JP2016138981A - Image forming apparatus and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can prevent the occurrence of cleaning failure and color shift even after a long-term use and provide good image quality.SOLUTION: There is provided an image forming apparatus comprising: an image forming part that includes an image carrier rotatably provided and forms a toner image on the surface of the image carrier while rotating the image carrier; lubricant supply means that supplies lubricant to the surface of the image carrier; and cleaning means that is arranged on the upstream side of the lubricant supply means in the direction of rotation of the image carrier, where the cleaning means includes an elastic member that is in contact with the surface of the image carrier, a contact release mechanism that releases the contact of the elastic member with the image carrier, and an inversion mechanism that inverts the image carrier; when the lubricant supply means supplies the lubricant to the cleaning means, the contact release mechanism releases the contact of the elastic member with the image carrier after completion of a cleaning operation, and the inversion mechanism inverts the image carrier.SELECTED DRAWING: Figure 4A

Description

  The present invention relates to an image forming apparatus and a process cartridge.

  Conventionally, in an electrophotographic image forming apparatus, an image carrier (hereinafter sometimes referred to as “photosensitive member”, “electrophotographic image carrier”, or “electrostatic latent image carrier”) is used as a recording medium, After the toner image is transferred to the intermediate transfer member or the like, the cleaning unit removes unnecessary toner or the like (residue) remaining on the surface of the image carrier as a member to be cleaned.

  The cleaning means includes a flat elastic member made of polyurethane rubber or the like, and a support member that fixes a part of the elastic member, since a superior cleaning performance can be obtained with a simple configuration. Many have a blade. In the cleaning blade having such a configuration, any one of the free ends of the elastic member is brought into contact with the surface of the rotating image carrier, and the residue is scraped off and removed. .

However, in order to meet the demand for higher image quality in recent years, the toner has characteristics such as higher transfer efficiency than conventional pulverized toner, and has a small particle size and a nearly spherical shape formed by a polymerization method (hereinafter referred to as polymerization). When the toner is used, the polymerized toner slips through a slight gap formed between the elastic member and the image carrier, which may cause a cleaning failure.
For the purpose of suppressing the poor cleaning, if the contact pressure against the image carrier is increased at the contact portion where the free end side of the elastic member is in contact with the image carrier, the contact portion and the image Friction with the carrier increases. Then, the contact portion is curled, local defects (local wear) are likely to occur on the end surface on the free end side, and further, when the swollen contact portion tries to restore to the original shape, In some cases, the contact portion and the image carrier are rubbed to generate abnormal noise.

  In order to solve these problems, it has been proposed to increase the hardness of the free end of the elastic member for the purpose of suppressing twisting of the contact portion. For example, a cleaning blade has been proposed in which the free end of the elastic member made of urethane rubber is impregnated with a curable composition and cured, and a surface layer is further provided to enhance the cleaning ability (see Patent Document 1).

  However, in this case, the contact portion wears over time, and the area in contact with the surface of the image carrier increases, so that the contact pressure per unit area is reduced and cleaning failure is likely to occur. Become. In addition, since the contact portion wears along the shape of the image carrier, the contact portion comes into close contact with the image carrier, so that the force that inhibits the rotation of the image carrier is strong. turn into. Then, in the case of color printing in which a toner image of each color is formed on a plurality of the image carriers and superimposed to form a multicolor toner image, the timing at which the image carriers are superimposed tends to be delayed, and the color of the printed image Misalignment is likely to occur.

  Therefore, when a small amount of lubricant is applied to the surface of the image carrier in order to reduce the wear of the contact portion, the cleaning blade has a high cleaning ability, so that not only the residue but also the lubrication. Therefore, there is a problem that the image quality deteriorates due to poor cleaning or color shift due to wear of the contact portion after long-term use without using the lubricant.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide an image forming apparatus capable of obtaining good image quality without causing poor cleaning and color shift even after long-term use.

  Means for solving the problems are as follows. That is, an image forming apparatus according to the present invention includes an image carrier that is rotatably provided, an image forming unit that forms a toner image on the surface of the image carrier while rotating the image carrier, and the image carrier. A lubricant supply means for supplying a lubricant to the surface of the body, and a cleaning means disposed on the upstream side of the lubricant supply means in the rotation direction of the image carrier, and the cleaning means An elastic member that contacts the surface of the image carrier, a contact release mechanism that releases contact between the elastic member and the image carrier, and a reversing mechanism that reverses the image carrier, and the lubricant. When the supply means supplies the lubricant to the cleaning means, at the end of the cleaning operation, the contact release mechanism releases the contact between the elastic member and the image carrier, and the reversing mechanism is the image carrier. Is reversed.

  According to the present invention, it is possible to provide an image forming apparatus capable of obtaining good image quality without causing poor cleaning and color misregistration even after long-term use.

FIG. 1 is a schematic sectional view showing an example of the image forming apparatus of the present invention. FIG. 2 is a schematic sectional view showing an image forming unit in an example of the image forming apparatus of the present invention. FIG. 3A is an explanatory diagram showing a method for measuring the average circularity of the toner. FIG. 3B is an explanatory diagram illustrating a method for measuring the average circularity of the toner. FIG. 4A is a schematic cross-sectional view illustrating an example of a cleaning unit having a contact release mechanism. FIG. 4B is a schematic cross-sectional view illustrating an example of a cleaning unit having a contact release mechanism. FIG. 5A is a schematic cross-sectional view illustrating another example of a cleaning unit having a contact release mechanism. FIG. 5B is a schematic cross-sectional view illustrating another example of the cleaning unit having the contact release mechanism. FIG. 6 is a perspective view showing an elastic member and a support member of the cleaning means shown in FIG. 4A. FIG. 7 is a schematic cross-sectional view showing the vicinity of the end of the elastic member shown in FIG. FIG. 8A is an explanatory view showing a state where the contact portion of the elastic member is rolled. FIG. 8B is an explanatory diagram illustrating a state in which the free end of the elastic member is locally lost. FIG. 8C is an explanatory diagram illustrating a state where the contact portion of the elastic member is missing. FIG. 9 is a schematic cross-sectional view showing a time-dependent state of the contact portion of the elastic member shown in FIG. FIG. 10 is an explanatory diagram illustrating a state in which the lubricant is supplied to the contact portion. FIG. 11 is an enlarged view of the vicinity of the contact portion shown in FIG.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention comprises at least an image carrier, a charging unit, an exposure unit, a developing unit, a transfer unit, a fixing unit, a cleaning unit, and a lubricant supply unit. Other means appropriately selected as necessary are provided. The charging unit and the exposure unit may be collectively referred to as an electrostatic latent image forming unit.

  The image forming method used in the present invention includes at least a charging step, an exposure step, a development step, a transfer step, a fixing step, a cleaning step, and a lubricant supply step, and further appropriately selected as necessary. Other steps. The charging process and the exposure process may be collectively referred to as an electrostatic latent image forming process.

  The image forming method used in the present invention can be preferably implemented by the image forming apparatus of the present invention, the charging step can be performed by the charging unit, and the exposure step can be performed by the exposing unit. The developing step can be performed by the developing unit, the transferring step can be performed by the transferring unit, the fixing step can be performed by the fixing unit, and the cleaning step is performed by the cleaning unit. The lubricant supply step can be performed by the lubricant supply means, and the other steps can be performed by the other means.

<Image carrier>
The shape, structure, size, material, etc. of the image carrier (hereinafter sometimes referred to as “photosensitive member”, “electrophotographic image carrier”, “electrostatic latent image carrier”) are particularly There is no restriction | limiting, According to the objective, it can select suitably.
The shape of the image carrier is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a drum shape and a belt shape.
There is no restriction | limiting in particular as a material of the said image carrier, According to the objective, it can select suitably, For example, an inorganic image carrier, an organic image carrier (OPC), etc. are mentioned.
Examples of the inorganic image carrier include amorphous silicon and selenium.
Examples of the organic image carrier include polysilane and phthalopolymethine.

<Charging step and charging means>
The charging step is a step of charging the surface of the image carrier, and is performed by the exposure unit.
The charging unit is not particularly limited as long as it can apply a voltage to the surface of the image bearing member to be uniformly charged, and can be appropriately selected according to the purpose. (1) There are roughly divided into a contact-type charging means for charging in contact with the image carrier and (2) a non-contact-type charging means for charging in a non-contact manner with the image carrier.
Examples of the contact type charging means (1) include a conductive or semiconductive charging roller, a magnetic brush, a fur brush, a film, and a rubber blade. Among these, the charging roller is preferable in that it can greatly reduce the amount of ozone generated compared to corona discharge, and is excellent in stability during repeated use of the image carrier.
In addition, the said magnetic brush is comprised from the nonmagnetic conductive sleeve which supports various ferrite particles, such as Zn-Cu ferrite, for example, and the magnet roll included in the said conductive sleeve. The fur brush is formed by, for example, winding or pasting a fur treated with carbon, copper sulfide, metal, metal oxide or the like around a metal or a treated metal core.
Examples of the non-contact charging means of (2) include, for example, a non-contact charger using a corona discharge, a needle electrode device, a solid discharge element; a conductive material disposed with a minute gap with respect to the image carrier; Examples thereof include a semiconductive charging roller.
Among these, the configuration of the roller-shaped charging member disposed in contact with the image bearing member and the voltage applying member that applies a DC voltage to the roller-shaped charging member has a charging voltage applied to the roller-shaped charging member. It is preferable in that the power supply cost can be reduced.

<Exposure process and exposure means>
The exposure step is a step of exposing the charged surface of the image carrier, and is performed by the exposure unit. The exposure can be performed, for example, by exposing the surface of the image carrier imagewise using the exposure unit.
The optical system in the exposure is roughly classified into an analog optical system and a digital optical system. The analog optical system is an optical system that directly projects a document onto the surface of the image carrier by an optical system, and the digital optical system receives image information as an electrical signal and converts the electrical signal into an optical signal. An optical system that exposes the image carrier to form an image.
The exposure means is not particularly limited as long as it can be exposed like an image to be formed on the surface of the image carrier charged by the charging means, and can be appropriately selected according to the purpose. Examples thereof include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system. Further, it is possible to adopt a back light system in which imagewise exposure is performed from the back side of the image carrier.
The light source of the exposure means is not particularly limited as long as it emits light, and can be appropriately selected according to the purpose. For example, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode ( LED), semiconductor laser (LD), electroluminescence (EL), and the like. Of these light sources, light emitting diodes and semiconductor lasers are preferred in that they have high irradiation energy and emit light having a wavelength range of 600 nm to 800 nm. In addition, these light sources can be used also for a static elimination lamp.
In addition, various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

<Development process and development means>
The developing step is a step of developing the electrostatic latent image into the toner image, and is performed by the developing unit.
The developing means is not particularly limited as long as it can be developed using toner, and can be appropriately selected according to the purpose. For example, the toner is accommodated and the toner is brought into contact with the electrostatic latent image. Or what has at least the developing device which can be provided non-contactingly is preferable.
The developing unit may be a dry developing type or a wet developing type, and may be a single color developing unit or a multicolor developing unit. For example, the toner is charged by friction stirring. What has a stirrer and the magnet roller which can rotate is preferable.
In the developing device having the stirrer and the magnet roller, the toner and a carrier are mixed and stirred as necessary, and the toner is charged by friction at that time, and the surface of the rotating magnet roller is in contact with the toner. A magnetic brush that is held in a standing state and is formed of toner is formed. Since the magnet roller is disposed in the vicinity of the image carrier, a part of the toner forming the magnetic brush formed on the surface of the magnet roller is electrically attracted to the electrostatic latent image. It moves to the surface of the image carrier by force. As a result, the electrostatic latent image is developed with the toner, and the toner image is formed on the surface of the image carrier.

The toner to be accommodated in the developing unit may be a developer containing the toner, and the developer may be a one-component developer or a two-component developer.
The toner is preferably two or more colors, and more preferably a full color toner.

