JP2023004624A - Image forming apparatus and cleaning method - Google Patents

Abstract

To provide an image forming apparatus and a cleaning method that can properly execute removal processing of removing an attachment attached to a contact member.SOLUTION: An image forming apparatus comprises: an intermediate transfer belt 41; a cleaning member 52 that removes an attachment attached to a surface of the intermediate transfer belt 41 in accordance with application of voltage with a negative polarity; an electric charge supply unit that includes a contact member 58 in contact with the intermediate transfer belt 41 and a first power supply 59 applying voltage with a positive polarity to the contact member 58, and supplies an electric charge with a positive polarity to the attachment passing through a contact position P5 of the intermediate transfer belt 41 and the contact member 58; and an execution control unit that, based on the output state of the first power supply 59, controls the amount of execution of removal processing of removing the attachment attached to the contact member 58.SELECTED DRAWING: Figure 5

Description

The present invention relates to an electrophotographic image forming apparatus and a cleaning method performed in the image forming apparatus.

2. Description of the Related Art An image forming apparatus is known that has an image carrier such as an intermediate transfer belt that carries a toner image and conveys the toner image to a transfer position on a transfer material. This type of image forming apparatus is provided with a cleaning member for removing deposits such as toner adhering to the surface of the image carrier. For example, the cleaning member removes the deposits in response to application of a predetermined second polarity voltage.

Further, in order to improve the cleaning performance of the cleaning member, the adhering matter is moved to a first polarity opposite to the second polarity on the upstream side of the cleaning member in the conveying direction of the toner image by the image carrier. 2. Description of the Related Art There is known an image forming apparatus having a charge supplying section for charging to . The charge supply section includes a contact member that contacts the image carrier, and a power source that applies the voltage of the first polarity to the contact member.

In addition, in order to recover the deterioration of the charging performance of the charge supply unit caused by the accumulation of the deposits on the contact member, the image forming method performs a removal process for removing the deposits adhering to the contact member. A device is known (see Patent Document 1).

JP 2018-180102 A

However, in the conventional image forming apparatus, the removing process is executed regardless of the adhesion state of the adhering matter on the contact member. In other words, in the conventional image forming apparatus, power may be wasted due to the unnecessary execution of the removal process. Further, in the conventional image forming apparatus, the amount of execution of the removal process is insufficient, and the charging performance of the charge supply unit may not be sufficiently recovered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus and a cleaning method that can perform removal processing for removing deposits adhering to a contact member just enough.

An image forming apparatus according to one aspect of the present invention includes an image carrier, a cleaning member, a charge supply section, and an execution control section. The image carrier carries a toner image, and conveys the toner image to a transfer position onto a transfer receiving body. The cleaning member removes deposits adhering to the surface of the image carrier in response to the application of the voltage of the second polarity. The charge supply unit contacts the image carrier downstream of the transfer position in the conveying direction of the toner image by the image carrier and upstream of the cleaning position of the cleaning member in the conveying direction. and a contact member, and a first power supply for applying a voltage of a first polarity opposite to the second polarity to the contact member, and applying a voltage of a first polarity opposite to the second polarity to the attached matter passing through the contact position between the image carrier and the contact member. supplying the first polarity charge; The execution control unit controls an execution amount of a removal process for removing the deposit adhering to the contact member based on the output state of the first power supply.

According to another aspect of the present invention, there is provided a cleaning method comprising: an image carrier carrying a toner image and conveying the toner image to a transfer position on a transfer receiving member; a cleaning member for removing deposits adhering to the surface of a carrier; a contact member that contacts the image carrier on an upstream side; and a first power supply that applies a voltage of a first polarity opposite to the second polarity to the contact member, wherein the image carrier and the contact member are connected to each other. a charge supply unit that supplies the charge of the first polarity to the adhering matter passing through the contact position of the image forming apparatus, and includes the following acquisition step and execution control step. In the acquiring step, the output status of the first power supply is acquired. In the execution control step, the amount of execution of the removing process for removing the adhering matter adhering to the contact member is controlled based on the output state of the first power supply.

According to the present invention, it is possible to perform the removal process for removing the deposits adhering to the contact member in just the right amount.

FIG. 1 is a diagram showing the configuration of an image forming apparatus according to the first embodiment of the invention. FIG. 2 is a block diagram showing the system configuration of the image forming apparatus according to the first embodiment of the invention. FIG. 3 is a diagram showing the configuration of the image forming section of the image forming apparatus according to the first embodiment of the present invention. FIG. 4 is a diagram showing the configuration of the image forming section of the image forming apparatus according to the first embodiment of the present invention. FIG. 5 is a diagram showing the configuration of the belt cleaning section of the image forming apparatus according to the first embodiment of the present invention. FIG. 6 is a flow chart showing the procedure of the first cleaning control process executed by the image forming apparatus according to the first embodiment of the present invention. FIG. 7 is a diagram showing the configuration of the belt cleaning section of the image forming apparatus according to the second embodiment of the invention. FIG. 8 is a flow chart showing the procedure of the second cleaning control process executed by the image forming apparatus according to the second embodiment of the invention. FIG. 9 is a diagram showing the configuration of the belt cleaning section of the image forming apparatus according to the third embodiment of the invention. FIG. 10 is a flow chart showing the procedure of the third cleaning control process executed by the image forming apparatus according to the third embodiment of the invention. FIG. 11 is a diagram showing a modification of the belt cleaning section of the image forming apparatus according to the third embodiment of the invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the following embodiment is an example that embodies the present invention, and does not limit the technical scope of the present invention.

[First embodiment]
First, the configuration of an image forming apparatus 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. Here, FIG. 1 is a sectional view showing the configuration of the image forming apparatus 100. As shown in FIG.

For convenience of explanation, the vertical direction in the installation state (the state shown in FIG. 1) in which the image forming apparatus 100 can be used is defined as the up-down direction D1. A front-rear direction D2 is defined with the left side of the image forming apparatus 100 shown in FIG. 1 as the front side. Further, the horizontal direction D3 is defined with reference to the front of the image forming apparatus 100 in the installed state.

The image forming apparatus 100 is a multifunction machine having a plurality of functions such as a scanning function for reading an image of a document, a printing function for forming an image based on image data, a facsimile function, and a copying function. The present invention may be applied to image forming apparatuses such as printers, facsimiles, and copiers capable of forming images by electrophotography.

