JP5633586B2 - Image forming apparatus - Google Patents

Description

  The present invention is provided in an image forming apparatus that forms an image using an image carrier such as a copying machine, a facsimile machine, and a printer, and is a cleaning device that cleans the image carrier, and in particular, is attached to the image carrier. Cleaning device including a cleaning member having an abrasive for removing foreign matter, a process cartridge including such a cleaning device and detachable from such an image forming device, and such an image forming device including such a cleaning device or a process cartridge About.

  In an image forming apparatus that forms an image using an image carrier, such as a copying machine, a facsimile machine, or a printer, as described in [Patent Document 1], [Patent Document 2], etc., it adheres to the surface of the image carrier. A configuration including a cleaning device for removing foreign matters such as residual toner is well known.

  However, since the cleaning performance of such a cleaning device is governed by various factors, the cleaning performance may be insufficient due to physical property values over time, environmental fluctuations, and image formation patterns, which may cause problems in image quality. One of them is medaka-like dirt. When the additive externally added to the toner is released and adheres to the surface of the image carrier, the medaka-like stain is accumulated on the surface of the image carrier with the additive as a starting point. Is further blocked by the additive and gradually adheres to the surface of the image carrier, so that a stain consisting of a medaka-like image appears on the background portion of the formed image, and the image quality is remarkably deteriorated.

  Conventionally, the medaka-like stain has been dealt with by replacing the image carrier. However, since this increases the cost, it has been disclosed in [Patent Literature 1] and [Patent Literature 2] in recent years. As described above, a technique for removing foreign matter on the surface of an image carrier has been proposed in which the cleaning blade that performs cleaning while contacting the image carrier is used as a polishing blade that is a cleaning blade with an abrasive.

  However, if the polishing blade is kept in contact with the image carrier at all times and used for a long time, the surface of the image carrier is scratched and wear is promoted, and eventually the image carrier is replaced at a shorter cycle than usual. Become. Further, when the polishing blade is always brought into contact with the image carrier, the polishing blade itself is rapidly deteriorated.

  Therefore, in [Patent Document 1] and [Patent Document 2], a contact / separation mechanism for contacting and separating the polishing blade to and from the image carrier is provided, and the surface of the image carrier is obtained by intermittently contacting the polishing blade to the image carrier. Technologies that suppress scratches and wear are proposed. This technique also has an effect of suppressing deterioration of the polishing blade itself.

  However, in such a configuration, as described in, for example, [Patent Document 1], the degree of such an action is low if the polishing blade is merely brought into and out of contact with the power supply of the image forming apparatus. For example, as described in [Patent Document 2], if the mode in which the polishing blade is brought into contact with the image carrier in order to clean the image carrier is set at a time other than the time of image formation, an image is displayed during the mode. Since the formation becomes impossible, the image forming efficiency is lowered.

  The present invention is provided in an image forming apparatus that forms an image using an image carrier, such as a copying machine, a facsimile machine, and a printer, and is a cleaning device that cleans the image carrier, and removes foreign matter adhering to the image carrier. A cleaning device having an abrasive for removing, a cleaning device that cleans the image carrier while preventing or suppressing a decrease in image forming efficiency, and a cleaning device that includes such a cleaning device, and is detachable from the image forming device It is an object of the present invention to provide a process cartridge, such a cleaning apparatus, or such an image forming apparatus including the process cartridge.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a first cleaning member that performs cleaning by contacting an image carrier and contact / separation means that contacts and separates the first cleaning member from the image carrier. A latent image writing operation in which the latent image writing operation is intermittently performed with respect to the image carrier during one image forming operation. between, during non-operation of the latent image writing operation, by said moving means, the state first cleaning member which is abutted from a state of being separated from the image bearing member, said first cleaning member to an image bearing member has a row cormorants cleaning device operations and, when separable said first cleaning member to said image bearing member by said moving means increases the distance between the latent image writing operation to the image carrier It is in the image forming apparatus.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the cleaning device is configured such that the first cleaning member is removed from the image carrier once during the non-operation of the latent image writing operation. From the state where the first cleaning member is brought into contact with the image carrier from the separated state, and from the state where the first cleaning member is brought into contact with the image carrier by the contact and separation means, One of the operations of separating one cleaning member from the image carrier is performed, and the contacted state may be maintained during the non-operation.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the cleaning device is an image carrier at a position upstream of a position where the first cleaning member contacts in the moving direction of the image carrier. And a second cleaning member that performs cleaning while abutting on the substrate.

According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the cleaning device corresponds to a cumulative time when the first cleaning member is in contact with the image carrier. The contacting / separating means varies the period in which the first cleaning member is brought into contact with the image carrier.

According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the cleaning device corresponds to an accumulated time when the first cleaning member is in contact with the image carrier. The contact time of the first cleaning member with the image carrier is varied by the contact / separation means.

According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, when the accumulated time when the first cleaning member contacts the image carrier reaches a predetermined time. And a notification means for notifying that the first cleaning member should be replaced.

The present invention includes a first cleaning member that makes contact with an image carrier and performs cleaning, and contact / separation means for bringing the first cleaning member into and out of contact with the image carrier, and carries an image on the image carrier. Non-operation of the latent image writing operation during the latent image writing operation when the latent image writing operation to the image carrier is intermittently performed during one image forming operation. sometimes, by the moving means, from the state in which the first cleaning member is separated from the image carrier, have row operations so as to be brought into contact with the first cleaning member to an image bearing member, by the moving means When the first cleaning member is brought into contact with or separated from the image carrier, the image forming apparatus increases the interval between the latent image writing operations with respect to the image carrier , thereby preventing or suppressing a decrease in image formation efficiency. While cleaning the image carrier Therefore, it is possible to provide an image forming apparatus that can maintain the image carrier in a clean state with time and contribute to good image formation with time.

  If there is a second cleaning member that contacts and cleans the image carrier at a position upstream of the position where the first cleaning member contacts in the moving direction of the image carrier, the first cleaning member By properly using the cleaning function of the image carrier and the cleaning function of the image carrier by the second cleaning member, it is possible to efficiently perform cleaning corresponding to various stains, and the first cleaning member can improve the image forming efficiency. The image carrier can be cleaned while preventing or suppressing the decrease, the image carrier can be kept clean over time, and can contribute to good image formation over time. A cleaning device can be provided.

  If the period in which the first cleaning member is brought into contact with the image carrier by the contact / separation means is changed according to the accumulated time that the first cleaning member is in contact with the image carrier, the first cleaning member is changed. By changing the period to cancel the deterioration of the cleaning performance of the cleaning member over time, the image carrier can be cleaned while preventing or suppressing the decrease in image formation efficiency. It is possible to provide a cleaning device that can be kept clean and can contribute to good image formation over time.

  If the time for which the first cleaning member is brought into contact with the image carrier by the contacting / separating means is varied according to the cumulative time that the first cleaning member is in contact with the image carrier, the first cleaning member is changed. By varying the time taken so as to counteract the deterioration of the cleaning performance of the cleaning member over time, the image carrier can be cleaned while preventing or suppressing the decrease in image formation efficiency. It is possible to provide a cleaning device that can be kept clean and can contribute to good image formation over time.

