JP2023173334A - Image forming apparatus and scraper aging method - Google Patents

Abstract

To provide an image forming apparatus and a scraper aging method that can prevent shortening of the life of an intermediate transfer belt caused by a rubbing mark on a scraper left in the initial period of use.SOLUTION: A color image forming apparatus of an intermediate transfer system transfers a toner image from a transfer surface of an intermediate transfer belt to a recording medium, and removes residual toner from the transfer surface with a scraper having an edge with higher hardness than that of the transfer surface. In scraper aging, the color image forming apparatus separates primary transfer rollers in YMC colors from photoreceptor drums (S1201), separates a secondary transfer roller from a secondary transfer opposite roller (S1202), and rotates and moves the intermediate transfer belt while supplying a toner in K color (S1203) to prevent visual recognition of a rubbing mark generated on the transfer surface.SELECTED DRAWING: Figure 12

Description

The present disclosure relates to an intermediate transfer image forming apparatus and a scraper aging method, and particularly relates to a technique for suppressing shortening of the life of an intermediate transfer body due to cleaning.

In electrophotographic image forming devices used in light printing machines, copiers, printers, etc., when a toner image is transferred from an image carrier such as a photoreceptor or intermediate transfer member to a transfer target such as an intermediate transfer member or recording medium. In addition, part of the toner image remains on the image carrier. By removing this residual toner from the image carrier, it is possible to prevent the toner image to be transferred next from being smudged by the residual toner, thereby preventing the image quality from deteriorating. A cleaning blade is generally used as a cleaning means for removing residual toner.

The cleaning blade is an elastic body made of urethane elastomer or the like. When the image carrier is rotated with the cleaning blade pressed in a counter direction with respect to the rotating direction of the image carrier, residual toner on the image carrier can be scraped off and removed by the cleaning blade. The cleaning blade, while fixed within the apparatus, presses the edge against the image carrier by its own elastic restoring force, or presses the edge against the image carrier by being biased by a spring or the like.

If too much load is applied to the edge of the cleaning blade due to this pressure contact, the edge may be turned over or damaged, and the residual toner may not be sufficiently removed. Therefore, toner is supplied as a lubricant to the edge of the cleaning blade.

Specifically, toner is applied to a cleaning blade during the manufacture of an image forming apparatus. Further, when the image forming apparatus is used, a toner supply section is provided, and toner is supplied to the contact position of the cleaning blade from the upstream side in the rotational direction of the image carrier.

In this way, even when the printing rate is low and therefore there is little residual toner on the image carrier, a sufficient amount of toner can be supplied to the cleaning blade as a lubricant.

However, since the image bearing member, especially the intermediate transfer member, is pressed against the recording medium when transferring the toner image, it is not only residual toner that adheres to the surface of the intermediate transfer member, but also paper dust generated from the recording medium. Foreign matter other than residual toner may also adhere. If such foreign matter gets caught in the edge of the cleaning blade, or the residual toner sticks to the foreign matter that gets caught in the edge and becomes larger, a cleaning failure occurs in which the residual toner slips through the edge of the cleaning blade. The residual toner smudges subsequent toner images, reducing image quality.

Poor cleaning also occurs when the cleaning blade becomes worn after long-term use.

To solve this problem, for example, if a scraper is brought into contact with the downstream side of the cleaning blade in the rotating direction of the intermediate transfer body, the residual toner that has passed through the cleaning blade can be removed.

Further, since the cleaning blade removes residual toner on the upstream side of the scraper in the rotational direction of the intermediate transfer body, the amount of toner supplied to the edge of the scraper is small. For this reason, if a scraper made of urethane elastomer is used, the scraper will curl up and be damaged, making it impossible to remove residual toner that has passed through the cleaning blade.

On the other hand, if a flexible metal scraper is used, it will not curl up like a urethane elastomer scraper and will have high durability, making it possible to achieve highly reliable cleaning over a long period of time.

JP 2018-041039 Publication Japanese Patent Application Publication No. 2018-036287

The intermediate transfer belt, which is an intermediate transfer member, is generally made of resin such as polyimide. In recent years, resin intermediate transfer belts have been coated with glass (Si) on the surface layer in order to meet the demands for higher image quality and longer service life for image forming apparatuses. In this way, by adjusting the surface roughness of the intermediate transfer belt and improving the releasability of the toner image, it is possible to ensure high transfer performance regardless of the type of recording medium, thereby achieving high image quality. I can do it.

Further, the surface of the intermediate transfer belt is scratched due to repeated contact with the photoreceptor, the recording medium, and the separating claw for separating the sheets over a long period of time. In addition, scratches are also caused on the surface of the intermediate transfer belt when the external additive of the toner rubs against the intermediate transfer belt at a location where the edge of the cleaning blade or scraper contacts the intermediate transfer belt.

Regarding this problem, if glass coating is applied, the surface hardness of the intermediate transfer belt becomes higher and it becomes less likely to be scratched, so that the life of the intermediate transfer belt can be extended.

However, even if the intermediate transfer belt is made to have a high hardness, the cleaning blade has a lower hardness than the intermediate transfer belt without glass coating, so the effect is small, but the scraper has a lower hardness than the intermediate transfer belt without glass coating. Although it has a high hardness, it has a lower hardness than an intermediate transfer belt with a glass coating, so if you use the same material, it will be more likely to wear out, resulting in poor cleaning and a shorter lifespan. (See Patent Documents 1 and 2).

One possible solution to this problem is to apply a coating to the edge surface of the scraper to make it harder than the surface of the intermediate transfer belt. In this way, poor cleaning due to wear of the scraper can be prevented and the life of the scraper can be extended.

In particular, by reducing the difference in hardness between the scraper and the intermediate transfer belt, it is possible to reduce the damage to the intermediate transfer belt caused by repeated rubbing with the scraper, but this is still not enough to affect image quality. However, slight scratches may appear during the early stages of use, creating new problems such as the following.

In other words, these slight scratches do not deteriorate over time through use of the image forming apparatus, but visual inspection reveals that they are scratches caused by manufacturing defects in the intermediate transfer belt or scratches that occur over time. It is difficult to distinguish them from other types of scars because they look similar to other types of scars.

If there are scratches on the intermediate transfer belt due to manufacturing defects, this will lead to a decrease in image quality, so the product will be rejected as a defective product during inspection at the time of shipment. Additionally, if the intermediate transfer belt becomes scratched over time, users or service personnel should replace it to avoid deterioration in image quality.

For this reason, if the slight scratches mentioned above are mistaken for manufacturing defects or scratches caused by aging, the intermediate transfer belt will be discarded as a defective product even though there is no problem with the image quality. The life of the unit will be extremely shortened.

The present disclosure has been made in view of the above-mentioned problems, and provides an image forming apparatus and scraper aging that can prevent shortening of the life of an intermediate transfer belt due to scratches caused by the scraper during initial use. The purpose is to provide a method.

To achieve the above object, an image forming apparatus according to an embodiment of the present disclosure is an intermediate transfer type image forming apparatus that transfers a toner image from a transfer surface of an intermediate transfer belt to a recording medium, and has a height higher than that of the transfer surface. A scraper that removes residual toner by rubbing a hard edge on the transfer surface, a determination means that determines whether or not aging of the scraper is necessary, and when it is determined that aging is necessary, the scratch marks that occur on the transfer surface can be visually confirmed. The present invention is characterized by comprising a scraper aging means that performs the aging by rubbing the edge of the scraper in a manner that prevents the aging from occurring.

In this case, the scraper aging means may reduce the rubbing force of the edge of the scraper against the transfer surface so that the scratches produced on the transfer surface cannot be visually recognized.

Further, the scraper aging unit may make the scratches generated on the transfer surface invisible by dispersing them in the width direction perpendicular to the rotational running direction of the intermediate transfer belt.

Further, the intermediate transfer belt may have a coating layer on the transfer surface side, and the scraper may have a coating layer on the edge thereof that is harder than the coating layer on the transfer surface.

Further, the scraper aging means has a transfer inhibiting means for inhibiting the transfer of toner from the transfer surface to the recording medium, and by rotating the intermediate transfer belt with the inhibiting means inhibiting the toner transfer, the scraper aging means can prevent the toner from being transferred to the recording medium. Aging may be performed while supplying toner to the rubbing portion between the edge and the transfer surface.

In addition, a cleaning blade that comes into contact with the intermediate transfer belt to clean residual toner is provided on the rotation path of the intermediate transfer belt, from the toner transfer position from the transfer surface to the recording medium to the scraping position of the scraper edge. and cleaning blade contact/separation means for bringing the cleaning blade into contact with and separating from the transfer surface, and the scraper aging means rotates the intermediate transfer belt while the cleaning blade is separated from the transfer surface. Aging may be performed while supplying toner to the rubbing area between the edge of the transfer surface and the transfer surface.

The scraper aging means controls the pressure force of the edge of the scraper against the transfer surface, and the scraper aging means performs aging while reducing the pressure force of the edge of the scraper against the transfer surface compared to when forming an image. You may do so.

The scraper aging means further includes photoconductors that form toner images of each YMCK color, and primary transfer means that transfers toner images of each YMCK color from the corresponding photoconductor to a transfer surface. By separating the primary transfer means from the photoreceptor, the belt tension of the intermediate transfer belt is lowered than when the primary transfer means for each YMC color is pressed against the photoreceptor, and the toner image formed on the K color photoreceptor is Aging may be performed by transferring the K toner onto the transfer surface and supplying the K color toner to the rubbing portion between the edge of the scraper and the transfer surface.

The belt tension control means changes the belt tension of the intermediate transfer belt by controlling the contact pressure of the tension roller against the inner circumferential surface of the intermediate transfer belt. Aging may be performed with the belt tension lowered.

Further, the apparatus may include an intermediate transfer belt displacement means for displacing the intermediate transfer belt in the width direction, and the scraper aging means may perform aging while continuing to displace the intermediate transfer belt in the width direction.

The device also includes a usage status storage means for storing whether or not the scraper is unused, and the aging necessity determining means determines that aging is necessary when the scraper is stored as unused. It's okay.

The device also includes a usage status detection means for detecting whether or not the scraper is unused, and the aging necessity determining means determines that aging is necessary when the scraper is detected to be unused. Good too.

Further, the cleaning blade is provided, and when at least one of the cleaning blade and the intermediate transfer belt is unused and the scraper is unused, the pressure contact force control means is in a state where the edge of the scraper is separated from the transfer surface. and a blade setting means for supplying toner to a sliding portion between the cleaning blade and the transfer surface by rotating the intermediate transfer belt, and the scraper aging means, after the blade setting means finishes supplying toner, Aging may be performed.

In addition, when the scraper aging means ages the scraper, at least one of the scraper and the intermediate transfer belt is moved against the other at the rubbing portion of the edge of the scraper on the rotation path of the intermediate transfer belt. A relative moving means for relatively moving the intermediate transfer belt in the width direction perpendicular to the rotational running direction of the intermediate transfer belt may be provided.

Further, regulating members may be provided for regulating the relative movement on the upstream and downstream sides of the sliding portion of the edge of the scraper on the rotational traveling path of the intermediate transfer belt.

Further, the coating layer on the transfer surface may have Si as a main component.

Additionally, the coating material on the edge of the scraper may be DLC.

Further, the scraper aging method according to the present disclosure is an intermediate transfer method in which a toner image is transferred from a transfer surface of an intermediate transfer belt to a recording medium, and residual toner is removed from the transfer surface with a scraper having an edge harder than the transfer surface. A scraper aging method executed by an image forming apparatus, comprising a determination step of determining whether or not aging of the scraper is necessary, and when it is determined that aging is necessary, making scratches generated on the transfer surface invisible. The method is characterized by including a scraper aging step of performing the aging by rubbing the edge of the scraper.

In this way, when it is determined that aging is necessary, the aging is performed by rubbing the edge of the scraper so that the scratches that occur on the transfer surface are not visible, so the scratches that are visually confirmed This can prevent scratches from being mistakenly judged as scratches that degrade image quality.

Therefore, even though there is no risk of deteriorating image quality, it is possible to prevent the intermediate transfer belt from being replaced or discarded, which improves the defect rate during production and reduces the man-hours for service personnel. It is possible to suppress an increase in the office cost of the image forming apparatus, and to improve the user's trust in the image forming apparatus.

