JP2009192568A - Image forming apparatus, and control program for image forming processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can appropriately maintain a friction coefficient between an image carrier and a cleaning device in order to maintain the surface property of the image carrier. <P>SOLUTION: The image forming apparatus includes: a driving motor 36 for rotating a photoreceptor drum 20 on the surface of which a toner image is formed; a contact type charging device 26 for charging the photoreceptor drum 20; a bias circuit 34 for applying superposed bias of AC voltage and DC voltage on the charging device 26; the cleaning device 28 for cleaning the surface of the photoreceptor drum 20 after transferring by being brought into contact with the surface of the photoreceptor drum 20; a detection sensor 37 for detecting an output current value of the driving motor 36 which is required for rotational drive of the photoreceptor drum 20 during an image forming process; a ROM 31 to which a defined value for output current of the driving motor 36 is stored; and a control circuit 30 for adjusting the AC output of the superposed bias by comparing an output value by the detection sensor 37 and the defined value for output current which is stored in the ROM 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a driving device that rotates an image carrier on which a toner image is formed on the surface, a contact-type charging device that charges the image carrier, and a bias that applies an alternating current and direct current bias to the charging device. The present invention relates to an image forming apparatus and an image forming processing control program including an application device, and a cleaning device that contacts the surface of the image carrier and cleans the surface of the image carrier after transfer.

  Conventionally, in an image forming apparatus such as a printer, a copier, a facsimile, or a multifunction machine equipped with these functionally, a contact-type charging device for charging the surface of an image carrier such as an amorphous silicon photosensitive drum is installed. Is well known.

  In this charging device, a method of applying a superimposed bias of a DC voltage and an AC voltage for charging is known (see, for example, Patent Document 1).

  This is because a current flows only in a low resistance region on the image carrier only by applying a DC voltage, and the image carrier cannot be uniformly charged. Further, when the surface of the image carrier is locally soiled, there is a problem that only that portion is not charged.

  However, if the applied voltage is too high, the image carrier may be worn away. Conversely, if the applied voltage is too low, the charge uniformity cannot be maintained, and the transferred image that has undergone the image formation process is uneven. This problem occurs. For this reason, it is necessary to set the applied voltage of the AC voltage to a minimum and optimum value.

Therefore, in the technique disclosed in Patent Document 1, an image carrier that is rotationally driven, a charging device that is placed in contact with or in proximity to the image carrier, and that is placed opposite to the image carrier. An electrode, a voltage detector that detects the amount of change in the surface potential of the image carrier that appears on the electrode, and an AC voltage or an AC current that is applied to the charging device is changed stepwise and charged based on the detection result of the voltage detector A control circuit for controlling the AC voltage or AC current applied to the device, and detecting the amount of change in the surface potential of the image carrier with a simple configuration to determine the optimum AC voltage or AC current to be applied to the charging device. ing.
By detecting changes in the rotational speed, drive torque, and drive current value of the charging roller that is in pressure contact with the image carrier, and controlling the amount of lubricant applied to the image carrier based on the detection results There are also known image forming apparatuses that have the effect of improving the cleaning property of the surface of the image bearing member, improving the toner yield associated with the reduction of the adhering toner, preventing image blur due to toner fixation, and preventing toner omission (for example, patents). Reference 2).

  By the way, the AC voltage necessary for charging the image carrier varies depending on the design condition and the environmental condition, but an appropriate value exists in any case.

  On the other hand, when the image forming process is continued, the image carrier and the charging device are warmed up, and the required AC voltage can be reduced.

  In such a case, an AC voltage is applied more than necessary, and discharge products are likely to be generated on the surface of the image carrier. If this discharge product adheres to the surface of the image carrier, the coefficient of friction increases, and if the amount of discharge product attached is small, it can be cleaned with a cleaning device. As the number increases, it becomes difficult to perform sufficient cleaning.

  Therefore, it is important to adjust the AC voltage and suppress the generation of discharge products.