<Transfer process and transfer means>
The transfer step is a step of transferring the toner image to a recording medium, and is performed by the transfer unit.
As the transfer process, for example, an intermediate transfer body is used, and a primary transfer process in which the toner image is transferred onto the surface of the intermediate transfer body to form a composite transfer image, and the composite transfer image is transferred to a recording medium. An embodiment including a secondary transfer step is preferable.
There is no restriction | limiting in particular as said intermediate transfer body, According to the objective, it can select suitably, For example, a transfer belt etc. are mentioned. The transfer can be performed by a transfer unit, for example, by charging a transfer roller.
The transfer means is not particularly limited and may be appropriately selected depending on the purpose. The primary transfer means for transferring the toner image onto the surface of the intermediate transfer member to form a composite transfer image, and the composite An embodiment having secondary transfer means for transferring the transfer image onto the recording medium is preferable.
The primary transfer unit and the secondary transfer unit preferably include at least a transfer unit that peels and charges the toner image formed on the surface of the image carrier on the recording medium.
There is no restriction | limiting in particular as said transfer device, According to the objective, it can select suitably, For example, the corona transfer device by a corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, an adhesive transfer device etc. are mentioned. There may be one transfer unit or two or more transfer units.

  The recording medium is not particularly limited as long as it can transfer the unfixed toner image after development, and can be appropriately selected according to the purpose, and is typically plain paper. However, for example, a PET base for OHP can also be used.

<Fixing process and fixing means>
The fixing step is a step of fixing the toner image transferred to the recording medium, and is performed by the fixing unit. When two or more color toners are used, the toner of each color may be fixed each time it is transferred to the recording medium, or the toners of all colors are transferred to the recording medium and stacked. It may be fixed.
There is no restriction | limiting in particular as said fixing means, According to the objective, it can select suitably, The heat fixing system using a well-known heating-pressing means is mentioned.
Examples of the heating and pressing means include a combination of a heating roller and a pressing roller, a combination of the heating roller, the pressing roller, and an endless belt. There is no restriction | limiting in particular as heating temperature, Although it can select suitably according to the objective, 80 to 200 degreeC is preferable. If necessary, a known optical fixing device may be used together with the fixing unit.

<Cleaning process and cleaning means>
The cleaning step is a step of removing residues such as the toner remaining on the surface of the image carrier after transferring the toner image to the recording medium, and is performed by the cleaning unit.
The cleaning means of the present invention includes an elastic member, a support member, and a contact release mechanism, and further includes other members as necessary.
As the cleaning unit, a contact release mechanism that releases the contact between the elastic member and the image carrier when the lubricant supply unit supplies the lubricant and the image carrier rotates in the reverse direction. Can be appropriately selected according to the purpose, but the support member fixed to a case of a process cartridge to be described later and a part of the support member are fixed freely. It is preferable to have an elastic member having an end.
The cleaning means scrapes off toner remaining on the surface of the image carrier by bringing any one of the long sides of the free end face of the elastic member into contact with the surface of the image carrier. Remove.
Here, the one side brought into contact with the surface of the image carrier is referred to as a contact side. Further, when the abutment side abuts on the surface of the image carrier, deformation and wear, such as curling, cause not only the abutment side but also the plate surface including the abutment side and the free end. Since the end surface contacts the surface of the image carrier, the plate surface including the contact side in the vicinity of the contact side and the end surface of the free end are referred to as a contact portion.
The angle (hereinafter referred to as “cleaning angle θ”) formed by the tangential plane of the image carrier at the position where the contact portion of the elastic member contacts and the end surface of the free end of the elastic member is particularly limited. However, it can be appropriately selected according to the purpose, but is preferably 65 ° to 85 °, more preferably 75 ° to 85 °.
When the cleaning angle θ is within a preferable range, it is easy to suppress the occurrence of the squeezing of the elastic member, and it is possible to easily reduce the occurrence of defective cleaning.

<< Elastic member >>
There is no restriction | limiting in particular about the shape, a magnitude | size, a material, a structure, etc. as said elastic member, According to the objective, it can select suitably.

  The shape of the elastic member is not particularly limited and may be appropriately selected depending on the purpose.For example, a pair of plate surfaces facing each other in the thickness direction of the elastic member, orthogonal to the plate surface, The shape which consists of two pairs of end surfaces which oppose in the in-plane direction of a plate surface is mentioned, Flat shape, strip shape, sheet shape, etc. are preferable.

There is no restriction | limiting in particular as a magnitude | size of the said elastic member, According to the magnitude | size of the said image carrier, it can select suitably.
There is no restriction | limiting in particular as average thickness of the said elastic member, Although it can select suitably according to the objective, 1.0 mm-3.0 mm are preferable.
Examples of the method for measuring the average thickness include a method of selecting an arbitrary plurality of points with respect to the elastic member and calculating an average of the thicknesses of the plurality of points. The average is preferably an average of 5 points, more preferably an average of 10 points, and particularly preferably an average of 20 points. In addition, it can calculate similarly about the average thickness of other layers, such as a surface layer mentioned later.
Examples of the average thickness measuring instrument include a micrometer.

There is no restriction | limiting in particular as a material of the said elastic member, Although it can select suitably according to the objective, A rubber | gum, an elastomer, etc. are preferable from the point which is easy to obtain high elasticity.
Examples of the rubber include urethane rubber.
Examples of the elastomer include urethane elastomer.
Among these, the urethane rubber is more preferable.

There is no restriction | limiting in particular as said urethane rubber, According to the objective, it can select suitably.
The raw material of the urethane rubber is not particularly limited and may be appropriately selected depending on the intended purpose. However, a polyol having 2 or 3 hydroxyl groups having an OH value of 28 to 168, a diisocyanate, and an OH value of 950 to 1830 What mixed the short chain polyol is preferable.
Examples of the diisocyanate include tolylene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), naphthylene 1,5-diisocyanate (NDI), o-tolidine diisocyanate (TODI). ), Etc.
Examples of the short-chain polyol having an OH number of 950 to 1830 include ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, glycerin, trimethylolethane, and trimethylolpropane.
These may be used individually by 1 type and may use 2 or more types together.
These are mixed as appropriate, poured into a centrifugal mold heated to 100 ° C. to 200 ° C., released after a predetermined time, and left to stand in a high temperature and high humidity environment such as 85% RH at 30 ° C. for one week for aging. After the characteristics are stabilized, it is manufactured by cutting into a predetermined shape such as a flat plate shape.

Moreover, there is no restriction | limiting in particular as durometer hardness of the said elastic member, Although it can select suitably according to the objective, 68-80 degree | times (JIS K6253) in 25 degreeC is preferable.
If the durometer hardness of the elastic member is within a preferable range, there is flexibility. For example, when the support member is attached with a slight inclination, the elastic member abuts against the image carrier in the long side direction of the elastic member. Since the pressure tends to be uniform, it is possible to suppress the deterioration of the cleaning property. In addition, when a polymer toner having a small particle diameter and a nearly spherical shape is used, the elastic member warps when the contact pressure is set high so as not to cause a cleaning failure, and the contact portion becomes the image carrier. It is possible to suppress a so-called “belly hitting phenomenon” in which the plate surface of the elastic member comes up from the surface of the body and comes into contact with the image carrier. When the anti-shock phenomenon occurs, the contact area between the elastic member and the surface of the image carrier increases, so that the contact pressure per unit area is conversely increased even if the contact force of the elastic member is increased. It becomes smaller and the cleaning property is lowered. In particular, in the configuration having a surface layer at the contact portion like the elastic member in the present invention, the anti-hit phenomenon often occurs remarkably, so the durometer hardness of the elastic member is in the range of 68 degrees to 80 degrees. Preferably there is.
The durometer hardness can be measured using, for example, a micro rubber hardness meter (trade name: MD-1, manufactured by Kobunshi Keiki Co., Ltd.) according to JIS K6253 standard.

There is no restriction | limiting in particular as a resilience elastic modulus of the said elastic member, Although it can select suitably according to the objective, 50% or less is preferable at 23 degreeC.
The rebound resilience coefficient of the elastic member may be measured using a trypso rebound resilience tester (trade name: Resilience Tester, manufactured by Toyo Seiki Seisakusyo Co., Ltd.) in accordance with JIS K6255 standard with a measurement environment of 23 ° C. it can.

  The layer structure of the elastic member is not particularly limited and may be appropriately selected depending on the purpose. For example, the durometer hardness may be a single layer structure of one type of elastic body, and the durometer hardness It is good also as a laminated structure which integrally molded two or more types of elastic bodies which differ. At that time, an appropriate material can be appropriately selected for the layer including the contact portion and the layer not including the contact portion. Moreover, there is no restriction | limiting in particular as durometer hardness of each layer, Although it can select suitably according to the objective, All layers have preferable 68 to 80 degree | times. In addition, when manufacturing two or more layers of urethane, it is integrated so that delamination does not occur by continuously injecting into a centrifugal mold before each layer of raw materials with different mixing ratios is completely cured. It is possible to mold it.

  As the structure of the elastic member, any one end of the plate-like elastic member is impregnated with a curable composition, contains a cured product of the curable composition, and the length of any one of the ends is long. When a side is used as the contact side, there is no particular limitation as long as the surface layer is provided on the plate surface including the contact side and the end surface of the end portion, and the appropriate selection is made according to the purpose. However, it is preferable to form the surface layer with the impregnated curable composition. Since the curable composition impregnated in the end portion and the curable composition for forming the surface layer are the same, an improvement in adhesion can be expected, and peeling of the surface layer can be suppressed. .

In order to contain the cured product of the curable composition at the end of the elastic member, for example, the end is swollen with a solvent contained in the curable composition and the curable composition is soaked. Impregnate. Then, the curable composition impregnated in the end portion is cured by ultraviolet irradiation, heating, and the like, and the solvent in which the end portion is swollen is vaporized, so that the crosslinked structure of the elastic member and the cure are cured. Since the cured product of the curable composition is entangled, the cured product of the curable composition can be contained in the elastic member in a state where it is difficult to peel from the elastic member.
Further, in order to form the surface layer on the plate surface including the contact side and the end surface of the end portion, the end portion is impregnated with the curable composition soaked and impregnated. The curable composition is applied to the plate surface including the contact side and the end surface by spray coating or the like so as to have a predetermined average thickness.

<<< Curable composition >>>
The curable composition is not particularly limited and may be appropriately selected depending on the purpose. However, the cured product having a desired hardness can be obtained simply by irradiating with ultraviolet rays, and can be manufactured at low cost. The ultraviolet curable composition is preferred.
When the end portion of the elastic member is impregnated when the curable composition is the ultraviolet curable composition, the ultraviolet curable composition is made inside the elastic member such as urethane rubber by irradiating ultraviolet rays. Since the network chain of the composition is formed, it is expected that the crosslink density of the elastic member itself increases in a pseudo manner and the wear resistance is improved. In this case, the point is that the ultraviolet curable composition and the elastic member will hardly be bonded chemically. Since the ultraviolet curable composition and the elastic member are less likely to chemically react with each other, it is possible to prevent the crosslinking density from becoming too high and close to glass rather than rubber. It is considered that elasticity can be secured and wear resistance is improved.

  The ultraviolet curable composition contains a (meth) acrylate compound, and further contains other components as necessary.

  The (meth) acrylate compound includes a (meth) acrylate compound having a functional group equivalent molecular weight of 350 or less, or a (meth) acrylate compound having a pentaerythritol-triacrylate structure having 3 to 6 functional groups, A (meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2 as necessary, or a fluorine-based compound having a perfluoropolyether structure having a functional group number of 2 or more ( Contains a meth) acrylate compound.

-(Meth) acrylate compound having a pentaerythritol triacrylate structure having a functional group equivalent molecular weight of 350 or less and having 3 to 6 functional groups-
As the (meth) acrylate compound having a pentaerythritol / triacrylate structure having a functional group equivalent molecular weight of 350 or less and a functional group number of 3 to 6, an appropriately synthesized one may be used. May be used. As said commercial item, brand name: DPHA, PETIA (above, Daicel Ornex Co., Ltd. product), brand name: KAYARAD (trademark) DPCA-120 (Nippon Kayaku Co., Ltd. product), etc. are mentioned, for example. These may be used individually by 1 type and may use 2 or more types together.
When the curable composition contains a (meth) acrylate compound having a pentaerythritol / triacrylate structure having a functional group equivalent molecular weight of 350 or less and a functional group number of 3 to 6, the impact on the surface layer is reduced. Since the strength can be secured, it is possible to suppress the occurrence of local defects (local wear) on the end face due to the contact portion of the elastic member being rolled, and to maintain good cleaning properties for a long period of time.

-(Meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2-
As the (meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2, an appropriately synthesized product or a commercially available product may be used. . As said commercial item, brand name: IBOA, ODA-N, HDDA, EBECRYL11, HDDA (above, Daicel Ornex Co., Ltd. make), brand name: UN2700 (made by Negami Kogyo Co., Ltd.), etc. are mentioned, for example. These may be used individually by 1 type and may use 2 or more types together.
When the (meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2 is included in the curable composition, flexibility is imparted to the surface layer. It is possible to improve environmental characteristics such as adjusting the physical properties of the surface layer and finely adjusting the behavior of the elastic member when, for example, abnormal noise occurs in a predetermined environmental condition. Become.