  The present invention resides in a process cartridge that includes such a cleaning device and an image carrier to be cleaned by the cleaning device, and is detachably integrated with an image forming apparatus that forms an image using the image carrier. Therefore, the image carrier can be cleaned while preventing or suppressing a decrease in image formation efficiency, and the cleaning device capable of keeping the image carrier clean with time and the image carrier and the like are integrated. Thus, it is possible to provide a process cartridge that can be attached to and detached from the image forming apparatus, has high workability such as replacement, and can contribute to good image formation over time.

  The present invention resides in such a cleaning device or an image forming apparatus provided with such a process cartridge, so that the image bearing member can be cleaned by a cleaning device capable of cleaning the image bearing member while preventing or suppressing a decrease in image forming efficiency. Can be maintained in a clean state over time, and it is possible to provide a reliable image forming apparatus that can perform good image formation over time.

  When the first cleaning member is brought into and out of contact with the image carrier by the contact / separation means, if the interval between the latent image writing operations with respect to the image carrier is increased, the first cleaning member is moved to the image carrier. The image carrier is aged by a cleaning device capable of cleaning or cleaning the image carrier while preventing or suppressing a decrease in the latent image writing accuracy due to contact with / separating from the body. Therefore, it is possible to provide a highly reliable image forming apparatus that can be kept clean and can perform good image formation over time.

  If there is an informing means for informing that the first cleaning member should be replaced when the accumulated time when the first cleaning member contacts the image carrier has reached a predetermined time, The image bearing member is changed over time by a cleaning device that can clean the image bearing member over time while urging the replacement of the first cleaning member and preventing or suppressing a decrease in image forming efficiency by replacing the first cleaning member. Therefore, it is possible to provide an image forming apparatus which can be kept clean and can perform good image formation over time and has high reliability and usability.

1 is a schematic front view of an image forming apparatus to which the present invention is applied. FIG. 2 is a schematic front view showing a configuration around one image carrier among a plurality of image carriers provided in the image forming apparatus shown in FIG. 1 and including a process cartridge. FIG. 3 is a perspective view of a mechanism that swings a first cleaning member provided in a cleaning device that constitutes the process cartridge shown in FIG. 2. FIG. 3 is a perspective view illustrating a configuration of a first cleaning member provided in a cleaning device that configures the process cartridge illustrated in FIG. 2. FIG. 3 is a schematic front view showing another configuration example around one image carrier among a plurality of image carriers provided in the image forming apparatus shown in FIG. 1 and including a process cartridge. FIG. 3 is a timing chart showing an example of contact timing of a first cleaning member provided in a cleaning device constituting the process cartridge shown in FIG. 2 with respect to an image carrier.

  FIG. 1 shows an outline of an image forming apparatus to which the present invention is applied. The image forming apparatus 100 is a complex machine of a color laser copying machine and a printer, but may be other image forming apparatuses such as other types of copying machines, facsimile machines, printers, and complex machines of these. The image forming apparatus 100 performs image forming processing based on image data of a document read by the image forming apparatus 100 or an image signal corresponding to image information received from the outside. The image forming apparatus 100 can form an image using plain paper generally used for copying, OHP sheets, thick paper such as cards and postcards, and envelopes as sheet-like recording media. .

  The image forming apparatus 100 includes a photosensitive member as a toner carrier that is a latent image carrier as an image carrier capable of forming an image as an image corresponding to each of the colors separated into yellow, magenta, cyan, and black. A tandem structure in which the drums 20Y, 20M, 20C, and 20BK are arranged in parallel, in other words, a tandem system is adopted.

  The photoconductor drums 20Y, 20M, 20C, and 20BK are OPC photoconductors, and are arranged in this order from the upstream side in the A1 direction that is the moving direction of the transfer belt 11 that is an intermediate transfer medium as a transfer medium that is an image carrier. Yes. Y, M, C, and BK added after the numerals of the respective symbols indicate members for yellow, magenta, cyan, and black.

  Each of the photosensitive drums 20Y, 20M, 20C, and 20BK has image forming units 60Y, 60M, 60C, and 60BK for forming yellow (Y), magenta (M), cyan (C), and black (BK) images, respectively. Is provided.

  The photosensitive drums 20Y, 20M, 20C, and 20BK are on the outer peripheral surface side of the transfer belt 11 as an intermediate transfer member, that is, an endless belt disposed slightly above the central portion inside the main body 99, that is, on the image forming surface side. Is located.

  The transfer belt 11 is movable in the direction of the arrow A1 while facing the photosensitive drums 20Y, 20M, 20C, and 20BK. Visible images, that is, toner images formed on the respective photoconductive drums 20Y, 20M, 20C, and 20BK are respectively superimposed and transferred onto the transfer belt 11 that moves in the direction of the arrow A1, and then transferred as a recording medium and a transfer medium. It is designed to be batch transferred onto paper. Illustration of the transfer paper is omitted.

  The upper portion of the transfer belt 11 faces the photosensitive drums 20Y, 20M, 20C, and 20BK, and the opposed portions transfer the toner images on the photosensitive drums 20Y, 20M, 20C, and 20BK. A primary transfer portion 98 for transferring to the belt 11 is formed.

  In the superimposing transfer to the transfer belt 11, the toner images formed on the photosensitive drums 20Y, 20M, 20C, and 20BK are transferred to the same position on the transfer belt 11 while the transfer belt 11 moves in the A1 direction. As described above, voltage application by the primary transfer rollers 12Y, 12M, 12C, and 12BK disposed at positions facing the photosensitive drums 20Y, 20M, 20C, and 20BK across the transfer belt 11 causes the A1 direction upstream. The timing is shifted toward the downstream side.

  The transfer belt 11 exhibits conductivity with a volume resistance of 10 ^ 5 to 10 ^ 11 Ω · cm 2. When the surface resistance is less than 10 ^ 5Ω / □, when the toner image is transferred from the photosensitive drums 20Y, 20M, 20C, and 20BK onto the transfer belt 11, the toner image is disturbed due to discharge, so-called transfer dust. If it exceeds 10 ^ 11Ω / □, the toner image is transferred from the transfer belt 11 to the sheet, and then the counter charge of the toner image remains on the transfer belt 11 and the afterimage on the next image. May appear as

  The transfer belt 11 is, for example, a belt-like shape obtained by extruding a metal oxide such as tin oxide or indium oxide, conductive particles such as carbon black, or a conductive polymer alone or in combination with a thermoplastic resin, and then extruding. Cylindrical plastics can be used. In addition, the above-mentioned conductive particles and conductive polymer are added to a resin solution containing a thermal crosslinking reactive monomer or oligomer, if necessary, and centrifugal molding is performed while heating to obtain an endless belt-shaped transfer belt 11. You can also.

  Each of the transfer belts 11 has a detent guide (not shown) as a detent member at each edge thereof. The offset guide is provided to prevent the transfer belt 11 from being biased in any direction perpendicular to the paper surface in FIG. 1 when the transfer belt 11 rotates in the A1 direction. The stopper guide is made of urethane rubber, but can be made of various rubber materials such as silicon rubber.