FIG. 5 shows the relationship between the surface potential of such an image carrier and the AC voltage. For example, when the internal temperature of the image forming apparatus main body is in a normal temperature environment (for example, the internal temperature is 23 ° C.), the image forming process starts. It is preferable that the AC voltage is around 1000 (V) at the time, but it is indicated that an AC voltage near 900 (V) may be applied during the continuous image forming process, and the image is displayed during the continuous image forming process. An extra alternating voltage of 100 (V) from the start of the forming process is applied. Further, when the in-machine environment at the start of the image forming process is a low temperature environment (for example, the in-machine temperature of 10 ° C.), it is preferable that the AC voltage is around 1500 (V), and the in-machine temperature is increased by continuous printing. The difference is more significant at 600 (V).
Japanese Patent Laid-Open No. 08-202137 Japanese Patent Laid-Open No. 08-328435

  However, the image forming apparatus configured as described above can sufficiently cope with an increase in the coefficient of friction between the surface of the image carrier and the cleaning device only by controlling the AC voltage charged on the image carrier. As a result, the cleaning device is damaged, and as a result, high cleaning performance cannot be maintained, and there is a problem in that the transferred image is affected by defective cleaning.

  Therefore, in consideration of the above circumstances, the present invention provides an image forming apparatus and an image forming process control capable of appropriately maintaining the friction coefficient between the image carrier and the cleaning device in order to maintain the surface property of the image carrier. The purpose is to provide a program.

  An image forming apparatus according to the present invention includes a driving device that rotates an image carrier on which a toner image is formed, a contact-type charging device that charges the image carrier, and an AC voltage and a DC voltage applied to the charging device. In an image forming apparatus comprising: a bias applying device that applies a superposed bias; and a cleaning device that contacts the surface of the image carrier and cleans the surface of the image carrier after transfer. A detection device that detects an output current value of the driving device required for rotational driving of the image carrier, a storage unit that stores a prescribed output current value of the driving device, an output value of the detection device, and a storage unit that stores the output current value And a control circuit that compares the output current specified value and adjusts the AC output of the superimposed bias.

  At this time, it is preferable that the control circuit adjusts the AC output of the superimposed bias when no electrostatic latent image is formed on the surface of the image carrier.

  Further, the control circuit determines an adjustment value of the AC output of the superimposed bias after detecting the output value of the driving device by the detection device and then confirming the amount of DC component flowing in the charging current of the image carrier. It is preferable to do this.

  Further, it is preferable that the control circuit performs an aging process or an aging process and a toner discharging process when the drive current of the drive device is higher than a preset specified value after executing the continuous image forming process. .

  The control circuit monitors the detection value of the detection device while performing an aging process or an aging process and a toner discharge process, and performs the next image forming process until the detection value from the detection device falls to the specified value. Is preferably not performed.

  The image forming process control program of the present invention includes an output current value detecting step for detecting an output current value of a driving device that rotationally drives the image carrier, an output current value of the detected driving device, and a preset output current. An output current comparison step for comparing with a specified value, a DC component inflow amount detecting step for detecting a DC component inflow amount of the charging current of the image carrier when the detected value is larger than the output current specified value, The inflow amount comparison step for comparing the DC component inflow detection value of the current with a preset DC component inflow specified value of the charging current, and the DC component inflow detection value of the charging current is the DC current inflow specification of the charging current And an AC voltage control step of dropping the AC voltage of the charging device when the value is larger than the value.

  The image forming apparatus of the present invention can appropriately maintain the friction coefficient between the image carrier and the cleaning device in order to maintain the surface property of the image carrier.

  Next, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory diagram of a tandem color printer as an image forming apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a main part according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a flow chart of a control routine of a control circuit according to an embodiment of the present invention.

(overall structure)
As shown in FIG. 1, a tandem color printer 11 as an image forming apparatus according to an embodiment of the present invention includes a paper feed cassette 13 that stores transfer paper (not shown) inside a printer main body 12. A paper feeding unit 14 for taking out the transfer paper from the paper feeding cassette 13, an image forming processing unit 15 for performing an image forming process on the transfer paper supplied from the paper feeding cassette 13 or a manual feed tray (not shown), and a paper feeding cassette 13 or a transfer paper transport path 16 that transports the transfer paper supplied from the manual feed tray, and a toner image that has undergone image formation processing (primary transfer) by the image forming processing section 15 onto the transfer paper transported through the transfer paper transport path 16. The image forming apparatus includes a secondary transfer unit 17 that performs transfer, and a fixing unit 18 that fixes the toner image transferred by the secondary transfer unit 17 onto a transfer sheet.

