in the image stabilization operation in the corresponding operation storage unit 503. Assuming that the wear countermeasure operation has also been executed, the monochrome replenishment rotation counter 507 and the intermediate rotation blade wear countermeasure counter 509 are reset together with the image stabilization execution counter 504 in order to delay the next execution timing. This is because, in the image stabilization operation, the developing rack 20 rotates to form the adjustment patch for each color, so even if the monochrome toner in the buffer of the cartridge 15K is reduced, it is replenished by the rotation and the monochrome replenishment rotation is performed. This is because no operation is required. Further, since the intermediate transfer belt blade 5 is pressed against and separated from the intermediate transfer belt 2 by the image stabilization operation, waste toner accumulated on the intermediate transfer belt blade 5 is dropped, and measures for wear of the intermediate transfer blade become unnecessary. .

  The corresponding operation storage unit 503 preferably stores the execution order of these operations in addition to the operations corresponding to the image stabilization operations. More preferably, when a plurality of types of adjustment / cleaning operations corresponding to the target adjustment / cleaning operations are performed, and image stabilization operations are included therein, as shown in FIG. Executed most recently. The image stabilization operation is an operation for adjusting various values based on the result of reading the adjustment image on the intermediate transfer belt 2 by the density sensor 18 as described above. Therefore, by performing the image stabilization operation most recently, the stabilization accuracy can be further improved when the adjustment / cleaning operation is completed. This operation order is the same for other adjustment / cleaning operations thereafter.

<ATVC operation>
Referring to FIG. 10, when printing operation is started in printer 1 (YES in step S201), determination unit 501 determines that the amount of change in the environmental value input from environmental sensor communication unit 55 is the threshold storage unit 502. It is confirmed whether or not the amount of change in the environmental value stored in is reached. When the change amount of the environmental value is within the threshold value (“less than 5 ° C.” in step S203), and the printing operation is continuously performed (YES in step S205), determination unit 501 sets ATVC execution counter 510. Addition is performed (step S207), and the number of continuous prints is counted. If printing is not continuously performed (NO in step S205), determination unit 501 clears ATVC execution counter 510 and ends the process. If the count value of the ATVC execution counter 510 has not reached 100, which is the threshold value stored in the threshold value storage unit 502 (“less than 100 sheets” in step S209), the determination unit 501 The process is terminated.

  When the count value of the ATVC execution counter 510 reaches the threshold value (“100 sheets or more” in step S209), the determination unit 501 stores the intermediate transfer stored in association with the ATVC operation in the corresponding operation storage unit 503. In order to determine the timing for executing blade cleaning, the count value of the intermediate blade cleaning counter 505 is a threshold value stored in the threshold value storage unit 502 as a threshold value used in connection with the ATVC operation. Check if a certain 50 sheets have been reached. When the threshold value has been reached (“50 sheets or more” in step S213), the determination unit 501 performs intermediate transfer blade cleaning even if the threshold value for execution alone (100 sheets) has not been reached. Then, the CPU 50 outputs a control signal to the necessary operation system (step S215). In that case, the determination unit 501 resets the intermediate transfer blade cleaning counter 505 (step S217). If the count value of the intermediate transfer blade cleaning counter 505 has not reached the threshold value (“less than 50 sheets” in step S213), the intermediate transfer blade cleaning is not executed.

  By performing the intermediate transfer blade cleaning in association with the ATVC operation, it is possible to prevent the waste toner adhering to the side surface of the intermediate transfer belt blade 5 from adhering to the intermediate transfer belt 2 during the ATVC operation. As a result, toner adhesion to the secondary transfer roller 12 is also prevented, and as a result, contamination on the back side of the printed paper can be prevented.

  Further, since the determination unit 501 determines the timing for executing the secondary transfer roller cleaning stored in the corresponding operation storage unit 503 in association with the ATVC operation, the count value of the secondary transfer roller cleaning counter 506 indicates that the ATVC operation is performed. It is confirmed whether or not the threshold value 100 stored in the threshold value storage unit 502 has been reached as a threshold value used in connection with. If the threshold value has been reached (“100 sheets or more” in step S219), even if the threshold value for executing alone (200 sheets) has not been reached, the determination unit 501 performs secondary transfer roller cleaning. It is determined to execute, and a control signal is output from the CPU 50 to a necessary operation system (step S221). In that case, the determination unit 501 resets the secondary transfer roller cleaning counter 506 (step S223). When the count value of the secondary transfer roller cleaning counter 506 has not reached the threshold value (“less than 100 sheets” in step S219), the secondary transfer roller cleaning is not executed.

  By performing the secondary transfer roller cleaning in association with the ATVC operation, the voltage of the secondary transfer roller 12 is correctly measured in the ATVC operation, and the optimum secondary transfer voltage is determined.

  Further, the determination unit 501 determines the timing for executing the monochrome supply rotation operation stored in the corresponding operation storage unit 503 in association with the ATVC operation, so that the count value of the monochrome supply rotation counter 507 is related to the ATVC operation. It is confirmed whether or not the threshold value 170 stored in the threshold value storage unit 502 has been reached as the threshold value used in the above. When the threshold value has been reached (“170 sheets or more” in step S225), the determination unit 501 executes the monochrome replenishment rotation operation even if the threshold value for independent execution (200 sheets) has not been reached. Then, the CPU 50 outputs a control signal to the necessary operation system (step S227). In that case, the determination unit 501 resets the monochrome supply rotation counter 507 (step S229). If the count value of the monochrome supply rotation counter 507 has not reached the threshold value (“less than 170 sheets” in step S225), the monochrome supply rotation operation is not executed.