-Fluorine (meth) acrylate compound having a perfluoropolyether structure having 2 or more functional groups-
As the fluorine-based (meth) acrylate compound having a perfluoropolyether structure having 2 or more functional groups, an appropriately synthesized one or a commercially available product may be used. As said commercial item, brand name: OPTOOL DAC-HP (made by Daikin Kogyo Co., Ltd.), brand name: MegaFac (registered trademark) RS-75 (made by Nippon Kayaku Co., Ltd.), etc. are mentioned, for example. These may be used individually by 1 type and may use 2 or more types together.
When the fluorine-containing (meth) acrylate compound having a perfluoropolyether structure having 2 or more functional groups is included in the curable composition, the end portion is obtained by impregnating the curable composition. When the surface layer is worn over time and the elastic member is exposed and contacts the surface of the image carrier, the elastic member and the surface of the image carrier The friction can be reduced and the occurrence of defects can be suppressed. Further, since the hardness of the elastic member can be prevented from being curled by increasing the hardness, the occurrence of abnormal noise (chattering noise) that occurs when returning from the curled state to the original shape is also reduced. be able to.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a polymerization initiator, a polymerization inhibitor, a solvent (diluent), etc. are mentioned.

--Polymerization initiator--
The polymerization initiator is not particularly limited as long as it initiates polymerization by light or heat, and can be appropriately selected according to the purpose. However, active species such as radicals and cations can be selected depending on the energy of light. A radical photopolymerization initiator, a cationic photopolymerization initiator, and the like that generate and initiate polymerization are preferred, and a radical photopolymerization initiator is more preferred.

Examples of the radical photopolymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazoles, and the like. Examples thereof include compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.
Specific compounds include, for example, acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl)- 2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxa , 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, bis (2,4,6-trimethylbenzoyl) -phenyl Phosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4-diethylthioxanthone, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together.

  A commercial item can be used as said radical photopolymerization initiator. Examples of the commercially available products include Irgacure (registered trademark, hereinafter the same) 651, Irgacure 184, Irgacure 2959, Irgacure 127, Irgacure 907, Irgacure 369, Irgacure 379, Irgacure 819, Irgacure 784, Irgacure OXE OX E01 Irgacure 754, DAROCUR (registered trademark) 1173, DAROCUR TPO, Lucirin (registered trademark) TPO, LR8883, LR8970 (above, manufactured by BASF Japan Ltd.); Speedcure (registered trademark) TPO (manufactured by Lambson); KAYACU Registered trademark) DETX-S (manufactured by Nippon Kayaku Co., Ltd.); Ubekrill P36 (manufactured by UCB), and the like. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as content of the said radical photopolymerization initiator, According to the objective, it can select suitably.

--- Polymerization inhibitor ---
There is no restriction | limiting in particular as said polymerization inhibitor, According to the objective, it can select suitably, For example, a phenol compound, a quinone compound, an amine compound, a nitro compound, an oxime compound, a sulfur compound etc. are mentioned.

Examples of the phenol compound include p-methoxyphenol, cresol, t-butylcatechol, di-t-butylparacresol, hydroquinone monomethyl ether, α-naphthol, 3,5-di-t-butyl-4-hydroxytoluene. 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-butylphenol), 4,4'-thiobis (3-methyl-6-t-) Butylphenol), and the like.
Examples of the quinone compound include p-benzoquinone, anthraquinone, naphthoquinone, phenanthraquinone, p-xyloquinone, p-toluquinone, 2,6-dichloroquinone, 2,5-diphenyl-p-benzoquinone, 2,5- Diacetoxy-p-benzoquinone, 2,5-dicaproxy-p-benzoquinone, 2,5-diacyloxy-p-benzoquinone, hydroquinone, 2,5-di-butylhydroquinone, mono-t-butylhydroquinone, monomethylhydroquinone, 2,5 -Di-t-amylhydroquinone, etc. are mentioned.
Examples of the amine compound include phenyl-β-naphthylamine, p-benzylaminophenol, di-β-naphthylparaphenylenediamine, dibenzylhydroxylamine, phenylhydroxylamine, diethylhydroxylamine, and the like.
Examples of the nitro compound include dinitrobenzene, trinitrotoluene, and picric acid.
Examples of the oxime compound include quinone dioxime and cyclohexanone oxime.
Examples of the sulfur compound include phenothiazine.
These may be used individually by 1 type and may use 2 or more types together.

-Solvent (diluent)-
The solvent is not particularly limited as long as it dissolves the (meth) acrylate compounds A to D and can swell the elastic member, and can be appropriately selected according to the purpose. Examples include hydrocarbon solvents, ester solvents, ketone solvents, ether solvents, alcohol solvents, and the like.

Examples of the hydrocarbon solvent include toluene and xylene.
Examples of the ester solvent include ethyl acetate, n-butyl acetate, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, and the like.
Examples of the ketone solvent include methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, and cyclopentanone.
Examples of the ether solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and the like.
Examples of the alcohol solvent include ethanol, propanol, 1-butanol, isopropyl alcohol, isobutyl alcohol, and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these solvents, cyclohexanone is particularly preferable.

  The concentration of the solvent is not particularly limited as long as it can dissolve the (meth) acrylate compound and swell the elastic member, and can be appropriately changed according to the purpose.

<<< Method for containing a cured product of the curable composition at the end of the elastic member >>>
The method for impregnating the end portion of the elastic member with the curable composition (impregnation treatment) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the end portion of the elastic member may be Examples of the method include impregnating the curable composition by brush coating, dip coating, and the like, followed by curing.

There is no restriction | limiting in particular as the impregnation depth from the said end surface, Although it can select suitably according to the objective, 50 micrometers-150 micrometers are preferable.
There is no restriction | limiting in particular as the impregnation depth from the said plate surface containing the said contact part, Although it can select suitably according to the objective, 20 micrometers-100 micrometers are preferable.
When the impregnation depth from the end surface and the impregnation depth from the plate surface including the contact portion are within a preferable range, the wear of the contact portion can be reduced, so that defective cleaning and color misregistration are caused. Less likely to occur.

  There is no restriction | limiting in particular as environmental temperature at the time of making the said edge part impregnate the said curable composition, Although it can select suitably according to the objective, 20 to 25 degreeC is preferable.

<<< Method for Measuring Content Depth of Curable Composition >>>
There is no restriction | limiting in particular as a method of measuring the containing depth of the said curable composition, According to the objective, it can select suitably, For example, the measuring method using microscopic FT-IR etc. are mentioned. When the microscopic FT-IR is used, the impregnation depth can be the distance (depth) between the surface where the curable composition is hardly detected and the surface.
As described above, the curable composition is detected inside the end portion of the elastic member by impregnating the end portion of the long side of the plate surface of the elastic member with the curable composition. The The detected intensity of the curable composition gradually decreases as it goes in the in-plane direction from the surface of the end portion on which the impregnation treatment is performed. That is, the curable composition impregnated inside the elastic member has a so-called concentration gradient.
For this reason, the impregnation depth is determined by measuring the cross section of the elastic member using, for example, an infrared microscope Nicolet Continuum manufactured by Thermo Fisher Scientific Co., which is a microscopic FT-IR. The method for determining the impregnation depth is a value obtained by measuring a plurality of cross sections of the elastic member while changing the measurement position based on the surface of the end face, and dividing the peak area near 1710 cm ^{−1 by} the peak area of 1415 cm ^−1. Can be used as an index.

<<< Method for Forming Surface Layer at End of Elastic Member >>>
There is no restriction | limiting in particular as a method of forming a surface layer in the said edge part of the said elastic member, According to the objective, it can select suitably, For example, the said curable composition is used for the said edge part of the said elastic member. Examples of the method include a method of curing after impregnation by spray coating, dip coating, or the like.
When the curable composition is an ultraviolet curable composition, the end portion of the elastic member is impregnated with the ultraviolet curable composition, sprayed onto the contact portion, and then irradiated with ultraviolet rays. Thus, the cured product of the curable composition is contained in the end portion of the elastic member, and the surface layer is formed on the plate surface and the end surface including the contact portion, and the hardness of the contact portion A rise can be aimed at.
In addition, by irradiating the ultraviolet curable resin impregnated in the elastic member before forming the surface layer with ultraviolet rays, the ultraviolet curable resin may be applied later to form the surface layer. The cured product of the ultraviolet curable resin can be contained in the elastic member in the impregnated state.

<<< Surface layer >>>
The surface layer is not particularly limited in shape, structure, size, material, and the like, and can be appropriately selected according to the purpose. However, the surface layer is preferably formed of a member harder than the elastic member. When the surface layer is formed of a member harder than the elastic member, the elastic member is less likely to be worn by the surface of the image carrier, and the elastic member is brought into direct contact with the surface of the image carrier. In comparison, the wear resistance of the contact portion can be improved. Further, the contact portion is less likely to be deformed, and the occurrence of wrinkles can be suppressed.

There is no restriction | limiting in particular as average thickness of a surface layer, Although it can select suitably according to the objective, 0.5 micrometer-2 micrometers are preferable. When the average thickness of the surface layer is within a preferable range, the hardness of the surface layer can be ensured, the contact portion is less likely to squeeze, and the toner slip-through is reduced for the following reasons, resulting in poor cleaning. It becomes difficult to do.
The reason why the toner slip can be reduced is that the surface layer forming method is a method of adhering a liquid to a solid like spray coating or dip coating, and therefore the average thickness of the surface layer exceeds 2 μm. Due to the influence of surface tension, the surface layer is less likely to be formed on the contact portion. For this reason, the difference between the average thickness of the abutting portion and the average thickness at a position away from the abutting portion is increased, and the angle of the abutting portion in the cross section is not a right angle but becomes obtuse. When the angle of the contact portion becomes an obtuse angle, compared to the case of a right angle, when the toner is blocked and accumulated on the end surface by a cleaning operation over a long period of time, the contact portion where the blocked toner is blunted It becomes easy to enter between the surface of the image carrier and is pushed out to the downstream side of the abutting portion in the rotation direction of the image carrier, resulting in poor cleaning.

<< support member >>
There is no restriction | limiting in particular about the shape, a structure, a magnitude | size, and a material as said support member, According to the objective, it can select suitably.
There is no restriction | limiting in particular as a shape of the said supporting member, According to the objective, it can select suitably, For example, flat form, strip shape, a sheet form, etc. are mentioned.
The structure of the support member is not particularly limited and can be appropriately selected according to the purpose. A structure that can be released is preferable.
There is no restriction | limiting in particular as a magnitude | size of the said supporting member, According to the magnitude | size of the said elastic member, it can select suitably.
There is no restriction | limiting in particular as a material of the said supporting member, According to the objective, it can select suitably, For example, a metal, a plastic, a ceramic, etc. are mentioned. Among these, a metal plate is preferable from the viewpoint of strength, and a steel plate such as stainless steel, an aluminum plate, and a phosphor bronze plate are particularly preferable.

<< Contact release mechanism >>
There is no restriction | limiting in particular about the structure etc. as said contact cancellation | release mechanism, According to the objective, it can select suitably.

The structure of the contact release mechanism is not particularly limited as long as the contact between the contact portion of the elastic member and the surface of the image carrier can be released, and can be appropriately selected depending on the purpose.
Specifically, the support member having a rotation shaft is rotatably arranged, and a force is applied from an elastic body such as a spring locked in an extended state at one end of the support member. A mechanism that acts so that the abutting portion of the elastic member and the surface of the image carrier abut on each other with the fulcrum as a fulcrum. In the contact release mechanism configured as described above, the contact can be released by moving one end of the spring to a position where it does not extend and applying no force from the spring.
Note that the normal printing operation and the contact release operation may be switched by using a mechanism in which the contact release mechanism is combined with a solenoid or a cam.

<<< Abrasion surface of contact part >>>
The wear surface of the contact portion is a surface formed by wear of the contact portion and the surface of the image carrier over time, and has a shape along the surface of the image carrier.

<< Reversal mechanism >>
There is no restriction | limiting in particular about the structure etc. as said inversion mechanism, According to the objective, it can select suitably.