(Configuration of the image forming processing unit 15)
For example, the image forming processing unit 15 employs a tandem system that performs image forming processing using toner (developer) of four colors of yellow (Y), magenta (M), cyan (C), and black (K). ing. In the following description, only in the case of color designation, the symbol of each arithmetic numeral is attached with a color (Y, M, C, K) in parentheses, and in the common case, only the arithmetic numeral is included. A description will be given with reference numerals.

  The image forming processing unit 15 corresponds to each color (Y, M, C, K), a plurality of toner containers 19 storing replenishing toner, and a print transmitted from each color toner from a personal computer (not shown). A plurality of photosensitive drums 20 as an amorphous silicon image carrier that forms a toner image based on image data included in the data, a plurality of developing devices 21 that supply toner to each photosensitive drum 20, and each photosensitive drum Between the endless intermediate transfer belt 22 to which the toner image formed on the drum 20 is primarily transferred, and the photosensitive drum 20 on the most downstream side in the rotational movement direction of the intermediate transfer belt 22 and the secondary transfer unit 17. The disposed toner concentration detection sensor 23 and a belt cleaner that is disposed on the substantially opposite side of the toner concentration detection sensor 23 and removes residual toner and the like adhering to the surface of the intermediate transfer belt 22. It includes a training device 24, an exposure unit 25 for emitting the beam light beam to each photosensitive drum 20, a.

<Configuration of Photosensitive Drum 20>
Each photoconductor drum 20 is for carrying a toner image of each color on the surface thereof based on the beam flux emitted from the exposure unit 25 and transferring the toner image to the intermediate transfer belt 22. 21 and the intermediate transfer belt 22. Further, around the photosensitive drum 20, a charging device (charging roller) 26, an exposure unit 25, a developing device 21, a primary transfer roller 27, a cleaning device 28, and a charge eliminating device 29 are arranged in the order of the transfer process.

  The toner image transferred onto the intermediate transfer belt 22 at each primary transfer portion configured by the cooperation of the photosensitive drum 20 and the primary transfer roller 27 passes through the transfer paper transport path 16 from the paper feed cassette 13 or the manual feed tray. The image is transferred by the secondary transfer unit 17 to the transfer paper conveyed through.

<Configuration of developing device 21>
Each developing device 21 basically has the same configuration and is disposed adjacently along the rotational movement direction below the intermediate transfer belt 22. Note that a well-known developing device 21 can be used, and a detailed description thereof is omitted here.

<Configuration of Intermediate Transfer Belt 22>
The intermediate transfer belt 22 is an endless belt disposed in the printer main body 12 so as to extend in the horizontal direction, and is circulated and driven in accordance with an image forming operation. Further, the toner image transferred onto the intermediate transfer belt 22 is transferred by the secondary transfer unit 17 to the transfer paper conveyed through the transfer paper conveyance path 16 from the paper feed cassette 13 or the manual feed tray.

  The transfer paper onto which the toner image has been transferred by the secondary transfer unit 17 is fixed by the fixing unit 18 through the transfer paper transport path 16 and then guided to the end of the transfer paper transport path 16 to be transferred to the printer main body 12. The paper is discharged toward a paper discharge tray 12a that also serves as an upper surface.

<Configuration of Toner Concentration Detection Sensor 23>
The toner density detection sensor 23 measures the reflection density of the toner image on the intermediate transfer belt 22 and outputs the detected value to the control circuit 30 as shown in FIG.

  A plurality of toner density detection sensors 23 can be provided in each of the rotational movement direction of the intermediate transfer belt 22 and the width direction orthogonal to the rotational movement direction. At this time, if the toner density detection sensor 23 detects the toner density only on one side in the width direction of the intermediate transfer belt 22, for example, a phenomenon in which a density difference occurs on both ends in the width direction of the intermediate transfer belt 22 (single burn phenomenon). It is preferable to arrange them in the vicinity of both widths because it is not possible to cope with the occurrence of the above.