  The image forming apparatus 100 is disposed in the main body 99 so as to oppose the four image forming units 60Y, 60M, 60C, and 60BK and the respective photosensitive drums 20Y, 20M, 20C, and 20BK. A transfer belt unit 10 as an intermediate transfer unit provided; a secondary transfer roller 5 as a secondary transfer bias roller as a transfer member which is disposed opposite to the transfer belt 11 and is driven by the transfer belt 11; And an optical scanning device 8 that is an optical writing unit serving as a latent image writing unit as a latent image forming unit disposed to face the image forming units 60Y, 60M, 60C, and 60BK.

  The image forming apparatus 100 also feeds a sheet as a sheet feeding cassette capable of stacking a large number of transfer sheets transported between the photosensitive drums 20Y, 20M, 20C, and 20BK and the transfer belt 11 in the main body 99. The sheet feeding device 61, which is a mechanism, and the transfer belt conveyed from the sheet feeding device 61 are transferred at a predetermined timing in accordance with the toner image formation timing by the image forming units 60Y, 60M, 60C, and 60BK. 11 and the secondary transfer roller 5, a registration roller 4 that feeds out toward the secondary transfer portion 97, and a sensor (not shown) that detects that the leading edge of the transfer paper has reached the registration roller 4.

  The image forming apparatus 100 also includes a fixing device 6 as a belt-fixing type fixing unit for fixing the toner image onto the transfer paper onto which the toner image has been transferred, and a fixed transfer paper in the main body 99. And a paper discharge roller 7 as a pair of paper discharge rollers for discharging to the outside.

  The image forming apparatus 100 also has a paper discharge tray 17 on the side of the main body 99 on which the transfer paper discharged from the main body 99 by the discharge rollers 7 is stacked. And an automatic document feeder (so-called ADF) 15 that is disposed above the reader 14 and feeds a document to the reader 14.

  The image forming apparatus 100 also includes a driving device (not shown) that rotationally drives the photosensitive drums 20Y, 20M, 20C, and 20BK, a power source as a bias applying unit (not shown) that applies a secondary transfer bias to the secondary transfer roller 5, and Bias control means, control means 35 including a CPU, memory, timer, etc. (not shown) for controlling the overall operation of the image forming apparatus 100 based on detection results by various detection means, etc. Has an operation panel 76 having various buttons and a display unit for instructing image formation start and confirming the state of the image forming apparatus 100.

  In addition to the transfer belt 11, the transfer belt unit 10 includes primary transfer rollers 12Y, 12M, 12C, and 12BK as primary transfer bias rollers, and a drive roller 36 that is a drive member around which the transfer belt 11 is wound. The cleaning counter roller 37, the driving roller 36, the tension rollers 38 and 39 that stretch the transfer belt 11 together with the cleaning counter roller 37, and the belt cleaning that is disposed facing the transfer belt 11 and cleans the transfer belt 11. And a cleaning device 13 as a device.

  The transfer belt unit 10 also includes a drive system (not shown) that rotationally drives the drive roller 36, and a power source and bias control as a bias application unit (not shown) that applies a primary transfer bias to the primary transfer rollers 12Y, 12M, 12C, and 12BK. Means.

  The primary transfer rollers 12Y, 12M, 12C, and 12BK press the transfer belt 11 from the back surface thereof toward the photosensitive drums 20Y, 20M, 20C, and 20BK to form primary transfer nips.

  In each primary transfer nip, a primary transfer electric field is formed between the photosensitive drums 20Y, 20M, 20C, and 20BK and the primary transfer rollers 12Y, 12M, 12C, and 12BK due to the influence of the primary transfer bias. . The toner images of the respective colors formed on the photosensitive drums 20Y, 20M, 20C, and 20BK are primarily transferred onto the transfer belt 11 due to the influence of the primary transfer electric field and nip pressure.

The driving roller 36 is in contact with the secondary transfer roller 5 via the transfer belt 11 to form a secondary transfer nip.
The tension roller 38 has a function as a tension roller as a pressure member that gives the transfer belt 11 a predetermined tension suitable for transfer.

  Although not shown in detail, the cleaning device 13 includes a cleaning brush and a cleaning blade disposed so as to face and contact the transfer belt 11, and remove foreign matters such as residual toner on the transfer belt 11. The transfer belt 11 is cleaned by scraping and removing with a cleaning brush and a cleaning blade.

The sheet feeding device 61 accommodates a plurality of transfer papers in a state where a plurality of transfer papers are stacked, and is arranged in multiple stages below the main body 99. The sheet feeding device 61 feeds the transfer paper toward the registration roller 4 at a predetermined timing.
The transfer paper fed from the sheet feeding device 61 reaches the registration roller 4 through the paper feed path and is sandwiched between the rollers of the registration roller 4.

  The fixing device 6 includes a belt unit 62 and a pressure roller 63 pressed against the belt unit 62. The belt unit 62 includes an endless fixing belt 64, a fixing roller 65 that moves the fixing belt 64 in an endless manner, and a heating roller 66 that has the fixing belt 64 wound around the fixing roller 65 and has a heat source (not shown) inside. have

  The fixing device 6 passes the transfer paper carrying the toner image through a fixing unit, which is a pressure contact part between the belt unit 62 and the pressure roller 63, so that the carried toner image is caused by the action of heat and pressure. It is fixed on the surface of the transfer paper.

  The configuration of the image forming units 60Y, 60M, 60C, and 60BK will be described as a representative of the configuration of the image forming unit 60Y that includes the photosensitive drum 20Y. Since the configurations of the other image forming units are substantially the same, in the following description, for the sake of convenience, reference numerals corresponding to the reference numerals assigned to the configuration of the image forming unit 60Y are used for the configurations of the other image forming units. Or omitted, and detailed description will be omitted as appropriate.

  As shown in FIG. 2, the image forming unit 60Y provided with the photosensitive drum 20Y performs primary transfer around the photosensitive drum 20Y along a rotational direction B1 that is a counterclockwise direction in the drawing. A roller 12Y, a cleaning device 40Y as a cleaning unit, a neutralizing device 30Y as a neutralizing unit, a charging device 90Y as a charging unit, a developing unit 80Y as a developing unit as a developing unit, and a cleaning unit 40Y And a waste tank (not shown) serving as a collection tank for collecting and storing unwanted materials such as transfer residual toner, carrier, and paper dust removed from the photosensitive drum 20Y.

  The photosensitive drum 20Y, the cleaning device 40Y, the charge eliminating device 30Y, the charging device 90Y, and the developing device 80Y are integrated to form an image forming unit 60Y as a process cartridge. The image forming unit 60Y, which is a process cartridge, is detachable from the main body 99. Such a process cartridge having a plurality of structures can be handled as a replacement part, so that maintainability is remarkably improved, which is very preferable. In addition, since the life of each part, which is an element of the process cartridge, is equal, unnecessary replacement is prevented and suppressed, and the structure is further preferable. Further, even in an image forming process in which development using a small particle toner as described later is performed by the process cartridge, a cleaning function described later on the image carrier including the photosensitive drum 20Y is maintained for a long time. As a result, deterioration of image quality is prevented or suppressed.