  Although the operation contents of the ATVC operation and the monochrome supply rotation operation are not related, the monochrome supply rotation operation is performed in association with the ATVC operation, thereby interrupting the printing for the ATVC operation and the printing for the monochrome supply rotation operation. It is possible to suppress a decrease in productivity without causing interruptions to occur continuously at short intervals. That is, even after the ATVC operation is executed, for example, 30 sheets are continuously printed without being interrupted by the monochrome supply rotation operation.

  Thereafter, the ATVC operation is executed in step S231, and at the same time, the ATVC execution counter 510 is reset.

  After the ATVC operation, the determination unit 501 counts the intermediate rotation blade wear countermeasure counter 509 in order to determine the timing of executing the intermediate rotation blade wear countermeasure operation stored in the corresponding operation storage unit 503 in association with the ATVC operation. It is confirmed whether or not the value has reached the threshold value of 70 sheets stored in the threshold value storage unit 502 as a threshold value used in connection with the ATVC operation. If the threshold value has been reached (“70 sheets or more” in step S233), even if the threshold value for execution alone (80 sheets) has not been reached, the determination unit 501 performs the intermediate rotation blade wear countermeasure operation. The CPU 50 outputs a control signal to the necessary operation system (step S235). In that case, the determination unit 501 resets the intermediate rotation blade wear countermeasure counter 509 (step S237). When the count value of the intermediate transfer blade wear countermeasure counter 509 has not reached the threshold value (“less than 70 sheets” in step S233), the intermediate transfer blade wear countermeasure operation is not executed.

  Although the operation contents of the ATVC operation and the intermediate rotation blade wear countermeasure operation are not related, the intermediate rotation blade wear countermeasure operation is performed in association with the ATVC operation, thereby interrupting printing for the ATVC operation and the intermediate rotation blade wear. It is possible to suppress a decrease in productivity without continuously interrupting printing for a countermeasure operation at short intervals.

  Further, the determination unit 501 determines the timing for executing the image stabilization operation stored in the corresponding operation storage unit 503 in association with the ATVC operation, so that the count value of the image stabilization execution counter 504 is the ATVC operation. It is confirmed whether or not the threshold value stored in the threshold value storage unit 502 as the threshold value used in connection with 970 has been reached. When the threshold value has been reached (“970 sheets or more” in step S239), the determination unit 501 executes the image stabilization operation even if the threshold value for executing alone (1000 sheets) has not been reached. Then, the CPU 50 outputs a control signal to the necessary operation system (step S241). In that case, the determination unit 501 resets the image stabilization execution counter 504 (step S243). If the count value of the image stabilization execution counter 504 has not reached the threshold value (“less than 970 sheets” in step S239), the image stabilization operation is not executed.

  Although the operation contents of the ATVC operation and the image stabilization operation are not related, the image stabilization operation is performed in association with the ATVC operation, thereby interrupting the printing for the ATVC operation and the printing for the image stabilization operation. It is possible to suppress a decrease in productivity without causing interruptions to occur continuously at short intervals.

<Medium rotation blade wear countermeasure action>
Referring to FIG. 11, when monochrome printing is continuously performed by printer 1, every time a printing operation is performed (YES in step S <b> 301), determination unit 501 causes intermediate rotation blade wear countermeasure counter 509. Addition is performed (step S303), and the number of continuously printed sheets is counted. When monochrome printing is not continuously performed (NO in step S301), the determination unit 501 clears the intermediate rotation blade wear countermeasure counter 509 and ends the process.

  When the count value of the intermediate rotation blade wear countermeasure counter 509 reaches 80, which is the threshold value stored in the threshold value storage unit 502 (“80 or more” in step S307), the determination unit 501 In order to determine the timing for executing the monochrome replenishment rotation operation stored in the operation storage unit 503 in association with the intermediate rotation blade wear countermeasure operation, first, the count value of the image stabilization execution counter 504 is determined by the intermediate rotation blade wear. It is checked whether or not the threshold value stored in the threshold value storage unit 502 as the threshold value used in connection with the countermeasure action has reached 970 sheets. If the threshold value has not been reached (“less than 970 sheets” in step S309), the count value of the monochrome replenishment rotation counter 507 is the threshold value used in connection with the intermediate rotation blade wear countermeasure operation. It is confirmed whether or not the threshold value 170 stored in the value storage unit 502 has been reached. If the threshold value has been reached (“170 sheets or more” in step S311), the determination unit 501 executes the monochrome replenishment rotation operation even if the threshold value for execution alone (200 sheets) has not been reached. Then, a control signal is output from the CPU 50 to a necessary operation system (step S313). In that case, the determination unit 501 resets the monochrome supply rotation counter 507 (step S315). If the count value of the monochrome supply rotation counter 507 has not reached the threshold value (“less than 170 sheets” in step S311), the monochrome supply rotation operation is not executed.

  The operation contents of the intermediate rotation blade wear countermeasure operation and the monochrome replenishment rotation operation are not related, but the monochrome replenishment rotation operation is performed in association with the intermediate transfer blade wear countermeasure operation, so that printing is performed for the intermediate rotation blade wear countermeasure operation. Immediately after the operation is interrupted, it is possible to prevent the printing operation from being interrupted due to the monochrome replenishment rotation operation, and it is possible to suppress a decrease in productivity. In other words, even after the intermediate rotation blade wear countermeasure operation is executed, for example, 30 sheets are continuously printed without being interrupted by the monochrome supply rotation operation.

  Thereafter, the intermediate blade wear countermeasure operation is executed in step S317, and the intermediate blade wear countermeasure counter 509 is reset in step S319.