<Configuration of Control Circuit 30>
The control circuit 30 controls each photosensitive drum 20 based on various control programs related to the overall image forming processing stored in the ROM 31, and supplies toner to each developing device 21 and bias voltage applied to the developing device 21. Development conditions such as, application voltage of a bias circuit 34 that applies a superimposed bias of a DC voltage and an AC voltage to the charging device 26, exposure such as laser power of laser light P (see FIG. 1) emitted from the exposure unit 25 Calibration of conditions, erase light quantity of the static elimination device 29, etc. is executed. The control circuit 30 controls the drive motor 36 that rotates the photosensitive drum 20 via the motor drive driver 35, and the detection value from the detection sensor 37 that detects the output current of the drive motor 36 and the photosensitive drum. The bias circuit 34 is controlled based on the detection value from the detection sensor 38 that detects the amount of DC component flowing in the charging current 20. Further, the count value from the counter 39 that counts the number of continuous image forming processes is input to the control circuit 30.

  The ROM 31 also stores a control program related to the image forming process correction of the present invention, and a microcomputer is configured with the control circuit 30 that executes the image forming process control program. Note that image data and the like when executing the image forming process are temporarily stored in the RAM 32 or the storage unit of the HDD 33 different from the ROM 31. Further, the control circuit 30 stores the detection result from the toner density detection sensor 23 in the RAM 32 or the HDD 33.

<Configuration of Cleaning Device 28>
On the other hand, as shown in FIG. 2, the cleaning device 28 is arranged in the transfer paper width direction (direction perpendicular to the paper surface) and has a depth in the inner side of the case 40 and rotates in the clockwise direction in the figure. By doing so, the collection spiral 41 that sends the collected toner to a transport waste toner container (not shown) in one direction in the width direction of the transfer paper, the cleaning blade 42 attached to the lower outside of the housing 40, and the inside of the housing 40 A rubbing roller 43 disposed on the upper side and in contact with the surface of the photosensitive drum 20 and a scraper 44 disposed on the upper surface of the rubbing roller 43 and in contact with the surface of the rubbing roller 43 are provided.

  The cleaning blade 42 is made of urethane rubber or the like, and the tip abuts against the surface of the photosensitive drum 20 from below the rotation shaft of the photosensitive drum 20. At this time, the tip of the cleaning blade 42 is in contact with the rotation direction of the photosensitive drum 20 (see the arrow in FIG. 2) in the counter direction.

  The rubbing roller 43 collects waste toner from the surface of the photoconductive drum 20 and polishes the surface of the photoconductive drum 20 with the waste toner adhering to the surface of the rubbing roller 43. For this reason, the rubbing roller 43 is formed in a cylindrical shape extending from the foamed rubber (for example, carbon-containing conductive foamed EPDM) in the depth direction of the transfer paper in order to maintain high retention of waste toner, and the tip of the cleaning blade 42 It is arranged on the upstream side of the photosensitive drum 20 in the rotation direction. Further, the rotation direction of the rubbing roller 43 rotates in the direction opposite to the rotation direction of the photosensitive drum 20.

  The scraper 44 is made of a thin sheet metal that ensures durability, and in order to make the amount of toner adhering to the surface of the rubbing roller 43 uniform, a counter direction is provided downstream of the rubbing roller 43 in the rotation direction. The tip is in contact.

(Example)
In the above configuration, the control circuit 30 executes the image forming process based on various control programs related to the overall image forming process stored in the ROM 31, and at the time of the image forming process, the charging device 26 is supplied with a DC voltage and an AC. The applied voltage of the bias circuit 34 for applying a superimposed bias with the voltage, the detection value from the detection sensor 37 for detecting the output current of the drive motor 36, and the detection sensor for detecting the DC component inflow amount of the charging current of the photosensitive drum 20 The bias circuit 34 is controlled based on the output current specified value of the drive motor 36 stored in advance in the ROM 31 (or HDD 33) and the DC component flow amount specified value of the charging current of the photosensitive drum 20 based on the detected value from the memory 38. .

  At this time, the control circuit 30 compares the output value of the detection sensor 37 with the output current regulation value stored in the ROM 31, and adjusts the AC output of the superimposed bias as shown in FIG.

  In the control example of the image forming apparatus shown in FIG. 3, in the case where the normal value is a system in which the drive current value of the drive motor 36 is 530 mA, and the current value of 30 mA increases, the AC output for charging is 50 V. However, if a control mismatch still occurs, the drive current increases, meaning that the voltage is dropped by an amount corresponding to each drive current value during successive image forming processes.