The structure of the reversing mechanism is not particularly limited as long as the image carrier can be reversed, and can be appropriately selected according to the purpose. For example, a driving force that reverses the image carrier by switching gears can be obtained. And a structure in which a switch for applying a DC voltage having a reverse polarity is provided to a DC drive unit that rotates the image carrier.
Specifically, when printing of a predetermined number of sheets is completed and the control means described later determines that the cleaning operation is finished, a DC voltage having a reverse polarity is applied to the DC drive unit together with the contact release command, and 1/5 reverse rotation is performed. I let you.

<< Gap between wear surface and image carrier surface >>
The gap between the wear surface of the elastic member and the surface of the image carrier formed when the contact release mechanism releases the contact between the elastic member and the image carrier is a deflection of the elastic member. In this state, the gap on the fixed end side becomes wider than the gap on the free end side.

<<< Timing of Lubricant Supply Unit Supplying Lubricant to Cleaning Unit >>>
The timing at which the lubricant supply means supplies the lubricant to the cleaning means is not particularly limited as long as the cleaning means supplies at the end of the cleaning operation in which the residue on the surface of the image carrier is removed. For example, after printing a predetermined number of sheets, the contact release mechanism releases the contact when the cleaning operation ends, and the image carrier rotates in the reverse direction. It is good also as timing. In this case, the predetermined number of sheets is not particularly limited and may be appropriately selected depending on the purpose. For example, the color composite machine of IMAGIO MP C5000 manufactured by Ricoh Co., Ltd. When the contact portion of the member is impregnated with a curable composition and further provided with the surface layer, the number is preferably 100 to 200.
Further, after calculating a driving torque from a driving current value of a driving motor for rotating the image carrier and determining that the predetermined upper limit value has been exceeded, at the end of the cleaning operation, the contact releasing mechanism releases the contact, The timing at which the image carrier rotates in the reverse direction may be used.

<Lubricant supply step and lubricant supply means>
The lubricant supply step is a step of applying a lubricant to the surface of the image carrier, and is performed by the lubricant supply means.

<Other processes and other means>
Examples of the other processes include a static elimination process, a recycling process, and a control process.
Examples of the other means include a static elimination means, a recycling means, and a control means.

<< Static elimination process and static elimination means >>
The neutralization step is a step of performing neutralization by applying a neutralization bias voltage to the image carrier, and is performed by the neutralization unit.
The neutralization means is not particularly limited as long as a neutralization bias voltage can be applied to the image carrier, and can be appropriately selected according to the purpose. Examples thereof include a neutralization lamp.

<< Recycling process and recycling means >>
The recycling step is a step of recycling the toner removed in the cleaning step to the developing unit, and is performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, According to the objective, it can select suitably, A well-known conveyance means etc. are mentioned.

<< Control process and control means >>
The control step is a step of controlling each of the steps, and is performed by a control unit.
The control means is not particularly limited as long as it can control the movement of each means, and can be appropriately selected according to the purpose. Examples thereof include devices such as sequencers and computers.

<Toner>
As the toner, it is preferable to use a polymerized toner produced by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which can easily increase the circularity and reduce the particle size in order to improve the image quality. In particular, it is preferable to use the polymerized toner having an average circularity of 0.97 or more and a volume average particle size of 5.5 μm or less. By using a material having an average circularity of 0.97 or more and a volume average particle size of 5.5 μm, a higher resolution image can be formed.

<< Average circularity of toner >>
The average circularity of the toner was measured by a flow type particle image analyzer (trade name: FPIA-2000, manufactured by Sysmex Corporation). Specifically, 0.1 mL to 0.5 mL of a surfactant (alkylbenzene sulfonate) is added as a dispersant to 100 mL to 150 mL of water from which impure solids in the container have been removed in advance, and a measurement sample (toner) About 0.1 to 0.5 g was added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for 1 to 3 minutes so that the concentration of the dispersion becomes 3,000 / μL to 10,000 / μL. Was set in the analyzer, and the shape and distribution of the toner were measured. Based on this measurement result, when the outer peripheral length of the actual toner projection shape shown in FIG. 3A is C1, its projection area is S, and the outer circumference of a perfect circle shown in FIG. C2 / C1 was determined, and the average value was defined as the average circularity.

<< Volume average particle diameter of toner >>
The volume average particle diameter of the toner was determined by a Coulter counter method. Specifically, the toner number distribution and volume distribution data measured by a Coulter Multisizer 2e type (manufactured by Beckman Coulter, Inc.) were sent to a computer via an interface (manufactured by Nikkiki Co., Ltd.) for analysis. More specifically, a 1% by mass NaCl aqueous solution using primary sodium chloride was prepared as an electrolytic solution. Then, 0.1 mL to 5 mL of a surfactant (alkyl benzene sulfonate) was added as a dispersant to 100 mL to 150 mL of the electrolytic aqueous solution. Further, 2 mg to 20 mg of toner as a test sample was added thereto, and dispersion treatment was performed for 1 minute to 3 minutes with an ultrasonic disperser. Then, 100 mL to 200 mL of the electrolytic aqueous solution was put into another beaker, and the solution after the dispersion treatment was added therein to a predetermined concentration, and applied to the Coulter Multisizer 2e type.
The aperture is 100 μm, and the particle size of 50,000 toner particles is measured. As a channel, it is 2.00 micrometers or more and less than 2.52 micrometers; 2.52 micrometers or more and less than 3.17 micrometers; 3.17 micrometers or more and less than 4.00 micrometers; 4.00 micrometers or more and less than 5.04 micrometers; 5.04 micrometers or more and less than 6.35 micrometers; .35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; Less than 40 μm; 25.40 μm or more and less than 32.00 μm; 13 channels of 32.00 μm or more and less than 40.30 μm were used, and toner particles having a particle size of 2.00 μm or more and 32.0 μm or less were targeted.
The volume average particle diameter was calculated based on the relational expression “volume average particle diameter = ΣXfV / ΣfV”. However, “X” is the representative diameter in each channel, “V” is the equivalent volume in the representative diameter of each channel, and “f” is the number of particles in each channel.

<Residue>
The residue is not particularly limited as long as it is attached to the surface of the image carrier and is to be removed by the cleaning unit, and can be appropriately selected according to the purpose. , Lubricants, inorganic fine particles, organic fine particles, dust, dust or a mixture thereof.

  The image forming apparatus of the present invention has the characteristics described above and can be widely used in various fields. However, the image forming apparatus of the present invention is particularly suitable for the process cartridge of the present invention in which the apparatuses incorporated in the image forming apparatus described below are combined. Preferably used.

(Process cartridge)
The process cartridge of the present invention is an apparatus (unit) that is detachably attached to the image forming apparatus. The image carrier, the cleaning unit, and the lubricant supply unit may be provided in the process cartridge instead of being fixed to the image forming apparatus. In this case, the process cartridge includes the image carrier, at least one of the charging unit, the exposure unit, the development unit, and the transfer unit, the cleaning unit, and the lubricant supply unit. In addition, other means are provided as necessary.

Here, an example of the image forming apparatus according to the present invention will be described with reference to the drawings.
In addition, the number, position, shape, and the like of the following constituent members are not limited to the present embodiment, and can be set to a preferable number, position, shape, and the like in carrying out the present invention.

FIG. 1 is a schematic sectional view showing an example of the image forming apparatus of the present invention.
As shown in FIG. 1, the image forming apparatus 500 includes at least an optical writing unit 40, an image forming unit 1, a transfer unit 60, a first paper feeding cassette 151 and a second paper feeding cassette 152, a fixing unit 80, and a toner cartridge 100. And, if necessary, have other configurations.

The optical writing unit 40 as the latent image forming means has at least a polygon mirror 41, and further has other configurations as required. The optical writing unit 40 is disposed near the center of the image forming apparatus 500 and emits laser light L based on image information.
This laser light L is polarized by using a polygon mirror 41 that is rotationally driven by a motor, and is described as yellow, magenta, cyan, black (hereinafter referred to as Y, C, M, K) through a plurality of optical lenses and mirrors. The image bearing units 3Y, 3C, 3M, and 3K of the image forming units 1Y, 1C, 1M, and 1K are irradiated. As a result, electrostatic latent images to be developed with Y, C, M, and K toners are formed on the surfaces of the image carriers 3Y, 3C, 3M, and 3K, respectively.
As described above, instead of the optical writing unit configured to irradiate the image forming unit with the laser light, an LED array may perform optical scanning on the image forming unit.

The image forming unit 1 includes at least four image forming units 1Y, 1C, 1M, and 1K, and has other configurations as necessary.
The image forming units 1Y, 1C, 1M, and 1K are disposed above the optical writing unit 40, have at least the image carriers 3Y, 3C, 3M, and 3K, and have other configurations as necessary. Thus, the electrostatic writing images formed on the surfaces of the image carriers 3Y, 3C, 3M, and 3K by the optical writing unit 40 are developed into toner images of respective colors.
The four image forming units 1Y, 1C, 1M, and 1K use Y, C, M, and K toners of different colors as image forming materials for developing the electrostatic latent image into the toner image. Other than that, the configuration is the same.

  The transfer unit 60 as transfer means includes at least the intermediate transfer belt 14, four primary transfer rollers 7Y, 7C, 7M, and 7K, a secondary transfer backup roller 66, a driving roller 67, an auxiliary roller 68, a tension roller 69, and a belt cleaning. It has the unit 162, the 1st bracket 63, and the 2nd bracket 64, and also has another structure as needed. The transfer unit 60 is disposed above the image forming unit 1 and superimposes toner images of respective colors formed on the surfaces of the image carriers 3Y, 3C, 3M, and 3K on the surface of the endless intermediate transfer belt 14. To form a four-color superimposed toner image (hereinafter sometimes referred to as a four-color toner image). The transfer unit 60 can also form a monochrome toner image using only the image carrier 3K by the operation of the first bracket 63.

The intermediate transfer belt 14 is driven while being stretched by eight roller members including four primary transfer rollers 7Y, 7C, 7M, and 7K, a secondary transfer backup roller 66, a drive roller 67, an auxiliary roller 68, and a tension roller 69. The roller 67 is driven to rotate counterclockwise in FIG. Further, a transfer bias voltage having a polarity (for example, negative polarity) opposite to the polarity (for example, positive polarity) of the toner is applied to the intermediate transfer belt 14 on the back surface (inside the loop).
The four primary transfer rollers 7Y, 7C, 7M, and 7K form a primary transfer nip by sandwiching the intermediate transfer belt 14 that moves endlessly with the image carriers 3Y, 3C, 3M, and 3K.
In the process of sequentially passing through the primary transfer nips for Y, C, M, and K along with the endless movement of the intermediate transfer belt 14, the intermediate transfer belt 14 has its front surface (loop) by electrostatic force. The Y, C, M, and K toner images on the surface of the image carriers 3Y, 3C, 3M, and 3K are superimposed on the outer side and primarily transferred. As a result, the four-color toner image is formed on the surface of the intermediate transfer belt 14.
The four-color toner image is transferred to the recording medium P supplied from the first paper feed cassette 151 or the second paper feed cassette 152 by the transfer unit 60.

The secondary transfer backup roller 66 sandwiches the intermediate transfer belt 14 between the secondary transfer roller 70 disposed outside the loop formed by the endless intermediate transfer belt 14 and forms a secondary transfer nip.
The registration roller pair 55 described above is directed toward the secondary transfer nip at a timing at which the recording medium P sandwiched between the rollers can be synchronized with the four-color toner image primarily transferred to the intermediate transfer belt 14 that moves endlessly. Transport.
The four-color toner image on the surface of the intermediate transfer belt 14 includes a secondary transfer electric field formed between the secondary transfer roller 70 and the secondary transfer backup roller 66 to which a secondary transfer bias voltage is applied, and a secondary transfer electric field. Due to the influence of the nip pressure caused by being sandwiched between the transfer roller 70 and the secondary transfer backup roller 66, the secondary transfer is collectively performed on the recording medium P at the secondary transfer nip. Then, the four-color toner image is combined with the white color of the recording medium P to become a full-color toner image.

  The belt cleaning unit 162 has a belt cleaning blade 162a. The belt cleaning unit 162 is disposed in the vicinity of the driving roller 67, and a belt cleaning blade 162 a is brought into contact with the front surface of the intermediate transfer belt 14 to scrape the transfer residual toner on the surface of the intermediate transfer belt 14. Take and remove.