1 is a diagram showing the main configuration of an image forming apparatus 1 according to a first embodiment of the present disclosure. 3 is a diagram showing the main configuration of a control section 160. FIG. 1 is a diagram showing the main configuration of a cleaning section 100. FIG. 3 is a diagram illustrating a coating layer formed on the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301. FIG. 3 is an enlarged view illustrating the shape of an edge of a new scraper 301. FIG. 3 is an enlarged view illustrating the shape of the edge of the scraper 301 after rubbing against the transfer surface of the intermediate transfer belt 116. FIG. 7 is an enlarged view illustrating a different shape from FIG. 6 of the edge of the scraper 301 after rubbing against the transfer surface of the intermediate transfer belt 116. FIG. 2 is a block diagram showing the main functional configuration of a control unit 160. FIG. (a) is a diagram illustrating the positions of the primary transfer rollers 115Y, 115M, and 115C when forming a color image, and (b) is a diagram illustrating the positions of the primary transfer rollers 115Y, 115M, and 115C during scraper aging and monochrome image formation. It is a figure which illustrates the position of 115C. (a) is a diagram illustrating the position of the secondary transfer roller 118 during image formation, and (b) is a diagram illustrating the position of the secondary transfer roller 118 during scraper aging. It is a flowchart explaining the processing procedure for performing scraper aging processing concerning a 1st embodiment of this indication. It is a flow chart explaining the contents of scraper aging processing concerning a 1st embodiment of this indication. FIG. 2 is a block diagram showing the main functional configuration of a control unit 160 according to a second embodiment of the present disclosure. 3 is a diagram illustrating a mechanism for changing the pressing force of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 and the contact/separation state of the cleaning blade 311 with the transfer surface. FIG. 7 is a flowchart illustrating a process for controlling the contact/separation state of the cleaning blade 311 with respect to the transfer surface of the intermediate transfer belt 116. FIG. FIG. 3 is a block diagram showing the main functional configuration of a control unit 160 according to a third embodiment of the present disclosure. 7 is a flowchart illustrating a process for controlling the pressure force of the scraper 301 against the transfer surface of the intermediate transfer belt 116. FIG. FIG. 3 is a block diagram showing the main functional configuration of a control unit 160 according to a fourth embodiment of the present disclosure. (a) is a diagram illustrating the position of the tension roller 1901 during image formation, and (b) is a diagram illustrating the position of the tension roller 1901 during scraper aging. It is a block diagram showing the main functional composition of control part 160 concerning a 5th embodiment of this indication. (a) is an enlarged view illustrating the scratches formed on the transfer surface when the intermediate transfer belt 116 is not swung in the width direction, and (b) is an enlarged view illustrating the scratches formed on the transfer surface when the intermediate transfer belt 116 is swung in the width direction. FIG. 3 is an enlarged view illustrating scratch marks on a transfer surface. It is a block diagram showing the main functional composition of control part 160 concerning a 7th embodiment of this indication. It is a flowchart explaining the processing procedure for performing blade set processing and scraper aging processing concerning a 7th embodiment of this indication. It is a flow chart explaining the contents of blade set processing concerning a 7th embodiment of this indication. It is a table comparing characteristics related to the hardness of the coating layer, the presence or absence of scraper aging, and scratch marks for the conventional technology and the present disclosure. FIG. 3 is an enlarged view illustrating a transfer surface with so few scratch marks that they cannot be visually confirmed, and a transfer surface with a large number of scratch marks that can be visually confirmed. 1 is a table showing evaluation results of Examples 1 to 9 and Comparative Examples 1 to 2.

Embodiments of an image forming apparatus and a scraper aging method according to the present disclosure will be described below with reference to the drawings.
[1] First Embodiment (1-1) Configuration of Image Forming Apparatus The configuration of the image forming apparatus according to this embodiment will be described.

As shown in FIG. 1, the image forming apparatus 1 is a so-called full-color tandem dry type electrophotographic multi-function peripheral (MFP). The image forming apparatus 1 includes an image forming section 110, a paper feeding section 120, a fixing section 130, an image reading section 140, an operation panel 150, and a control section 160.

When the image forming apparatus 1 receives an image forming job under the monitoring control by the control unit 160, it operates each part of the image forming apparatus 1 as follows according to instructions in the image forming job to perform image forming processing. Execute.

The image forming unit 110 includes photoreceptor drums 111Y, 111M, 111C, and 111K, and a charging device 112Y to form toner images of yellow (Y), magenta (M), cyan (C), and black (K). , 112M, 112C and 112K, exposure devices 113Y, 113M, 113C and 113K, and developing devices 114Y, 114M, 114C and 114K.

The image forming unit 110 also includes a cleaning unit that cleans the outer peripheral surfaces of the photoreceptor drums 111Y, 111M, 111C, and 111K after primary transfer, which will be described later, and a cleaning unit that applies lubricant to the outer peripheral surfaces of the photoreceptor drums 111Y, 111M, 111C, and 111K. It is common to have a lubricant application means for applying the lubricant.

The photoreceptor drums 111Y, 111M, 111C, and 111K have photoreceptor layers along their outer peripheral surfaces. When the photoreceptor layer becomes electrically conductive through exposure, the electrical charge at the exposed portion on the outer circumferential surface disappears due to a ground fault.

The charging devices 112Y, 112M, 112C, and 112K uniformly charge the outer peripheral surfaces of the photoreceptor drums 111Y, 111M, 111C, and 111K.

The exposure devices 113Y, 113M, 113C, and 113K read image data specified in an image forming job from a storage unit 211, which will be described later, and emit laser light modulated according to image data of each color of YMCK that constitutes the image data. The outer peripheral surfaces of the photoreceptor drums 111Y, 111M, 111C, and 111K are irradiated.

The exposure devices 113Y, 113M, 113C, and 113K are equipped with an LD (Laser Diode) as a light emitting element, and when the amount of light emitted from the LD is controlled according to image data, the outer peripheral surfaces of the photoreceptor drums 111Y, 111M, 111C, and 111K are On the top, the charging state changes depending on the amount of incident light. In this way, electrostatic latent images corresponding to the image data of each color of YMCK are formed.

Developing devices 114Y, 114M, 114C, and 114K supply toners of each color, YMCK, to the outer peripheral surfaces of photoreceptor drums 111Y, 111M, 111C, and 111K, respectively, to develop electrostatic latent images. As a result, toner images of each color of YMCK (monochrome toner images) are formed.

Primary transfer rollers 115Y, 115M, 115C, and 115K transfer the YMCK color toner images from the outer circumferential surfaces of photoreceptor drums 111Y, 111M, 111C, and 111K to the outer circumferential surface of intermediate transfer belt 116 (hereinafter referred to as "transfer surface"). .) Electrostatically transfer onto the surface (primary transfer).

When forming a color image (color toner image) having Y, M, C, and K as color components, toner images of each color of YMCK are sequentially electrostatically transferred so as to overlap each other on the transfer surface.

When forming a monochrome image (monochrome toner image) having only K as a color component, only a K color toner image is formed, and no YMC color toner image is formed. Further, as will be described later, when forming a monochrome image, the image forming apparatus 1 moves the intermediate transfer belt 116 to the photoreceptor drums 111Y, 111M, and 111C by moving the primary transfer rollers 115Y, 115M, and 115C. separate from In this way, the belt tension applied to the intermediate transfer belt 116 is lower than when forming a color image.

The intermediate transfer belt 116 carries the toner image on its transfer surface and rotates in the direction of arrow A to convey the toner image to the secondary transfer position.

The intermediate transfer belt 116 is an endless belt wound around a plurality of rollers including a drive roller 117, and rotates and runs as the drive roller 117 rotates. The intermediate transfer belt 116 is an image carrier that carries and conveys a toner image.

It goes without saying that, in place of the drive roller 117, another roller around which the intermediate transfer belt 116 is wound may be used to rotate and drive the intermediate transfer belt 116.

As the intermediate transfer belt 116, for example, a belt made of a material such as polyimide or polyamide in which a conductive material is added to a resin can be used. Furthermore, in order to improve transferability when a recording medium with an uneven surface, such as embossed paper, is used, a belt may be used that has an elastic layer such as rubber on at least the surface that contacts the recording medium.

Further, in order to provide the intermediate transfer belt 116 with appropriate conductivity, the above-mentioned resin generally contains an appropriate amount of a conductive agent such as carbon black or an ion conductive agent. The intermediate transfer belt 116 is configured to have a volume resistivity of 10 ⁶ to 10 ¹⁴ Ω·cm, and the thickness of the intermediate transfer belt 116 is, for example, about 0.1 mm.

The paper feed unit 120 supplies the type of recording medium specified in the image forming job from a paper feed tray, a manual feed tray provided outside the apparatus, or the like. The recording medium is conveyed to the secondary transfer position in synchronization with the intermediate transfer belt 116 conveying the toner image to the secondary transfer position.

The secondary transfer roller 118 electrostatically transfers the toner image from the transfer surface of the intermediate transfer belt 116 onto the printing surface of the recording medium at the secondary transfer position (secondary transfer). Specifically, the secondary transfer roller 118 forms a secondary transfer nip by coming into pressure contact with the secondary transfer opposing roller 119 with the intermediate transfer belt 116 in between. By inserting a recording medium into the secondary transfer nip while a predetermined secondary transfer voltage is applied to the secondary transfer roller 118, the toner image carried on the intermediate transfer belt 116 is transferred to the recording medium side. It is electrostatically attracted and transferred onto the printing surface of the recording medium.

Note that the secondary transfer roller 118 can be separated from the secondary transfer opposing roller 119. When the secondary transfer roller 118 is separated from the secondary transfer opposing roller 119 and the secondary transfer voltage is not applied to the secondary transfer roller 118, the recording medium is not supplied from the paper feed unit 120. When the intermediate transfer belt 116 is rotated, the toner carried on the transfer surface of the intermediate transfer belt 116 is transported directly to the cleaning section (cleaning unit) 100 without being secondarily transferred at the secondary transfer position. Ru.

In order to press the secondary transfer roller 118 into contact with and separate from the secondary transfer opposing roller 119, for example, a cam (not shown) as described later is used to connect the bearing of the rotating shaft of the secondary transfer roller 118 to the secondary transfer opposing roller 119. It may be displaced in the direction toward 119. Further, it goes without saying that the secondary transfer roller 118 may be pressed against and separated from the secondary transfer opposing roller 119 using a means other than the cam.

The recording medium carrying the secondarily transferred toner image is conveyed to the fixing device 130.

Furthermore, after the toner image is secondarily transferred from the transfer surface of the intermediate transfer belt 116 onto the printing surface of the recording medium, depending on the charging state of the toner and the surface conditions of the intermediate transfer belt 116 and the recording medium, the toner image may be Some of the toner remains on the transfer surface of the intermediate transfer belt 116 without being secondarily transferred.

The cleaning device 100 cleans the transfer surface of the intermediate transfer belt 116 to remove residual toner. In this way, it is possible to prevent the residual toner from staining the toner image that has been primarily transferred thereafter, so that excellent image quality can be achieved.

The fixing device 130 includes a fixing roller 131 and a pressure roller 132, and when the pressure roller 132 is pressed against the fixing roller 131, a fixing nip is formed. The recording medium inserted into the fixing nip has a toner image melted and pressed by a high-temperature fixing roller 131 (thermal fixing).

The fixing roller 131 has a cylindrical shape and has a built-in halogen lamp heater. This halogen lamp heater generates heat by being energized under the control of the control unit 160 to raise the temperature of the cylindrical portion. Further, the fixing roller 131 is driven and rotated by a rotary drive means such as a motor (not shown) under the control of the control unit 160, and conveys the recording medium.

The pressure roller 132 is urged toward the fixing roller 131 by an unillustrated elastic member, so that it is in pressure contact with the fixing roller 181 and rotates as the fixing roller 181 rotates.

Note that the pressure roller 132 may be driven and rotated by a rotation drive means such as a motor (not shown) under the control of the control unit 160.

After the toner image is thermally fixed on the front surface of the recording medium, if an image is to be further formed on the back surface of the recording medium, the recording medium is conveyed to the switchback path 121 and turned over. The recording medium with its front and back sides reversed is conveyed again to the secondary transfer position, and an image is formed on the back side.

After the toner image is thermally fixed on the front side of the recording medium in single-sided printing and after the toner image is thermally fixed on the back side of the recording medium in double-sided printing, the recording medium is discharged onto the paper discharge tray 133.

Note that a plurality of pairs of paper conveyance rollers are arranged on the conveyance path of the recording medium from a paper feed source such as a paper feed tray or a manual feed tray to the paper discharge tray 133. The paper transport roller pair is a pair of paper transport rollers pressed against each other to form a transport nip. When a recording medium is inserted into the conveyance nip with one paper conveyance roller rotationally driven and the other paper conveyance roller driven to rotate, the recording medium is conveyed in the rotational direction of the paper conveyance roller.

The image reading section 140 includes an automatic document transport section 141 and a scanner section 142, and reads a document using a sheet-through method and a platen set method to generate image data. The image reading unit 140 stores the generated image data in a storage unit 211, which will be described later.

The image reading unit 140 generates monochrome image data according to specifications in a scan job. Alternatively, color image data consisting of monochrome image data for each color component of R (red), G (green), and B (blue) may be generated.

When reading a document using the sheet-through method, the automatic document transport unit 141 feeds the document one sheet at a time from a stack of documents placed on the document tray, and feeds the document one by one over the reading position of the scanner unit 142. A section 142 reads the original. The documents that have been read are sequentially discharged onto the paper discharge tray of the automatic document transport section 141.

When reading a document using the platen set method, the document is read with the reading surface of the document pressed against the platen glass of the scanner unit 142. A white background plate is provided on the lower surface of automatic document transport section 141, and when reading a document, automatic document transport section 141 can be closed to cover the document.

The operation panel 150 includes hard keys 151 and a touch panel 152. The touch panel 152 is a touch pad superimposed on the display screen of a flat display panel (FDP) such as a liquid crystal display (LCD), and is used to perform screen display using the flat display panel. Touch pads can be used to receive touch input.