  The control circuit 30 preferably adjusts the AC output of the superimposed bias when an electrostatic latent image is not formed on the surface of the photosensitive drum 20 (for example, between sheets or during post-aging processing). Also. The control circuit 30 confirms the adjustment value of the AC output of the superimposed bias after detecting the output value of the drive motor 36 by the detection sensor 37 and confirms the amount of DC component flowing in the charging current of the photosensitive drum 20 with the detection sensor 38. It is preferable to determine. Further, the control circuit 30 performs an aging process or an aging process and a toner discharge process when the drive current of the drive motor is higher than a preset predetermined value after executing the continuous image forming process, and also detects the detection sensor. It is preferable to monitor the detected value 37 and perform the aging process or the aging process and the toner discharging process until the detected value falls to the specified value, and the next image forming process is not executed.

In the aging process (aging operation), a developer layer is formed on the developing roller of the developing device 21 that supplies toner to the photosensitive drum 20, but the surface of the photosensitive drum 20 is static. This is a state in which the electrostatic latent image is not formed (the photosensitive drum 20 is neither charged nor irradiated with laser light) and is driven so that the toner is not substantially supplied to the photosensitive drum 20. An operation for stabilizing the developing device 21, the intermediate transfer belt 20, the secondary transfer unit 17, and the like. By performing this operation, the rubbing roller 43 polishes the surface of the photosensitive drum 20, and the photosensitive drum 20 surfaces are cleaned.

  In addition, the toner discharging process supplies a predetermined amount of toner from the developing roller of the developing device 21 to the photosensitive drum 20 during non-printing as an abrasive when the rubbing roller 43 polishes the surface of the photosensitive drum 20. Is the action.

A specific control routine of the control circuit 30 will be described below based on the flowchart of FIG. In the flowchart, for example, the description will be made from the time when the print data output from the printer is received and the image forming process is started.
(Step S1)
In step S1, the control circuit 30 receives the output current value of the drive motor 36 from the detection sensor 37 with the start of the image forming process, and proceeds to step S2.

(Step S2)
In step S2, the control circuit 30 compares the output current value (detection value) of the drive motor 36 received from the detection sensor 37 with an output current specified value (for example, 530 mA) stored in the ROM 31, and the detection value is If the output current is less than the specified value, the process loops to step S1 and the image forming process is continued. If the detected value is larger than the specified output current, charging is insufficient and image defects are prevented from occurring. Therefore, the process proceeds to step S3.

(Step S3)
In step S3, the control circuit 30 receives the DC component flow amount of the charging current of the photosensitive drum 20 from the detection sensor 38, and proceeds to step S4.

(Step S4)
In step S4, the control circuit 30 compares the DC component inflow amount (detection value) of the charging current received from the detection sensor 38 with the DC component inflow amount regulation value (for example, 90 μA) stored in the ROM 31. If the detected value is equal to or less than the specified value, the process loops to step S1 to continue the image forming process. If the detected value is larger than the specified value, the process proceeds to step S5.

(Step S5)
In step S5, the control circuit 30 drops the charging AC voltage between the sheets, and proceeds to step S6.

(Step S6)
In step S6, the control circuit 30 receives the count value from the counter 39, confirms whether or not the count value has reached a predetermined count value (for example, 10 sheets) stored in the ROM 31, and sets the predetermined count value. If it has reached, the process loops to step S1 in order to continue the image forming process, and if it has not reached the predetermined count value, the process proceeds to step S7.

(Step S7)
In step S7, the control circuit 30 confirms whether or not the image forming process is completed. If the image forming process is continued, the control circuit 30 loops to step S1, and if the image forming process is completed, the control circuit 30 steps. The process proceeds to S8.

(Step S8)
In step S8, the control circuit 30 again receives the output current value of the drive motor 36 from the detection sensor 37 and proceeds to step S9 in order to execute the post-aging process upon completion of the image forming process (step S9). )
In step S9, the control circuit 30 compares the output current value (detected value) of the drive motor 36 received from the detection sensor 37 with the output current specified value (for example, 530 mA) stored in the ROM 31, and the detected value is If it is equal to or less than the specified value, the routine is terminated. If the detected value is greater than the specified value, the process proceeds to step S10.