As shown in FIGS. 1 and 2, the image forming apparatus 100 includes an ADF (Auto Document Feeder) 1, an image reading section 2, an image forming section 3, a paper feeding section 4, an operation display section 5, a storage section 6, and A control unit 7 is provided.

The ADF 1 conveys a document to be read by the scanning function. The ADF 1 includes a document set section, a plurality of transport rollers, a document presser, and a paper discharge section.

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

The image forming section 3 realizes the printing function. Specifically, the image forming section 3 forms a color or monochrome image on a sheet supplied from the paper feeding section 4 according to the electrophotographic method.

The paper feeding unit 4 supplies sheets to the image forming unit 3 . The paper feed unit 4 includes a paper feed cassette, a manual feed tray, and a plurality of transport rollers.

The operation display unit 5 is a user interface of the image forming apparatus 100 . The operation display unit 5 includes a display unit such as a liquid crystal display for displaying various information according to control instructions from the control unit 7, and operation keys or a touch panel for inputting various information to the control unit 7 according to user operations. It has an operation part such as

The storage unit 6 is a nonvolatile storage device. For example, the storage unit 6 is a storage device such as non-volatile memory such as flash memory and EEPROM (registered trademark), SSD (Solid State Drive), or HDD (Hard Disk Drive).

The control unit 7 controls the image forming apparatus 100 as a whole. As shown in FIG. 2, the control unit 7 includes a CPU 11, a ROM 12, and a RAM 13. The CPU 11 is a processor that executes various kinds of arithmetic processing. The ROM 12 is a non-volatile storage device in which information such as control programs for causing the CPU 11 to execute various processes is stored in advance. The RAM 13 is a volatile or nonvolatile storage device used as a temporary memory (work area) for various processes executed by the CPU 11 . The CPU 11 comprehensively controls the image forming apparatus 100 by executing various control programs stored in advance in the ROM 12 .

Note that the control unit 7 may be a control unit provided separately from the main control unit that controls the image forming apparatus 100 in an integrated manner. Also, the control unit 7 may be configured by an electronic circuit such as an integrated circuit (ASIC).

[Configuration of Image Forming Unit 3]
Next, the configuration of the image forming section 3 will be described with reference to FIGS. 1 to 4. FIG. Here, FIG. 3 is a cross-sectional view showing a configuration of part of the image forming section 3 in a state where the roller support section 30 is arranged at the first position P1. FIG. 4 is a cross-sectional view showing the configuration of part of the image forming section 3 in which the roller support section 30 is arranged at the second position P2. In addition, in FIG.3 and FIG.4, the roller support part 30 is shown by the dashed-dotted line.

As shown in FIGS. 1 and 3, the image forming section 3 includes four image forming units 20, an optical scanning device 25, an intermediate transfer device 26, a secondary transfer roller 27, a fixing device 28, a paper discharge tray 29, and A roller support 30 is provided. Further, as shown in FIG. 2 , the image forming section 3 includes a first driving section 14 , a second driving section 15 and a third driving section 16 .

Of the four image forming units 20, the image forming unit 21 (see FIG. 3) forms a Y (yellow) toner image. Of the four image forming units 20, the image forming unit 22 (see FIG. 3) forms a C (cyan) toner image. Of the four image forming units 20, the image forming unit 23 (see FIG. 3) forms an M (magenta) toner image. Of the four image forming units 20, the image forming unit 24 (see FIG. 3) forms a K (black) toner image. As shown in FIGS. 1 and 3, the four image forming units 20 are arranged side by side in the order of yellow, cyan, magenta, and black from the front side of the image forming apparatus 100 along the front-rear direction D2.

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

An electrostatic latent image is formed on the surface of the photosensitive drum 31 . The photosensitive drum 31 receives the rotational driving force supplied from the first driving section 14 and rotates in the direction of the arrow shown in FIG. Thereby, the photosensitive drum 31 conveys the toner image formed on the surface.

The charging roller 32 charges the surface of the photosensitive drum 31 according to the application of a preset charging voltage. For example, the charging roller 32 positively charges the surface of the photosensitive drum 31 . The surface of the photosensitive drum 31 charged by the charging roller 32 is irradiated with light based on image data emitted from the optical scanning device 25 . Thereby, an electrostatic latent image is formed on the surface of the photosensitive drum 31 .

The developing device 33 develops the electrostatic latent image formed on the surface of the photoreceptor drum 31 . The developing device 33 includes a pair of stirring members and a developing roller. The pair of agitation members agitate the developer containing toner and carrier housed inside the developing device 33 . As a result, the toner contained in the developer is positively charged by friction with the carrier contained in the developer. The developing roller scoops up the developer stirred by the pair of stirring members. The developer drawn up by the developing roller forms a magnetic brush due to the magnetic force of magnetic poles provided inside the developing roller. Further, the developing roller conveys the magnetic brush to a position facing the photosensitive drum 31 . Further, the developing roller supplies the toner contained in the magnetic brush conveyed to the facing position to the photosensitive drum 31 in response to application of a preset developing bias voltage. Thereby, the electrostatic latent image formed on the surface of the photoreceptor drum 31 is visualized (developed). Toner is supplied from a toner container 36 to the developing device 33 .

The primary transfer roller 34 transfers the toner image formed on the surface of the photosensitive drum 31 to the outer circumferential surface of the intermediate transfer belt 41 in accordance with the supply of a preset primary transfer current. As shown in FIG. 3, the primary transfer roller 34 is provided facing the photosensitive drum 31 with the intermediate transfer belt 41 interposed therebetween.

The drum cleaning section 35 removes toner remaining on the surface of the photosensitive drum 31 after the toner image is transferred by the primary transfer roller 34 .

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

The intermediate transfer device 26 conveys the toner image transferred from the photosensitive drum 31 of each image forming unit 20 to the intermediate transfer belt 41 . As shown in FIGS. 1 and 3 , the intermediate transfer device 26 includes an intermediate transfer belt 41 , driving rollers 42 , tension rollers 43 and belt cleaning section 44 .

The intermediate transfer belt 41 carries toner images transferred from the photosensitive drums 31 of the image forming units 20 . Further, the intermediate transfer belt 41 conveys the toner image carried thereon to a secondary transfer position P3 (see FIG. 3) (an example of the transfer position of the present invention) onto a sheet (an example of a transfer target body). The intermediate transfer belt 41 is an example of the image carrier of the invention.