  The static eliminator 30Y neutralizes the surface of the photoreceptor drum 20Y to make it electrically clean, and is disposed in the vicinity of the surface of the photoreceptor drum 20Y. The neutralization device 30Y is configured as a neutralization charger, but may be configured as a neutralization roller or a neutralization lamp.

  The charging device 90Y is a uniform charging unit that uniformly charges the surface of the photosensitive drum 20Y by applying a uniform charge on the surface of the photosensitive drum 20Y that has been discharged by the discharging device 30Y. It is disposed close to the surface of the drum 20Y. The charging device 90Y is configured as a charging charger, but may be configured as a charging roller.

  The optical scanning device 8 irradiates the region between the charging region where the charging device 90Y faces the photosensitive drum 20Y and the developing region where the developing device 80Y faces the scanning light beam while scanning the optically modulated and deflected laser light L. The image information corresponding to the original image is exposed by spot irradiation on the surface to be scanned of the photosensitive drum 20Y after being charged by the charging device 90Y and visualized as a yellow toner image by the developing device 80Y. An electrostatic latent image is written as a latent image corresponding to the above. Therefore, as shown in FIG. 1, the optical scanning device 8 includes a laser optical system such as a light source 31 that is a semiconductor laser, a polygon mirror 32 that is a polygonal polygon mirror that rotates at high speed, an fθ lens 33, and a reflection mirror 34. Have.

  As shown in FIG. 2, the developing device 80Y includes a developing roller 81Y carrying a two-component developer (hereinafter referred to as developer) including a toner and a carrier disposed in close proximity to the photosensitive drum 20Y, and a developing roller 81Y. A doctor blade 82Y that regulates the developer on the roller 81Y to a certain height and a first conveying screw 83Y that is arranged to face each other and stirs the developer and supplies the developer to the developing roller 81Y. The second conveying screw 84Y, the partition wall 87Y provided between the first conveying screw 83Y and the second conveying screw 84Y, the toner bottle 88Y containing yellow toner, and the developing bias of the DC component with the developing roller 81Y. And a bias applying means (not shown) for applying to.

  The developing roller 81Y has a developing sleeve (not shown) that is a developer carrying member that carries the developer on the surface thereof. The bias applying means applies a developing bias having an appropriate size between the exposed portion and the non-exposed portion of the photosensitive drum 20Y to the developing sleeve.

  In the developing device 80Y, a partition wall 87Y forms a first supply unit that accommodates the developing roller 81Y and the first conveyance screw 83Y and a second supply unit that accommodates the second conveyance screw 84Y. Has been.

  The first transport screw 83Y is rotationally driven by a driving unit, and supplies the developer in the first supply unit to the developing roller 81Y while transporting the developer from the back side to the front side in FIG. The developer conveyed to the vicinity of the end in the first supply unit by the first conveyance screw 83Y enters the second supply unit through an opening (not shown) formed in the partition wall 87Y.

  In the second supply unit, the second transport screw 84Y transports the developer sent from the first supply unit in the direction opposite to that of the first transport screw 83Y by being rotationally driven by the driving unit. The developer transported to the vicinity of the end of the second supply unit by the second transport screw 84Y returns to the first supply unit through another opening (not shown) provided in the partition wall 87Y.

  The developer in the developing case 85Y is a two-component developer containing a magnetic carrier and yellow toner. The developer is supplied and supplied with yellow toner from the toner bottle 88Y, and the first transport screw 83Y and The supplied yellow toner and developer are agitated and mixed while being agitated and conveyed by the second conveying screw 84Y, are frictionally charged, and are supplied and carried on the developing roller 81Y.

  The developing roller 81Y whose developer thickness is regulated by the doctor blade 82Y and whose layer thickness is regulated is developed in the developing region between the developing roller 81Y and the photosensitive drum 20Y by the rotation and the developing bias by the bias applying means. An appropriate amount of developer is carried by the doctor blade 82Y, and the yellow toner in the developer is electrostatically transferred to the electrostatic latent image formed on the surface of the photosensitive drum 20Y, and the electrostatic latent image is formed. A visible image is formed as a yellow toner image.

The developer that has consumed the yellow toner by the development is returned to the developing device 80Y as the developing roller 81Y rotates.
In this embodiment, the DC component developing bias is applied by the bias applying means. However, the developing bias may be an AC component, or an AC component superimposed on the DC component.

  The toner is a small particle toner in which at least silica fine particles are externally added to a toner base particle mainly composed of a colorant and polyester and containing a charge control agent, and the charge control agent is on the surface of the toner base particle. The ratio M / T of the weight M present in the toner and the weight T present in the entire toner base particles is 100 to 1000. Here, the weight ratio M / T is not present in components other than the charge control agent, but is present only in the charge control agent, in the long-period type periodic table excluding H, C, O, and rare gas elements. It is a value measured by X-ray photoelectron spectroscopy (XPS) for one element up to the fifth period. Since this toner uses polyester having a low glass transition point (Tg) as a binder resin, it is excellent in low-temperature fixability, and the charge control agent is overwhelming as indicated by the value of the weight ratio M / T. Therefore, the toner has excellent charging stability.

  An external additive composed of inorganic fine particles such as silica is externally added to the surface of the toner particles in order to assist fluidity and chargeability of the toner particles. Here, inorganic fine particles such as silica and titania have negative polarity, and in this toner using a charge control agent having the same negative polarity such as a salicylic acid metal complex and salts, external additives and charge control are performed on the surface of the toner. Electrical repulsion with the agent occurs. In addition, since the charge control agent is hard, inorganic fine particles such as silica tend to be detached from the toner. Among the inorganic fine particles, especially silica fine particles are detached from the toner and adhere to the image bearing member, and it has become clear from the inventors' tests that they easily become components of an adhering substance that affects the image quality. However, in the image forming apparatus 100 equipped with a cleaning device, which will be described later, by using such toner, it is possible to remove the adhered substances generated on the image carrier, and the image quality is kept high.

  The unnecessary object storage unit is not provided only for the image forming unit 60Y, and is a configuration common to the image forming units 60M, 60C, and 60BK, and further to the cleaning device 13. Accommodate all at once. The unnecessary object storage section is detachable from the main body 99, and when the inside is filled with an unnecessary object, the maintenance for removing the unnecessary object from the main body 99 is facilitated.

  The cleaning device 40Y is housed in a cleaning case 49Y having a housing and the front end of the cleaning device 49Y is in contact with the photoconductive drum 20Y, and the transfer residual toner, carrier, paper dust, etc. on the photoconductive drum 20Y. A cleaning blade 41Y as a first cleaning member that scrapes off, collects and cleans foreign matter, and abuts on the photosensitive drum 20Y at a position upstream of the position where the cleaning blade 41Y contacts in the rotation direction B1 of the photosensitive drum 20Y. It has a cleaning blade 42Y as a second cleaning member that scrapes off and collects foreign matters such as transfer residual toner, carrier, paper dust and the like on the photosensitive drum 20Y.