The operation panel 150 uses the touch panel 152 under the control of the control unit 160 to display an operation screen showing the status of the image forming apparatus 1 and the contents of input operations to the touch panel 152. Present information to users. Further, the operation panel 150 receives a user's instruction input using the hard keys 151 and the touch panel, and thereby outputs an operation signal according to the instruction input to the control unit 160.
(1-2) Control unit 160
Next, the configuration of the control section 160 will be explained.

As shown in FIG. 2, the control unit 160 includes a CPU (Central Processing Unit) 201, a RAM (Random Access Memory) 202, a ROM (Read Only Memory) 203, and an NIC (Network Interface Card).

Further, the control unit 160 uses the internal bus 221 to control the cleaning unit 100, image forming unit 110, paper feeding unit 120, fixing unit 130, image reading unit 140, storage unit 211, image processing unit 212, and operation panel 150. Connected so that they can communicate with each other.

The CPU 201 reads and executes various control programs, setting data, etc. stored in the ROM 203 and the storage unit 211, thereby monitoring the status of each part of the image forming apparatus 1 and controlling its operation. .

For example, the control unit 160 controls the paper feeding unit 120 to supply a recording medium and causes the image forming unit 110 to form an image on the recording medium based on the image data stored in the storage unit 211.

The RAM 202 provides a working memory space for the CPU 201 and stores temporary data.

The ROM 203 stores various control programs executed by the CPU 201, setting data, and the like. Note that in place of the ROM 203, a rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

The NIC 204 executes processing for transmitting and receiving data with external computers, other image forming apparatuses, and the like. The NIC 204 may be configured by, for example, any of various serial interfaces.

The storage unit 211 is constituted by a storage means such as a semiconductor memory such as a DRAM (Dynamic Random Access Memory) or an HDD (Hard Disk Drive), and stores various data. The storage unit 211 stores image data acquired by the scanner 15, image data received from the outside using the NIC 204, and the like.

Note that these image data and the like may be stored in the RAM 202. Furthermore, the storage unit 211 stores a print number counter that counts the number of printed sheets.

The image processing section 212 includes a rasterization processing section, a color conversion section, a gradation correction section, a halftone processing section, and the like. The image processing unit 212 performs various types of image processing on the image data stored in the storage unit 211 under the control of the control unit 160 and causes the storage unit 211 to store the results.
(1-3) Cleaning section 100
Next, the cleaning section 100 will be explained.

As shown in FIG. 3, the cleaning section 100 includes a first cleaning means 310 and a second cleaning means 300. The first cleaning unit 310 cleans residual toner on the transfer surface of the intermediate transfer belt 116 after the secondary transfer.

The second cleaning means 300 is disposed downstream of the first cleaning means 310 in the rotational running direction of the intermediate transfer belt 116 . The second cleaning unit 300 cleans toner remaining on the transfer surface of the intermediate transfer belt 116 after cleaning by the first cleaning unit 310.
(1-3-1) First cleaning means 310
The first cleaning means 310 includes a cleaning blade 311 , a conveying screw 314 , a cleaning unit housing 315 , a toner storage roller 316 , and a regulating member 317 .

The cleaning blade 311 has an elastic blade 312 attached to a support metal plate 313. The edge of the blade 312 is brought into pressure contact with the transfer surface of the intermediate transfer belt 116 in a direction counter to the rotational direction of the intermediate transfer belt 116.

The blade 312 is made of, for example, solid rubber such as polyurethane or NBR (Nitrile-Butadiene Rubber).

The support metal plate 313 is pivotally supported by a swing shaft that is elongated in the width direction of the intermediate transfer belt 116, and swings around the swing shaft. A blade 312 is attached to one end of the support metal plate 313 across the swing axis, and a spring 319 is attached to the other end, and the support plate 313 is swung by the elastic restoring force of the spring 319. The edge may be brought into pressure contact with the transfer surface of the intermediate transfer belt 116 (spring pressure contact type).

In addition, instead of the supporting metal plate 313, the blade 312 is attached to the cleaning unit housing 315 using screws or the like (not shown), and the elastic restoring force of the blade 312 allows the edge of the blade 312 to be attached to the intermediate transfer belt 116. It may be pressed against the transfer surface (fixed pressure contact type).

At a position where the edge of the blade 312 comes into pressure contact with the rotation path of the intermediate transfer belt 116, the cleaning opposing roller 321 is in contact with the back side of the transfer surface. In this way, the blade 312 is deflected more than when the intermediate transfer belt 116 is pushed by the edge and deforms in the direction of pressure contact with the edge.

Then, since the elastic restoring force of the blade 312 increases, the pressing force of the edge against the transfer surface of the intermediate transfer belt 116 increases. As a result, the edge of the blade 312 can closely fit along the transfer surface of the intermediate transfer belt 116 to form a stable nip, thereby suppressing residual toner from slipping through the nip and improving cleaning performance. be able to.

The residual toner removed from the transfer surface of the intermediate transfer belt 116 by the cleaning blade 311 is collected into the cleaning unit housing 315 and then transported into a waste toner bottle (not shown) using the transport screw 314.

Further, a portion of the residual toner collected in the cleaning unit housing 315 is accumulated in a toner storage section 318 by a toner storage roller 316. By rotating the toner storage roller 316 in the direction of arrow B, residual toner is conveyed from the toner storage section 318 onto the transfer surface of the intermediate transfer belt 116.

The regulation member 317 regulates the amount of toner conveyed by the toner storage roller 316 so that the toner layer formed on the outer peripheral surface of the toner storage roller 316 has a predetermined thickness. As a result, the amount of residual toner supplied onto the transfer surface of the intermediate transfer belt 116 is regulated.

The residual toner supplied onto the transfer surface of the intermediate transfer belt 116 by the toner storage roller 316 acts on the edge of the cleaning blade 311 as a lubricant. In this way, the edge of the cleaning blade 311 can be prevented from being damaged, so that the life of the cleaning blade 311 can be extended.

Note that the toner storage roller 316 may be a foamed roller made of NBR or the like, but the material and structure are not limited thereto. Although the regulating member 317 is a flexible metal member made of SUS (Stainless Use Steel) or the like, the material and structure are not limited thereto.

Similarly, the materials of the parts used within the cleaning unit are not particularly limited. Further, the configuration is not limited to the above content, and a roller, a brush, etc. for adjusting the toner polarity may be used.
(1-3-2) Second cleaning means 300
If the cleaning blade 311 constituting the first cleaning unit 310 is damaged or worn due to use, or if foreign matter suddenly gets caught in it, residual toner may not be completely removed. The second cleaning means 300 cleans such removed and leaked toner.

The second cleaning means 300 includes a scraper 301, a conveying screw 305, and a cleaning unit housing 306. The residual toner scraped by the scraper 301 from the transfer surface of the intermediate transfer belt 116 is collected in the cleaning unit housing 306, and then conveyed by the conveyance screw 305 into a waste toner bottle (not shown).

The scraper 301 has a flexible metal blade 302 sandwiched between support metal plates 303 and 304. Like the cleaning blade 311, the scraper 301 may be a spring pressure contact type using a spring 307 or a fixed pressure contact type.

The metal blade 302 is a plate-like member that is elongated in the width direction of the intermediate transfer belt 116. The edge of the metal blade 302 is pressed against the transfer surface of the intermediate transfer belt 116 in a direction counter to the rotational running direction of the intermediate transfer belt 116. In this pressurized state, the metal blade 302 scrapes off residual toner adhering to the transfer surface.

The metal blade 302 has a base material and a coating layer formed on a portion including an edge. The base material is, for example, a thin plate of metal such as iron or stainless steel with a thickness of about several tens to several hundred μm.

Further, the coating layer can be composed of, for example, a hard carbon film containing amorphous carbon such as DLC (Diamond-Like Carbon), a silicon carbide (SiC) film, metal plating, or the like. The coating layer has higher hardness than the coating layer of the intermediate transfer belt 116.

At the pressure contact position of the metal blade 302 on the rotation path of the intermediate transfer belt 116, the metal blade 302 is in pressure contact with the back side of the transfer surface of the intermediate transfer belt 116, thereby preventing the intermediate transfer belt 116 from displacing. Preferably there is nothing.

However, at the pressure contact position of the metal blade 302, sufficient belt tension must be applied to the intermediate transfer belt 116. In the present embodiment, it is desirable that sufficient belt tension be applied to the intermediate transfer belt 116 along the rotation path of the intermediate transfer belt 116 from the cleaning opposing roller 321 to the drive roller 117.

Note that even if the intermediate transfer belt 116 is driven to rotate by using another roller around which the intermediate transfer belt 116 is wound instead of the drive roller 117, the intermediate transfer belt 116 from the cleaning facing roller 321 to the roller 117 It is desirable that sufficient belt tension be applied to the intermediate transfer belt 116 along the rotational travel path of the transfer belt 116.

Similarly, if another roller is disposed on the rotation path of the intermediate transfer belt 116 from the cleaning opposing roller 321 to the pressure contact position of the metal blade 302, from the other roller to the driving roller (or just a roller) ) 117, it is desirable that sufficient belt tension be applied to the intermediate transfer belt 116 on the rotational travel path of the intermediate transfer belt 116.

When the metal blade 302 is brought into pressure contact with the intermediate transfer belt 116 under belt tension, and the flexible metal blade 302 is bent, the elastic restoring force of the metal blade 302 itself causes the edge of the metal blade 302 to be pressed against the intermediate transfer belt 116. 116.

In this way, the edge of the metal blade 302 can be brought into close contact with the transfer surface of the intermediate transfer belt 116, so that the cleaning performance of the metal blade 302 can be improved.

Note that the second cleaning unit 300 is disposed downstream of the first cleaning unit 310 in the rotational running direction of the intermediate transfer belt 116, in other words, in the residual toner conveyance direction. Therefore, only the residual toner that could not be removed by the first cleaning means 310 is conveyed to the pressure contact position of the metal blade 302.

For this reason, if a cleaning blade is used instead of the metal blade 302 in the second cleaning means 300, the cleaning blade may be damaged or worn due to the lack of residual toner that can be used as a lubricant. It becomes easier. For this reason, the second cleaning means 300 uses a metal blade 302 instead of a cleaning blade.

In this way, there is no need to supply residual toner as a lubricant to the metal blade 302, and therefore, unlike the first cleaning means 310, there is no need to store the collected residual toner. Therefore, all the residual toner collected by the second cleaning means 300 is transported into a waste toner bottle (not shown) using the transport screw 305.

Note that when the scraper 301 is placed in pressure contact with the rotation path of the intermediate transfer belt 116, a rigid member is placed so as to face the edge of the scraper 301 and come into contact with the inner peripheral surface of the intermediate transfer belt 116. There is no Therefore, the intermediate transfer belt 116 can be freely bent toward the inner circumferential side according to the pressure applied by the scraper 301.

Since the edge of the metal blade 302 has high hardness, even if it is pressed against the transfer surface of the intermediate transfer belt 116, the edge will not be crushed and no nip will be formed. If a rigid member is in contact with the inner peripheral surface of the intermediate transfer belt 116 at a position opposite to the edge of the metal blade 302 while sandwiching the intermediate transfer belt 116, the edge of the metal blade 302 may Excessive pressure may be applied, or a gap may be created between the edge of the metal blade 302 and the transfer surface of the intermediate transfer belt 116.

On the other hand, as in this embodiment, if a rigid member is not provided that presses the edge of the metal blade 302 across the intermediate transfer belt 116, the edge of the metal blade 302 presses against the intermediate transfer belt 116. can be bent freely.

Therefore, due to the pressure contact, the edge of the metal blade 302 is brought into a state where it bites into the transfer surface of the intermediate transfer belt 116, so that residual toner can be removed from the transfer surface of the intermediate transfer belt 116 without leaking.

Furthermore, with such a configuration, when the belt tension of the intermediate transfer belt 116 is reduced, the pressing force of the edge of the metal blade 302 against the transfer surface of the intermediate transfer belt 116 is reduced. Scratch marks from the edge of the metal blade 302 are less likely to be left on the transfer surface of the metal blade 302.
(1-4) Edge shape of scraper 301 Next, the edge shape of scraper 301 will be explained.

As shown in FIG. 4, the scraper 301 includes a base material 401 and a coating layer 402 formed on a portion of the base material 401 including the edges. Further, the intermediate transfer belt 116 includes a base material 411 and a coating layer 412 formed on the transfer surface of the base material 411. The coating layer 412 of the intermediate transfer belt 116 may be, for example, a glass layer made of a material containing Si, or may be made of another material.

The coating layer 402 of the scraper 301 has a higher hardness than the coating layer 412 of the intermediate transfer belt 116. Therefore, when the coating layers 402 and 412 are rubbed, rubbing marks are left on the coating layer 412 of the intermediate transfer belt 116.

Further, FIG. 5 is an example of an enlarged view of the edge of the new scraper 301 magnified 4000 times. In the example of FIG. 5, a new scraper 301 has a protrusion 501 on its edge with a width of 10 to 20 μm and a height of about 5 μm.