The first bracket 63 is used when a monochrome image is formed, and is disposed so as to be positioned in the horizontal direction of the primary transfer rollers 7Y, 7C, and 7M. The first bracket 63 rotates at a predetermined rotation angle about the rotation axis of the auxiliary roller 68 as the solenoid (not shown) is turned on / off.
When forming and printing a monochrome image, the image forming apparatus 500 rotates the first bracket 63 a little counterclockwise in FIG. 1 by driving the solenoid. Then, the Y, C, and M primary transfer rollers 7Y, 7C, and 7M simultaneously rotate counterclockwise in FIG. It can be separated from the image carriers 3Y, 3C, 3M for C and M. Accordingly, it is possible to avoid wear of each member constituting the image forming unit 1 due to wasteful driving of the Y, C, M image forming unit 1 during monochrome image formation.
Of the four image forming units 1Y, 1C, 1M, and 1K, only the K image forming unit 1K is driven to form a monochrome image.

The first paper feed cassette 151 and the second paper feed cassette 152 are arranged to vertically overlap below the optical writing unit 40, and at least the first paper feed roller 151a, the second paper feed roller 152a, the paper feed path 153, a conveyance roller pair 154, and a registration roller pair 55, and other configurations as necessary.
In each of these paper feed cassettes, a plurality of recording media P are accommodated in a stack of paper sheets. The uppermost recording medium P has a first paper feeding roller 151a and a second paper feeding cassette. The paper rollers 152a are in contact with each other. When the first paper feed roller 151a is rotated counterclockwise in FIG. 1 by driving means (not shown), the uppermost recording medium P in the first paper feed cassette 151 is moved to the first paper feed cassette 151 in FIG. The paper is discharged toward the paper feed path 153 arranged to extend in the vertical direction in the right direction. When the second paper feed roller 152a is driven to rotate counterclockwise in FIG. 1 by driving means (not shown), the uppermost recording medium P in the second paper feed cassette 152 is discharged toward the paper feed path 153. Is done.
A plurality of conveying roller pairs 154 are arranged in the paper feed path 153. The plurality of transport roller pairs 154 transport the recording medium P transported to the paper feed path 153 along the paper feed path 153 in the vertical direction in FIG.
The registration roller pair 55 is disposed on the downstream side of the conveyance roller pair 154 in the conveyance direction of the paper feed path 153, and the recording medium P conveyed by the conveyance roller pair 154 is sandwiched between the rollers and at the same time the rotation of both rollers is performed. Is temporarily stopped. After the stop, the registration roller pair 55 is placed between the secondary transfer backup roller 66 and the secondary transfer roller 70 disposed outside the loop of the intermediate transfer belt 14 at an appropriate timing. The transfer belt 14 is conveyed to a secondary transfer nip formed with the transfer belt 14 interposed therebetween.
The recording medium P transported to the secondary transfer nip is transferred by the transfer unit 60 with the four-color toner image formed on the intermediate transfer belt 14 and transported to the fixing unit 80.

The fixing unit 80 is disposed above the secondary transfer nip, and includes at least a heating roller 83, a tension roller 85, a driving roller 86, a fixing belt 84 as a fixing member, a pressure heating roller 81, a temperature sensor (not shown), and a fixing power supply circuit. Etc., and other configurations as necessary. The fixing unit 80 fixes the four-color toner image transferred to the recording medium P by heating and pressing.
The heating roller 83, the tension roller 85, and the drive roller 86 are stretched endlessly in the counterclockwise direction in FIG. In the process of endless movement, the fixing belt 84 is heated from the back side by a heating roller 83 containing a heat source such as a halogen lamp.
The pressure heating roller 81 is in contact with the heating roller 83 via the fixing belt 84 at a portion where the fixing belt 84 is wound around the heating roller 83, and is driven to rotate clockwise in FIG. Thus, a fixing nip where the pressure heating roller 81 and the fixing belt 84 abut is formed. Note that, similarly to the heating roller 83, the pressure heating roller 81 includes a heat generation source.
A temperature sensor (not shown) is arranged outside the loop of the endless fixing belt 84 so as to face the front surface of the fixing belt 84 with a predetermined gap, and immediately before entering the fixing nip. The surface temperature of the fixing belt 84 is detected. This detection result is transmitted to a fixing power supply circuit (not shown). The fixing power supply circuit performs on / off control of power supply to the heat generation source included in the heating roller 83 and the heat generation source included in the pressure heating roller 81 based on the detection result by the temperature sensor.

  The recording medium P that has passed through the secondary transfer nip is conveyed after being separated from the intermediate transfer belt 14 into the fixing unit 80 configured as described above. The fixing unit 80 fixes the full-color toner image by heating and pressing the conveyed recording medium P in the process of being nipped by the fixing nip and conveyed in the vertical direction in FIG.

  The recording medium P on which the full-color toner image has been fixed is conveyed by a pair of paper discharge rollers 87 and then discharged to a stack unit 88 formed on the upper surface of the casing of the main body of the image forming apparatus 500. In the stack portion 88, the discharged recording media P are sequentially stacked.

The toner cartridge 100 includes at least toner cartridges 100Y, 100C, 100M, and 100K, and further has other configurations as necessary. The toner cartridge 100 is disposed above the transfer unit 60. The toner cartridges 100Y, 100C, 100M, and 100K contain Y, C, M, and K toners. These Y, C, M, and K toners are appropriately supplied to the developing devices 5Y, 5C, 5M, and 5K of the image forming units 1Y, 1C, 1M, and 1K.
The toner cartridges 100Y, 100C, 100M, and 100K are independent of the image forming units 1Y, 1C, 1M, and 1K, and are detachably disposed on the image forming apparatus 500.

FIG. 2 is a schematic sectional view showing an image forming unit in an example of the image forming apparatus of the present invention.
As shown in FIG. 2, the image forming unit 1 includes at least an image carrier 3, a charging roller 4, a developing device 5, a primary transfer roller 7, a cleaning device 6, a lubricant supply device 10, a static elimination lamp (not shown), and the like. And, if necessary, have other configurations.

Around the image carrier 3 as an image carrier, a charging roller 4, a developing device 5, a primary transfer roller 7, a cleaning device 6, a lubricant supply device 10, An unillustrated static elimination lamp or the like is arranged. The image carrier 3 rotates in the reverse direction when the lubricant supply device 10 supplies the lubricant to the surface of the image carrier 3.
In FIG. 2, the image carrier 3 has a drum shape, but may have a sheet shape or an endless belt shape.

The charging roller 4 is a charging member that is disposed in a non-contact manner with a predetermined distance from the image carrier 3 and is provided in a charging device as a charging unit. The charging roller 4 charges the image carrier 3 with a predetermined polarity and a predetermined potential. The surface of the image carrier 3 uniformly charged by the charging roller 4 is irradiated with the laser light L from the optical writing unit 40 shown in FIG. 1 based on the image information to form an electrostatic latent image.
The charging device is a non-contact proximity arrangement system in which the charging roller 4 is brought close to the image carrier 3, but has a known configuration including a corotron, a scorotron, and a solid state charger (solid state charger). Can be used. Among these charging methods, the contact charging method or the non-contact proximity arrangement method is more desirable, and has advantages such as high charging efficiency, a small amount of ozone generation, and miniaturization of the apparatus.

The developing device 5 is a developing unit that develops the electrostatic latent image formed on the surface of the image carrier 3 into a toner image. The developing device 5 has a developing roller 51 as a developer carrier.
A developing bias voltage is applied to the developing roller 51 from a power source (not shown). A developer is accommodated in the casing of the developing device 5, and a supply screw 52 and an agitation screw 53 are provided for stirring the developer while conveying the developer in opposite directions. A doctor 54 is provided for regulating the developer carried on the developing roller 51. The toner in the developer stirred and conveyed by the two screws of the supply screw 52 and the stirring screw 53 is charged to a predetermined polarity. The developer is pumped up on the surface of the developing roller 51, and then regulated by the doctor 54, and the electrostatic latent image in which toner is formed on the surface of the image carrier 3 in the development region facing the image carrier 3. The electrostatic latent image is developed into a toner image.

  The primary transfer roller 7 is a primary transfer member provided in a primary transfer device as a primary transfer unit that transfers the toner image on the surface of the image carrier 3 to the intermediate transfer belt 14.

  The cleaning device 6 is a cleaning unit that cleans the residue such as the toner remaining on the surface of the image carrier 3 after the toner image is transferred to the intermediate transfer belt 14. Details of the cleaning device 6 will be described later.

The lubricant supply device 10 is a lubricant supply unit that applies a lubricant to the surface of the image carrier 3 after the cleaning device 6 cleans it.
The lubricant supply device 10 includes a fur brush 101, a solid lubricant 103, a lubricant pressurizing spring 103a, and a bracket 103b.
The solid lubricant 103 is urged in a direction toward the fur brush 101 by the lubricant pressurizing spring 103a while being held by the bracket 103b.
The fur brush 101 is an application brush that applies a solid lubricant 103 to the surface of the image carrier 3, and the solid lubricant 103 is shaved by rotating in a rotational direction with respect to the rotation direction of the image carrier 3. A lubricant is applied to the surface of the image carrier 3. When the fur brush 101 applies a lubricant to the image carrier 3, the friction coefficient on the surface of the image carrier 3 is maintained at 0.2 or less during non-image formation.

  A neutralization lamp (not shown) is a neutralization unit that neutralizes the surface of the image carrier 3 after cleaning.

  As the toner used in the image forming apparatus 500, a polymerized toner manufactured by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which is easy to increase the circularity and reduce the particle size from the viewpoint of improving the image quality, is used. Is preferred. Among these, from the viewpoint of forming a high-resolution image, it is preferable to use a polymerized toner having an average circularity of 0.97 or more and a volume average particle size of 5.5 μm or less.

Next, an image forming operation in the image forming apparatus 500 will be described with reference to FIGS.
First, when a print execution signal is received from an operation unit (not shown) or the like, a predetermined voltage or current is sequentially applied to the charging roller 4 and the developing roller 51 at predetermined timings. Similarly, a predetermined voltage or current is sequentially applied to the optical writing unit 40 and a light source such as a static elimination lamp at a predetermined timing. In synchronism with this, the image carrier 3 is rotationally driven in the direction of the arrow in FIG. 2 by an image carrier drive motor (not shown) as drive means.

When the image carrier 3 is driven in the rotation direction indicated by the arrow R1 in FIG. 2, first, the charging roller 4 uniformly charges the surface of the image carrier 3 to a predetermined potential. Then, the laser beam L corresponding to the image information is irradiated from the optical writing unit 40 onto the surface of the image carrier 3, and the portion of the surface of the image carrier 3 irradiated with the laser beam L is neutralized so that an electrostatic latent image is obtained. Is formed.
The surface of the image carrier 3 on which the electrostatic latent image is formed is rubbed by a developer magnetic brush formed on the surface of the developing roller 51 at a portion facing the developing device 5. At this time, since the negatively charged toner on the surface of the developing roller 51 is moved to the electrostatic latent image side by a predetermined developing bias voltage applied to the developing roller 51, the electrostatic latent image is developed into a toner image. .
In each image forming unit 1, the same image forming process is executed, and the toner image of each color is formed on the surface of each image carrier 3Y, 3C, 3M, 3K of each image forming unit 1Y, 1C, 1M, 1K. The
As described above, in the image forming apparatus 500, the electrostatic latent image formed on the surface of the image carrier 3 is reversely developed with the negatively charged toner by the developing device 5. In this embodiment, an example using a non-contact charging roller system of N / P (negative positive: toner adheres to a place where the potential is low) has been described, but the present invention is not limited to this.

The toner images of the respective colors formed on the surfaces of the image carriers 3Y, 3C, 3M, and 3K are sequentially primary-transferred so as to overlap on the surface of the intermediate transfer belt 14. As a result, the four-color toner image is formed on the surface of the intermediate transfer belt 14.
The four-color toner image formed on the intermediate transfer belt 14 is fed from the first paper feed cassette 151 or the second paper feed cassette 152, passes between the rollers of the registration roller pair 55, and is fed to the secondary transfer nip. It is transferred to the recording medium P to be paper. At this time, the recording medium P is temporarily stopped while being sandwiched between the pair of registration rollers 55, and is supplied to the secondary transfer nip in synchronization with the intermediate transfer belt 14 on which the four-color toner image is formed. The recording medium P onto which the four-color toner image has been transferred is separated from the intermediate transfer belt 14 and conveyed to the fixing unit 80. The fixing unit 80 that has conveyed the recording medium P fixes the four-color toner image on the recording medium P by the action of heat and pressure. The recording medium P on which the four-color toner image is fixed is discharged and placed on the stack unit 88 provided on the upper surface of the image forming apparatus 500.