  Even when the count value of the intermediate rotation blade wear countermeasure counter 509 has reached 80, which is the threshold value stored in the threshold value storage unit 502, the count value of the image stabilization execution counter 504 Has reached the threshold value of 970 sheets stored in the threshold value storage unit 502 as the threshold value used in connection with the intermediate rotation blade wear countermeasure operation (“80 sheets or more” in step S307). In step S309, “970 sheets or more”), the determination unit 501 skips the monochrome supply rotation operation in step S313 and the intermediate blade wear countermeasure operation in step S317. In the image stabilization operation, the developing rack 20 rotates to form the adjustment patch for each color, so even if the monochrome toner in the buffer of the cartridge 15K is reduced, it is replenished by the rotation. Further, since the intermediate transfer belt blade 5 is pressed and separated from the intermediate transfer belt 2 by the image stabilization operation, the waste toner accumulated on the intermediate transfer belt blade 5 is dropped. For this reason, by performing the image stabilization operation, the same effect as when these operations are performed can be obtained, and these operations can be made unnecessary.

  After the intermediate rotation blade wear countermeasure operation, the determination unit 501 determines the timing for executing the secondary transfer roller cleaning stored in the corresponding operation storage unit 503 in association with the intermediate transfer blade wear countermeasure operation. Whether or not the count value of the transfer roller cleaning counter 506 has reached the threshold value 170 stored in the threshold value storage unit 502 as a threshold value used in connection with the intermediate blade wear countermeasure operation Confirm. If the threshold value has been reached (“170 sheets or more” in step S321), the determination unit 501 performs the secondary transfer roller cleaning even if the threshold value for executing alone (200 sheets) has not been reached. It is determined to execute, and a control signal is output from the CPU 50 to a necessary operation system (step S323). In that case, the determination unit 501 resets the secondary transfer roller cleaning counter 506 (step S325). When the count value of the secondary transfer roller cleaning counter 506 has not reached the threshold value (“less than 170 sheets” in step S321), the secondary transfer roller cleaning is not executed.

  The operation contents of the intermediate transfer blade wear countermeasure operation and the secondary transfer roller cleaning are not related, but the secondary transfer roller cleaning is performed in association with the intermediate transfer blade wear countermeasure operation, so that the intermediate transfer blade wear countermeasure operation is performed. Immediately after the printing operation is interrupted, it is possible to prevent the printing operation from being interrupted for cleaning the secondary transfer roller, and it is possible to suppress a decrease in productivity. In other words, even after the intermediate transfer blade wear countermeasure operation is performed, for example, 30 sheets are continuously printed without being interrupted for the secondary transfer roller cleaning.

  Further, the determination unit 501 determines the timing for executing the ATVC operation stored in the corresponding operation storage unit 503 in association with the intermediate rotation blade wear countermeasure operation, so that the count value of the ATVC execution counter 510 indicates the intermediate rotation blade wear. It is confirmed whether or not the threshold value 70 stored in the threshold value storage unit 502 is reached as a threshold value used in connection with the countermeasure action. If the threshold value has been reached (“70 sheets or more” in step S327), the determination unit 501 determines that the ATVC operation is to be executed even if the threshold value for execution alone (100 sheets) has not been reached. Then, a control signal is output from the CPU 50 to a necessary operation system (step S329). In that case, the determination unit 501 resets the ATVC execution counter 510 (step S331). If the count value of the ATVC execution counter 510 has not reached the threshold value (“less than 70 sheets” in step S327), the ATVC operation is not executed.

  The operation contents of the intermediate rotation blade wear countermeasure operation and the ATVC operation are not related, but the ATVC operation is performed in association with the intermediate transfer blade wear countermeasure operation, so that the printing operation is interrupted for the intermediate transfer blade wear countermeasure operation. Immediately after that, it is possible to prevent the printing operation from being interrupted due to the ATVC operation, and it is possible to suppress a decrease in productivity. That is, for example, 30 sheets are continuously printed without being interrupted by the ATVC operation even after the intermediate blade blade wear countermeasure operation is executed.

  Further, the determination unit 501 determines the timing for executing the image stabilization operation stored in the corresponding operation storage unit 503 in association with the intermediate rotation blade wear countermeasure operation, so that the count value of the image stabilization execution counter 504 is It is confirmed whether or not the threshold value 970 sheets stored in the threshold value storage unit 502 has been reached as a threshold value used in connection with the intermediate rotation blade wear countermeasure operation. If the threshold value has been reached (“970 sheets or more” in step S333), the determination unit 501 performs the image stabilization operation even if the threshold value for executing alone (1000 sheets) has not been reached. Then, the CPU 50 outputs a control signal to the necessary operation system (step S335). In that case, the determination unit 501 resets the image stabilization execution counter 504 (step S337). If the count value of the image stabilization execution counter 504 has not reached the threshold value (“less than 970 sheets” in step S333), the image stabilization operation is not executed.

  The operation contents of the intermediate rotation blade wear countermeasure operation and the image stabilization operation are not related, but the image stabilization operation is performed in association with the intermediate transfer blade wear countermeasure operation, so that printing is performed for the intermediate rotation blade wear countermeasure operation. Immediately after the operation is interrupted, it is possible to prevent the printing operation from being interrupted for the image stabilization operation, and it is possible to suppress a decrease in productivity. That is, even after the intermediate blade wear countermeasure operation is executed, for example, 30 sheets are continuously printed without being interrupted for the image stabilization operation.

  Note that the intermediate transfer blade wear countermeasure operation is an operation that is performed when monochrome printing in which the intermediate transfer belt blade 5 is not pressed against and separated from the intermediate transfer belt 2 continues, and when color printing that is separated from the pressure contact is continued. This is in an exclusive relationship with the intermediate rotation blade cleaning that is performed. Therefore, the intermediate rotation blade cleaning is not associated with the intermediate rotation blade wear countermeasure operation in the corresponding operation storage unit 503, and the execution timing of the intermediate rotation blade cleaning is not determined when the intermediate rotation blade wear countermeasure operation is performed.