The intermediate transfer belt 41 is a stretched endless belt-like member. The intermediate transfer belt 41 is stretched by the drive roller 42, the tension roller 43, and the four primary transfer rollers 34 when the roller support section 30 is arranged at the first position P1 (see FIG. 3). In addition, the intermediate transfer belt 41 is configured such that the drive roller 42, the tension roller 43, and one of the four primary transfer rollers 34 are used when the roller support portion 30 is arranged at the second position P2 (see FIG. 4). It is stretched by the department.

The driving roller 42 receives the rotational driving force supplied from the second driving section 15 and rotates in the first rotational direction D5 shown in FIG. As a result, the intermediate transfer belt 41 runs along the conveying direction D4 shown in FIG. 3, and conveys the toner image formed on the outer peripheral surface to the secondary transfer position P3 (see FIG. 3) by the secondary transfer roller 27. do.

The belt cleaning section 44 cleans the outer peripheral surface of the intermediate transfer belt 41 after the toner image has been transferred by the secondary transfer roller 27 .

The secondary transfer roller 27 transfers the toner image borne by the intermediate transfer belt 41 onto the sheet supplied from the paper feeding unit 4 in accordance with the supply of a preset secondary transfer current.

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

A sheet on which the toner image is fixed by the fixing device 28 is discharged to the discharge tray 29 .

Of the four primary transfer rollers 34 corresponding to the four image forming units 20, the roller supporting portion 30 supports three primary transfer rollers 34A (see FIG. 3) excluding the primary transfer roller 34B (see FIG. 3) corresponding to the image forming unit 24 3) is supported so that it can be raised and lowered.

Specifically, the roller support portion 30 includes a support member elongated in the front-rear direction D2. Three bearing portions corresponding to the three primary transfer rollers 34A are formed in the support member along the front-rear direction D2. Each of the bearings rotatably supports the primary transfer roller 34A.

Further, the roller supporting portion 30 is supported by the housing of the image forming apparatus 100 so as to be movable between a first position P1 shown in FIG. 3 and a second position P2 shown in FIG. The second position P2 is a position above the first position P1. The roller supporting portion 30 receives the driving force supplied from the third driving portion 16 and moves between the first position P1 and the second position P2. As the roller support section 30 moves, the three primary transfer rollers 34A supported by the support member also move integrally with the roller support section 30 .

When the roller support portion 30 is placed at the first position P1, the intermediate transfer belt 41 is pressed downward by the three primary transfer rollers 34A, and the three photosensitive rollers corresponding to the intermediate transfer belt 41 and the three primary transfer rollers 34A are exposed. body drum 31 (see FIG. 3). Further, when the roller supporting portion 30 is moved from the first position P1 to the second position P2, the tension of the intermediate transfer belt 41 is reduced, and the intermediate transfer belt 41 is moved to three photosensitive rollers corresponding to the three primary transfer rollers 34A. away from body drum 31 (see FIG. 4).

The first driving section 14 drives each image forming unit 20 . For example, the first driving section 14 includes a motor and a power transmission mechanism that transmits rotational driving force generated by the motor to each of the image forming units 20 . The photoreceptor drum 31 rotates by receiving a rotational driving force supplied from the first driving section 14 .

The second driving section 15 drives the intermediate transfer device 26 . For example, the second driving section 15 includes a motor and a power transmission mechanism that transmits the rotational driving force generated by the motor to the intermediate transfer device 26 . The driving roller 42 rotates by receiving the rotational driving force supplied from the second driving section 15 .

The third drive section 16 drives the roller support section 30 . For example, the third drive section 16 includes a motor and a cam member that converts rotational motion of the drive shaft of the motor into linear motion along the moving direction of the roller support section 30 . The roller supporting portion 30 receives the driving force supplied from the third driving portion 16 and moves between the first position P1 (see FIG. 3) and the second position P2 (see FIG. 4).

[Configuration of Belt Cleaning Unit 44]
Next, the configuration of the belt cleaning section 44 will be described with reference to FIG. Here, FIG. 5 is a sectional view showing the configuration of the belt cleaning section 44. As shown in FIG. In addition, in FIG. 5, the energization path of each configuration is indicated by a two-dot chain line.

The belt cleaning unit 44 removes deposits adhering to the surface of the intermediate transfer belt 41 .

Specifically, the adhering matter includes toner remaining on the surface of the intermediate transfer belt 41 after passing through the secondary transfer position P3 (see FIG. 3) by the secondary transfer roller 27 . Here, the toner remaining on the surface of the intermediate transfer belt 41 includes negatively charged toner in addition to positively charged toner. For example, the toner on the intermediate transfer belt 41 may be negatively charged due to the separation discharge that occurs when the sheet separates from the intermediate transfer belt 41 at the secondary transfer position P3.

Further, the adhering matter includes paper dust adhering to the surface of the intermediate transfer belt 41 due to contact with the sheet at the secondary transfer position P3. Here, the paper dust adhering to the intermediate transfer belt 41 includes paper dust that is negatively charged due to separation discharge that occurs when the sheet is separated from the intermediate transfer belt 41 at the secondary transfer position P3.

Also, the deposit includes a carrier. Specifically, in the image forming apparatus 100 , the carrier contained in the magnetic brush may be transferred from the developing roller of the developing device 33 to the photosensitive drum 31 . Also, the carrier transferred to the photosensitive drum 31 may transfer to the intermediate transfer belt 41 together with the toner. Therefore, the adhered matter may contain a carrier.

Note that the developer may not contain a carrier. In this case, the deposit does not contain the carrier.

As shown in FIG. 5, the belt cleaning section 44 includes a housing 51, a cleaning member 52, a collection roller 53, a second power source 54, a blade member 55, a toner transport path 56, a transport member 57, a contact member 58, a first power source 59 , a voltage detector 60 , a first switch 61 and a second switch 62 .

The housing 51 accommodates the cleaning member 52 , collection roller 53 , blade member 55 , conveying member 57 and contact member 58 . Further, as shown in FIG. 5, a toner transport path 56 is formed inside the housing 51 .

The cleaning member 52 removes the deposits adhering to the surface of the intermediate transfer belt 41 in response to application of a negative voltage (an example of the second polarity of the present invention). The cleaning member 52 is, as shown in FIG. 5, a brush roller rotatably provided at a position in contact with the surface of the intermediate transfer belt 41 . The cleaning member 52 receives the rotational driving force supplied from the second driving section 15 and rotates in the second rotational direction D6 shown in FIG.