  The cleaning device 40Y also contacts the photosensitive drum 20Y at a position upstream of the position where the cleaning blade 42Y contacts in the rotational direction B1 of the photosensitive drum 20Y, and rotates in the direction shown in the figure to rotate on the photosensitive drum 20Y. A cleaning brush 43Y that is a brush roller as a third cleaning member that scrapes off, collects, and cleans foreign matters such as transfer residual toner, carrier, and paper dust, and cleaning blades 41Y and 42Y that rotate in the direction shown in the figure. A collection coil 44Y as a discharge member that collects foreign matter removed from the photosensitive drum 20Y by the cleaning brush 43Y and discharges it toward the waste storage unit, and a tip abuts against the cleaning brush 43Y, and cleaning is performed by rotation of the cleaning brush 43Y. Adhered to the brush 43Y And a flicker bar 45Y as scraping member for emitting toward the drop recovery coil 44Y hit the essential things.

  The cleaning device 40Y also includes contact / separation means 50Y for bringing the cleaning blade 41Y into and out of contact with the photosensitive drum 20Y, a support member 46Y that supports the cleaning blade 42Y and the flicker bar 45Y and fixed to the cleaning case 49Y, and the cleaning blade 41Y. 3 has a swinging mechanism 70Y shown in FIG. 3 that swings in the extending direction perpendicular to the paper surface.

  The cleaning blade 42Y mainly removes residual toner on the photosensitive drum 20Y, that is, transfer residual toner and paper dust. It is made of a material selected from metal, resin, rubber and the like, and rubbers such as fluorine rubber, silicone rubber, butyl rubber, butadiene rubber, isoprene rubber, urethane rubber are preferably used, and among these, urethane rubber is particularly preferable.

  As shown in FIG. 4, the cleaning blade 41Y is a polishing blade as a polishing blade having a two-layer structure of a blade base layer 47Y as a substrate and an abrasive particle-containing layer 48Y as a polishing layer. The blade base layer 47Y is made of a material selected from rubber, resin, metal, and the like. Among these, like the cleaning blade 42Y, rubber is preferably used, and urethane rubber is particularly preferable. The abrasive particle-containing layer 48Y is formed by dispersing abrasive particles in rubber such as urethane rubber. The hardness when the blade base layer 47Y is made of rubber and the hardness of the rubber used for the abrasive particle-containing layer 48Y are preferably 65 degrees or more and 85 degrees or less. This is because when the hardness is less than 65 degrees, the progress of wear is fast, and when the hardness is greater than 85 degrees, the edge is easily chipped.

  As the material of the abrasive particles, nitrides such as silicon nitride, silicates such as aluminum silicate, magnesium silicate, mica and calcium silicate, calcareous substances such as calcium carbonate and gypsum, silicon carbide, boron carbide, tantalum carbide, titanium carbide And carbides such as aluminum carbide and zirconium carbide, and oxides such as cerium oxide, chromium oxide, titanium oxide and aluminum oxide. Among these, cerium oxide having excellent polishing power is preferable. The average particle size of the abrasive particles is preferably 0.05 μm or more and 150 μm or less, and more preferably 100 μm or more and 150 μm or less. If the average particle size is less than 0.05 μm, the particles are too fine, making it difficult to uniformly disperse in rubber, or the polishing power as a polishing blade cannot be obtained sufficiently. This is because if it exceeds 150 μm, the surface of the photosensitive drum 20Y is damaged because the polishing force is too large.

  The content of the abrasive particles is preferably from 0.5 wt% to 50 wt% of the abrasive particle-containing layer 48Y. When the content of abrasive particles is less than 0.5 wt%, dispersion becomes sparse and uniform polishing cannot be performed, and when the content of abrasive particles exceeds 50 wt%, the density of the abrasive particles is low. This is because it becomes too high, and it becomes easy to peel off or the cost becomes high.

  The thickness of each of the blade base layer 47Y and the abrasive particle-containing layer 48Y can be arbitrarily set, but the thickness of the abrasive particle-containing layer 48Y is 0.5% or more and 50% or less of the entire thickness of the cleaning blade 41Y. It is preferable. If the thickness of the abrasive particle-containing layer 48Y is less than 0.5%, there is no allowance for blade wear, so that the quality over time cannot be maintained, and the thickness of the abrasive particle-containing layer 48Y is 50 If the ratio exceeds 50%, the elastic function inherent to rubber cannot be exhibited, and the photosensitive drum 20Y cannot be uniformly polished.

  The cleaning blade 41Y having such a two-layer structure is installed such that the polishing surface formed by the abrasive particle-containing layer 48Y is in contact with the photosensitive drum 20Y. The cleaning blade 41Y removes foreign matters such as adhering substances on the photosensitive drum 20Y mainly composed of inorganic fine particles detached from the toner by scraping off the polished surface and leaking from the cleaning blade 42Y, that is, cleaning. Toner, paper dust, etc. that have not been removed by the blade 42Y and have passed through the cleaning blade 41Y are also removed.

  The abrasive particle-containing layer 48Y dispersed with a certain width of the abrasive particles comes into contact with the photoconductive drum 20Y, so that the film scraping of the photoconductive drum 20Y becomes uniform and prevents the photoconductive drum 20Y from being defective. Or reduced.

  The cleaning blade 41Y may not be a two-layer structure, but may be a polishing blade in which an abrasive is coated on the surface of the blade base layer 47Y or a polishing blade in which an abrasive is mixed in the blade base layer 47Y. In the structure, since the polishing agent is less peeled off or scraped off in a short time, an excellent cleaning function is maintained in the long term.

  In the cleaning blade 41Y, when the blade base layer 47Y is made of rubber and the cleaning blade 42Y is also made of rubber, it is preferable that the rubber hardness of the blade base layer 47Y is higher than the rubber hardness of the cleaning blade 42Y. This is for removing adhered substances and the like that could not be removed by the cleaning blade 42Y with a stronger polishing force.

  The manner in which the cleaning blade 41Y and the cleaning blade 42Y come into contact with the photosensitive drum 20Y will be described. The cleaning blade 41Y is in contact with the photosensitive drum 20Y by a trailing method, and the cleaning blade 42Y is in contact with a counter method.

  The reason why the cleaning blade 41Y is of the trailing method is to prevent turning-up due to the rotation of the photosensitive drum 20Y at the time of contact with the photosensitive drum 20Y. Since there is almost no toner or paper dust input to the cleaning blade 41Y, it is easy to turn over, but this is avoided by the contact of the trailing method, so the cleaning performance is slightly lower than the counter method However, the trailing method is adopted.

  The contact pressure of the cleaning blade 41Y with respect to the photosensitive drum 20Y is preferably 10 gf / cm or more and 60 gf / cm or less. When the contact pressure of the cleaning blade 41Y is less than 10 gf / cm, the contact pressure is low, so that the foreign matter on the photosensitive drum 20Y can easily pass through the cleaning blade 41Y and cannot be removed sufficiently. The contact pressure is 60 gf. If it exceeds / cm, the film scraping amount of the photosensitive drum 20Y increases, which may shorten the life of the photosensitive drum 20Y, which is not preferable. By bringing the cleaning blade 41Y into contact with the photosensitive drum 20Y with the contact pressure in such a range, good cleaning is performed.