<Central rotation blade cleaning>
Referring to FIG. 12, when color printing is performed in which intermediate transfer belt blade 5 is pressed and separated from intermediate transfer belt 2 (YES in step S401), determination unit 501 determines intermediate transfer blade cleaning counter 505 for each printing. Are added (step S403), and the number of continuous prints is counted. If color printing is not continuously performed (NO in step S401), the determination unit 501 clears the intermediate transfer blade cleaning counter 505 and ends the process.

  When the count value of the intermediate transfer blade cleaning counter 505 reaches 100, which is the threshold value stored in the threshold value storage unit 502 (“100 or more” in step S407), the determination unit 501 In order to determine the timing for executing the monochrome replenishment rotation operation stored in the storage unit 503 in association with the intermediate rotation blade cleaning, first, the count value of the image stabilization execution counter 504 is related to the intermediate rotation blade cleaning. It is confirmed whether or not the threshold value stored in the threshold value storage unit 502 has reached 970 sheets. If the threshold value has not been reached (“less than 970 sheets” in step S409), the count value of the monochrome replenishment rotation counter 507 is stored as a threshold value used in connection with the intermediate blade cleaning. It is confirmed whether or not the threshold value 170 stored in the section 502 has been reached. If the threshold value has been reached (“170 sheets or more” in step S411), the determination unit 501 executes the monochrome replenishment rotation operation even if the threshold value for execution alone (200 sheets) has not been reached. Then, the CPU 50 outputs a control signal to the necessary operation system (step S413). In that case, the determination unit 501 resets the monochrome supply rotation counter 507 (step S415). If the count value of the monochrome supply rotation counter 507 has not reached the threshold value (“less than 170 sheets” in step S411), the monochrome supply rotation operation is not executed.

  As described above, the monochrome replenishment rotation operation is performed when the toner in the buffer of the cartridge 15K becomes insufficient due to continuous monochrome printing. On the other hand, the intermediate transfer blade cleaning is executed when color printing is continuously performed as described above. Therefore, these operations are in an exclusive relationship and do not need to be executed simultaneously. However, in the case of printing on thick paper or the like even in monochrome printing, there are cases where the fixing property is secured by lowering the conveyance speed at the time of fixing than that of plain paper depending on the thickness of the paper. When the conveyance speed is lower than that of the plain paper, the conveyance speed is the same as that of the plain paper until the image is transferred to the intermediate transfer belt 2, and then the intermediate transfer belt 2 is rotated idly by one rotation. During this, the transfer speed is lowered to perform secondary transfer and fixing. In this way, when fixing is performed by reducing the conveyance speed, the intermediate transfer belt blade 5 is intermediate-transferred before the leading edge of the image reaches the intermediate transfer belt blade 5 during idling to reduce the conveyance speed even in monochrome printing. The intermediate transfer belt blade 5 is controlled so as to be separated from the belt 2 and press the intermediate transfer belt blade 5 after the rear end of the image passes. Therefore, in such a case, intermediate blade cleaning is required even for monochrome printing. Therefore, preferably, the determination unit 501 uses the intermediate transfer blade cleaning counter 505 to count the number of continuous prints in the thick paper mode.

  In monochrome printing in the thick paper mode, the monochrome replenishment rotation operation is performed in association with the intermediate transfer blade cleaning, so that the monochrome replenishment rotation operation is performed within the predetermined range at the time when the intermediate transfer blade cleaning is executed (remaining When the number of sheets is 30 or less), a monochrome replenishment rotation operation is performed in parallel with the intermediate rotation blade cleaning, and a reduction in productivity can be suppressed.

  When the count value of the image stabilization execution counter 504 reaches 970 sheets which is a threshold value stored in the threshold value storage unit 502 as a threshold value used in connection with the intermediate blade cleaning. In addition, the monochrome replenishment rotation operation in step S413 is not executed (“more than 970 sheets” in S409). In the image stabilization operation, the developing rack 20 rotates to form the adjustment patch for each color, so even if the monochrome toner in the buffer of the cartridge 15K is reduced, it is replenished by the rotation. For this reason, by performing the image stabilization operation, the same effect as when the monochrome supply rotation operation is performed can be obtained, and the operation can be made unnecessary.

  Thereafter, the intermediate transfer blade cleaning is executed in step S417, and the intermediate transfer blade cleaning counter 505 is reset in step S419.

  After the intermediate transfer blade cleaning, the determination unit 501 determines the timing for executing the ATVC operation stored in the corresponding operation storage unit 503 in association with the intermediate transfer blade cleaning. It is confirmed whether or not the threshold value 70 stored in the threshold value storage unit 502 has been reached as a threshold value used in connection with the intermediate blade cleaning. If the threshold value has been reached (“70 sheets or more” in step S421), the determination unit 501 determines that the ATVC operation is to be executed even if the threshold value for execution alone (100 sheets) has not been reached. Then, a control signal is output from the CPU 50 to a necessary operation system (step S423). In that case, the determination unit 501 resets the ATVC execution counter 510 (step S425). If the count value of the ATVC execution counter 510 has not reached the threshold value (“less than 70 sheets” in step S421), the ATVC operation is not executed.

  If the intermediate transfer blade cleaning is necessary during the execution of the ATVC operation, the waste toner adhering to the intermediate transfer belt blade 5 flies and adheres to the secondary transfer roller 12, and the voltage of the secondary transfer roller 12 is not correctly measured. . Therefore, the ATVC operation is not executed at the timing of executing the intermediate blade cleaning. However, since the ATVC operation is executed in association with the intermediate transfer blade cleaning, it is possible to prevent the print operation from being interrupted due to the ATVC operation immediately after the print operation is interrupted due to the intermediate transfer blade cleaning. , Productivity reduction can be suppressed. That is, even after the intermediate transfer blade cleaning is performed, for example, 30 sheets are continuously printed without being interrupted by the ATVC operation.