Specifically, the cleaning member 52 has a rotary shaft 71 and brush bristles 72 . The rotating shaft 71 is made of metal and provided extending in the left-right direction D3. The brush bristles 72 are planted on a synthetic resin base cloth wrapped around the peripheral surface of the rotary shaft 71 . For example, the brush bristles 72 are made of acrylic resin, nylon resin, or the like to which conductivity is imparted by containing carbon or the like.

The collection roller 53 collects the adhering matter removed from the surface of the intermediate transfer belt 41 by the cleaning member 52 . The recovery roller 53 is a metal roller rotatably provided at a position in contact with the brush bristles 72 of the cleaning member 52, as shown in FIG. The collection roller 53 receives the rotational driving force supplied from the second drive section 15 and rotates in the third rotation direction D7 shown in FIG.

The second power supply 54 is electrically connected to the rotating shaft of the collecting roller 53 and applies a negative voltage to the collecting roller 53 .

When a negative voltage is applied to the collection roller 53 , a negative voltage is applied to the cleaning member 52 via the collection roller 53 . Thereby, an electric field is formed between the collection roller 53 and the cleaning member 52 . Further, an electric field is formed between the brush bristles 72 and the intermediate transfer belt 41 at the cleaning position P4 (see FIG. 5) where the brush bristles 72 of the cleaning member 52 and the intermediate transfer belt 41 are in contact with each other.

Among the deposits adhering to the surface of the intermediate transfer belt 41, the positively charged deposits are transferred to the brush bristles 72 by the electric field formed between the brush bristles 72 and the intermediate transfer belt 41 at the cleaning position P4. relocate. Further, the deposits transferred to the brush bristles 72 are transferred to the surface of the collecting roller 53 by the electric field formed between the collecting roller 53 and the cleaning member 52 at the contact position between the cleaning member 52 and the collecting roller 53. .

The blade member 55 is provided in contact with the recovery roller 53 and scrapes off the adhering portion adhering to the surface of the recovery roller 53 . For example, the blade member 55 is a rubber blade having one end fixed to the housing 51 so that the other end contacts the surface of the collection roller 53 . The adhering matter scraped off from the collecting roller 53 by the blade member 55 falls into the toner conveying path 56 .

The toner transport path 56 is provided below the blade member 55 inside the housing 51 and extends in the left-right direction D3.

The conveying member 57 is rotatably provided in the toner conveying path 56 and conveys the adhering matter in the toner conveying path 56 . For example, the transport member 57 is a transport screw extending in the left-right direction D3. The conveying member 57 rotates by receiving the rotational driving force supplied from the second driving section 15 . The adhering matter scraped off the collection roller 53 by the blade member 55 and dropped into the toner conveying path 56 is conveyed by the conveying member 57 to a toner container (not shown).

The contact member 58 is located downstream of the secondary transfer position P3 (see FIG. 3) in the transport direction D4 and upstream of the cleaning position P4 (see FIG. 5) of the cleaning member 52 in the transport direction D4. It contacts the surface of the transfer belt 41 . The contact member 58 is a brush-shaped member that extends in the width direction (lateral direction D3) of the intermediate transfer belt 41 perpendicular to the conveying direction D4. The contact member 58 contacts the adhering matter adhering to the surface of the intermediate transfer belt 41 and moves the adhering matter on the intermediate transfer belt 41 , thereby reducing the mechanical adhesion of the adhering matter to the intermediate transfer belt 41 . Lower. In addition, the contact member 58 charges the adhering matter adhering to the surface of the intermediate transfer belt 41 to a positive polarity (an example of the first polarity of the present invention).

Specifically, the contact member 58 has a proximal end 73 and bristles 74 . The base end portion 73 is made of metal and provided to extend in the left-right direction D3. The brush bristles 74 are in contact with the intermediate transfer belt 41 and are planted on a synthetic resin base cloth provided on the surface of the base end portion 73 . For example, the brush bristles 74 are made of acrylic resin or nylon resin to which conductivity is imparted by containing carbon or the like that functions as a conductive material. The brush bristles 74 are longer than the distance between the base end portion 73 and the intermediate transfer belt 41 and bite into the surface of the intermediate transfer belt 41 .

The first power supply 59 is electrically connected to the proximal end portion 73 of the contact member 58 and applies a positive voltage to the contact member 58 .

Specifically, the first power supply 59 controls the current supplied to the contact member 58 by constant current control. That is, the first power supply 59 controls the voltage applied to the contact member 58 so that the current supplied to the contact member 58 matches the predetermined target current.

When a positive voltage is applied to the contact member 58 by the first power source 59, the intermediate transfer belt 41 and the contact member 58 contact the contact member 58 via the deposit passing through the contact position P5 (see FIG. 5) between the intermediate transfer belt 41 and the contact member 58. A current flows between it and the intermediate transfer belt 41 . As a result, a positive electric charge is supplied to the deposit passing through the contact position P5. The contact member 58 and the first power source 59 are examples of the charge supply section of the present invention.

In the image forming apparatus 100, the contact member 58 aligns the charging polarity of the adhering matter that has passed through the contact position P5 (see FIG. 5) to positive polarity. Therefore, even if the adhering matter that has passed through the secondary transfer position P3 (see FIG. 3) includes both the negatively charged adhering matter and the positively charged adhering matter, The deposit is removed by the cleaning member 52 .

The voltage detection section 60 detects voltage applied to the contact member 58 . The voltage detection section 60 is provided on the current path between the first power supply 59 and the contact member 58 . The voltage detection section 60 outputs a detection signal indicating the detection result to the control section 7 .

The first switch 61 is provided in the current path between the second power supply 54 and the collection roller 53, and can switch between conduction and interruption of the current path. For example, the first switch 61 is a semiconductor switch such as a transistor. The first switch 61 switches between conduction and interruption of the energization path between the second power source 54 and the collection roller 53 according to the input of the control signal from the control section 7 .

The second switch 62 is provided in the current path between the first power supply 59 and the contact member 58, and can switch between conduction and interruption of the current path. For example, the second switch 62 is a semiconductor switch such as a transistor. The second switch 62 switches conduction and interruption of the energization path between the first power supply 59 and the contact member 58 according to the input of the control signal from the control section 7 .