On the other hand, the transfer residual toner on the surface of the intermediate transfer belt 14 that has transferred the toner image onto the recording medium P at the secondary transfer nip is removed by the belt cleaning unit 162.
Further, residual toner after transfer is removed by the cleaning device 6 on the surface of the image carrier 3 on which the toner images of the respective colors are transferred to the intermediate transfer belt 14 at the primary transfer nip, and the lubricant is supplied by the lubricant supply device 10. After being applied, the charge is removed by a charge removal lamp (not shown).

As shown in FIG. 2, the image forming unit 1 of the image forming apparatus 500 includes an image carrier 3, a charging roller 4, a developing device 5, a cleaning device 6, a lubricant supply device 10, and the like as process means. ing. The image forming unit 1 is detachable from the main body of the image forming apparatus 500 as a process cartridge.
In the image forming apparatus 500, the image forming unit 1 has a configuration in which the image carrier 3 as a process cartridge and the process unit are integrated. However, the image forming unit 1 is not limited thereto, and the image carrier 3 and the charging roller 4 are not limited thereto. The developing device 5, the cleaning device 6, and the lubricant supply device 10 may be integrated.

Next, cleaning means having a contact release mechanism will be described with reference to the drawings.
4A and 4B are schematic cross-sectional views illustrating an example of a cleaning unit having a contact release mechanism. 4A is a schematic cross-sectional view of a state where the elastic member 622 is in contact with the image carrier 3, and FIG. 4B is a schematic cross-sectional view of a state where the contact with the image carrier 3 is released.
4A, the cleaning device 6 includes an elastic member 622, a support member 621, and a first contact release mechanism 631, and further includes other configurations as necessary. The cleaning device 6 is a device that can release the contact between the contact portion 62 c of the elastic member 622 and the surface of the image carrier 3 by the first contact release mechanism 631.
One end of the elastic member 622 is fixed to the support member 621, and the long side of one end of the free end is brought into contact with the image carrier 3 as a contact portion 62 c, so that the elastic member 622 is placed on the surface of the image carrier 3. Remove residue.
The support member 621 includes a side plate 621a, a rotation shaft 621b and a spring locking hole 621c provided in the side plate 621a, and is made of a rigid material such as metal or hard plastic.
The first contact release mechanism 631 includes a spring 631a, a spring locking member 631b, and a guide 631c.
The spring 631a is extended and stretched by a spring locking member 631b and a spring locking hole 621c, and a restoring force is applied to the support member 621 through the spring locking hole 621c in the direction indicated by the arrow F1 in FIG. 4A. The contact portion 62c of the elastic member 622 is brought into contact with the surface of the image carrier 3 with the rotation shaft 621b as a fulcrum.
When the guide 631c releases the contact between the contact portion 62c and the surface of the image carrier 3, as shown in FIG. 4B, the spring 631a contracts so that the restoring force cannot be obtained. Guide 631b.
In FIG. 4B, when the spring locking member 631b is moved in the release direction indicated by the arrow S in FIG. 4B by a drive unit (not shown), the spring 631a does not extend and no restoring force acts on the spring locking hole 621c. The contact between the contact portion 62c and the surface of the image carrier 3 is released.

5A and 5B are schematic cross-sectional views showing another example of the cleaning unit having the contact release mechanism.
5A, the cleaning device 6 includes an elastic member 622, a support member 621, and a second contact release mechanism 641, and further has other configurations as necessary. In the cleaning device 6, the second contact release mechanism 641 releases the contact between the contact portion 62 c of the elastic member 622 and the surface of the image carrier 3, similarly to the cleaning device 6 shown in FIG. 4A. It is possible.
4A and 4B, the elastic member 622 has one end fixed to the support member 621, abuts the long side of the free end and the image carrier 3, Residues on the surface of the image carrier 3 are removed.
The support member 621 includes a side plate 621a and a holding member 641a provided on the side plate 621a. The holding member 641a has a rotation shaft 641b that is locked to the housing of the image forming apparatus.
The second contact release mechanism 641 includes a holding member 641aa, a rotation shaft 641b, and a drive unit (not shown) connected to a part of the side plate 621a. The drive unit rotates the elastic member 622 slightly with the rotation shaft 641b as a fulcrum, thereby bringing the contact portion 62c of the elastic member 622 into contact with the surface of the image carrier 3.
In FIG. 5B, the contact between the contact portion 62 c and the surface of the image carrier 3 is released by releasing the drive force by a drive unit (not shown).

FIG. 6 is a perspective view showing an elastic member and a support member of the cleaning means shown in FIG. 4A, and shows an elastic member 622 and a support member 621 of the cleaning device 6 as the cleaning means.
The elastic member 622 contains the cured product by impregnating the curable composition at the end of the free end. A surface layer 623 is formed on the end surface 62a and the plate surface 62b including the contact portion 62c at the end surface over the blade longitudinal direction.

FIG. 7 is a schematic cross-sectional view showing the vicinity of the end of the elastic member shown in FIG.
In FIG. 7, the impregnation depth t1 of the curable composition on the end surface 62a is 50 μm to 150 μm, and the impregnation depth t2 of the curable composition on the plate surface 62b is 20 μm to 100 μm.
Further, the average thickness t3 of the surface layer 623 formed on the end surface 62a and the average thickness t4 of the surface layer 623 formed on the plate surface 62b are both 0.5 μm to 2 μm.

In the case where the configuration shown in FIGS. 6 and 7 is not used, as shown in FIGS. 8A to 8C, the contact portion 62c is bent, local wear occurs on the end surface 62a, and the contact portion 62c is lost. There is a case.
As shown in FIG. 8A, in the case where the end portion of the elastic member 622 is not impregnated with the curable composition and further the surface layer is not formed, the elastic member 622 is pulled in the rotation direction of the image carrier 3, The abutting part 62c will be rolled. When the bent contact portion 62c is restored to its original shape against the bending, an abnormal noise may be generated.
Further, if the cleaning is continued in a state where the contact portion 62c is swollen, as shown in FIG. 8B, local wear occurs on the end surface 62a.
If the cleaning is further continued in such a state, the local wear increases, and finally, as shown in FIG. 8C, the contact portion 62c is lost. If the contact portion 62c is lost, the toner cannot be properly cleaned, resulting in poor cleaning.

In the cleaning device 6 configured as shown in FIGS. 6 and 7, the occurrence of local wear and defects is reduced by preventing the contact portion 62 c from curling. In addition, as shown in FIG. 9, the impregnation region 62d is exposed in the contact portion 62c and the wear surface 65 is formed along the shape of the surface of the image carrier 3 over time, but the remaining surface layer 623 remains. In addition, the effect of suppressing the wrinkle by the impregnation region 62d is sustained.
However, since the contact portion 62c of the elastic member 622 is worn and the contact area that contacts the surface of the image carrier increases, the contact pressure per unit area with respect to the surface of the image carrier decreases. Since the residue cannot be blocked by the end face 62a, a cleaning failure occurs. Further, since the contact portion 62c wears along the shape of the image carrier, the contact portion 62c comes into close contact with the image carrier, so that the force that inhibits the rotation of the image carrier is strong. turn into. Then, in the case of color printing in which the toner images of each color are formed on a plurality of the image carriers and superimposed to form a multicolor toner image, the contact portion 62c having a strong force to inhibit rotation is provided. The overlapping timing of the image carrier tends to be delayed, and color misregistration tends to occur in the printed image.
Therefore, in the image forming apparatus of the present invention, when the lubricant supply device supplies the lubricant to the surface of the image carrier for the purpose of delaying the progress of wear of the contact portion, the image carrier is The lubricant is sandwiched between the contact portion and the surface of the image carrier by reversing and releasing the contact between the contact portion and the surface of the image carrier. It was made possible to obtain a good image quality over a wide range.

FIG. 10 is an explanatory diagram illustrating a state in which the lubricant is supplied to the contact portion.
In FIG. 10, the lubricant supply device 10 supplies the lubricant to the surface of the image carrier 3, and the first contact release is performed at the timing when the image carrier 3 rotates in the reverse direction indicated by the arrow R2 in FIG. The mechanism 631 releases the contact between the contact portion 62 c and the surface of the image carrier 3. Then, the lubricant is supplied so as to be sandwiched in the gap between the contact portion 62 c and the surface of the image carrier 3.
Further, since the image carrier 3 rotates in the reverse direction and the lubricant is supplied to the cleaning device 6, the cleaning device 6 is positioned upstream of the lubricant supply means 10 in the reverse direction. The rotation angle until the lubricant is supplied to 6 can be reduced.

FIG. 11 is an enlarged view of the vicinity of the contact portion shown in FIG.
In FIG. 11, over time, the elastic member 622 has a wear surface 65 along the shape of the surface of the image carrier 3, and the first contact release mechanism 631 shown in FIG. When the contact with the body 3 is released, a gap E is formed by the wear surface 65 and the surface of the image carrier 3. Since the gap E is formed, the lubricant is easily supplied to the wear surface 65 when the image carrier 3 is reversed, so that no cleaning failure or color misregistration occurs even after long-term use. Good image quality can be obtained.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Elastic member>
As the elastic member, six urethane rubbers having the following structure and physical properties at 25 ° C. were used. Table 1 summarizes the structure and physical properties at 25 ° C.
Elastic member 1: Single layer structure, durometer hardness 72 degrees, rebound resilience 31% (manufactured by Toyo Tire & Rubber Co., Ltd.)
Elastic member 2: Single layer structure, durometer hardness 69 degrees, rebound resilience 50% (manufactured by Toyo Tire & Rubber Co., Ltd.)
Elastic member 3: Single layer structure, durometer hardness 68 degrees, rebound resilience 30% (manufactured by Toyo Tire & Rubber Co., Ltd.)
Elastic member 4: Single layer structure, durometer hardness 75 degrees, rebound resilience 45% (manufactured by Toyo Tire & Rubber Co., Ltd.)
Elastic member 5: two-layer structure, durometer hardness 80 degrees (layer including the abutting portion), 75 degrees (layer not including the abutting portion), rebound resilience 25% (manufactured by Toyo Tire & Rubber Co., Ltd.)
Elastic member 6: two-layer structure, durometer hardness 66 degrees (layer including the contact portion), 75 degrees (layer not including the contact portion), rebound resilience 30% (manufactured by Bando Chemical Co., Ltd.)

<Durometer hardness of elastic member>
The durometer hardness of the elastic member was measured using a micro rubber hardness meter MD-1 manufactured by Kobunshi Keiki Co., Ltd. according to JIS K6253. In addition, about the said elastic member of 2 layer structure, it measured from the surface of each layer, respectively. As the measurement sample, the elastic member having a size of 10 mm × 20 mm and having an average thickness of 1.8 mm was used.

<Rebound resilience of elastic member>
The rebound resilience of the elastic member was measured according to JIS K6255 using a Reirientester (No. 221) manufactured by Toyo Seiki Seisakusho. As a measurement sample, a sheet in which two sheets having an average thickness of 1.8 mm were overlapped for convenience in order to make the thickness close to 4 ± 0.1 mm was used.

  As the curable composition, seven curable compositions having the following compositions were prepared. Moreover, what was put together about the composition of each curable composition was shown to Table 2-1 and Table 2-2.