  Further, the determination unit 501 determines the timing of executing the image stabilization operation stored in the corresponding operation storage unit 503 in association with the intermediate blade cleaning, so that the count value of the image stabilization execution counter 504 is It is confirmed whether or not the threshold value stored in the threshold value storage unit 502 as the threshold value used in connection with blade cleaning reaches 970 sheets. When the threshold value has been reached (“970 sheets or more” in step S427), the determination unit 501 executes the image stabilization operation even if the threshold value for executing alone (1000 sheets) has not been reached. Thus, the CPU 50 outputs a control signal to the necessary operating system (step S429). In that case, the determination unit 501 resets the image stabilization execution counter 504 (step S431). If the count value of the image stabilization execution counter 504 has not reached the threshold value (“less than 970 sheets” in step S427), the image stabilization operation is not executed.

  The operation contents of the intermediate rotation blade wear countermeasure operation and the image stabilization operation are not related, but the image stabilization operation is performed in association with the intermediate transfer blade wear countermeasure operation, so that printing is performed for the intermediate rotation blade wear countermeasure operation. Immediately after the operation is interrupted, it is possible to prevent the printing operation from being interrupted for the image stabilization operation, and it is possible to suppress a decrease in productivity. That is, even after the intermediate blade wear countermeasure operation is executed, for example, 30 sheets are continuously printed without being interrupted for the image stabilization operation.

  If the intermediate transfer blade cleaning is necessary during the image stabilization operation, the waste toner adhering to the intermediate transfer belt blade 5 flies and adheres to the intermediate transfer belt 2 for density adjustment and laser light quantity adjustment. The patch for γ correction is not detected correctly. Therefore, as described above, at the timing of executing the image stabilization operation, when the intermediate transfer blade cleaning is necessary, the intermediate transfer blade cleaning is executed (steps S111 to S115 described above). There is no need to perform an image stabilization operation at the timing of executing blade cleaning. However, since the image stabilization operation is executed in association with the intermediate transfer blade cleaning, the print operation is interrupted for the image stabilization operation immediately after the print operation is interrupted for the intermediate transfer blade cleaning. Can be prevented, and a decrease in productivity can be suppressed. That is, even after the intermediate transfer blade cleaning is performed, for example, 30 sheets are continuously printed without being interrupted for the image stabilization operation.

  Note that the intermediate transfer blade wear countermeasure operation is an operation that is performed when monochrome printing in which the intermediate transfer belt blade 5 is not pressed against and separated from the intermediate transfer belt 2 continues, and when color printing that is separated from the pressure contact is continued. This is in an exclusive relationship with the intermediate rotation blade cleaning that is performed. For this reason, in the corresponding operation storage unit 503, the intermediate rotation blade wear countermeasure action is not associated with the intermediate rotation blade cleaning, and the execution timing of the intermediate transfer blade wear countermeasure action is not determined when executing the intermediate blade cleaning.

  Similarly, the secondary transfer roller cleaning is necessary when monochrome printing is continuously performed while the secondary transfer roller 12 is pressed against the intermediate transfer belt 2. The state in which the secondary transfer roller 12 is in pressure contact with the intermediate transfer belt 2 is maintained in a mode in which the intermediate transfer belt 2 is not idling while the image is transferred onto the intermediate transfer belt 2. The belt blade 5 remains pressed against the intermediate transfer belt 2. On the other hand, the intermediate transfer blade cleaning is necessary when color printing that repeats the press contact and separation of the intermediate transfer belt blade 5 to the intermediate transfer belt 2 is continuously performed. Therefore, these operations are in an exclusive relationship and need not be executed simultaneously.

<Monochrome replenishment rotation operation>
Referring to FIG. 13, when monochrome printing is continuously performed (YES in step S501), determination unit 501 increments monochrome supply rotation counter 507 for each printing (step S503), and counts the number of continuously printed sheets. To do. Further, the determination unit 501 calculates the consumption amount of monochrome toner based on the number of dots, adds the monochrome consumption amount counter 508 (step S505), and counts the consumption amount. If monochrome printing is not continuous (NO in step S501), the determination unit 501 resets the monochrome supply rotation counter 507 and the monochrome consumption counter 508 (steps S507 and S509).

  When the count value of the monochrome replenishment rotation counter 507 reaches 200, which is the threshold value stored in the threshold value storage unit 502, or the count value of the monochrome consumption counter 508 is stored in the threshold value storage unit 502 When the threshold value of 4 g is reached (YES in step S511), the determination unit 501 first determines the threshold value at which the count value of the image stabilization execution counter 504 is used in connection with the monochrome replenishment rotation operation. It is confirmed whether or not the threshold value stored in the threshold value storage unit 502 has reached 970 sheets. If the threshold value has not been reached (“less than 970 sheets” in step S513), the monochrome supply rotation operation is executed in step S515, and the monochrome supply rotation counter 507 is reset in step S517.

  Thereafter, the determination unit 501 determines the timing of executing the intermediate rotation blade wear countermeasure operation stored in the corresponding operation storage unit 503 in association with the monochrome replenishment rotation operation. Whether or not the threshold value stored in the threshold value storage unit 502 is 70 as a threshold value used in connection with the monochrome replenishment rotation operation. If the threshold value has been reached (“70 sheets or more” in step S519), even if the threshold value for execution alone (80 sheets) has not been reached, the determination unit 501 performs the intermediate rotation blade wear countermeasure operation. The CPU 50 outputs a control signal to the necessary operating system (step S521). In that case, the determination unit 501 resets the intermediate rotation blade wear countermeasure counter 509 (step S523). If the count value of the intermediate transfer blade wear countermeasure counter 509 has not reached the threshold value (“less than 70 sheets” in step S519), the intermediate transfer blade wear countermeasure operation is not executed.