  On the other hand, since the cleaning blade 42Y is in contact with the photosensitive drum 20Y in a counter manner, the cleaning blade 42Y has high cleaning properties, and the transfer residual toner and paper dust are efficiently removed.

  As shown in FIG. 5, both the cleaning blade 41Y and the cleaning blade 42Y may be configured to come into contact with the photosensitive drum 20Y in a counter manner. In this configuration, the spring 54Y is a tension spring.

  When the cleaning blade 41Y is of the counter type, the adhering substance on the photosensitive drum 20Y is removed by utilizing the impact when the cleaning blade 41Y comes into contact with the photosensitive drum 20Y as will be described later, and the cleaning property is excellent. Is obtained. The function of the cleaning blade 42Y is the same as described above.

  The contact angle of the cleaning blade 41Y with respect to the photosensitive drum 20Y is preferably 5 degrees or more and 25 degrees or less. If the contact angle is less than 5 degrees, the cleaning blade 41Y becomes bumpy with respect to the photosensitive drum 20Y, and the polishing function is not exerted over time due to the creep phenomenon, and if it exceeds 25 degrees, the job ends. This is because if the reverse rotation of the photosensitive drum 20Y occurs, the cleaning blade 41Y may be turned over. The contact pressure of the cleaning drum 41Y with the photosensitive drum 20Y is preferably 10 gf / cm or more and 60 gf / cm or less. The reason for this is the same as the configuration in which the cleaning blade 42Y contacts the photosensitive drum 20Y by the trailing method.

  The amount of biting of the cleaning blade 41Y into the photosensitive drum 20Y obtained by the relationship between the hardness of the cleaning blade 41Y and the contact pressure is preferably 0.2 mm or more and 1.5 mm or less. This is because the role of the polishing blade for removing the deposits can be sufficiently exerted without excessively increasing the film scraping amount of the photosensitive drum 20Y.

  As shown in FIG. 3, the swing mechanism 70Y includes a gear 71Y that rotates integrally with the photosensitive drum 20Y, a gear 72Y with a swing cam that meshes with the gear 71Y, a pressure holder 74Y that supports the cleaning blade 41Y, A bearing (not shown) disposed at the caulking tip of the pressure holder 74Y and a spring (not shown) that urges the bearing so as to abut against the gear 72Y with a sliding cam are provided. The peristaltic cam gear 72Y has a cam surface 75Y against which the bearing hits.

  When the photosensitive drum 20Y is rotated in the arrow B1 direction by the swing mechanism 70Y having such a configuration, the swing cam-equipped gear 72Y rotates in the arrow D1 direction, and the cleaning blade 41Y swings in the arrow E direction. Therefore, even if there is a slight deviation in the dispersion of the abrasive particles in the abrasive particle-containing layer 48Y, this is compensated for and the film scraping of the photoreceptor drum 20Y is made uniform.

  Although the cleaning blade 42Y does not contain abrasive particles, it slightly causes film scraping of the photosensitive drum 20Y. Therefore, the cleaning blade 42Y also swings by the swing mechanism similar to the swing mechanism 70Y. It is preferable to constitute so as to be. When the cleaning blade 41Y and the cleaning blade 42Y are swung, it is preferable that the cleaning blade 41Y and the cleaning blade 42Y are swung in different phases in order to make the film abrasion of the photosensitive drum 20Y more uniform. As a configuration for swinging them at different phases, for example, a configuration in which the cam surface of the gear with a peristaltic cam in each peristaltic mechanism is in a different phase, or a configuration in which the peristaltic mechanism 70Y is deformed is cleaned. The blade 41Y and the cleaning blade 42Y are used in common, and a cam surface of another phase for swinging the cleaning blade 42Y is provided inside the cam surface 75Y of the gear 72Y with the swing cam, and the cam surface is rocked by different cam surfaces. The mechanism to move is mentioned.

  The cleaning brush 43Y rotates while contacting the surface of the photosensitive drum 20Y after the toner image is transferred to the transfer belt 11 at the primary transfer nip, and remains on the photosensitive drum 20Y after the transfer. Part of the foreign matter such as transfer residual toner is removed. The remaining foreign matter is dammed by the tip edge portion of the cleaning blade 42Y and scraped off from the surface of the photosensitive drum 20Y. If foreign matter still remains on the photosensitive drum 20Y, it is scraped off by the cleaning blade 41Y. As a result, the surface of the photosensitive drum 20Y on the downstream side of the cleaning device 40Y in the rotational direction B1 of the photosensitive drum 20Y is removed. It is in a clean state.

  The cleaning brush 43Y itself scrapes off foreign matter from the photosensitive drum 20Y, and in addition, receives the foreign matter scraped by the cleaning blade 42Y and the cleaning blade 41Y and dropped downward, and rotates to expose these foreign matter. It is conveyed away from the surface of the body drum 20Y. The foreign matter carried by the rotation of the cleaning brush 43Y is knocked down by the flicker bar 45Y and discharged toward the recovery coil 44Y.

  The recovery coil 44Y is made of, for example, a screw or a coil, and the foreign matter discharged to the recovery coil 44Y is conveyed and stored in an unnecessary object storage section outside the cleaning case 49Y by rotational driving in the direction of the arrow in the drawing.

  The rotation directions of the cleaning brush 43Y and the recovery coil 44Y may be opposite to those shown in FIG. Alternatively, the cleaning brush 43Y may use a cleaning blade 42Y and a toner collection blade that simply collects the foreign matter scraped by the cleaning blade 41Y and dropped downward and conveys it toward the collection coil 44Y.

  The contact / separation means 50Y includes a shaft 51Y supported by the cleaning case 49Y, a blade support that supports the cleaning blade 41Y at one end thereof, and a central portion that is rotatably supported by the shaft 51Y and that rotates about the shaft 51Y. A body 52Y, a solenoid 53Y that is connected to the other end of the blade support 52Y and rotates the blade support 52Y so that the cleaning blade 41Y contacts the photoreceptor drum 20Y when energized, and the cleaning blade 41Y from the photoreceptor drum 20Y. It has a spring 54Y as a pressing spring as a biasing member that biases the blade support 52Y so as to be spaced apart. Energization of the solenoid 53Y is controlled by the control means 35.

  Therefore, when the control means 35 energizes the solenoid 53Y, the blade support 52Y rotates counterclockwise around the shaft 51Y against the biasing force of the spring 54Y, and the cleaning blade 41Y is exposed to light. It contacts the body drum 20Y. In this way, the cleaning blade 41Y contacts the photosensitive drum 20Y only when the solenoid 53Y is energized. Here, the control means 35 functions as a cleaning control means and constitutes a part of the contact / separation means 50Y. The timing of energizing the solenoid 53Y and other configurations of the cleaning device 40Y will be described later.