When the edge of the scraper 301 is rubbed against the transfer surface of the intermediate transfer belt 116, the pressing force is concentrated at the tip of the protrusion of the edge, so that a scratch with a width of about 1 μm is left on the transfer surface of the intermediate transfer belt 116.

Many protrusions similar to the protrusions 501, such as protrusions 502 and 503, are likely to be formed on the edge of the scraper 301, and it is difficult to eliminate them by improving the precision in manufacturing the base material 401 of the scraper 301. When manufacturing the scraper 301, the remaining portions of a rolled thin metal plate are masked with photoresist, and the unmasked portions are melted by etching to form a desired shape. Even if the rolling direction and etching method were changed, it was not possible to eliminate the minute protrusions on the edges.

If there are protrusions on the base material 401 of the scraper 301 as described above, even if the coating layer 402 is provided, if the thickness of the coating layer 402 is about 1 μm, the protrusions will remain on the surface of the coating layer 402. Therefore, even if the coating layer 402 is provided, it is not possible to avoid the occurrence of scratch marks.

The scratch marks formed on the intermediate transfer belt 116 vary depending on the overall undulation of the scraper 301, the state of the surface layer of the intermediate transfer belt 116, and the contact state between the intermediate transfer belt 116 and the scraper 301. It is difficult to judge in advance whether marks will be generated.

For example, large protrusions such as edge abnormalities and dents do not attract much pressure, so abrasions, especially collections of fine scratches, do not occur on the transfer surface. Therefore, even if an inspection is performed to observe the protrusions on the edge of the scraper 301, it is not possible to identify and remove protrusions that may cause scratches.

Furthermore, in order to detect minute protrusions, a high-magnification microscope is required, which makes the inspection too time-consuming and impractical. As described above, it is difficult to identify whether or not the edge of the scraper 301 has a protrusion that causes scratches on the transfer surface of the intermediate transfer belt 116, and to eliminate the scraper 301 having such a protrusion.

However, even if a used scraper 301 that has been used to some extent rubs against the intermediate transfer belt 116, no scratches will be generated on the transfer surface. This is because when the scraper 301 rubs against the intermediate transfer belt 116 during use, the state of the edge of the scraper 301 changes and there are no minute protrusions that would cause scratches on the transfer surface.

FIG. 6 is an enlarged view illustrating the edge after the scraper 301 illustrated in FIG. 5 is rubbed on the intermediate transfer belt 116. As shown in FIG. 6, edges 601, 602, and 603 corresponding to the protrusions 501, 502, and 503 shown in FIG. 5 are all flat.

The protrusion on the edge may include a portion where the coating layer 402 is thick, or a portion where the coating layer 402 is not thick but has a protrusion on the base body 401. The coating layer 402 of the scraper 301 has high hardness and therefore does not deform even if an external force is applied thereto, whereas the base body 401 is made of metal and can deform when an external force is applied to it.

In contrast, by sliding the scraper 301 on the intermediate transfer belt 116, the base 401 can be deformed and the edges can be flattened. After the edge is flattened, even if the scraper 301 is rubbed against the intermediate transfer belt 116, it becomes difficult to leave scratch marks on the transfer surface.

Specifically, the edge of the scraper 301 can be flattened by rubbing the scraper 301 against the intermediate transfer belt 116 by about 50 m to 100 mm. The time required for this rubbing is, for example, about 125 seconds to 250 seconds in an image forming apparatus in which the rotation speed of the intermediate transfer belt 116 is 400 mm/sec.

When the scraper 301 with the flattened edge was cut and the cross-sectional shape was observed, it was found that the thickness of the coating layer 402 did not change, and only the metal base 401 was deformed, resulting in flattening.

Even if the scraper is not provided with a coating layer, if the scraper is made of metal, the edges can be flattened by rubbing against the intermediate transfer belt in the same way. Furthermore, in this case, there is no need to wear out the protrusion on the edge, but only to deform it, so the sliding distance (sliding time) between the scraper and the intermediate transfer belt can be short.

Note that when manufacturing the base body 401 of the scraper 301 by etching, the photoresist serving as masking is naturally removed after etching. Further, before forming the coating layer 402, the substrate 401 is subjected to ultrasonic cleaning.

Even in this case, although it is rare, the residue of the photoresist used during the etching process may remain on the surface of the base 401. Furthermore, foreign matter other than photoresist residue may adhere to the surface of the base 401.

If the coating layer 402 is formed with foreign matter attached to the surface of the base 401 in this way, the foreign matter may cause a protrusion on the edge of the scraper 301 even if the base 401 has no protrusion.

Even if a protrusion is generated on the edge due to foreign matter attached to the surface of the base 401, the protrusion can be eliminated by rubbing the scraper 301 against the intermediate transfer belt 116.

If the protrusion 501 in FIG. 5 is caused by a foreign object, the foreign object and the coating layer 402 covering the foreign object are removed all together due to the rubbing between the scraper 301 and the intermediate transfer belt, as illustrated in FIG. Although the base body 401 of the scraper 301 is exposed at the detached portion 701, the protrusion on the edge has been eliminated, so even if the scraper 301 is rubbed against the intermediate transfer belt 116 in this state, the transfer surface of the intermediate transfer belt 116 will not be exposed. No scratches occur.

As described above, the protrusion on the edge of the scraper 301 can be eliminated by aging the scraper 301 that rubs against the intermediate transfer belt 116 (hereinafter referred to as "scraper aging") at the initial stage of use of the scraper 301. . Therefore, even if the scraper 301 rubs against the intermediate transfer belt 116 in subsequent use, no scratches will be left on the transfer surface of the intermediate transfer belt 116.

However, if scratches are left on the transfer surface of the intermediate transfer belt 116 during scraper aging, problems caused by the scratches cannot be solved. Therefore, in the present embodiment, scraper aging is performed in which the scraper 301 is rubbed against the intermediate transfer belt 116 under conditions different from those used during image formation, as described below.
(1-5) Scraper Aging In order to perform scraper aging, the control unit 160 has functions as shown in FIG. 8. That is, they are a scraper aging section 801 , an aging necessity determining section 802 , a primary transfer roller contact/separation control section 803 , and a secondary transfer roller pressure contact/separation control section 804 .

The scraper aging unit 801 executes scraper aging using the aging necessity determining unit 802, the primary transfer roller contact/separation control unit 803, and the secondary transfer roller pressure contact/separation control unit 804. Specifically, the determination result of the aging necessity determining unit 802 regarding whether or not scraper aging is necessary is referred to.

When scraper aging is necessary, the primary transfer roller contact/separation control unit 803 is used to separate the primary transfer rollers 115Y, 115M, and 115C corresponding to YMC colors from the photoreceptor drums 111Y, 111M, and 111C. At the same time, the secondary transfer roller 118 is separated from the secondary transfer opposing roller 119 using the secondary transfer roller pressure contact/separation control unit 804 .

Thereafter, the scraper aging section 801 forms an electrostatic latent image on the outer circumferential surface of the photoreceptor drum 111K with an exposure device 113K, supplies K toner with a developing device 114K, and supplies K toner with a primary transfer roller 115K. The toner image is primarily transferred onto the transfer surface of the intermediate transfer belt 116. The toner image may be, for example, a solid image, or it may be an image other than a solid image as long as the necessary amount of toner can be supplied over the entire width of the edge of the cleaning blade 311 or the edge of the scraper 301. Good too.

Intermediate transfer belt 116 transports the toner image to cleaning section 100. As a result, when the K color toner is supplied as a lubricant to the cleaning blade 311 and the scraper 301, the sliding force between the edge of the scraper 301 and the transfer surface of the intermediate transfer belt 116 is relaxed, so the transfer surface Scratch marks are less likely to form on the surface.

The aging necessity determination unit 802 is a usage status detection unit that determines whether scraper aging is necessary. The storage unit 211 serves as a usage status storage means in that it stores aging completion information 811 indicating whether or not the scraper aging of the scraper 301 has been completed. The aging completion information is set to "incomplete" when the image forming apparatus 1 is shipped and when the scraper 301 is replaced, and is set to "completed" when the scraper aging is performed.

The aging necessity determining unit 802 refers to the aging completion information 811, and determines that scraper aging is necessary if it is “incomplete”, and determines that scraper aging is necessary if it is “completed”. It is determined that there is no.

The primary transfer roller contact/separation control unit 803 controls the primary transfer rollers 115Y, 115M, and 115C to contact and separate from the photoreceptor drums 111Y, 111M, and 111C in response to a request from the scraper aging unit 801.

The primary transfer rollers 115Y, 115M, and 115C are each provided with an actuator (not shown) that displaces the bearing of the rotating shaft, and the primary transfer roller contact/separation control unit 803 controls the actuator to Perform contact/separation control.

Note that the primary transfer rollers 115Y, 115M, and 115C may be brought into contact with and separated from the photoreceptor drums 111Y, 111M, and 111C, respectively, using means other than the actuator.

When forming a color image, the primary transfer roller contact/separation control unit 803 brings the primary transfer rollers 115Y, 115M, and 115C into contact with the photoreceptor drums 111Y, 111M, and 111C, respectively, as shown in FIG. 11(a). let As a result, YMC toner images can be primarily transferred from the outer peripheral surfaces of the photoreceptor drums 111Y, 111M, and 111C to the transfer surface of the intermediate transfer belt 116.

On the other hand, during scraper aging and when forming a monochrome image, primary transfer rollers 115Y, 115M, and 115C are separated from photoreceptor drums 111Y, 111M, and 111C, respectively, as shown in FIG. 11(b).

In this way, the belt tension of the intermediate transfer belt 116 is reduced, so that the pressing force of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is reduced. As a result, the sliding force of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is reduced, making it difficult to form scratch marks.

In addition, since the outer peripheral surfaces of the photoreceptor drums 111Y, 111M, and 111C and the transfer surface of the intermediate transfer belt 116 no longer rub, the outer peripheral surfaces of the photoreceptor drums 111Y, 111M, and 111C and the transfer surface of the intermediate transfer belt 116 are worn out. can also be suppressed.

The secondary transfer roller press-contact/separation control unit 804 controls the secondary transfer roller 118 to press-contact/separate from the secondary transfer opposing roller 119 in response to a request from the scraper aging unit 801 . When the secondary transfer roller pressure contact/separation control unit 804 separates the secondary transfer roller 118 from the secondary transfer opposing roller 119, the transfer of the toner image from the transfer surface of the intermediate transfer belt 116 to the recording medium is prohibited. The secondary transfer roller pressure contact/separation control section 804 serves as a transfer prohibition means.

For example, by bringing the cam 1001 into contact with the rotating shaft of the secondary transfer roller 118, the secondary transfer roller 118 may be pressed against and separated from the secondary transfer opposing roller 119. As shown in FIG. 10A, when forming an image, if the large diameter portion of the cam 1001 is directed toward the rotation axis of the secondary transfer roller 118, the secondary transfer roller 118 can be moved to the secondary transfer opposing roller 119. It can be pressed into contact with the

In addition, as shown in FIG. 10(b), when performing scraper aging, the small diameter portion of the cam 1001 is directed toward the rotation axis of the secondary transfer roller 118, so that the secondary transfer roller 118 is moved toward the secondary transfer opposite side. It can be spaced apart from roller 119.

Note that instead of the cam 1001, a means other than the cam 1001, such as an actuator, may be used to press and separate the secondary transfer roller 118 from the secondary transfer opposing roller 119.

When the secondary transfer roller 118 is separated from the secondary transfer opposing roller 119, secondary transfer of toner from the transfer surface of the intermediate transfer belt 116 to the recording medium is prohibited, so that the toner supplied by the developing device 114K is transferred to the secondary transfer roller 119. It can be transported to the cleaning section 100 as it is without adhering to the transfer roller 118.

Therefore, a large amount of toner can be transported to the cleaning section 100, so even if a portion of the toner is scraped off by the cleaning blade 311, a sufficient amount of toner can be supplied to the edge of the scraper 301 as a lubricant. can.

Therefore, the sliding force between the edge of the scraper 301 and the transfer surface of the intermediate transfer belt 116 can be reliably reduced, making it difficult for scratches to form on the transfer surface and making the scratches invisible.

The number of scratches and the condition of the scratches are significantly different depending on whether or not toner is present on the edge of the scraper 301. When toner is not supplied to the edge of the scraper 301, as the intermediate transfer belt 116 rotates and runs, thin scratch marks with a width of about 1 μm concentrate in a width of several 100 μm, and become noticeable enough to be seen with the naked eye. .

Level 1 is defined as a state in which the scratches have a width of several tens of micrometers to 200 μm, and level 2 is defined as a state in which the scratches have increased to a width of 200 μm or more. At level 1, the user or service person of the image forming apparatus 1 cannot see or notice the scratch marks, so there is no risk that the scraper 301 will be mistakenly determined to be initially defective or deteriorated over time. do not have.

On the other hand, when level 2 is reached, a user of the image forming apparatus 1 or a service person may mistakenly judge the scratches to be scratches on the transfer surface, and there is a possibility that the scraper 301 is initially defective or deteriorates over time.