  Although the operation contents of the monochrome replenishment rotation operation and the intermediate rotation blade wear countermeasure operation are not related, the intermediate rotation blade wear countermeasure operation is performed in association with the monochrome replenishment rotation operation, so that the printing operation can be performed for the monochrome replenishment rotation operation. Immediately after the interruption, it is possible to prevent the printing operation from being interrupted due to the intermediate blade wear countermeasure operation, and it is possible to suppress a decrease in productivity. That is, even after the monochrome replenishment rotation operation is performed, for example, 30 sheets are continuously printed without being interrupted for the intermediate blade blade wear countermeasure operation.

  Note that when the count value of the monochrome replenishment rotation counter 507 reaches 200, which is the threshold value stored in the threshold value storage unit 502, or the count value of the monochrome consumption counter 508 is equal to the threshold value storage unit 502. Even when the threshold value 4g, which is stored in the table, is reached, the count value of the image stabilization execution counter 504 is used as a threshold value used in connection with the monochrome replenishment rotation operation. When the threshold value of 970 sheets is reached (YES in step S511 and “970 sheets or more” in step S513), the determination unit 501 performs the monochrome replenishment rotation operation in step S515, and the step S515. In S521, the intermediate rotation blade wear countermeasure operation is skipped. In the image stabilization operation, the developing rack 20 rotates to form the adjustment patch for each color, so even if the monochrome toner in the buffer of the cartridge 15K is reduced, it is replenished by the rotation. Further, since the intermediate transfer belt blade 5 is pressed and separated from the intermediate transfer belt 2 by the image stabilization operation, the waste toner accumulated on the intermediate transfer belt blade 5 is dropped. For this reason, by performing the image stabilization operation, the same effect as when these operations are performed can be obtained, and these operations can be made unnecessary.

  Further, since the determination unit 501 determines the timing for executing the secondary transfer roller cleaning stored in the corresponding operation storage unit 503 in association with the monochrome replenishment rotation operation, the count value of the secondary transfer roller cleaning counter 506 is It is confirmed whether or not the threshold value 170 stored in the threshold value storage unit 502 has been reached as a threshold value used in connection with the monochrome replenishment rotation operation. If the threshold value has been reached (“170 sheets or more” in step S525), the determination unit 501 performs the secondary transfer roller cleaning even if the threshold value for execution alone (200 sheets) has not been reached. The CPU 50 determines that it is to be executed, and outputs a control signal to the necessary operating system from the CPU 50 (step S527). In that case, the determination unit 501 resets the secondary transfer roller cleaning counter 506 (step S529). Note that even if the developing rack 20 is rotated by the monochrome replenishment rotation operation during the secondary transfer roller cleaning, there is no problem in the secondary transfer roller cleaning. Therefore, these operations may be performed in parallel. If the count value of the secondary transfer roller cleaning counter 506 has not reached the threshold value (“less than 170 sheets” in step S525), the secondary transfer roller cleaning is not executed.

  Although the operation contents of the monochrome supply rotation operation and the secondary transfer roller cleaning are not related, the secondary transfer roller cleaning is performed in association with the monochrome supply rotation operation, so that the printing operation is interrupted due to the monochrome supply rotation operation. Immediately after that, it is possible to prevent the printing operation from being interrupted for cleaning the secondary transfer roller, and it is possible to suppress a decrease in productivity. That is, even after the monochrome replenishment rotation operation is performed, for example, 30 sheets are continuously printed without being interrupted for the secondary transfer roller cleaning.

  Further, the determination unit 501 determines the timing for executing the ATVC operation stored in association with the monochrome replenishment rotation operation in the corresponding operation storage unit 503, so that the count value of the ATVC execution counter 510 is equal to the monochrome replenishment rotation operation. It is confirmed whether or not the threshold value 70 stored in the threshold value storage unit 502 has been reached as a threshold value used in relation. When the threshold value has been reached (“70 sheets or more” in step S531), the determination unit 501 determines that the ATVC operation is to be executed even if the threshold value for executing alone (100 sheets) has not been reached. Then, a control signal is output from the CPU 50 to a necessary operation system (step S533). In that case, the determination unit 501 resets the ATVC execution counter 510 (step S535). Note that even if the developing rack 20 is rotated by the monochrome supply rotation operation during the ATVC operation, there is no problem with the ATVC operation, and therefore these operations may be executed in parallel. If the count value of the ATVC execution counter 510 has not reached the threshold value (“less than 70 sheets” in step S531), the ATVC operation is not executed.

  Although the operation contents of the monochrome supply rotation operation and the ATVC operation are not related, the ATVC operation is performed in association with the monochrome supply rotation operation, so that the ATVC operation is performed immediately after the printing operation is interrupted for the monochrome supply rotation operation. For this reason, it is possible to prevent the printing operation from being interrupted, and to suppress a decrease in productivity. That is, even after the monochrome replenishment rotation operation is performed, for example, 30 sheets are continuously printed without being interrupted by the ATVC operation.

  Further, the determination unit 501 determines the timing for executing the image stabilization operation stored in the corresponding operation storage unit 503 in association with the monochrome supply rotation operation. It is confirmed whether or not the threshold value 970 sheets stored in the threshold value storage unit 502 is reached as a threshold value used in connection with the rotation operation. If the threshold value has been reached (“970 sheets or more” in step S537), even if the threshold value for executing alone (1000 sheets) has not been reached, the determination unit 501 performs the image stabilization operation. Then, the CPU 50 outputs a control signal to the necessary operation system (step S539). In that case, the determination unit 501 resets the image stabilization execution counter 504 (step S541). If the count value of the image stabilization execution counter 504 has not reached the threshold value (“less than 970 sheets” in step S537), the image stabilization operation is not executed.