  In such an image forming unit 60Y, an image is formed by a negative-positive process. In response to an image formation start instruction from the user using the operation panel 76 or the like, rotation of the photosensitive drum 20Y is started, and an image forming operation is started. As the photosensitive drum 20Y rotates in the B1 direction, the surface is uniformly negatively charged by the charging device 90Y, and the electrostatic latent image corresponding to the yellow color is obtained by the exposure scanning of the laser light L emitted from the optical scanning device 8. An image is formed. The electrostatic latent image forming step is performed by such charging operation of the charging device 90Y and such latent image writing operation of the optical scanning device 8.

  The electrostatic latent image is developed with the yellow toner in the developer by the developing device 80Y, and the yellow toner image obtained by the developing process is transferred to the transfer belt 11 that is moved in the A1 direction by the primary transfer roller 12Y. After the primary transfer, the transfer process is performed, the transfer residual toner remaining after the transfer is removed by the cleaning device 40Y, the cleaning process is performed, and the surface of the photosensitive drum 20Y after the cleaning by the cleaning process is left by the static eliminator 30Y. A neutralization process for removing the charge is performed and initialized, and is used for the next charging by the charging device 90Y. The cleaning device 40Y accommodates the collected toner in an unnecessary object container, but may be configured to perform a predetermined recycling process so that the collected toner can be used again for development.

  Similarly, toner images of the respective colors are formed on the other photosensitive drums 20M, 20C, and 20BK, and the formed toner images of the respective colors are transferred to the A1 direction by the primary transfer rollers 12M, 12C, and 12BK. 11 is sequentially transferred to the same position on the head. As the transfer belt 11 rotates in the A1 direction, the toner image superimposed on the transfer belt 11 moves to the secondary transfer nip, which is the position facing the secondary transfer roller 5, and closely contacts the transfer paper. Secondary transfer is performed on the transfer paper by the action of the transfer bias and nip pressure, and a full-color image is formed on the transfer paper.

The transfer paper transported between the transfer belt 11 and the secondary transfer roller 5 is fed from the sheet feeding device 61 and fed, and is transferred onto the transfer belt 11 by the registration roller 4 based on a detection signal from the sensor. The leading edge of the toner image is sent out at the timing when it faces the secondary transfer roller 5.
The secondary transfer roller 5 is applied with a potential having a polarity opposite to the polarity of toner charging by bias applying means.

  When the toner image of all colors is transferred and carried on the transfer paper, it enters the fixing device 6 and passes through the fixing portion between the pressure roller 63 and the belt unit 62 due to the action of heat and pressure. The carried toner image is fixed, and a full-color image is fixed on the transfer paper. The fixed transfer paper that has passed through the fixing device 6 and has undergone the fixing process passes through the paper discharge roller 7 and is stacked on the paper discharge tray 17. On the other hand, the surface of the transfer belt 11 after passing through the secondary transfer nip after the secondary transfer is cleaned by a cleaning brush and a cleaning blade provided in the cleaning device 13 to prepare for the next development process. When the user-designated image formation is completed, the rotation of the photosensitive drums 20Y, 20M, 20C, and 20BK is stopped, and the image forming operation is completed.

  As described above, the image forming apparatus 100 performs an image forming operation including an electrostatic latent image forming process, a developing process, a transfer process, a fixing process, a charge eliminating process, and the like.

  As described above, in an image forming apparatus that uses toner to form an image, such as the image forming apparatus 100, there may be a problem in image quality due to medaka-like stains on the image carrier. Conventionally, the medaka-like stain has been dealt with by replacing the image carrier. However, since this increases the cost, the image carrier is recently adopted in the image forming apparatus 100 as well. A configuration is known in which a cleaning blade that performs cleaning in contact with the surface is a polishing blade that is a cleaning blade with an abrasive to remove foreign matter on the surface layer of the image carrier. According to such a configuration, as in the image forming apparatus 100, the starting point of the medaka-like stain or the medaka-like stain is efficiently removed.

  However, if the polishing blade is kept in contact with the image carrier at all times and used for a long time, the surface of the image carrier is scratched and wear is promoted, and eventually the image carrier is replaced at a shorter cycle than usual. Become. Further, when the polishing blade is always brought into contact with the image carrier, the polishing blade itself is rapidly deteriorated.

  Therefore, as used in the image forming apparatus 100, a contact / separation mechanism for bringing the polishing blade into contact with and separating from the image carrier is provided, and the surface of the image carrier is obtained by intermittently contacting the polishing blade with the image carrier. A configuration that suppresses scratches and wear is known. According to this configuration, there is an effect that deterioration of the polishing blade itself is also suppressed.

  However, in such a configuration, for example, simply by moving the polishing blade in contact with the on / off of the power supply of the image forming apparatus, the degree of such action is low, but for example, for cleaning the image carrier. If the mode in which the polishing blade is brought into contact with the image carrier is set at a time other than the time of image formation, image formation becomes impossible during the mode, so that the image formation efficiency is lowered.

Therefore, in the image forming apparatus 100, the image carrier cleaning device is configured to clean the image carrier while preventing or suppressing a decrease in image forming efficiency.
This cleaning device will be described as a representative of the cleaning device 40Y of the image forming unit 60Y. A cleaning device having the same configuration as that of the cleaning device 40Y is similarly provided in the image forming units 60M, 60C, and 60BK, but the description thereof is omitted.

  In the cleaning device 40Y, in order to clean the photosensitive drum 20Y, during the image forming operation, in other words, during the driving of the photosensitive drum 20Y for carrying an image made of toner on the photosensitive drum 20Y, the contacting / separating means 50Y. The cleaning blade 41Y is brought into contact with the photosensitive drum 20Y.

This is illustrated in FIG. In the figure, the cleaning operation means that the cleaning blade 41Y is in contact with the photosensitive drum 20Y and cleaning is performed.
As described above, the cleaning is performed during the image forming operation, while preventing the image forming efficiency from being lowered.

  However, since the contact / separation operation of the cleaning blade 41Y with respect to the photoconductor drum 20Y slightly causes vibration of the photoconductor drum 20Y, an abnormal image may occur if the contact / separation operation is performed during the latent image writing operation. is there. For example, if a contact / separation operation is performed during a latent image writing operation for forming a halftone image, an abnormal image such as uneven image density may occur.

  Therefore, the timing at which the cleaning blade 41Y is brought into and out of contact with the photosensitive drum 20Y by the contacting / separating means 50Y is the non-operation time of the latent image writing operation with respect to the photosensitive drum 20Y, as shown in FIG. .

  However, in the configuration in which the cleaning blade and the cleaning brush are used together and the cleaning is performed by using the cleaning blade method and the fur brush cleaning method as in the image forming apparatus 100, high-speed image formation of 1000 sheets / min is supported. However, in such a high-speed image forming machine, since the interval between the latent image writing operations is short, as shown in FIG. 6, the contact timing of the cleaning blade 41Y with respect to the photosensitive drum 20Y is set to the latent image. Even when the image writing operation is not performed, the next latent image writing operation may be started before the vibration of the photosensitive drum 20Y due to the contact and separation of the cleaning blade 41Y with respect to the photosensitive drum 20Y is sufficiently attenuated. There is sex.