By the way, in order to recover the deterioration of the charging performance of the contact member 58 caused by the accumulation of the deposits on the contact member 58, the image forming apparatus executes a removal process for removing the deposits adhering to the contact member 58. It has been known.

However, in the conventional image forming apparatus, the removing process is executed regardless of the adhesion state of the adhering matter on the contact member 58 . In other words, in the conventional image forming apparatus, power may be wasted due to the unnecessary execution of the removal process. In addition, in the conventional image forming apparatus, the execution amount of the removing process is insufficient, and the charging performance of the contact member 58 may not be sufficiently recovered.

On the other hand, in the image forming apparatus 100 according to the first embodiment of the present invention, as described below, it is possible to perform the removal process for removing the deposits adhering to the contact member 58 just enough. is.

[Configuration of control unit 7]
Next, the configuration of the control unit 7 will be described with reference to FIGS. 2 to 5. FIG.

As shown in FIG. 2 , the control section 7 includes an execution control section 81 .

Specifically, a cleaning control program for causing the CPU 11 to function as the execution control section 81 is stored in advance in the ROM 12 of the control section 7 . The CPU 11 functions as an execution control section 81 by executing the cleaning control program stored in the ROM 12 .

The cleaning control program is recorded on a computer-readable recording medium such as a CD, DVD, and flash memory, and may be read from the recording medium and stored in a storage device such as the storage unit 6. Also, the execution control unit 81 may be configured by an electronic circuit such as an integrated circuit (ASIC).

The execution control unit 81 controls the amount of execution of the removing process for removing the deposits adhering to the contact member 58 based on the output state of the first power supply 59 (see FIG. 5). Here, the execution amount of the removing process is the execution time of the removing process, or the number of repetitions of the tension reduction process and the tension increase process, which will be described later. Also, the amount of execution of the removal process includes non-execution of the removal process (zero execution time).

Specifically, the execution control unit 81 executes the removal process when the voltage applied to the contact member 58 by the first power supply 59 exceeds a predetermined first threshold.

When the amount of deposits adhering to the contact member 58 increases, the electrical resistance at the contact position P5 (see FIG. 5) increases, making it difficult for current to flow. Since the first power supply 59 controls the current supplied to the contact member 58 by constant current control, when the current supplied to the contact member 58 decreases, the applied voltage is increased accordingly. In other words, the voltage applied by the first power supply 59 increases as the amount of the deposit adhering to the contact member 58 increases. Therefore, by setting the first threshold value corresponding to the allowable limit value of the amount of deposits adhering to the contact member 58, execution of the removal process is continued until the amount of deposits exceeds the allowable limit value. Can be restricted. In other words, it is possible to restrict unnecessary execution of the removal process.

For example, the execution control unit 81 uses the voltage detection unit 60 to cause the first power supply 59 to A voltage applied to the contact member 58 is detected. Then, when the voltage detected by the voltage detection unit 60 exceeds the first threshold, the execution control unit 81 interrupts the printing process and executes the removal process. On the other hand, the execution control section 81 continues the printing process when the voltage detected by the voltage detection section 60 is equal to or lower than the first threshold.

Here, the interruption of the printing process involves stopping the first driving section 14, stopping the second driving section 15, stopping power supply by the second power supply 54, and stopping power supply by the first power supply 59. FIG. That is, the execution control section 81 stops driving the first driving section 14 and the second driving section 15 . The execution control unit 81 also inputs a control signal to the first switch 61 to cut off the current path between the second power supply 54 and the collecting roller 53 . The execution control unit 81 also inputs a control signal to the second switch 62 to cut off the current path between the first power supply 59 and the contact member 58 .

In the removal process, a tension reduction process for reducing the tension of the intermediate transfer belt 41 and a tension increase process for increasing the tension of the intermediate transfer belt 41 are alternately executed while the driving of the intermediate transfer belt 41 is stopped. .

Specifically, the tension reduction process is a process of moving the roller supporting portion 30 from the first position P1 (see FIG. 3) to the second position P2 (see FIG. 4). Further, the tension increasing process is a process of moving the roller supporting portion 30 from the second position P2 (see FIG. 4) to the first position P1 (see FIG. 3).

Further, in the removing process, the intermediate transfer belt 41 is subjected to A region switching process is executed to switch the region facing the contact member 58 . For example, the first specific number of times is one.

Specifically, the area switching process is a process of driving the second driving unit 15 and running the intermediate transfer belt 41 for a specific distance or more that realizes the switching of the facing areas. Note that the area switching process may be a process of driving the first driving section 14 together with the second driving section 15 . Thereby, it is possible to suppress the occurrence of friction between the photosensitive drum 31 and the intermediate transfer belt 41 . Further, the area switching process may be a process that is executed while the roller supporting portion 30 is arranged at the second position P2 (see FIG. 4). In this case, the first driving section 14 may be driven together with the second driving section 15 and the driving force of the first driving section 14 may be supplied only to the image forming unit 24 among the four image forming units 20 . Also, the execution control unit 81 does not have to execute the area switching process.

Further, the execution control unit 81 performs the removal process when the voltage applied to the contact member 58 by the first power supply 59 is less than a second threshold lower than the first threshold during execution of the removal process. finish.

Specifically, the execution control unit 81 uses the first power source 59 to generate a predetermined short period of time each time either the tension reduction process or the tension increase process is executed a predetermined second specific number of times. A short-time output process is performed to output a positive voltage to the contact member 58 only for a period of time. For example, the second specific number of times is five.

When the voltage detected by the voltage detection unit 60 during execution of the short-time output process is less than the second threshold, the execution control unit 81 ends the removal process and restarts the print process. do. On the other hand, the execution control section 81 continues the removal process when the voltage detected by the voltage detection section 60 is equal to or higher than the second threshold.

It should be noted that the energization path between the first power source 59 and the contact member 58 may be conductive during the execution of the removal process. In this case, the execution control unit 81 does not need to execute the short time output process.

The first threshold value, the second threshold value, the first specific number of times, and the second specific number of times may be predetermined values that cannot be changed, or may be set according to an operation on the operation display unit 5. It may be a value set arbitrarily.

[First cleaning control process]
Hereinafter, the cleaning method of the present invention will be described together with an example of the procedure of the first cleaning control process executed by the control section 7 (execution control section 81) in the image forming apparatus 100, with reference to FIG. Here, steps S11, S12, . Note that the control unit 7 executes the first cleaning control process when the printing process is executed. The first cleaning control process is continuously executed until execution of the printing process is completed.