  The monochrome supply rotation operation and the image stabilization operation are not related to the operation content, but immediately after the printing operation is interrupted due to the monochrome supply rotation operation by performing the image stabilization operation in association with the monochrome supply rotation operation. Therefore, it is possible to prevent the printing operation from being interrupted for the image stabilization operation, and to suppress a decrease in productivity. That is, even after the monochrome replenishment rotation operation is performed, for example, 30 sheets are continuously printed without being interrupted for the image stabilization operation.

<Secondary transfer roller cleaning>
Referring to FIG. 14, when monochrome printing is continuously performed (YES in step S601), determination unit 501 increments secondary transfer roller cleaning counter 506 every time printing is performed (step S603), and the number of continuously printed sheets. Count. If monochrome printing is not continuous (NO in step S601), the determination unit 501 resets the secondary transfer roller cleaning counter 506 (step S605).

  When the count value of the secondary transfer roller cleaning counter 506 reaches 200 threshold values stored in the threshold value storage unit 502 (“200 or more” in step S607), the determination unit 501 In order to determine the timing for executing the monochrome supply rotation operation stored in the operation storage unit 503 in association with the secondary transfer roller cleaning, the count value of the monochrome supply rotation counter 507 is related to the secondary transfer roller cleaning. It is confirmed whether or not the threshold value 170 stored in the threshold value storage unit 502 has been reached as the threshold value used in the above. When the threshold value has been reached (“170 sheets or more” in step S609), the count value of the image stabilization execution counter 504 is further set as a threshold value used in connection with the secondary transfer roller cleaning. It is confirmed whether or not the threshold value 970 sheets stored in the value storage unit 502 has been reached. If the threshold value has not been reached (“less than 970 sheets” in step S611), the determination unit 501 determines to execute the monochrome replenishment rotation operation, and the CPU 50 outputs a control signal to the necessary operation system ( Step S613). In that case, the determination unit 501 resets the monochrome supply rotation counter 507 (step S615). Note that even if the developing rack 20 is rotated by the monochrome replenishment rotation operation during the secondary transfer roller cleaning, there is no problem in the secondary transfer roller cleaning. Therefore, these operations may be performed in parallel. This is a case where the count value of the monochrome replenishment rotation counter 507 has reached the threshold value of 170 sheets stored in the threshold value storage unit 502 as a threshold value used in connection with the secondary transfer roller cleaning. However, the count value of the image stabilization execution counter 504 reaches 970 sheets which is the threshold value stored in the threshold value storage unit 502 as the threshold value used in connection with the secondary transfer roller cleaning. If it is determined that “170 sheets or more” in step S609 and “970 sheets or more” in step S611, the determination unit 501 skips the monochrome replenishment rotation operation in step S613. Since the intermediate transfer belt blade 5 is pressed and separated from the intermediate transfer belt 2 by the image stabilization operation, the waste toner accumulated on the intermediate transfer belt blade 5 is dropped. For this reason, by performing the image stabilization operation, the same effect as when the monochrome supply rotation operation is performed can be obtained, and the operation can be made unnecessary.

  Although the operation contents of the secondary transfer roller cleaning and the monochrome replenishment rotation operation are not related, the monochrome replenishment rotation operation is performed in association with the secondary transfer roller cleaning, so that the printing operation is interrupted for the secondary transfer roller cleaning. Immediately after the printing is performed, the printing operation can be prevented from being interrupted due to the monochrome replenishing rotation operation, and a reduction in productivity can be suppressed. That is, even after the secondary transfer roller cleaning is performed, for example, 30 sheets are continuously printed without being interrupted by the monochrome supply rotation operation.

  Thereafter, secondary transfer roller cleaning is executed in step S617, and the secondary transfer roller cleaning counter 506 is reset in step S615.

  After the secondary transfer roller cleaning, the determination unit 501 executes the ATVC operation stored in association with the secondary transfer roller cleaning in the corresponding operation storage unit 503 in step S621, and resets the ATVC execution counter 510 in step S623. To do.

  Since the ATVC operation is executed in association with the secondary transfer roller cleaning, even if the resistance value of the secondary transfer roller 12 is changed by the secondary transfer roller cleaning, an appropriate application is performed by the ATVC operation. Adjusted to voltage.

  Further, the determination unit 501 determines the timing for executing the image stabilization operation stored in the corresponding operation storage unit 503 in association with the secondary transfer roller cleaning, so that the count value of the image stabilization execution counter 504 is 2. It is confirmed whether or not the threshold value stored in the threshold value storage unit 502 has reached 970 sheets as a threshold value used in connection with the next transfer roller cleaning. If the threshold value has been reached (“970 sheets or more” in step S625), even if the threshold value for executing alone (1000 sheets) has not been reached, the determination unit 501 performs the image stabilization operation. Then, the CPU 50 outputs a control signal to the necessary operation system (step S627). In that case, the determination unit 501 resets the image stabilization execution counter 504 (step S629). If the count value of the image stabilization execution counter 504 has not reached the threshold value (“less than 970 sheets” in step S625), the image stabilization operation is not executed.

  Although the operation contents of the secondary transfer roller cleaning and the image stabilization operation are not related, the image stabilization operation is performed in association with the secondary transfer roller cleaning, so that the printing operation is interrupted for the secondary transfer roller cleaning. Immediately after the printing, the printing operation can be prevented from being interrupted for the image stabilization operation, and the reduction in productivity can be suppressed. That is, even after the secondary transfer roller cleaning is performed, for example, 30 sheets are continuously printed without being interrupted for the image stabilization operation.