(Preparation Example 1)
<Preparation of curable composition 1>
A curable composition 1 was prepared from the following composition by a conventional method.
A functional group equivalent molecular weight of 350 or less and a number of functional groups of 3 to 6 pentaerythritol. A (meth) acrylate compound having a triacrylate structure (trade name: PETIA, manufactured by Daicel Ornex Co., Ltd., functional group number: 3 , Functional group equivalent molecular weight: 99)... 8 parts by mass A (meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2 (trade name: ODA-N, Number of functional groups: 1, functional group equivalent molecular weight: 226, manufactured by Daicel Ornex Co., Ltd.) ... 2 parts by mass Fluorine-based (meth) acrylate compound having a perfluoropolyether structure having 2 or more functional groups : OPTOOL DAC-HP, number of functional groups: 2 or more, manufactured by Daikin Industries, Ltd.) 0.1 part by mass Polymerization initiator (trade name: Irgacure 184, manufactured by BASF Japan Ltd.) 0.5 parts by mass Solvent (cyclohexanone) 89.4 parts by mass

(Preparation Example 2)
<Preparation of curable composition 2>
A curable composition 2 was prepared from the following composition by a conventional method.
A (meth) acrylate compound having a pentaerythritol triacrylate structure having a functional group equivalent molecular weight of 350 or less and having 3 to 6 functional groups (trade name: PETIA, functional group number: 3, functional group equivalent molecular weight: 99 , Manufactured by Daicel Ornex Co., Ltd.) 7 parts by mass A (meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2 (trade name: HDDA, number of functional groups : 2, Functional group equivalent molecular weight: 113, manufactured by Daicel Ornex Co., Ltd.) 3 parts by mass Polymerization initiator (trade name: Irgacure 184, manufactured by BASF Japan Ltd.) 0.5 parts by mass Solvent (Cyclohexanone) 89.5 parts by mass

(Preparation Example 3)
<Preparation of curable composition 3>
A curable composition 3 was prepared from the following composition by a conventional method.
A (meth) acrylate compound having a pentaerythritol triacrylate structure having a functional group equivalent molecular weight of 350 or less and having 3 to 6 functional groups (trade name: PETIA, functional group number: 3, functional group equivalent molecular weight: 99 , Manufactured by Daicel Ornex Co., Ltd.) 8 parts by mass A (meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2 (trade name: IBOA, functional group number) 1: Functional group equivalent molecular weight: 198, manufactured by Daicel Ornex Co., Ltd.) 2 parts by mass-Fluorine-based (meth) acrylate compound having a perfluoropolyether structure having 2 or more functional groups (trade name: OPTOOL) DAC-HP, number of functional groups: 2 or more, manufactured by Daikin Industries, Ltd.) 0.1 mass part Polymerization initiator (trade name: A LUGACURE 184, manufactured by BASF Japan Ltd.) 0.5 parts by mass Solvent (cyclohexanone) 89.4 parts by mass

(Preparation Example 4)
<Preparation of curable composition 4>
From the following composition, a curable composition 4 was prepared by a conventional method.
A (meth) acrylate compound having a pentaerythritol triacrylate structure having a functional group equivalent molecular weight of 350 or less and having 3 to 6 functional groups (trade name: PETIA, functional group number: 3, functional group equivalent molecular weight: 99 , Manufactured by Daicel Ornex Co., Ltd.) 7 parts by mass A (meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2 (trade name: EBECRYL11, functional group number) : 2, functional group equivalent molecular weight: 263, manufactured by Daicel Ornex Co., Ltd.) 3 parts by mass-Fluorine-based (meth) acrylate compound having a perfluoropolyether structure having 2 or more functional groups (trade name: OPTOOL) DAC-HP (manufactured by Daikin Industries, Ltd.) ... 0.1 parts by mass -Polymerization initiator (trade name: Irgaku A, 184, manufactured by BASF Japan Ltd.) 0.5 parts by mass Solvent (cyclohexanone) 89.4 parts by mass

(Preparation Example 5)
<Preparation of curable composition 5>
From the following composition, a curable composition 5 was prepared by a conventional method.
A (meth) acrylate compound having a pentaerythritol triacrylate structure having a functional group equivalent molecular weight of 350 or less and a functional group number of 3 to 6 (trade name: DPHA, functional group number: 6, functional group equivalent molecular weight: 96 , Manufactured by Daicel Ornex Co., Ltd.) 10 parts by mass Polymerization initiator (trade name: Irgacure 184, manufactured by BASF Japan Ltd.) 1 part by mass Solvent (cyclohexanone) 89.0 parts by mass

(Preparation Example 6)
<Preparation of curable composition 6>
A curable composition 6 was prepared from the following composition by a conventional method.
A functional group equivalent molecular weight of 350 or less and a number of functional groups of 3 to 6 pentaerythritol. A (meth) acrylate compound having a triacrylate structure (trade name: KAYARAD DPCA-120, functional group number: 6, functional group equivalent. Molecular weight: 325, manufactured by Nippon Kayaku Co., Ltd.) ... 8 parts by mass-(Meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2 (trade name: IBOA, number of functional groups: 1, functional group equivalent molecular weight: 198, manufactured by Daicel Ornex Co., Ltd.) ... 2 parts by mass Fluorine-based (meth) acrylate compound having a perfluoropolyether structure having 2 or more functional groups ( Product name: Megafuck (registered trademark) RS-75, number of functional groups: 2 or more, manufactured by DIC Corporation) 0.1 mass part Initiator (trade name: Irgacure 184, manufactured by BASF Japan Ltd.) 0.5 parts by mass Solvent (cyclohexanone) 89.4 parts by mass

(Preparation Example 7)
<Preparation of curable composition 7>
A curable composition 7 was prepared from the following composition by a conventional method.
A (meth) acrylate compound having a pentaerythritol triacrylate structure having a functional group equivalent molecular weight of 350 or less and having 3 to 6 functional groups (trade name: PETIA, functional group number: 3, functional group equivalent molecular weight: 99 , Manufactured by Daicel Ornex Co., Ltd.) 5 parts by mass A (meth) acrylate compound having a functional group equivalent molecular weight of 100 to 1,000 and a functional group number of 1 to 2 (trade name: UN2700, number of functional groups : 2, Functional group equivalent molecular weight: 1,000, manufactured by Negami Kogyo Co., Ltd.) 5 parts by mass-Fluorine-based (meth) acrylate compound having a perfluoropolyether structure having 2 or more functional groups (trade name: MEGAFACE (registered trademark) RS-75, the number of functional groups: 2 or more, manufactured by DIC Corporation ... 0.1 parts by mass Polymerization initiator (trade name: A Gakyua 184, manufactured by BASF Japan Co., Ltd.) ... 0.5 parts by weight solvent (cyclohexanone) ... 89.4 parts by mass

Example 1
<Preparation of cleaning means 1>
<< Elastic member impregnation treatment and surface layer formation treatment >>
The end portion of the long side of the plate surface of the elastic member 1 and 1.8 mm from the end surface of the end portion was impregnated with the curable composition 5 for 1.5 minutes, and then air-dried for 3 minutes.
Next, among the portions of 1.8 mm from the end face of the end part impregnated, the plate surface including the contact part and the end face are again used with the curable composition 5 by the spray coating method. A surface layer was formed.
Specifically, the surface layer is formed by repeatedly applying the curable composition 5 to the end face so that the surface layer has a predetermined average thickness at a spray gun moving speed of 10 mm / s by spray coating, Natural drying was performed for 3 minutes, and the fingertips were not soiled with the curable composition 5 by touching the center of the end face.
Next, of the plate surface portion impregnated with the curable composition 5, a spray gun moving speed of 10 mm / s is applied to the plate surface portion including the contact portion by spray coating in the same manner as the end surface. Then, the surface layer was overcoated so as to have a predetermined average thickness, naturally dried for 3 minutes, and the center of the plate surface was touched so that the fingertip was not soiled with the curable composition 5. At this time, the region where the surface layer was not formed was restricted so as not to be spray-coated by applying a masking tape.
After drying, using a belt conveyor type ultraviolet irradiation device (trade name: UVC-2534 / 1MNLC3, manufactured by Ushio Electric Co., Ltd.) that irradiates ultraviolet rays while passing through a light source disposed inside, the belt conveyor type ultraviolet rays are used. When the irradiation apparatus was allowed to pass one pass (one pass), the condition was such that the ultraviolet ray dose was 2000 mJ / cm ^2, and three passes (three passes) were made. Next, drying was performed for 30 minutes at an internal temperature of 100 ° C. using a heat dryer.

<< Method for Measuring Content Depth of Curable Composition >>
The impregnation depth of the curable composition was determined by measuring the cross section of the elastic member using a microscopic FT-IR (trade name: Infrared microscope Nicolet Continuum, manufactured by Thermo Fisher Scientific Co., Ltd.). Judgment based on.
The method for determining the impregnation depth is based on the end surface or the surface of the plate surface impregnated with the curable composition, measuring a plurality of cross sections of the elastic member while changing the measurement position, and the vicinity of 1710 cm ⁻¹ . The value obtained by dividing the peak area by the peak area near 1415 cm ⁻¹ and normalized by the value of the non-impregnated part was used as an index.
Peak area around 1710 cm ^-1 is calculated from the area ^{1730cm -1 ~1680cm} -1 at the baseline ^{1775 cm} -1 1650 cm ^-1, the peak area in the vicinity of 1415cm ^-1 is at baseline ^{1425cm -1 ~1400cm} -1 also it was calculated from the area ^{1425cm -1 ~1400cm} -1.
As the measurement sample, the elastic member impregnated separately in the same manner was a cross-sectional slice of the elastic member produced using a cryomicrotome (trade name: EM FCS, manufactured by Leica).

<< Average thickness of surface layer >>
The average thickness of the surface layer was measured using a microscope VHX-100 manufactured by Keyence Corporation. The measurement sample was prepared by cutting the elastic member, which was separately applied and provided with the surface layer, using a trimming razor for SEM sample preparation manufactured by EM Japan Co., Ltd.

<< Contact release mechanism >>
As the contact release mechanism, a mechanism similar to the second contact release mechanism 641 shown in FIG. 5A is modified and provided, and control means not shown in FIG. 5A is provided.
The control means cleans the surface of the image carrier every time 100 sheets are printed in a sheet passing test to be described later, then supplies the lubricant by the lubricant supply means, and reverses the image carrier. The contact release by the second contact release mechanism is performed.

<Assembly of image forming apparatus>
The cleaning blade 1 attached to the contact release mechanism is connected to the image carrier and the color multifunction peripheral (product name: imagio MP C5000, manufactured by Ricoh Co., Ltd.) having the same configuration as the image forming apparatus 500 shown in FIG. Abutted. At this time, when the support member is moved toward the center of the image carrier from a state where the tip of the elastic member of the cleaning blade 1 is in contact with the image carrier to a state where the elastic member is bent. When the moving distance of the tip is the tip biting amount, the tip biting amount is set to 0.8 mm, and the cleaning angle θ is set to 79 °.

<Toner>
In the verification experiment, a toner prepared by a polymerization method was used. The physical properties of the toner are as follows.
Toner base (circularity 0.98, average particle size 4.9 μm)
・ External additive ・ Small particle size silica (trade name: H1303, manufactured by Clariant Japan Co., Ltd.) 1.5 parts by mass・ 0.5 mass part ・ Large particle size silica (trade name: UFP-35HH, manufactured by Denki Kagaku Kogyo Co., Ltd.) ... 1.0 mass part

<Conditions for paper passing test>

  The conditions for the paper-passing test were as follows. Using the color multifunction machine, the usage environment was 65% RH at 21 ° C., and the character chart with an image area ratio of 5% was 100 sheets / job, 250,000 sheets (A4 size horizontal) Printed.

<Noise>
During the paper passing test, whether or not the elastic member generates an abnormal sound (vibration) in the audible range was confirmed by the tester's own hearing. In addition, if the elasticity of the elastic member is too high, vibration on the high frequency side is likely to occur, and if the elasticity is too low, vibration on the low frequency side is likely to occur.

<Wear area>
The wear area is determined by placing the elastic member in the initial stage of manufacture and after the paper passing test in a state where the plate surface including the contact portion is directed upward, and the contact portion is obliquely upward from a direction of 45 °. It measured using the company Keyence laser microscope VK-9500.
In addition, the said wear area was calculated | required from the change of the cross-sectional shape calculated | required with the laser microscope in the same location of the said elastic member.

<Poor cleaning>
After the paper passing test, 20 evaluation images (A4 size horizontal) of three charts, which are images in which three vertical lines (with respect to the paper traveling direction) of 43 mm wide three lines are equally spaced, were printed. The presence or absence of an abnormal image was confirmed by visual observation of the evaluation image. The abnormal image means an image or a white spot image that appears in a streak or a strip shape in the printed image due to poor cleaning.

<Color shift>
The color misregistration was judged by whether or not four-color superposed thin lines (thin lines parallel to the axial direction of the image carrier) were output and overlapped at the same position.