In other words, since it is difficult to distinguish these scratches from scratches caused by long-term use or scratches caused by some kind of abnormality, inspectors may judge the product to be defective, or users or service personnel may decide that it should be replaced. become. As a result, they end up being discarded even though they are only used for a short period of time and do not degrade image quality. During manufacturing, the defective rate increases, leading to increased costs, and the cost of replacing belts and units results in large losses for users.

On the other hand, as described above, if the sliding force between the edge of the scraper 301 and the transfer surface of the intermediate transfer belt 116 is reduced, the generation of sliding marks can be suppressed. Therefore, it is possible to prevent the level 2 condition in which scratches are intensively formed over a width of 200 μm or more, and therefore, it is possible to avoid an extreme shortening of the life of the scraper 301.

Further, since a large amount of toner is supplied to the edge of the cleaning blade 311 during scraper aging, the edge of the cleaning blade 311 can be protected and damage and wear can be prevented.

To summarize the operation of the image forming apparatus 1 regarding scraper aging, as shown in FIG. ).

If the content of the aging completion information 811 is "not completed", the scraper aging process is not yet completed (S1102: YES), so the scraper aging process is executed (S1103).

In the scraper aging process, as shown in FIG. 111C to lower the belt tension of the intermediate transfer belt 116 (S1201).

Further, the secondary transfer roller pressure contact/separation control unit 804 separates the secondary transfer roller 118 from the secondary transfer opposing roller 119 to prohibit secondary transfer from the transfer surface of the intermediate transfer belt 116 to the recording medium ( S1202). In this way, all the toner supplied from the K color developing device 114K can be conveyed to the cleaning section 100.

Thereafter, the intermediate transfer belt 116 is rotated while supplying K color toner from the developing device 114K (S1203). In this way, the toner can be supplied as a lubricant to the edge of the scraper 301 and the sliding force between the edge of the scraper 301 and the transfer surface of the intermediate transfer belt 116 can be reduced. Scraper aging can be performed while preventing scratches from forming on the transfer surface.

In this manner, when the aging period has elapsed (S1204: YES), the scraper aging is ended and the process returns to the upper level routine. Note that the aging period may be defined using the rotational travel distance of the intermediate transfer belt 116, or may be defined using the rotational travel time of the intermediate transfer belt 116.

Regardless of how the aging period is defined, the aging period is used to eliminate protrusions on the edge of the scraper 301 to the extent that no scratches from the edge of the scraper 301 are left on the transfer surface of the intermediate transfer belt 116 in actual use. It is desirable that the length be as long as possible.

Returning to FIG. 11, after the scraper aging process (S1103) is completed, and if the scraper aging has already been completed (S1102: YES), it is checked whether there is an image forming job to be executed. As a result of the confirmation, if there is an image forming job to be executed (S1104: YES), the image forming job is executed (S1105).

After the execution of the image forming job is completed, and if there is no image forming job to be executed (S1104: NO), the process advances to step S1101 and the above processing is repeated. The reason why the process advances to step S1101 is that when the scraper 301 is replaced with a new one, it is necessary to perform scraper aging on the new scraper 301.

Therefore, when the entire cleaning unit 100 or the second cleaning means 300 is replaced, the user or service person of the image forming apparatus 1 must manually set the aging completion information 811 to "incomplete", or The image forming apparatus 1 itself automatically sets the aging completion information 811 to "incomplete".
[2] Second Embodiment In the first embodiment described above, an example will be taken in which a large amount of toner is supplied as a lubricant to the edge of the cleaning blade 311 and the edge of the scraper 301 during scraper aging. Although described above, in this embodiment, the following processing is performed instead of or in addition to this.

That is, as shown in FIG. 13, the control section 160 according to the present embodiment further includes a cleaning blade contact/separation control section 1305. The cleaning blade contact/separation control unit 1305 is a cleaning blade contact/separation unit that controls the edge of the cleaning blade 311 to contact and separate from the transfer surface of the intermediate transfer belt 116 .

As shown in FIG. 14, the supporting metal plate 313 of the cleaning blade 311 is provided with a swing shaft 1412. A blade 312 is attached to one end of the support metal plate 313, and the other end engages with the arm of the actuator 1411.

Therefore, by moving the arm of the actuator 1411 back and forth to swing the support metal plate 313, the edge of the blade 312 can be brought into contact with and separated from the transfer surface of the intermediate transfer belt 116.

It goes without saying that a means other than the actuator 1411 may be used to bring the edge of the blade 312 into contact with and away from the transfer surface of the intermediate transfer belt 116.

In the scraper aging process according to this embodiment, as shown in FIG. 15, step S1503 is further executed in the scraper aging process (S1103) according to the first embodiment.

That is, before the intermediate transfer belt 116 starts rotating during scraper aging, the cleaning blade contact/separation control unit 1305 of the control unit 160 controls the actuator 1411 to transfer the edge of the cleaning blade 311 to the intermediate transfer belt. It is separated from the transfer surface of the belt 116.

In this way, it is possible to prevent the edge of the cleaning blade 311 from being worn out due to rubbing against the transfer surface of the intermediate transfer belt 116 during scraper aging.

Furthermore, the toner supplied from the developing device 114K is conveyed to the edge of the scraper 301 without being scraped off by the cleaning blade 311. Therefore, compared to the case where scraper aging is performed with the cleaning blade 311 in contact with the intermediate transfer belt 116, the amount of toner supplied to the edge of the scraper 301 can be increased.

Therefore, the transfer surface of the intermediate transfer belt 116 can be reliably protected and scratch marks caused by the edge of the scraper 301 can be prevented.

Moreover, even if the amount of toner supplied from the developing device 114K is smaller than in the first embodiment, it is possible to secure the amount of toner that can be transported to the edge of the scraper 301, so scraper aging is performed. It is possible to save on toner consumption when printing.
[3] Third Embodiment When scraper aging is performed while the cleaning blade 311 is in contact with the intermediate transfer belt 116 as in the first embodiment, a sufficient amount of toner is deposited on the edge of the scraper 301. may not be supplied. In contrast, in the present embodiment, the pressing force of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is controlled.

For this reason, as shown in FIG. 16, the control section 160 according to the present embodiment further includes a scraper pressure contact force control section 1605. The scraper pressure contact force control unit 1605 is a pressure contact force control unit that controls the pressure contact force of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116.

As shown in FIG. 14, the support plate 304 of the scraper 301 is provided with a swing shaft 1402. One end of the support metal plate 304 is held by the metal blade 302 together with one end of the support metal plate 303, and the other end is engaged with the arm of the actuator 1401.

When the arm of the actuator 1401 is moved back and forth, the support plate 304 swings, so the pressure of the edge of the metal blade 302 against the transfer surface of the intermediate transfer belt 116 can be controlled.

It goes without saying that the pressing force of the edge of the metal blade 302 against the transfer surface of the intermediate transfer belt 116 may be controlled using means other than the actuator 1401.

In the scraper aging process according to this embodiment, as shown in FIG. 17, step S1703 is further executed in the scraper aging process (S1103) according to the first embodiment.

That is, before starting the rotational movement of the intermediate transfer belt 116 in scraper aging, the scraper pressure contact force control unit 1305 of the control unit 160 controls the actuator 1401 so that the scraper 301 is applied to the transfer surface of the intermediate transfer belt 116. The pressing force at the edge of the image is lower than that during image formation.

In this way, even if the amount of toner supplied to the edge of the scraper 301 is small during scraper aging, it is possible to suppress the formation of scratch marks on the transfer surface of the intermediate transfer belt 116.

Moreover, even if the amount of toner supplied from the developing device 114K is smaller than in the first embodiment, it is possible to secure the amount of toner that can be transported to the edge of the scraper 301, so scraper aging is performed. It is possible to save on toner consumption when printing.

Furthermore, when a new scraper 301 is mounted, the edge of the scraper 301 may be separated from the transfer surface of the intermediate transfer belt 116 using the actuator 1401 until scraper aging is started.

In this way, it is possible to prevent scratch marks from being formed on the transfer surface of the intermediate transfer belt 116 by using the scraper 301 for which scraper aging has not been completed.

Further, as long as the cleaning blade 311 is not worn out due to use, residual toner can be sufficiently cleaned without using the scraper 301. Therefore, even if the scraper 301 is separated from the intermediate transfer belt 116, there is no problem in practical terms because there is a low possibility that image quality will deteriorate due to residual toner.

Therefore, user convenience can be improved by changing the order of scraper aging and other controls and setting the timing to perform scraper aging depending on the usage status of the image forming apparatus 1.
[4] Fourth Embodiment In the first embodiment described above, by displacing the primary transfer roller and controlling the contact pressure of the tension roller 1901 against the inner peripheral surface of the intermediate transfer belt 116, Although the case where the belt tension of the intermediate transfer belt 116 is changed has been described as an example, the following may be used instead of or in addition to this.

That is, as shown in FIG. 18, the control section 160 includes a belt tension control section 1805. As shown in FIG. 19(a), a tension roller 1901 is in contact with the inner peripheral surface of the intermediate transfer belt 116.

The belt tension control unit 1805 controls a tension roller drive mechanism (not shown) and displaces the tension roller 1901 from the same position 1901' as the tension roller 1901 in FIG. This is a belt tension control means that controls the contact pressure of the tension roller 1901 against the surface and changes the belt tension of the intermediate transfer belt 116.

Specifically, during image formation, the belt tension control unit 1805 displaces the tension roller 1901 so that the contact pressure of the tension roller 1901 against the intermediate transfer belt 116 is increased, as shown in FIG. 19(a). By doing so, the belt tension of the intermediate transfer belt 116 is increased.

Furthermore, the belt tension control unit 1805 controls the tension roller 1901 so that during scraper aging, the contact pressure of the tension roller 1901 against the intermediate transfer belt 116 is lower than during image formation, as shown in FIG. 19(b). By displacing the intermediate transfer belt 116, the belt tension of the intermediate transfer belt 116 is lowered.

Note that the tension roller drive mechanism may use an actuator to displace the tension roller 1901, or may use a cam to displace the tension roller 1901. Furthermore, it goes without saying that the tension roller 1901 may be displaced using means other than the actuator or the cam.

In FIG. 12, if the belt tension of the intermediate transfer belt 116 is lowered using the tension roller 1901 instead of step S1201 or in addition to step S1201, the belt tension of the intermediate transfer belt 116 can be lowered by rubbing against the edge of the scraper 301 during scraper aging. It is possible to suppress the formation of scratch marks on the transfer surface of the intermediate transfer belt 116.
[5] Fifth Embodiment If the scratches left on the transfer surface of the intermediate transfer belt 116 during scraper aging are concentrated within a narrow range, they are likely to be mistaken for scratches that degrade image quality. Therefore, in this embodiment, the rubbing marks are dispersed in the width direction of the intermediate transfer belt 116 to prevent them from being mistaken as scratches. The width direction of the intermediate transfer belt 116 is a direction perpendicular to the rotational running direction of the intermediate transfer belt 116 on the transfer surface of the intermediate transfer belt 116.

That is, as shown in FIG. 20, the control section 160 includes an intermediate transfer belt swing control section 2005. The intermediate transfer belt swing control unit 2005 swings the intermediate transfer belt 116 in the direction (width direction) perpendicular to the rotational running direction at the scraping position of the edge of the scraper 301. This is intermediate transfer belt displacement means for displacing the intermediate transfer belt in the width direction.

Note that by displacing the scraper 301 instead of or in addition to the intermediate transfer belt 116, the intermediate transfer belt 116 and the scraper 301 can be separated from each other in the rotating direction of the intermediate transfer belt. It may also be relatively moved in the width direction perpendicular to . The intermediate transfer belt swing control unit 2005 is an example of relative movement means that performs such relative movement.

Therefore, the intermediate transfer belt swing control unit 2005 controls the intermediate transfer belt swing mechanism (not shown) to move the intermediate transfer belt 116 perpendicular to the rotational running direction at the sliding position of the edge of the scraper 301. (width direction).

Even if the image forming apparatus 1 is not equipped with such an intermediate transfer belt swinging mechanism, the intermediate transfer belt 116 may meander to some extent. Then, as illustrated in FIG. 21(a), a scratch mark is formed with a width of several tens to several hundreds of micrometers, so that it becomes easily noticeable and becomes apparent by visual inspection.

On the other hand, when the intermediate transfer belt 116 is made to meander by about 1 mm, for example, as illustrated in FIG. 21(b), the rubbing marks are dispersed over a wide width, making them difficult to notice and becoming obvious when visually observed. Nothing happens.

Note that if the intermediate transfer belt 116 is oscillated only during scraper aging and not during image formation, the oscillation of the intermediate transfer belt 116 will affect the image quality. can be avoided.

Further, even during image formation, if a member is provided to restrict the swinging of the intermediate transfer belt 116 so as not to affect the primary transfer and secondary transfer, the effect on image quality can be suppressed. Therefore, the intermediate transfer belt 116 may be oscillated.

As a mechanism for swinging the intermediate transfer belt 116, for example, a cleaning opposing roller 321 arranged to face the cleaning blade 311 may be moved back and forth in the width direction of the intermediate transfer belt 116. For this purpose, a mechanism for reciprocating the cleaning opposing roller 321 together with its bearing can be adopted.