<Step S11>
First, in step S<b>11 , the control section 7 uses the voltage detection section 60 to detect the voltage applied to the contact member 58 by the first power supply 59 . Then, the control unit 7 determines whether or not the voltage detected by the voltage detection unit 60 exceeds the first threshold.

Here, when the control unit 7 determines that the voltage detected by the voltage detection unit 60 exceeds the first threshold value (Yes side of S11), the process proceeds to step S12. Further, if the voltage detected by the voltage detection unit 60 does not exceed the first threshold (No side of S11), the control unit 7 determines whether the voltage detected by the voltage detection unit 60 exceeds the first threshold in step S11. wait for it to pass.

The process of detecting (obtaining) the voltage applied to the contact member 58 by the first power supply 59 in step S11 is an example of the obtaining step of the present invention. Also, switching the subsequent process based on the acquired result is an example of the execution control step of the present invention.

<Step S12>
At step S12, the control unit 7 interrupts the printing process. Then, the control unit 7 executes the removal process. In the first cleaning control process, the removal process is a series of processes from step S13 to step S19.

Specifically, the control unit 7 stops driving the first driving unit 14 and the second driving unit 15 . The control unit 7 also inputs a control signal to the first switch 61 to cut off the current path between the second power source 54 and the collecting roller 53 . The control unit 7 also inputs a control signal to the second switch 62 to cut off the current path between the first power source 59 and the contact member 58 .

<Step S13>
At step S13, the control unit 7 executes the tension reduction process.

Specifically, the control section 7 drives the third drive section 16 to move the roller support section 30 from the first position P1 (see FIG. 3) to the second position P2 (see FIG. 4).

<Step S14>
At step S14, the control unit 7 executes the tension increasing process.

Specifically, the control section 7 drives the third drive section 16 to move the roller support section 30 from the second position P2 (see FIG. 4) to the first position P1 (see FIG. 3).

By sequentially executing the processes of steps S13 and S14, the intermediate transfer belt 41 mechanically vibrates along the conveying direction D4. Due to this mechanical vibration, the deposit adhering to the contact member 58 is discharged from the contact member 58 .

Note that in the image forming apparatus 100, the roller support section 30 is arranged at the second position P2 (see FIG. 4) during execution of the printing process for printing a monochrome image. Therefore, when the first cleaning control process is executed together with the printing process for printing a monochrome image, the order of the processes in steps S13 and S14 may be reversed.

<Step S15>
In step S15, the control unit 7 determines whether or not the process of step S14 (the tension increasing process) has been performed the first specific number of times.

Here, when the control unit 7 determines that the process of step S14 has been executed the first specific number of times (Yes side of S15), the process proceeds to step S16. Further, if the process of step S14 has not been executed the first specific number of times (No side of S15), the control unit 7 shifts the process to step S17.

<Step S16>
In step S16, the control unit 7 executes the area switching process.

Specifically, the control unit 7 drives the second driving unit 15 to make the intermediate transfer belt 41 travel the specific distance or longer. As a result, the adhering matter discharged from the contact member 58 is conveyed downstream in the conveying direction D4 from the contact position P5 (see FIG. 5). Therefore, it is possible to prevent the adhering matter discharged from the contact member 58 from accumulating at the contact position P5 and restricting the removal effect due to vibration due to the accumulated adhering matter.

Note that the processing of steps S15 and S16 may be omitted.

<Step S17>
In step S17, the control unit 7 determines whether or not the process of step S14 (the tension increasing process) has been performed the second specific number of times.

Here, when the control unit 7 determines that the process of step S14 has been executed the second specific number of times (Yes side of S17), the process proceeds to step S18. Further, if the process of step S14 has not been executed the second specific number of times (No side of S17), the control unit 7 shifts the process to step S13.

<Step S18>
In step S18, the control unit 7 executes the short time output process.

Specifically, the control unit 7 inputs a control signal to the second switch 62 to turn on the current path between the first power supply 59 and the contact member 58 for the short time.

<Step S19>
In step S19, the control unit 7 determines whether or not the voltage detected by the voltage detection unit 60 during execution of the short time output process is less than the second threshold.

Here, when the control unit 7 determines that the voltage detected by the voltage detection unit 60 is less than the second threshold value (Yes side of S19), the process proceeds to step S20. Moreover, if the voltage detected by the voltage detection unit 60 is not less than the second threshold value (No side of S19), the control unit 7 shifts the process to step S13.

<Step S20>
In step S20, the control section 7 terminates the removal process and restarts the printing process.

Specifically, the control unit 7 starts driving the first driving unit 14 and the second driving unit 15 . Further, the control unit 7 inputs a control signal to the first switch 61 to turn on the current path between the second power source 54 and the collecting roller 53 . Further, the control unit 7 inputs a control signal to the second switch 62 to turn on the current path between the first power supply 59 and the contact member 58 . Then, the control unit 7 inputs image data to be printed to the optical scanning device 25 and causes the image forming unit 3 to resume forming a toner image.

As described above, in the image forming apparatus 100 according to the first embodiment, the execution amount of the removing process for removing the deposits adhering to the contact member 58 is controlled based on the output state of the first power supply 59 . Thereby, it is possible to perform the removal process with an execution amount according to the adhesion state of the deposit on the contact member 58 . Therefore, it is possible to perform the removing process for removing the deposits adhering to the contact member 58 just enough.

Note that the execution control unit 81 controls the execution amount of the removal process (the execution time of the removal process, or the number of repetitions of the tension reduction process and the tension increase process) may be set.

Further, the first power supply 59 may control the voltage applied to the contact member 58 by constant voltage control. That is, the first power supply 59 may always apply a constant voltage to the contact member 58 . In this case, the execution control unit 81 may perform the removal process when the current supplied to the contact member 58 by the first power supply 59 is less than the predetermined first current value. Further, the execution control unit 81 controls the removal process when the current supplied to the contact member 58 by the first power supply 59 exceeds a second current value higher than the first current value during execution of the removal process. Processing should be terminated.

[Second embodiment]
An image forming apparatus 100 according to the second embodiment of the present invention will be described below with reference to FIG.