  Note that the intermediate transfer blade wear countermeasure operation is an operation that is performed when monochrome printing in which the intermediate transfer belt blade 5 does not press against and separate from the intermediate transfer belt 2 continues, and when color printing that is pressed and separated continues. This is in an exclusive relationship with the executed secondary transfer roller cleaning. For this reason, in the corresponding operation storage unit 503, the intermediate transfer blade wear countermeasure operation is not associated with the secondary transfer roller cleaning, and the execution timing of the intermediate transfer blade wear countermeasure operation is not determined when the secondary transfer roller cleaning is performed. .

  When the above-described operation is performed in the printer 1 and the execution timing of a certain adjustment / cleaning operation is reached, the other adjustment / cleaning operation not related to the operation content is performed. If the execution timing of the cleaning operation is within a predetermined range (for example, about one job), other adjustment / cleaning operations are also executed in conjunction with the operation. Further, when these adjustment / cleaning operations do not interfere with each other, they are performed in parallel. As a result, immediately after the printing operation is interrupted by executing an adjustment / cleaning operation (at a short time interval), the printing operation may be interrupted again by executing another adjustment / cleaning operation. Is prevented. That is, the frequency of interruption of the printing operation can be suppressed. As a result, a decrease in productivity of the printer 1 can be suppressed.

  In addition, when the timing for execution of an adjustment / cleaning operation is reached, the timing of execution of other adjustment / cleaning operations related to the adjustment / cleaning operation and the content of the operation is not It is executed in connection with the adjustment / cleaning operation. Thereby, the frequency of interruption of the printing operation is suppressed, and the adjustment / cleaning operation is effectively performed.

  In addition, when another adjustment / cleaning operation is included in a certain adjustment / cleaning operation, the other adjustment / cleaning operation is performed when the adjustment / cleaning operation is performed, and the other adjustment / cleaning operation is performed. The next execution timing is determined. As a result, the frequency of interruption of the printing operation is suppressed, and the other adjustment / cleaning operations are prevented from being performed repeatedly.

  In the above example, the threshold value storage unit 502 executes the process in relation to other actions associated with the corresponding action storage unit 503 as a threshold value for determining execution of the adjustment / cleaning operation. It is assumed that a threshold value for determining is stored for each of the other operations. However, this threshold value may not be different for each of the other operations. Therefore, as a threshold value for determining the execution of the adjustment / cleaning operation, the threshold value for determining the execution of the operation alone and the determination of the execution in relation to other unspecified operations. Two types of threshold values may be stored.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Printer, 2 Intermediate transfer belt, 3 Photoconductor, 5 Intermediate transfer belt blade, 6 Exposure part, 8 Primary transfer roller, 9 Paper, 10 Cassette, 11 Conveyance roller, 12 Secondary transfer roller, 13 Fixing roller, 14 Exhaust Paper roller, 15, 15Y, 15M, 15C, 15K cartridge, 16 charging unit, 17 environmental sensor, 18 density sensor, 19, 19Y, 19M, 19C, 19K developing roller, 20 developing rack, 50 CPU, 51 ROM, 52 RAM 53 EEPROM, 54 Density sensor communication unit, 55 Environmental sensor communication unit, 56 Primary transfer control unit, 57 Secondary transfer control unit, 58 Intermediate transfer blade control unit, 59 Development rack control unit, 100 controller, 501 judgment unit, 502 threshold storage unit, 503 corresponding operation storage unit, 504 image stabilization Execution counter, 505 Chuten blade cleaning counters, 506 secondary transfer roller cleaning counter 507 monochrome replenishment revolution counter, 508 monochrome consumption counters, 509 Chuten blade wear prevention counter, 510 ATVC execution counter.

Claims (6)

A print operation mechanism;
Multiple different types of adjustment and cleaning operation mechanism,
Control means for controlling the operating mechanism to perform the adjustment / cleaning operation;
Threshold value storage means for storing a threshold value defining the execution timing for each of the plurality of types of adjustment / cleaning operations;
A correspondence storage means for storing a correspondence relationship between the adjustment / cleaning operation and other adjustment / cleaning operations;
When the control means determines the execution timing of the first adjustment / cleaning operation using the threshold value, the control means performs the second adjustment / cleaning operation associated with the first adjustment / cleaning operation. An image forming apparatus including determination means for determining execution timing.   When the determination means determines that the first adjustment / cleaning operation is to be performed, the timing associated with the execution of the first adjustment / cleaning operation is the timing at which the second adjustment / cleaning operation is performed. The image forming apparatus according to claim 1, wherein:   The determination means determines that the first adjustment / cleaning operation is performed when the execution timing of the second adjustment / cleaning operation is within a predetermined range when it is determined that the first adjustment / cleaning operation is performed. The image forming apparatus according to claim 1, wherein a timing related to execution of the cleaning operation is determined as a timing of executing the second adjustment / cleaning operation. The first adjustment / cleaning operation and the second adjustment / cleaning operation are related to the operation content,
The timing of performing the second adjustment / cleaning operation related to the execution of the first adjustment / cleaning operation is immediately before or after the first adjustment / cleaning operation. Image forming apparatus. The first adjustment / cleaning operation and the second adjustment / cleaning operation do not interfere with each other,
The timing of executing the second adjustment / cleaning operation related to the execution of the first adjustment / cleaning operation is a timing parallel to the first adjustment / cleaning operation. Image forming apparatus. The combination of the first adjustment / cleaning operation and the second adjustment / cleaning operation is:
・ Combination including image stabilization operation and intermediate blade cleaning,
-Combinations including ATVC (Auto Transfer Voltage Control) operation and intermediate blade cleaning,
The image forming apparatus according to claim 1, wherein the image forming apparatus is any one of a combination including an ATVC operation and a secondary transfer roller cleaning, and a combination including a secondary transfer roller cleaning and an ATVC operation.

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