(Step S10)
In step S10, the control circuit 30 starts an aging process, and hereinafter, the output current value (detection value) of the drive motor 36 received from the detection sensor 37 and the output current specified value (for example, 530 mA) stored in the ROM 31. And this routine is repeated until the detected value is equal to or less than the specified value.

  As described above, the output current value of the drive motor required for the rotational drive of the photosensitive drum 20 during the image forming process is detected by the detection sensor 37, and the output value of the detection sensor 37 and the output current specified value stored in the ROM 31. And adjusting the AC output of the superimposed bias by the control circuit, the surface property of the photosensitive drum 20 can be maintained, and the coefficient of friction between the photosensitive drum 20 and the cleaning blade 42 of the cleaning device 28 is appropriately set. Therefore, the occurrence of image defects can be prevented by suppressing the turning-up of the cleaning blade 42 and the like.

  The control circuit 30 may perform control so that a small amount of toner is applied to the photosensitive drum 20 in order to suppress the aging time during the post-aging process.

  In the above embodiment, the image forming apparatus according to the present invention is applied to the color printer 11. However, it is needless to say that the present invention can be applied to all image forming apparatuses such as copying machines and multifunction peripherals.

1 is an explanatory diagram of a tandem color printer as an image forming apparatus according to an embodiment of the present disclosure. It is explanatory drawing of the principal part which concerns on one Embodiment of this invention. It is a graph of the relationship between the drive current and control value which concern on one Embodiment of this invention. It is a flowchart of the control routine of the control circuit which concerns on one Embodiment of this invention. 3 is a graph showing the relationship between the surface potential of the image carrier and the AC voltage in the image forming apparatus. FIG.

Explanation of symbols

11. Color printer (image forming apparatus)
20 ... Photosensitive drum (image carrier)
26: Charging device 28 ... Cleaning device 30 ... Control circuit 31 ... ROM (storage unit)
33. HDD (storage unit)
34 ... Bias circuit (bias application device)
36 ... Drive motor (drive device)
37 ... Detection sensor (detection device)

Claims (6)

A driving device that rotates an image carrier on which a toner image is formed on a surface, a contact-type charging device that charges the image carrier, and a bias application that applies a superimposed bias of an AC voltage and a DC voltage to the charging device In an image forming apparatus comprising: a device; and a cleaning device that contacts the surface of the image carrier and cleans the surface of the image carrier after transfer.
A detection device that detects an output current value of the drive device required for rotational driving of the image carrier during image formation processing, a storage unit that stores a prescribed output current value of the drive device, and an output value of the detection device An image forming apparatus comprising: a control circuit that adjusts an alternating current output of a superimposed bias by comparing with an output current regulation value stored in the storage unit.   The image forming apparatus according to claim 1, wherein the control circuit performs adjustment of an AC output of a superimposed bias when an electrostatic latent image is not formed on the surface of the image carrier.   The control circuit determines an adjustment value of the AC output of the superimposed bias after detecting the output value of the driving device by the detection device and then confirming the amount of DC component flowing in the charging current of the image carrier. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The control circuit performs an aging process or an aging process and a toner discharging process when the driving current of the driving device is higher than a preset specified value after executing the continuous image forming process. The image forming apparatus according to claim 1.   The control circuit monitors the detection value of the detection device while performing an aging process or an aging process and a toner discharge process, and executes the next image forming process until the detection value from the detection device falls to the specified value. The image forming apparatus according to claim 4, wherein the image forming apparatus is not. An output current value detecting step for detecting an output current value of a driving device for rotationally driving the image carrier;
An output current comparison step for comparing the detected output current value of the driving device with a preset output current specified value;
A DC current inflow amount detection step for detecting a DC current in the charging current of the image carrier when the detected value is larger than a specified output current;
A flow amount comparison step for comparing a DC component flow amount detection value of the charging current with a preset DC component flow amount defined value of the charging current;
AC voltage control step of dropping the AC voltage of the charging device when the DC component inflow detection value of the charging current is larger than the DC component inflow detection value of the charging current,
An image forming process control program for causing a computer to execute the above.

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