In the image forming apparatus 100 according to the second embodiment, the configuration of the belt cleaning section 44 is different from that of the first embodiment. Also, the contents of the removal process are different from those of the first embodiment. Other configurations are common between the first embodiment and the second embodiment.

Specifically, the belt cleaning section 44 of the image forming apparatus 100 according to the second embodiment includes the third switch 63 shown in FIG.

The third switch 63 is provided in the current path between the second power supply 54 and the contact member 58, and can switch between conduction and interruption of the current path. For example, the third switch 63 is a semiconductor switch such as a transistor. The third switch 63 switches conduction and interruption of the energization path between the second power supply 54 and the contact member 58 according to the input of the control signal from the control section 7 .

In the image forming apparatus 100 according to the second embodiment, by using the first switch 61 and the third switch 63, the output destination of the negative voltage of the second power supply 54 can be changed between the cleaning member 52 and the contact member 58. It is possible to switch between The second power supply 54, first switch 61, and third switch 63 in the second embodiment are examples of the second power supply of the present invention.

Further, in the removal process performed by the image forming apparatus 100 according to the second embodiment, a positive voltage is applied to the contact member 58 using the first power supply 59 while the driving of the intermediate transfer belt 41 is stopped. A first output process of outputting and a second output process of outputting a negative voltage to the contact member 58 using the second power supply 54 are alternately executed.

In addition, in the removal process executed by the image forming apparatus 100 according to the second embodiment, each time one of the first output process and the second output process is executed the first specific number of times, the region A switching process is executed.

[Second cleaning control process]
An example of the procedure of the second cleaning control process executed by the control unit 7 in the image forming apparatus 100 according to the second embodiment will be described below with reference to FIG. Similar to the first cleaning control process, the second cleaning control process is executed when the printing process is executed.

Some of the processes included in the second cleaning control process overlap in content with the first cleaning control process. In FIG. 8, the same reference numerals as the first cleaning control process are assigned to the processes that overlap with the first cleaning control process. Below, among the processes included in the second cleaning control process, only the processes different in content from the first cleaning control process will be described.

<Step S31>
In step S31, the control unit 7 executes the first output process.

Specifically, the control unit 7 inputs a control signal to the second switch 62 to turn on the current path between the first power source 59 and the contact member 58 . Further, when the energization path between the second power supply 54 and the contact member 58 is conductive, the control unit 7 inputs a control signal to the third switch 63 to cut off the energization path.

<Step S32>
In step S32, the controller 7 determines whether or not the voltage detected by the voltage detector 60 during execution of the first output process is less than the second threshold.

Here, when the control unit 7 determines that the voltage detected by the voltage detection unit 60 is less than the second threshold value (Yes side of S32), the process proceeds to step S20. Further, if the voltage detected by the voltage detection unit 60 is not less than the second threshold (No side of S32), the control unit 7 shifts the process to step S33.

<Step S33>
At step S33, the control unit 7 executes the second output process.

Specifically, the controller 7 inputs a control signal to the second switch 62 to cut off the current path between the first power source 59 and the contact member 58 . The control unit 7 also inputs a control signal to the third switch 63 to turn on the current path between the second power supply 54 and the contact member 58 .

By sequentially executing the processes of steps S31 and S33, the electrostatic force directed toward the contact member 58 and the electrostatic force directed toward the intermediate transfer belt 41 are sequentially applied to the adhering matter adhering to the contact member 58. works. In other words, the adhering matter adhering to the contact member 58 vibrates electrostatically. Due to this electrostatic vibration, the deposits adhering to the contact member 58 are discharged from the contact member 58 .

As described above, in the image forming apparatus 100 according to the second embodiment, the first output process and the second output process are alternately performed, and the adhered matter adhering to the contact member 58 is electrostatically charged. vibration is applied. As a result, as in the first embodiment, the deposits adhering to the contact member 58 can be removed.

[Third embodiment]
An image forming apparatus 100 according to the third embodiment of the present invention will be described below with reference to FIG.

In the image forming apparatus 100 according to the third embodiment, the configuration of the belt cleaning section 44 is different from that of the first embodiment. Also, the contents of the removal process are different from those of the first embodiment. Other configurations are common between the first embodiment and the third embodiment.

Specifically, the belt cleaning unit 44 of the image forming apparatus 100 according to the third embodiment includes a third power source 64 shown in FIG. 9 instead of the second power source 54 .

The third power supply 64 applies either a predetermined negative first specific voltage or a second specific voltage having the same polarity as the first specific voltage and being higher than the first specific voltage to the cleaning member. 52. That is, the third power supply 64 is a power supply that can switch the output voltage. The third power supply 64 is another example of the second power supply of the invention.

Here, the first specific voltage is a voltage applied to the cleaning member 52 when the cleaning member 52 is used to remove the deposit adhering to the surface of the intermediate transfer belt 41 . The cleaning member 52 removes the deposits adhering to the surface of the intermediate transfer belt 41 in response to the application of the first specific voltage.

For example, the second specific voltage has a voltage value twice that of the first specific voltage. The second specific voltage is the electrical resistance in the current path from the third power supply 64 to the ground via the collection roller 53, the distance along the outer peripheral surface of the intermediate transfer belt 41 from the cleaning position P4 to the contact position P5, and , and the electrical resistance of the surface layer of the intermediate transfer belt 41 .

Further, in the removal process performed by the image forming apparatus 100 according to the second embodiment, a positive voltage is applied to the contact member 58 using the first power supply 59 while the driving of the intermediate transfer belt 41 is stopped. A first output process of outputting and a third output process of outputting the second specific voltage to the cleaning member 52 using the third power supply 64 are alternately executed.

In addition, in the removal process executed by the image forming apparatus 100 according to the third embodiment, each time either the first output process or the third output process is executed the first specific number of times, the region A switching process is executed.

[Third cleaning control process]
An example of the procedure of the third cleaning control process executed by the control unit 7 in the image forming apparatus 100 according to the third embodiment will be described below with reference to FIG. 10 . Similar to the first cleaning control process, the third cleaning control process is executed when the printing process is executed.

A portion of the processing included in the third cleaning control processing overlaps with the content of the second cleaning control processing. In FIG. 10, the same reference numerals as the second cleaning control process are given to the processes whose content overlaps with the second cleaning control process. In the following, among the processes included in the third cleaning control process, only processes different in content from the second cleaning control process will be described.

<Step S41>
In step S41, the control unit 7 executes the first output process.