In the configuration shown in FIG. 3, a member capable of regulating the swinging of the intermediate transfer belt 116 is disposed on the rotation path of the intermediate transfer belt 116 from the cleaning opposing roller 321 to the position where the edge of the scraper 301 is rubbed. Therefore, by reciprocating the cleaning opposing roller 321, a frictional force between the cleaning opposing roller 321 and the inner peripheral surface of the intermediate transfer belt 116 acts, and the intermediate transfer belt 116 can be swung.

Note that it goes without saying that the intermediate transfer belt 116 may be oscillated using other mechanisms.
[6] Sixth Embodiment In the first embodiment described above, a case was explained using the aging completion information 811 as an example to determine whether or not to perform scraper aging. Needless to say, the present invention is not limited to this, and the following may be used instead.

For example, using information indicating whether the scraper 301 is new, it may be determined that scraper aging should be performed if the scraper 301 is new. Whether the scraper 301 is new or not can be determined by detecting the state of the scraper 301, or by making a setting to that effect when the user or service person of the image forming apparatus 1 replaces the scraper 301 with a new one. good.

In addition, since the image forming apparatus 1 itself is new, the bundled unit may also be new, or the entire cleaning section 100 is replaced with a new one, or the entire intermediate transfer unit including the cleaning section 100 is replaced with a new one. You may use information indicating such as.

Furthermore, by using the individual identification information given to the scraper 301, it is possible to detect whether or not the scraper 301 has been replaced, so even if it is determined that the scraper 301 is new if replacement is detected. good. Alternatively, it may be determined whether the scraper 301 is new or not based on its dirt or shape (degree of wear).

Since there are few opportunities to replace the scraper 301, the timing for acquiring information about the scraper 301 is, in principle, the timing when the power is turned off and then turned on again.

However, since the cleaning unit 100 may be replaced while the power is on without turning off the power, information on the scraper 301 is also acquired when the opening/closing of the cover required to replace the cleaning unit 100 is detected. There is a need to.
[7] Seventh Embodiment When the entire cleaning unit 100 is replaced with a new one, it is necessary not only to age the scraper 301 but also to set the cleaning blade 311. The blade setting of the cleaning blade 311 is a process of supplying toner to the sliding portion between the edge of the cleaning blade 311 and the transfer surface of the intermediate transfer belt 116 .

By performing blade setting, the sliding force between the edge of the cleaning blade 311 and the transfer surface of the intermediate transfer belt 116 can be reduced, so wear and tear on the edge of the cleaning blade 311 can be suppressed and the length of the cleaning blade 311 can be reduced. It is possible to extend the service life.

For this reason, the control section 160 according to the present embodiment includes a cleaning blade contact/separation control section 2205 and a blade set control section 2206, as shown in FIG. The scraper pressure contact force control section 2205 is the same as the scraper pressure contact force control section 1605 described in the third embodiment.

Further, the blade set control unit 2205 controls the cleaning blade 311 by causing the intermediate transfer belt 116 to rotate while the scraper pressure contact force control unit 1605 separates the edge of the scraper 301 from the transfer surface of the intermediate transfer belt 116. This is a blade setting means that supplies toner to the sliding portion between the edge and the transfer surface of the intermediate transfer belt 116.

When performing scraper aging, the control unit 160 executes blade set processing (S2303) prior to the scraper aging processing (S2304), as shown in FIG. 23.

In the blade setting process (S2304), as shown in FIG. 24, first, the edge of the scraper 301 is separated from the transfer surface of the intermediate transfer belt 116 (S2041). Next, after separating the primary transfer rollers 115Y, 115M, and 115C from the photoreceptor drums 111Y, 111M, and 111C (S2402), while supplying K color toner onto the transfer surface of the intermediate transfer belt 116, intermediate transfer The belt 116 is rotated (S2403).

When supplying K toner onto the transfer surface of the intermediate transfer belt 116, a predetermined electrostatic latent image is formed on the outer peripheral surface of the photoreceptor drum 111K, and this electrostatic latent image is developed by the developing device 114K. Then, a K color toner image is obtained, and this toner image is primarily transferred onto the transfer surface of the intermediate transfer belt 116 by a primary transfer roller 115K.

Thereafter, when the blade setting period has elapsed (S2404: YES), the scraper 301 is brought into pressure contact with the transfer surface of the intermediate transfer belt 116 (S2405), and the process returns to the upper level routine.

When a new scraper 301 is mounted, it is necessary to immediately perform scraper aging to prevent scratches from occurring on the intermediate transfer belt 116.

On the other hand, if the scraper 301 is separated from the transfer surface of the intermediate transfer belt 116, the scraper 301 will not rub against the transfer surface of the intermediate transfer belt 116, and no scratches will be left. By changing the execution order, the timing at which scraper aging is performed can be changed freely.

The cleaning blade 311 is often replaced as a new part of the cleaning unit 100 at the same time as the scraper 301. Therefore, if the cleaning blade 311 is set with the edge of the scraper 301 separated from the transfer surface of the intermediate transfer belt 116 before scraper aging, the cleaning blade 311 can be set when scraper aging is performed. Edges can be protected.
[8] Comparison between the prior art and the present disclosure FIG. 25 is a table comparing the prior art and the present disclosure.

In FIG. 25, conventional techniques 1 to 3 do not perform scraper aging, whereas present disclosures 1 and 2 both perform scraper aging.

Further, Prior Art 1 to 3 correspond to the changes in the coating layer as described above, and in Prior Art 1, no coating layer is formed on either the intermediate transfer belt or the scraper.

In Prior Art 2, a coating layer is formed on the transfer surface of the intermediate transfer belt, but no coating is formed on the scraper. In Prior Art 3, a coating layer is formed on the transfer surface of the intermediate transfer belt, and a coating layer is also formed on the edge of the scraper.

Further, in the present disclosure 1, a coating layer is formed on both the transfer surface of the intermediate transfer belt and the edge of the scraper, whereas in the present disclosure 2, a coating layer is formed on both the transfer surface of the intermediate transfer belt and the edge of the scraper. No coating layer is formed on either of them.

In Conventional Technology 1, the edge of the scraper has a higher hardness than the transfer surface of the intermediate transfer belt, so at the beginning of use, the protrusions on the edge cause scratches (hereinafter referred to as "initial scratches") on the transfer surface. It gets wet. Furthermore, if the transfer surface is scratched due to use, the image quality may deteriorate or the life of the intermediate transfer belt may be shortened.

In conventional technology 2, a coating layer is provided on the transfer surface of the intermediate transfer belt to make it harder than the edge of the scraper, so there is no risk of initial scratch marks being formed on the transfer surface due to protrusions on the edge at the initial stage of use. . Furthermore, the transfer surface will not be damaged by use. However, the edge of the scraper has lower hardness than the transfer surface and is more likely to wear out with use, which shortens the life of the scraper.

In Conventional Technology 3, a coating layer is provided on the edge of the scraper in addition to the transfer surface of the intermediate transfer belt, and since the edge of the scraper is harder than the transfer surface, the life of the scraper is reduced compared to Conventional Technology 2. It can be longer than . However, initial scratch marks and damage to the transfer surface due to use are the same as in Prior Art 1.

The present disclosure 1 corresponds to the case where scraper aging is performed in the prior art 3. In the present disclosure 1, initial scratches are suppressed by scraper aging. For example, FIGS. 26(a) and 26(b) illustrate initial scratches observed when the transfer surface of the intermediate transfer belt is magnified 1000 times with a microscope.

The initial scratch marks illustrated in FIG. 26(a) are thin and shallow scratches each having a width of about 1 μm and a depth of about 1 μm. From this state, as the intermediate transfer belt 116 rotates many times, the number of intermediate transfer belts 116 increases in the width direction, and the total length is several tens to several hundreds of μm, as illustrated in FIG. 26(b). When the number increases until it reaches the width of , it becomes so obvious that it can be visually confirmed.

The initial scratches of each scratch are thin and shallow scratches, so increasing the number of scratches will not affect the image quality, but like scratches caused by long-term use or due to some kind of abnormality, the image quality will deteriorate. It is difficult to distinguish from belt scratches.

For this reason, if the number increases to the point where inspectors during shipping inspections and users and service personnel when replacing units can visually check them, inspectors may mistakenly judge the image forming apparatus 1 to be an initially defective product. A user or a service person may mistakenly decide that the cleaning unit 100 should be replaced.

As a result, the cleaning unit 100 ends up being discarded even though it can be used normally without any risk of deteriorating image quality. In this way, the defective rate at the time of shipment increases, leading to an increase in costs, and the user suffers a large loss due to belt and unit replacement.

According to the present disclosure 1, since scraper aging is performed, the above problems can be solved. Further, since the advantage of conventional technology 3 that both the intermediate transfer belt and the scraper can have a long service life is not impaired by scraper aging, the present disclosure 1 also aims to extend the service life of the intermediate transfer belt 116 and the scraper 301. be able to.

The present disclosure 2 corresponds to the case where scraper aging is performed in the prior art 1. In the present disclosure 2, initial scratches are suppressed by scraper aging. However, deterioration in image quality due to use and shortening of the life of the intermediate transfer belt are the same as in Prior Art 1.
[9] Evaluation of Examples and Comparative Examples Next, evaluation results of Examples and Comparative Examples are shown. Examples and comparative examples to be evaluated are as follows.

The image forming apparatuses according to Examples 1 to 9 and Comparative Examples 1 to 2 are equipped with an intermediate transfer belt cleaning system having an intermediate transfer belt 116 and a scraper 301, as shown in FIG. Further, in Examples 1 to 9, scraper aging is performed, but in Comparative Examples 1 to 2, scraper aging is not performed.

Furthermore, since it is necessary to evaluate the scratch marks caused on the intermediate transfer belt by the scraper in the initial stage of use, a new scraper is used in both Examples 1 to 9 and Comparative Examples 1 to 2. Regarding the intermediate transfer belt, a new intermediate transfer belt was used in all Examples 1 to 9 and Comparative Examples 1 to 2 in order to evaluate the number and condition of scratch marks.

In this evaluation, for Examples, after performing scraper aging, a predetermined number of images are formed under predetermined conditions, and the subsequent rubbing marks on the transfer surface of the intermediate transfer belt are visually evaluated. On the other hand, for the comparative example, images were formed on a predetermined number of sheets under predetermined conditions without performing scraper aging, and then the scratch marks on the surface of the intermediate transfer belt were visually evaluated.

The evaluation items for the scratches are the number of scratches and the condition of the scratches. In this evaluation, regarding the number of scratches, an aggregate of fine scratches is counted as one as a whole, rather than individual fine scratches. Furthermore, the condition of the scratches is evaluated in three levels: "no-occurrence level," "OK level," and "NG level."

The "non-occurrence level" is a level where there are thin scratch marks, but they have not become noticeable to the extent that they can be visually confirmed. Since they cannot be visually confirmed, the number of scratch marks is not counted.

The "OK level" refers to scratch marks clustered in a width of several 10 to 200 μm, which is not impossible to visually confirm, but is at a level that is not noticeable enough for service personnel or users to notice. Therefore, it is OK in the sense that the cleaning unit 100, which has no problem with image quality and can be used normally, is not likely to be replaced by mistake.

At the "NG level", the width of the area where the scratches are gathered is wide enough to be 200 μm or more, and the scratches are visible enough for service personnel and users to visually check and are so obvious that they are easily noticed. Therefore, even though the image quality is not affected, the cleaning unit 100 is determined to be a defective product and is mistakenly replaced, which is NG.

As the experimental machine, AccurioPress C4080 manufactured by Konica Minolta was used. However, the cleaning unit had the configuration of the example and comparative example. The environmental conditions were a normal environment of temperature 23° C. and humidity 55%. New intermediate transfer belts and scrapers were always used for each evaluation.

Regarding units other than the intermediate transfer belt and scraper, since the number of images formed during evaluation was not large, new units were prepared and these new units were continued throughout the evaluation of Examples 1 to 9 and Comparative Examples 1 to 2. I used it. Maintenance was performed on the transfer unit and cleaning unit when the intermediate transfer belt and scraper were replaced.

In both Examples 1 to 9 and Comparative Examples 1 to 2, after printing 200 A3 sheets of horizontal band images with a printing rate of 5% for each color in color mode (driving for about 5 minutes), the intermediate transfer belt The number and condition of the scratches on the surface were observed.

For Examples 1 to 9, after scraper aging was performed for 3 minutes (running distance of about 60 m), images were formed as described above and evaluated. For Comparative Examples 1 and 2, evaluation was performed after forming images as described above without performing scraper aging.

The features of Examples 1 to 9 and Comparative Examples 1 to 2 will be explained below.
(9-1) Example 1
In this embodiment, a Si coating layer is formed on the transfer surface of the intermediate transfer belt 116, and a DLC coating layer is formed on the edge of the scraper 301. The DLC coating layer has higher hardness than the Si coating layer.

As described above, since a new scraper 301 is used, scraper aging is performed.

Prior to scraper aging, blade setting of the cleaning blade 311 is performed.

During scraper aging, toner is supplied to the transfer surface of the intermediate transfer belt 116 from the developing devices 114Y, 114M, 114C, and 114K with the secondary transfer roller 118 separated from the secondary transfer opposing roller 119.