(Example 2)
<Preparation of cleaning means 2>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member 1 is replaced with the elastic member 5, the curable composition 5 is replaced with the curable composition 6, and the end face side and the plate A cleaning means 2 of Example 2 was obtained in the same manner as in Example 1 except that the impregnation depth on the surface side and the average thickness of the surface layer on the end surface side and the plate surface side were changed.
Using the obtained cleaning means 2, in the same manner as in Example 1, the abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

(Example 3)
<Preparation of cleaning means 3>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member 1 is replaced with the elastic member 2, the curable composition 5 is replaced with the curable composition 1, and the end face side and the plate A cleaning means 3 of Example 3 was obtained in the same manner as in Example 1 except that the impregnation depth on the surface side and the average thickness of the surface layer on the end surface side and the plate surface side were changed.
Using the obtained cleaning means 3, in the same manner as in Example 1, abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

Example 4
<Preparation of cleaning means 4>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member 1 is replaced with the elastic member 4, the curable composition 5 is replaced with the curable composition 2, and the end face side and the plate A cleaning means 4 of Example 4 was obtained in the same manner as in Example 1 except that the impregnation depth on the surface side and the average thickness of the surface layer on the end surface side and the plate surface side were changed.
Using the obtained cleaning means 4, in the same manner as in Example 1, abnormal noise, wear area, poor cleaning, and color misregistration were evaluated. The results are shown in Table 3.

(Example 5)
<Preparation of cleaning means 5>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member 1 is the elastic member 6, the curable composition 5 is the curable composition 7, and the second contact. Example 1 except that the release mechanism is replaced with the first abutment release mechanism shown in FIG. In the same manner as in Example 1, the cleaning means 5 of Example 5 was obtained.
Using the obtained cleaning means 5, in the same manner as in Example 1, the abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

(Example 6)
<Preparation of cleaning means 6>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the curable composition 5 is changed to the curable composition 4, and the second contact release mechanism is changed to the first contact release mechanism. A cleaning means 6 of Example 6 was obtained in the same manner as in Example 1 except that the impregnation depth on the plate surface side and the average thickness of the surface layer on the plate surface side were changed in place of the contact release mechanism.
Using the obtained cleaning means 6, in the same manner as in Example 1, abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

(Example 7)
<Preparation of cleaning means 7>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member 1 is the elastic member 3, the curable composition 5 is the curable composition 3, and the second contact is made. The contact release mechanism was replaced with the first contact release mechanism, and the same procedure as in Example 1 was performed except that the impregnation depth on the end surface side and the average thickness of the surface layer on the end surface side and the plate surface side were changed. The cleaning means 7 of Example 7 was obtained.
Using the obtained cleaning means 7, in the same manner as in Example 1, the abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

(Example 8)
<Preparation of cleaning means 8>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member 1 is the elastic member 2, and the second contact release mechanism is the first contact release mechanism. Instead, the cleaning means 8 of Example 8 was obtained in the same manner as in Example 1 except that the impregnation depth on the end surface side and the plate surface side and the average thickness of the surface layer on the end surface side and the plate surface side were changed. .
Using the obtained cleaning means 8, in the same manner as in Example 1, abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

(Comparative Example 1)
<Preparation of cleaning means 9>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member is fixed without providing the second contact release mechanism, and the end surface side and the plate surface side The cleaning means 9 of Comparative Example 1 was obtained in the same manner as in Example 1 except that the impregnation depth was changed and the average thickness of the surface layer on the end surface side and the plate surface side was changed.
Using the obtained cleaning means 9, in the same manner as in Example 1, the abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

(Comparative Example 2)
<Preparation of cleaning means 10>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member 1 is replaced with the elastic member 6 and the curable composition 5 is replaced with the curable composition 1, and the second The elastic member is fixed without providing a contact release mechanism, and the elastic member is not impregnated with the curable composition 1, and the average thickness of the surface layer on the end surface side and the plate surface side is changed. In the same manner as in Example 1, the cleaning means 10 of Comparative Example 2 was obtained.
Using the obtained cleaning means 10, in the same manner as in Example 1, abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

(Comparative Example 3)
<Preparation of cleaning means 11>
In Example 1, as shown in Table 1, Table 2-1, and Table 2-2, the elastic member 1 is replaced by the elastic member 2, the curable composition 5 is replaced by the curable composition 2, and the second The elastic member is fixed without providing the contact release mechanism, the surface layer on the end surface side and the plate surface side is not provided, the impregnation time in the curable composition 2, and the impregnation depth on the end surface side and the plate surface side A cleaning means 11 of Comparative Example 3 was obtained in the same manner as Example 1 except that the size was changed.
Using the obtained cleaning means 11, in the same manner as in Example 1, the abnormal noise, wear area, poor cleaning, and color shift were evaluated. The results are shown in Table 3.

Table 3 summarizes the results of the evaluation experiments of Examples 1 to 8 and Comparative Examples 1 to 3.
In Table 3, in Examples 1 to 8 including the cleaning device having the predetermined impregnation treatment and the elastic member provided with the surface layer and the contact release mechanism, 250,000 sheets of the paper passing The abrasion area after the paper passing test could be suppressed to 120 μm ² or less without generating any abnormal noise during the test. As a result, there was no cleaning failure or color misregistration after the paper passing test, and good image quality could be obtained over a long period of time. On the other hand, in Comparative Examples 1 to 3 having no contact release mechanism, the wear area was widened, resulting in abnormal noise, poor cleaning, and color misregistration.

As an aspect of this invention, it is as follows, for example.
<1> An image forming unit that includes a rotatable image carrier, and forms a toner image on the surface of the image carrier while rotating the image carrier;
Lubricant supply means for supplying a lubricant to the surface of the image carrier;
Cleaning means disposed on the upstream side of the lubricant supply means in the rotational direction of the image carrier,
An elastic member that contacts the surface of the image carrier; a contact release mechanism that releases contact between the elastic member and the image carrier; and a reversing mechanism that reverses the image carrier; With
When the lubricant supply means supplies the lubricant to the cleaning means, at the end of the cleaning operation, the contact release mechanism releases the contact between the elastic member and the image carrier, and the reversing mechanism An image forming apparatus characterized by inverting an image carrier.
<2> The elastic member has a wear surface along the shape of the surface of the image carrier,
The image forming apparatus according to <1>, wherein a gap is formed by the wear surface and the surface of the image carrier when the contact release mechanism releases the contact between the elastic member and the image carrier. is there.
<3> The cleaning unit includes a support member that fixes one end of the elastic member,
When the long side of the free end of the elastic member is a contact side that makes contact with the image carrier,
The elastic member is
A region at a depth of 20 μm to 100 μm in the thickness direction from the plate surface including the contact side at the end of the free end;
In the direction from the end face of the free end to the opposing end face, a depth of 50 μm to 150 μm,
The image forming apparatus according to any one of <1> to <2>, including a cured product of a curable composition containing a (meth) acrylate compound.
<4> The elastic member has a surface layer containing a cured product of the curable composition on a plate surface including the abutting side at an end portion of the free end and an end surface of the free end,
The image forming apparatus according to <3>, wherein an average thickness of the surface layer is 0.5 μm to 2 μm.
<5> The curable composition has a functional group equivalent molecular weight of 350 or less and a (meth) acrylate compound having a pentaerythritol triacrylate structure having 3 to 6 functional groups, and a functional group equivalent molecular weight of 100 to 100. The image forming apparatus according to any one of <3> to <4>, wherein the image forming apparatus includes 1,000 and a (meth) acrylate compound having 1 to 2 functional groups.
<6> The curable composition according to any one of <3> to <5>, wherein the curable composition has a perfluoropolyether structure in a molecule and contains a fluorine-based (meth) acrylate compound having two or more functional groups. The image forming apparatus described.
<7> The image forming apparatus according to any one of <1> to <6>, wherein the elastic member is rubber including a urethane group in a molecule.
<8> The image forming apparatus according to <1> to <6>, wherein the elastic member is formed by laminating two different types of rubber containing a urethane group in a molecule.
<9> The image forming unit includes the image carrier, a charging unit that charges the surface of the image carrier, and an exposure unit that exposes the charged image carrier to form an electrostatic latent image; <1 including developing means for developing the electrostatic latent image into a toner image, transfer means for transferring the toner image to a recording medium, and fixing means for fixing the toner image transferred to the recording medium. > To <8>.
<10> The image carrier, a lubricant supply unit that supplies a lubricant to the surface of the image carrier, a cleaning unit that contacts the surface of the image carrier and removes residues, and the image carrier A charging unit that charges the surface of the image bearing member, an exposure unit that exposes the charged surface of the image carrier to form an electrostatic latent image, a developing unit that develops the electrostatic latent image into a toner image, and the toner image At least one of transfer means for transferring to a recording medium;
An elastic member that contacts the surface of the image carrier; a contact release mechanism that releases contact between the elastic member and the image carrier; and a reversing mechanism that reverses the image carrier; With
When the lubricant supply means supplies the lubricant to the cleaning means, at the end of the cleaning operation, the contact release mechanism releases the contact between the elastic member and the image carrier, and the reversing mechanism A process cartridge for inverting an image carrier.

DESCRIPTION OF SYMBOLS 3 Image carrier 6 Cleaning apparatus 10 Lubricant supply apparatus 51 Developing roller 62a End surface 62b Plate surface 62c Contact part 62d Impregnation area | region 65 Wear surface 101 Fur brush 103 Solid lubricant 621 Support member 622 Elastic member 623 Surface layer

JP 2010-152295 A

Claims (10)

An image forming unit that includes a rotatable image carrier, and forms a toner image on the surface of the image carrier while rotating the image carrier;
Lubricant supply means for supplying a lubricant to the surface of the image carrier;
Cleaning means disposed on the upstream side of the lubricant supply means in the rotational direction of the image carrier,
An elastic member that contacts the surface of the image carrier; a contact release mechanism that releases contact between the elastic member and the image carrier; and a reversing mechanism that reverses the image carrier; With
When the lubricant supply means supplies the lubricant to the cleaning means, at the end of the cleaning operation, the contact release mechanism releases the contact between the elastic member and the image carrier, and the reversing mechanism An image forming apparatus characterized by inverting an image carrier. The elastic member has a wear surface along the shape of the surface of the image carrier;
The image forming apparatus according to claim 1, wherein when the contact release mechanism releases the contact between the elastic member and the image carrier, a gap is formed by the wear surface and the surface of the image carrier. The cleaning means includes a support member that fixes one end of the elastic member;
When the long side of the free end of the elastic member is a contact side that makes contact with the image carrier,
The elastic member is
A region having a depth of 20 μm to 100 μm in the thickness direction from the plate surface including the contact side at the end of the free end;
A region having a depth of 50 μm to 150 μm in a direction from the end surface of the free end toward the opposite end surface,
The image forming apparatus according to claim 1, comprising a cured product of a curable composition containing a (meth) acrylate compound. The elastic member has a surface layer containing a cured product of the curable composition on the plate surface including the abutting side at the end of the free end and the end surface of the free end,
The image forming apparatus according to claim 3, wherein an average thickness of the surface layer is 0.5 μm to 2 μm.   The curable composition has a functional group equivalent molecular weight of 350 or less and a (meth) acrylate compound having a pentaerythritol triacrylate structure having 3 to 6 functional groups, and a functional group equivalent molecular weight of 100 to 1,000. The image forming apparatus according to claim 3, wherein the image forming apparatus contains a (meth) acrylate compound having 1 to 2 functional groups.   The image forming apparatus according to claim 3, wherein the curable composition contains a fluorine-based (meth) acrylate compound having a perfluoropolyether structure in a molecule and having two or more functional groups.   The image forming apparatus according to claim 1, wherein the elastic member is a rubber containing a urethane group in a molecule.   The image forming apparatus according to claim 1, wherein the elastic member is formed by laminating two different types of rubber containing urethane groups in the molecule.   The image forming unit includes the image carrier, a charging unit that charges the surface of the image carrier, an exposure unit that exposes the charged image carrier to form an electrostatic latent image, and the electrostatic The developing unit for developing a latent image into a toner image, a transfer unit for transferring the toner image to a recording medium, and a fixing unit for fixing the toner image transferred to the recording medium. The image forming apparatus according to any one of the above. The image carrier, lubricant supply means for supplying a lubricant to the surface of the image carrier, cleaning means for contacting the surface of the image carrier to remove residues, and the surface of the image carrier. Charging means for charging, exposure means for exposing the charged surface of the image carrier to form an electrostatic latent image, developing means for developing the electrostatic latent image into a toner image, and using the toner image as a recording medium At least one of transfer means for transferring; and
An elastic member that contacts the surface of the image carrier; a contact release mechanism that releases contact between the elastic member and the image carrier; and a reversing mechanism that reverses the image carrier; With
When the lubricant supply means supplies the lubricant to the cleaning means, at the end of the cleaning operation, the contact release mechanism releases the contact between the elastic member and the image carrier, and the reversing mechanism A process cartridge for inverting an image carrier.