Specifically, the control unit 7 inputs a control signal to the second switch 62 to turn on the current path between the first power source 59 and the contact member 58 . Further, when the energization path between the third power source 64 and the collection roller 53 is electrically connected, the control section 7 inputs a control signal to the first switch 61 to cut off the energization path.

<Step S42>
At step S42, the control unit 7 executes the third output process.

Specifically, the controller 7 inputs a control signal to the second switch 62 to cut off the current path between the first power source 59 and the contact member 58 . Further, the control unit 7 inputs a control signal to the first switch 61 to turn on the energization path between the third power source 64 and the collection roller 53, and outputs the second specific voltage to the third power source 64. Let

A portion of the negative current supplied from the third power source 64 to the cleaning member 52 is also supplied to the contact member 58 by executing the process of step S42. As a result, an electric field opposite to that when the first output process is executed is formed at the contact position P5. Therefore, by sequentially executing the processes of steps S41 and S42, the adhering matter adhering to the contact member 58 is electrostatically vibrated. Due to this electrostatic vibration, the adhering matter adhering to the contact member 58 is discharged from the contact member 58 .

In addition, as shown in FIG. 11, a branch path leading to the ground may be provided in the current path between the first power supply 59 and the contact member 58, and the fourth switch 65 may be provided in the branch path. For example, the fourth switch 65 is a semiconductor switch such as a transistor. The control unit 7 uses the fourth switch 65 to cut off the branch path when executing the first output process, and closes the fourth switch 65 when executing the third output process. may be used to conduct the branch path.

As described above, in the image forming apparatus 100 according to the third embodiment, the first output process and the third output process are alternately executed to electrostatically vibration is applied. As a result, as in the first embodiment, the deposits adhering to the contact member 58 can be removed.

Incidentally, the image carrier of the present invention may be the photosensitive drum 31 . In this case, the cleaning member 52 , the contact member 58 , and the first power source 59 may be provided in correspondence with the photosensitive drum 31 .

Also, the first polarity of the present invention may be a negative polarity.

Further, the removal processing of the present invention is not limited to the content described above, and may include conventionally known content.

3 Image forming unit 4 Paper feeding unit 7 Control unit 14 First driving unit 15 Second driving unit 16 Third driving unit 20 Image forming unit 25 Optical scanning device 26 Intermediate transfer device 27 Secondary transfer roller 28 Fixing device 29 Paper discharge tray 30 roller supporting section 31 photoreceptor drum 34 primary transfer roller 41 intermediate transfer belt 44 belt cleaning section 52 cleaning member 54 second power source 58 contact member 59 first power source 60 voltage detection section 81 execution control section 100 image forming apparatus

Claims (10)

an image carrier that carries a toner image and conveys the toner image to a transfer position on a transfer material;
a cleaning member that removes deposits adhering to the surface of the image carrier in response to application of a voltage of the second polarity;
a contact member that contacts the image carrier downstream of the transfer position in the conveying direction of the toner image by the image carrier and upstream of the cleaning position of the cleaning member in the conveying direction; a first power supply that applies a voltage of a first polarity opposite to the second polarity to the member, and charges the first polarity to the attached matter passing through the contact position between the image carrier and the contact member; a charge supply unit that supplies
an execution control unit that controls an execution amount of a removal process for removing the deposits attached to the contact member based on the output state of the first power supply;
An image forming apparatus comprising: The first power supply controls current supplied to the contact member by constant current control,
The execution control unit executes the removal process when the voltage applied to the contact member by the first power supply exceeds a predetermined first threshold.
The image forming apparatus according to claim 1. The execution control unit terminates the removal process when the voltage applied to the contact member by the first power supply during execution of the removal process is less than a second threshold lower than the first threshold.
The image forming apparatus according to claim 2. The image carrier is a stretched belt-like member,
In the removal process, a tension reduction process for reducing the tension of the image carrier and a tension increase process for increasing the tension of the image carrier are alternately performed while the image carrier is stopped from being driven.
The image forming apparatus according to any one of claims 1 to 3. In the removing process, each time one of the tension reduction process and the tension increase process is executed a predetermined number of times, a region switching process is executed to switch a region of the image carrier facing the contact member. Ru
The image forming apparatus according to claim 4. a second power source capable of switching an output destination of the voltage of the second polarity between the cleaning member and the contact member;
In the removing process, a first output process of outputting the voltage of the first polarity to the contact member using the first power supply and the second power supply are used in a state in which the driving of the image carrier is stopped. A second output process of outputting the voltage of the second polarity to the contact member is alternately executed.
The image forming apparatus according to any one of claims 1 to 3. In the removing process, each time one of the first output process and the second output process is executed a predetermined number of times, a region switching process is performed to switch a region facing the contact member on the image carrier. executed,
The image forming apparatus according to claim 6. The cleaning member removes the deposits adhering to the surface of the image carrier in response to application of a predetermined first specific voltage,
The image forming apparatus is
a second power supply that outputs either the first specific voltage or a second specific voltage having the same polarity as the first specific voltage and higher than the first specific voltage to the cleaning member;
In the removing process, a first output process of outputting the voltage of the first polarity to the contact member using the first power supply and the second power supply are used in a state in which the driving of the image carrier is stopped. a third output process of outputting the second specific voltage to the cleaning member is alternately executed;
The image forming apparatus according to any one of claims 1 to 3. In the removing process, each time one of the first output process and the third output process is executed a predetermined number of times, a region switching process is performed to switch a region facing the contact member on the image carrier. executed,
The image forming apparatus according to claim 8. An image carrier that carries a toner image and conveys the toner image to a transfer position on a transfer receiving body, and removes deposits adhering to the surface of the image carrier in response to application of a voltage of a second polarity. a cleaning member; and a contact member that contacts the image carrier downstream of the transfer position in the conveying direction of the toner image by the image carrier and upstream of the cleaning position of the cleaning member in the conveying direction. , and a first power source for applying a voltage of a first polarity opposite to the second polarity to the contact member, and applying a voltage of the first polarity to the attached matter passing through the contact position between the image carrier and the contact member. A cleaning method performed in an image forming apparatus comprising: a charge supply unit that supplies charges of one polarity,
an acquisition step of acquiring the output status of the first power supply;
an execution control step of controlling, based on the output state of the first power supply, the amount of execution of a removal process for removing the deposits adhering to the contact member;
Cleaning method including.

Images