During scraper aging, the edge of the cleaning blade 311 is separated from the transfer surface of the intermediate transfer belt 116.

Therefore, the toner supplied from the developing devices 114Y, 114M, 114C, and 114K reaches the edge of the scraper 301 without being removed by the cleaning blade, reducing the sliding force between the scraper 301 and the intermediate transfer belt 116. A sufficient amount of toner is supplied as a lubricant to protect the transfer surface of the intermediate transfer belt 116 from scratches.
(9-2) Example 2
Example 2 differs from Example 1 in that a coating layer is not formed on either the intermediate transfer belt 116 or the scraper 301. Therefore, the durability of the intermediate transfer belt 116 and the scraper 301 is lower than in the first embodiment.

Except for this difference in durability, scraper aging is performed in the same manner as in Example 1, and during scraper aging, toner is abundantly supplied to the edge of the scraper and the transfer surface is protected.
(9-3) Example 3
The third embodiment has a configuration in which the pressure contact force of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is further controlled in the first embodiment. During scraper aging, by reducing the pressure of the scraper 301 against the transfer surface of the intermediate transfer belt 116, it is possible to prevent the edge of the scraper 301 from forming scratch marks on the transfer surface of the intermediate transfer belt 116. .
(9-4) Example 4
The fourth embodiment is different from the third embodiment in that the edge of the cleaning blade 311 is not separated from the transfer surface of the intermediate transfer belt 116 during scraper aging, but is kept in contact with the transfer surface of the intermediate transfer belt 116.

Therefore, during scraper aging, the amount of toner supplied to the edge of the scraper 301 is smaller than in the third embodiment. However, when the image forming apparatus 1 and the cleaning section 100 are shipped from the factory, the edges of the scraper 301 are generally coated with toner to some extent.

Also in this embodiment, the sliding force between the edge of the scraper 301 and the transfer surface of the intermediate transfer belt 116 is reduced to some extent by the toner applied in advance.

Further, in the same manner as in the third embodiment, in this embodiment as well, the pressing force of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is reduced during scraper aging. This prevents scratch marks from the edge of the scraper 301 from being formed on the transfer surface of the intermediate transfer belt 116.
(9-5) Example 5
In the fifth embodiment, instead of keeping the edge of the cleaning blade 311 in contact with the transfer surface of the intermediate transfer belt 116 during scraper aging in the first embodiment, primary transfer rollers 115Y, 115M and 115C is separated from the photoreceptor drums 111Y, 111M, and 111C, respectively.

For the same reason as in Example 4 above, the amount of toner supplied to the edge of the scraper 301 during scraper aging is smaller than in Example 1.

On the other hand, when primary transfer rollers 115Y, 115M, and 115C are separated from photoreceptor drums 111Y, 111M, and 111C, respectively, the belt tension of intermediate transfer belt 116 decreases. Therefore, the pressure of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is reduced, so that the transfer surface of the intermediate transfer belt 116 can be protected from scratches.
(9-6) Example 6
In the sixth embodiment, instead of keeping the edge of the cleaning blade 311 in contact with the transfer surface of the intermediate transfer belt 116 during scraper aging in the first embodiment, This configuration includes a tension roller 1901 that can control the contact force against the tension roller 1901 and a control mechanism thereof.

Since the edge of the cleaning blade 311 is kept in contact with the transfer surface of the intermediate transfer belt 116, the toner carried while being carried on the transfer surface of the intermediate transfer belt 116 is removed during scraper aging. The toner is removed by the cleaning blade 311 and the amount of toner supplied to the edge of the scraper 301 is reduced.

Therefore, it is difficult to sufficiently protect the transfer surface of the intermediate transfer belt 116 from scratches by using toner as a lubricant.

However, during scraper aging, the contact pressure of the tension roller 1901 against the inner peripheral surface of the intermediate transfer belt 116 is reduced, so that the belt tension of the intermediate transfer belt 116 is reduced. When the belt tension of the intermediate transfer belt 116 decreases, the pressure of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 decreases.

In this sense, the transfer surface of the intermediate transfer belt 116 can be protected from scratches.
(9-7) Example 7
In addition to the configuration of Example 1, Example 7 has a configuration in which primary transfer rollers 115Y, 115M, and 115C are separated from photoreceptor drums 111Y, 111M, and 111C, respectively, during scraper aging.

Therefore, during scraper aging, the amount of toner supplied to the edge of the scraper 301 increases, and the sliding force between the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301 is reduced, so that the intermediate transfer It is possible to prevent scratches from being formed on the transfer surface of the belt 116.

Furthermore, primary transfer rollers 115Y, 115M, and 115C are spaced apart from photoreceptor drums 111Y, 111M, and 111C, respectively, to reduce the belt tension of intermediate transfer belt 116. The pressing force of the edge is reduced, making it difficult for scratches to form on the transfer surface of the intermediate transfer belt 116.
(9-8) Example 8
In addition to the configuration of Example 1, Embodiment 8 has a configuration in which the contact pressure of tension roller 1901 against the inner circumferential surface of intermediate transfer belt 116 is reduced during scraper aging.

In this way, during scraper aging, the amount of toner supplied that reduces the sliding force between the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301 increases, so that the amount of toner supplied to the transfer surface of the intermediate transfer belt 116 increases. It is possible to prevent scratches from forming.

Further, if the contact pressure of the tension roller 1901 against the inner circumferential surface of the intermediate transfer belt 116 decreases, the belt tension of the intermediate transfer belt 116 decreases, and the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 decreases. The contact force with the product decreases.

Therefore, since the sliding force between the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301 is reduced, it becomes difficult for the transfer surface of the intermediate transfer belt 116 to be left with scratch marks.
(9-9) Example 9
In the ninth embodiment, instead of keeping the edge of the cleaning blade 311 in contact with the transfer surface of the intermediate transfer belt 116 during scraper aging in the first embodiment, the intermediate transfer belt 116 is moved in the width direction. It is configured to swing.

Since the edge of the cleaning blade 311 is kept in contact with the transfer surface of the intermediate transfer belt 116, it is impossible to prevent scratch marks from being formed on the transfer surface of the intermediate transfer belt 116.

However, whereas the scratch marks are elongated along the rotational direction of the intermediate transfer belt 116, if the intermediate transfer belt 116 is swung in the width direction, The locations where marks are made can be dispersed.

Therefore, it is possible to prevent the rubbing marks from concentrating within a narrow range in the width direction of the intermediate transfer belt 116 and becoming easily visible, thereby reducing the image quality on the transfer surface of the intermediate transfer belt 116. It is possible to prevent the user from being mistakenly recognized as having such scratches.
(9-10) Comparative example 1
Comparative Example 1 corresponds to Example 1 without scraper aging. In the first embodiment, toner is supplied to the edge of the scraper 301 during scraper aging, but since scraper aging is not performed, toner is not supplied to the edge of the scraper 301.

Therefore, as described in Embodiment 4, in general, when the image forming apparatus 1 and the cleaning section 100 are shipped from the factory, the only lubricant available is the toner applied to the edge of the scraper 301 to some extent, so the intermediate transfer belt An image is formed in a state where the sliding force between the transfer surface 116 and the edge of the scraper 301 cannot be sufficiently reduced.
(9-11) Comparative example 2
Comparative Example 2 corresponds to Example 2 without scraper aging. In the second embodiment, toner is supplied to the edge of the scraper 301 during scraper aging, but since scraper aging is not performed, toner is not supplied to the edge of the scraper 301.

Therefore, in Comparative Example 2, compared to Example 2, the amount of toner applied to the edge of the scraper 301 is insufficient, which prevents scratches from forming on the transfer surface of the intermediate transfer belt 116. Since this cannot be sufficiently prevented, there is a risk that scratches may be left on the transfer surface of the intermediate transfer belt 116 when forming an image.

The difference between Comparative Examples 1 and 2 is whether a coating layer is formed on the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301. Therefore, in Comparative Example 2, the durability of the intermediate transfer belt 116 and the scraper 301 is lower than that in Comparative Example 1, so that a longer life cannot be achieved.
(9-12) Evaluation Results FIG. 27 is a table showing the evaluation results of Examples 1 to 9 and Comparative Examples 1 and 2.

If the condition of the scratch marks on the transfer surface of the intermediate transfer belt 116 is either "no occurrence" or "OK level", the overall evaluation is given as "〇", and if it is "NG level", the overall evaluation is given. was marked as "x". Examples 1 to 9 all had an overall evaluation of "○", and there were no NG-level scratches. The overall evaluation of Comparative Examples 1 and 2 is "x" for both.

Details of the evaluation results are shown below.
(9-12-1) Toner supply during scraper aging Examples 1 and 2 and Comparative Examples 1 and 2 will be compared for differences in evaluation results depending on the amount of toner supply during scraper aging. Embodiments 1 and 2 execute control to supply a sufficient amount of toner to the edge of the scraper 301 during scraper aging. Therefore, even if scratches may be formed during the aging mode, they remain at an "OK level" and never reach an "NG level."

On the other hand, in Comparative Examples 1 and 2, since scraper aging is not performed, the amount of toner supplied to the edge of the scraper 301 is small, and the transfer surface of the intermediate transfer belt 116 cannot be sufficiently protected. For this reason, when image formation is performed, "NG level" scratches are generated.

Therefore, if a sufficient amount of toner is supplied to the edge of the scraper 301 during scraper aging, the condition of the scratches can be prevented from deteriorating to the "NG level" and kept at the "OK level". It can be said that this has been obtained.
(9-12-2) Presence or absence of coating layer Examples 1 and 2 will be compared regarding the difference in evaluation results depending on the presence or absence of a coating layer on the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301.

In both Examples 1 and 2, the edge of the scraper has a higher hardness than the transfer surface of the intermediate transfer belt 116, so by rubbing against the edge of the scraper 301, the transfer surface of the intermediate transfer belt 116 is rubbed. What they have in common is that they leave scratches.

On the other hand, Examples 1 and 2 differ in whether a coating layer is formed on the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301.

However, according to the evaluation results, regardless of the presence or absence of a coating layer on the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301, in both Examples 1 and 2, during scraper aging, the edge of the scraper 301 If a sufficient amount of toner is supplied, the condition of the scratch marks can be kept at an "OK level".

Note that Comparative Examples 1 and 2 also differ in the presence or absence of a coating layer on the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301, but in both cases, the amount of toner supplied to the edge of the scraper 301 is insufficient. Therefore, if images are continued to be formed, the condition of the scratch marks will deteriorate to an "NG level".

In this way, by supplying a sufficient amount of toner to the edge of the scraper 301, it was possible to obtain the effect of suppressing the deterioration of the condition of the scratch marks, regardless of the presence or absence of the coating layer.
(9-12-3) Pressure force of scraper 301 In Examples 1 and 3, the amount of toner supplied to the edge of the scraper 301 during scraper aging is the same, but in Example 3, the amount of toner supplied to the edge of the scraper 301 is This embodiment is different from the first embodiment in that the pressure of the edge of the scraper 301 against the transfer surface of the image forming apparatus 116 is lowered than during image formation.

As shown in the table of FIG. 27, in Example 3, the condition of the scratches did not even reach the "OK level" and remained at the "non-occurrence level." During scraper aging, by reducing the pressure of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116, the force applied to minute protrusions on the edge of the scraper 301 that causes thin scratch marks can be reduced. .

It is thought that this suppressed the occurrence of thin scratch marks, resulting in the "non-occurrence level". In this way, during scraper aging, in addition to increasing the amount of toner supplied to the edge of the scraper 301, by reducing the pressure of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116, it is possible to reduce the amount of scratches. We were able to suppress the situation to a "non-occurrence level."
(9-12-4) When the amount of toner supplied to the edge of the scraper 301 is small In Examples 4 to 6, scraper aging is performed with the cleaning blade 311 in contact with the intermediate transfer belt 116, so the scraper Not enough toner is supplied to the edges of 301. This is the same condition as in Comparative Examples 1 and 2, and it is not possible to secure a sufficient amount of toner required as a lubricant to protect the transfer surface of the intermediate transfer belt 116 from scratches.

On the other hand, in Examples 4 to 6, the pressing force of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is reduced during scraper aging. That is, in Example 4, in the same manner as in Example 3, by reducing the pressure contact force of the edge of the scraper 301, it was possible to reduce the state of the scratch marks to the "non-occurrence level".

In Example 5, the belt tension of the intermediate transfer belt 116 is reduced by separating the primary transfer rollers 115Y, 115M, and 115C from the photosensitive drums 111Y, 111M, and 111C in the same manner as when forming a monochrome image. Even in this manner, it was possible to reduce the pressure contact force of the edge of the scraper 301, suppress the number of scratch marks to one, and bring it to an "OK level" close to the "non-occurrence level".

In Example 6, by displacing the tension roller 1901 to reduce the belt tension of the intermediate transfer belt 116 and reducing the pressure contact force of the edge of the scraper 301, the number of scratch marks can be reduced as in Example 5. We were able to reduce the number to one, bringing it to an "OK level" close to the "non-occurrence level."
(9-12-5) Example 7
In the seventh embodiment, during scraper aging, the amount of toner supplied to the edge of the scraper 301 is sufficiently increased, and in the same manner as in the fifth embodiment, the primary transfer rollers 115Y, 115M, and 115C are replaced with the photoreceptor drums 111Y, 111M. and 111C to reduce the belt tension of the intermediate transfer belt 116.