  Therefore, when the cleaning blade 41Y is brought into and out of contact with the photosensitive drum 20Y by the contacting / separating means 50Y, the interval between the latent image writing operations on the photosensitive drum 20Y is increased so that the vibration of the photosensitive drum 20Y is sufficiently attenuated. It is supposed to be. At the same time, other timing such as sheet feeding timing is also changed.

  Since the edge portion of the cleaning blade 41Y that contacts the photosensitive drum 20Y wears with time, the cleaning performance per unit time is lowered, and the medaka-like dirt removal performance is also lowered. According to the inventor's research, it has been found that the wear of the cleaning member proceeds in proportion to the contact time with the image carrier.

  Therefore, in the cleaning device 40Y, the control means 35 performs cumulative calculation of the energization time to the solenoid 53Y, and the calculated cumulative time is used as the cumulative time that the cleaning blade 41Y contacts the photosensitive drum 20Y, that is, the cumulative time. The contact time and the contact time of the cleaning blade 41Y to the photosensitive drum 20Y by the contact / separation means 50Y are varied according to the accumulated contact time. Here, the control means 35 functions as an accumulated contact time calculation means, a contact cycle control means, and a contact time control means.

  Specifically, as an example of changing the contact cycle, as the cumulative contact time increases, the cleaning operation of Example 3 shown in FIG. 6, that is, the cleaning operation for one image formation time for three image formations. The mode to be performed is changed to the cleaning operation of Example 2 shown in the figure, that is, the mode in which the cleaning operation is performed only for one image forming time for two image formations. Further, as an example of changing the contact time, as the cumulative contact time increases, the cleaning operation of Example 3 shown in FIG. 6 to the cleaning operation of Example 1 shown in FIG. For example, the mode may be changed to a mode in which the cleaning operation is performed over time.

  However, even if such control is performed, the life itself of the cleaning blade 41Y cannot be extended. Therefore, it is necessary to replace the cleaning blade 41Y when the cleaning blade 41Y is deteriorated so that its cleaning performance cannot be sufficiently exhibited.

  Therefore, in the cleaning device 40Y, a predetermined time indicating that the cleaning blade 41Y is to be deteriorated, which is compared with the accumulated contact time, is stored in the memory of the control unit 35 and indicates a replacement time of the cleaning blade 41Y. The replacement guide time is stored, and when the accumulated contact time reaches the replacement guide time, the control means 35 displays on the display unit of the operation panel 76 that the cleaning blade 41Y should be replaced. Here, the operation panel 76 functions as a notification means for notifying the user that the cleaning blade 41Y should be replaced, and the control means 35 functions as a replacement guide time storage means and also as a notification control means. As a result, the user replaces the cleaning blade 41Y when necessary, maintains the cleaning performance of the cleaning device 40Y, prevents or suppresses medaka-like stains, and maintains the image forming performance of the image forming apparatus 100 well. The Rukoto.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.

  For example, the contact / separation means may be other configurations such as a configuration using a motor and a cam instead of a configuration using a solenoid. The cleaning device to which the present invention is applied is provided for an image carrier other than the image carrier on which a latent image is formed, such as an intermediate transfer member, like the cleaning device 13 in the above-described embodiment. It may be. At this time, it is desirable that the timing at which the first cleaning member is brought into contact with and separated from the image carrier is during non-operation of the transfer operation to and / or from the image carrier.

  The first cleaning member and the second cleaning member do not necessarily have a blade shape. The second cleaning member may be a cleaning brush instead of the cleaning blade. The third cleaning member may not be provided.

  The developer used for developing the image carrier by the developing means is not limited to the two-component developer as described above, and the component is a one-component developer whose component is composed only of toner or mainly composed of toner. Also good.

  The process cartridge may include at least the image carrier and the cleaning device, and may be detachable from the image forming apparatus main body. Selection of other components constituting the process cartridge, for example, developing means, charging means, etc. Is appropriately performed in consideration of the lifetime of each component, the cost, the structural ease of forming a process cartridge, and the like.

  The present invention is not a so-called tandem image forming apparatus, but also a so-called 1-drum image forming apparatus that sequentially forms toner images of each color on one photosensitive drum and sequentially superimposes the color toner images to obtain a color image. Can be applied as well. Further, the present invention can be applied not only to a color image forming apparatus but also to a monochrome image forming apparatus. In any type of image forming apparatus, a toner image of each color may be directly transferred onto a transfer sheet or the like without using an intermediate transfer member. In the configuration in which direct transfer is performed without using an intermediate transfer member, the transfer unit may be in the form of a roller as in the above-described configuration, may be in the form of a belt, or may be a transfer charger. .

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

20Y, 20M, 20C, 20BK Image carrier 40Y Cleaning device 41Y First cleaning member 42Y Second cleaning member 50Y Contact / separation means 60Y, 60M, 60C, 60BK Process cartridge 76 Notification means 100 Image forming apparatus B1 Image carrier Direction of movement

JP 2001-296781 JP 2006-293286 A

Claims (6)

A first cleaning member that contacts the image carrier and performs cleaning;
Contacting and separating means for contacting and separating the first cleaning member to and from the image carrier,
During an image forming operation for supporting an image on an image carrier, and when a latent image writing operation on the image carrier is performed intermittently during one image forming operation , during the non-operation of the latent image write operation, the by moving means, from the state in which the first cleaning member is separated from the image bearing member, an operation of a state in which the first cleaning member is brought into contact with the image bearing member the has a row cormorants cleaning device, when the contact and separation of the first cleaning member to said image bearing member by said moving means includes an image forming apparatus to increase the spacing between the latent image writing operation to the image carrier . The image forming apparatus according to claim 1.
The cleaning device abuts the first cleaning member against the image carrier from a state where the first cleaning member is separated from the image carrier for each non- operation of the latent image writing operation. One of the operation to make the first cleaning member and the operation to move the first cleaning member away from the image carrier from the state in which the first cleaning member is brought into contact with the image carrier by the contact and separation means. And an image forming apparatus that maintains the contacted state during the non-operation. The image forming apparatus according to claim 1 or 2,
The cleaning device, an image, characterized in that a second cleaning member for cleaning in contact with the image carrier at a position upstream of the position where the first cleaning member abuts in the direction of movement of the image bearing member Forming equipment. The image forming apparatus according to any one of claims 1 to 3,
The cleaning device varies the period in which the first cleaning member is brought into contact with the image carrier by the contact / separation means according to the accumulated time of the first cleaning member in contact with the image carrier. An image forming apparatus. The image forming apparatus according to any one of claims 1 to 4,
The cleaning device varies the time during which the first cleaning member is brought into contact with the image carrier by the contact / separation means according to the cumulative time during which the first cleaning member is brought into contact with the image carrier. An image forming apparatus. 6. The image forming apparatus according to claim 1, wherein when the cumulative time when the first cleaning member contacts the image carrier reaches a predetermined time, the first cleaning member is removed. An image forming apparatus comprising an informing means for informing that replacement is to be performed.

Images