Therefore, as in the first embodiment, even if the amount of toner supplied to the edge of the scraper 301 is sufficiently increased, the belt tension of the intermediate transfer belt 116 may not be reduced, and as in the fifth embodiment, the belt tension of the intermediate transfer belt 116 may not be reduced. Even if the belt tension is reduced, compared to the case where the amount of toner supplied from the edge of the scraper 301 is not increased, the state of the scratch marks after image formation is at the "non-occurrence level", and in Examples 1 and 5. It was confirmed that scratches were less likely to be formed on the transfer surface of the intermediate transfer belt 116.
(9-12-6) Example 8
In the eighth embodiment, during scraper aging, the amount of toner supplied to the edge of the scraper 301 is sufficiently increased, and in the same manner as in the sixth embodiment, the tension roller 1901 is displaced to increase the belt tension of the intermediate transfer belt 116. By lowering the pressure, the pressure of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is reduced.

Therefore, as in the first embodiment, even if the amount of toner supplied to the edge of the scraper 301 is sufficiently increased, the belt tension of the intermediate transfer belt 116 may not be reduced, and as in the sixth embodiment, the belt tension of the intermediate transfer belt 116 may not be reduced. Even if the pressure force of the edge of the scraper 301 against the transfer surface is reduced, compared to the case where the amount of toner supplied by the edge of the scraper 301 is not increased, the state of the scratch marks after image formation is reduced to the "non-occurrence level". It was confirmed that rubbing marks were less likely to be formed on the transfer surface of the intermediate transfer belt 116 than in Examples 1 and 6.
(9-12-7) Example 9
In Embodiment 9, during scraper aging, sufficient toner is not supplied to the edge of the scraper 301, and the pressure of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116 is not reduced. , the intermediate transfer belt 116 is swung in the width direction at the position where the edge of the scraper 301 is pressed.

Therefore, in Example 9, similarly to Comparative Examples 1 and 2, it is not possible to suppress the formation of scratch marks on the transfer surface of intermediate transfer belt 116 due to the edge of scraper 301.

However, if the intermediate transfer belt 116 is swung in the width direction, the rubbing marks will be dispersed in the width direction. Therefore, on the transfer surface of the intermediate transfer belt 116, the scratch marks are not concentrated within a range of several tens to several hundreds of μm in the width direction of the intermediate transfer belt 116, so it is necessary to visually check the scratch marks. Things become difficult and don't manifest themselves.

For these reasons, it was confirmed that the condition of the scratch marks after image formation was at a "non-occurrence level".

As described above, in Comparative Examples 1 and 2, if images were formed as they were without performing scraper aging, the rubbing marks would be concentrated on the transfer surface of the intermediate transfer belt 116 and become visible to the naked eye. The overall evaluation was "x".

On the other hand, in Examples 1 to 9, the scraper aging was performed so that the scratch marks did not become visible on the transfer surface of the intermediate transfer belt 116, so the overall evaluation was "○" in all cases.

Note that if scraper aging is performed prior to image formation, it is possible to suppress the formation of scratch marks on the transfer surface of the intermediate transfer belt 116 during image formation.

However, during scraper aging, it is necessary to increase the amount of toner supplied to the edge of the scraper 301, reduce the pressure contact force of the edge of the scraper 301 against the transfer surface of the intermediate transfer belt 116, or reduce the pressure in the width direction of the intermediate transfer belt 116. If the scratches are not dispersed, the scratches will tend to concentrate on the transfer surface of the intermediate transfer belt 116 within a range of several 10 to several 100 μm during scraper aging. As in 1 and 2, the overall evaluation is considered to be "x".

In this sense as well, Examples 1 to 9 are effective in achieving the objectives of the present disclosure.
[10] Modifications Although the present disclosure has been described above based on the embodiments, it goes without saying that the present disclosure is not limited to the above-described embodiments, and the following modifications can be implemented. .
(10-1) Photosensitive drums 111Y, 111M, 111C and 111K, charging devices 112Y, 112M, 112C and 112K, exposure devices 113Y, 113M, 113C and 113K, and developing devices 114Y, 114M, 114C that constitute image forming apparatus 1 114K, the primary transfer rollers 115Y, 115M, 115C and 115K, the fixing section 130, etc., may use any known electrophotographic technology.

Further, the material of the intermediate transfer belt 116 and the material of the belt cleaning section 100 are not limited to those described above.
(10-2) As the usage status of the scraper 301, any value may be used as long as it is an index indicating the degree of usage after the scraper 301 is replaced with a new one in the image forming apparatus 1. For example, as the usage status of the scraper 301, the number of printed sheets in the image forming apparatus 1, the driving distance or driving time of the intermediate transfer belt 116, the amount of toner consumption, the number of dots of toner images formed on the intermediate transfer belt 116, etc. may be used. I can do it.
(10-3) In the above embodiment, the case where a coating layer is formed on the transfer surface of the intermediate transfer belt 116 and the edge of the scraper 301 has been described as an example, but it goes without saying that the present disclosure is not limited to this. Alternatively, the coating layer may not be formed on either the transfer surface of the intermediate transfer belt 116 or the edge of the scraper 301. Even in such a case, similar effects can be obtained by applying the present disclosure.
(10-4) In the above embodiment, the case where the image forming apparatus 1 is a multifunction device has been described as an example, but it goes without saying that the present disclosure is not limited to this. Furthermore, even if the present disclosure is applied to a single-function device such as a facsimile device having a facsimile function, similar effects can be obtained as long as the device uses an intermediate transfer method.
(10-5) The present disclosure may be a scraper aging method executed by the image forming apparatus 1. Further, the present disclosure may be a scraper aging program that causes the image forming apparatus 1 to execute the scraper aging method. Furthermore, the present disclosure may be a computer-readable recording medium on which the scraper aging program is recorded. In either case, the effects of the present disclosure can be obtained.

The intermediate transfer type image forming apparatus and the scraper aging method according to the present disclosure are useful as techniques that can suppress unnecessary shortening of the life of the intermediate transfer body due to cleaning.

1... Image forming apparatus 100... Cleaning section 110... Image forming sections 111K, 111M, 111C, 111K... Photosensitive drums 112Y, 112M, 112C, 112K... Charging devices 113Y, 113M, 113C, 113K... Exposure devices 114Y, 114M , 114C, 114K...Developing devices 115Y, 115M, 115C, 115K...Primary transfer roller 116...Intermediate transfer belt 117...Drive roller 118...Secondary transfer roller 119...Secondary transfer opposing roller 160...Control unit 300...Second cleaning Means 301...Scraper 302...Metal blades 303, 304...Supporting metal plate 305...Transportation screws 306, 315...Cleaning unit housing 307, 319...Spring 310...First cleaning means 311...Cleaning blade 312...Blade 313...Supporting metal plate 314...Transportation Screw 316...Toner storage roller 317...Regulation member 318...Toner storage section 321...Cleaning opposing roller 401...Base 402, 412...Coating layer 411...Base 501, 502, 503...Protrusion 801, 1301, 1601, 1801, 2001, 2201... Scraper aging section 802, 1302, 1602, 1802, 2002, 2202... Aging necessity determining section 803, 1303, 1603, 1803, 2003, 2203... Primary transfer roller contact/separation control section 804, 1304, 1604, 1804 , 2004, 2204... Secondary transfer roller contact/separation control section 811, 1311, 1611, 1811, 2011, 2211... Aging completion information 1305... Cleaning blade contact/separation control section 1605, 2205... Scraper pressure contact/separation control section 1805... Belt tension Control unit 2005... Intermediate transfer belt swing control unit 2206... Blade set control unit 1001... Cams 1401, 1411... Actuator 1901... Tension roller

Claims (18)

An intermediate transfer image forming apparatus that transfers a toner image from a transfer surface of an intermediate transfer belt to a recording medium,
A scraper that removes residual toner by rubbing an edge that is harder than the transfer surface against the transfer surface;
A determining means for determining whether or not aging of the scraper is necessary;
An image characterized by comprising a scraper aging means that performs the aging by rubbing the edge of the scraper so that the scratch marks generated on the transfer surface are not visible when it is determined that aging is necessary. Forming device. 2. The image forming apparatus according to claim 1, wherein the scraper aging means reduces the sliding force of the edge of the scraper against the transfer surface, thereby making the scratches generated on the transfer surface invisible. Image forming according to claim 1, characterized in that the scraper aging means makes the scratches generated on the transfer surface invisible by dispersing them in the width direction perpendicular to the rotational running direction of the intermediate transfer belt. Device The intermediate transfer belt has a coating layer on the transfer surface side,
2. The image forming apparatus according to claim 1, wherein the scraper has a coating layer on its edge that is harder than the coating layer on the transfer surface. Scraper aging means
It has a transfer inhibiting means for inhibiting the transfer of toner from the transfer surface to the recording medium,
Claim 1 characterized in that aging is performed while supplying toner to the rubbing area between the edge of the scraper and the transfer surface by rotating the intermediate transfer belt while the transfer of the toner is prohibited by the inhibiting means. The image forming apparatus described in . a cleaning blade that comes into contact with the intermediate transfer belt to clean residual toner between the toner transfer position from the transfer surface to the recording medium and the scraping position of the edge of the scraper on the rotation path of the intermediate transfer belt;
A cleaning blade contact/separation means for bringing the cleaning blade into contact with and separating the cleaning blade from the transfer surface,
The scraper aging means performs aging while supplying toner to the rubbing area between the edge of the scraper and the transfer surface by rotating the intermediate transfer belt with the cleaning blade separated from the transfer surface. The image forming apparatus according to claim 1. It has a pressing force control means for controlling the pressing force of the edge of the scraper against the transfer surface,
2. The image forming apparatus according to claim 1, wherein the scraper aging unit performs the aging while reducing the pressure of the edge of the scraper against the transfer surface compared to when forming the image. A photoreceptor that forms toner images of each YMCK color,
A primary transfer means for transferring toner images of each color of YMCK from a corresponding photoreceptor to a transfer surface,
The scraper aging means further separates the primary transfer means for each YMC color from the photoreceptor, lowering the belt tension of the intermediate transfer belt than when the primary transfer means for each YMC color is pressed against the photoreceptor, and A claim characterized in that aging is performed by transferring a toner image formed on a K color photoreceptor onto a transfer surface, thereby supplying K color toner to a sliding portion between an edge of a scraper and the transfer surface. 5. The image forming apparatus according to 5. comprising a belt tension control means for changing the belt tension of the intermediate transfer belt by controlling the contact pressure of the tension roller against the inner circumferential surface of the intermediate transfer belt;
2. The image forming apparatus according to claim 1, wherein the scraper aging means performs aging with the belt tension of the intermediate transfer belt lower than that during image formation. Equipped with intermediate transfer belt displacement means for displacing the intermediate transfer belt in the width direction,
2. The image forming apparatus according to claim 1, wherein the scraper aging means performs aging while continuously displacing the intermediate transfer belt in the width direction. Equipped with a usage status storage means for storing whether or not the scraper is unused,
2. The image forming apparatus according to claim 1, wherein the aging necessity determining means determines that aging is necessary when it is stored that the scraper is unused. Equipped with a usage status detection means for detecting whether the scraper is unused,
The image forming apparatus according to claim 1, wherein the aging necessity determining means determines that aging is necessary when it is detected that the scraper is unused. Equipped with a cleaning blade,
When at least one of the cleaning blade and the intermediate transfer belt is unused, and the scraper is unused,
blade setting means for supplying toner to a sliding portion between the cleaning blade and the transfer surface by rotating the intermediate transfer belt with the pressure contact force control means separating the edge of the scraper from the transfer surface; ,
8. The image forming apparatus according to claim 7, wherein the scraper aging means performs aging after the blade setting means finishes supplying toner. When the scraper aging means ages the scraper,
At the rubbing part of the edge of the scraper on the rotation path of the intermediate transfer belt,
The image according to claim 1, further comprising a relative moving means for moving at least one of the scraper and the intermediate transfer belt relative to the other in a width direction perpendicular to a rotational running direction of the intermediate transfer belt. Forming device. 15. The image forming apparatus according to claim 14, further comprising regulating members for regulating the relative movement on the upstream and downstream sides of the sliding portion of the edge of the scraper on the rotation path of the intermediate transfer belt. 5. The image forming apparatus according to claim 4, wherein the coating layer on the transfer surface contains Si as a main component. 5. The image forming apparatus according to claim 4, wherein the coating material on the edge of the scraper is DLC. A scraper aging method performed by intermediate transfer type image forming apparatuses that transfers a toner image from the transfer surface of an intermediate transfer belt to a recording medium and removes residual toner from the transfer surface with a scraper that has a harder edge than the transfer surface. There it is,
a determination step of determining whether or not aging of the scraper is necessary;
A scraper aging step of performing the aging by rubbing the edge of the scraper while making the scratch marks generated on the transfer surface invisible when it is determined that aging is necessary. Aging methods.