JP2010096988A - Lubricant feeding device, cleaning device, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant feeding device which is simple in composition and stably feeds a lubricant onto an image carrier even if the traveling speed of the image carrier is changed in an image forming process; and to provide a cleaning device, a process cartridge and an image forming apparatus. <P>SOLUTION: The lubricant feeding device feeds the lubricant onto an image carrier 21. In addition, the device has a brush-like rotary member 25b in which the piles of a brush, which contact the image carrier 21 and a solid lubricant 45, are circumferentially provided and to which a voltage is applied from a power supply 50. The voltage, which is applied to the brush-like rotary member 25b from the power supply 50, is changed in accordance with the traveling speed of the image carrier 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lubricant supply device (lubricant application device) for supplying a lubricant onto an image carrier such as a photoconductor drum, a photoconductor belt, and an intermediate transfer belt, and a cleaning device, process cartridge, and In particular, the present invention relates to a lubricant supply device, a cleaning device, a process cartridge, and an image forming device in which the traveling speed of an image carrier is variable.

  Conventionally, in an image forming apparatus using an electrophotographic method such as a copying machine, a printer, a facsimile, or a composite machine thereof, the deposits such as untransferred toner adhered on an image carrier such as a photosensitive drum are cleaned. A technique is known that uses a lubricant supply device that supplies a lubricant onto the image carrier in order to reliably clean the device and reduce wear of the image carrier and the cleaning blade (for example, Patent Documents). 1, see Patent Document 2).

  Specifically, the untransferred toner remaining on the image carrier after the transfer process should be completely removed by a cleaning blade (cleaning device) that contacts the image carrier. However, when the cleaning blade deteriorates with time due to contact with the image carrier (abrasion), cleaning failure may occur due to slipping through the gap between the cleaning blade where the untransferred toner is worn and the image carrier. Even when the cleaning blade is not deteriorated, when small toner or spherical toner is used, the toner enters a slight gap between the cleaning blade and the image carrier and eventually passes through the gap. A cleaning failure sometimes occurred. Furthermore, if toner or an external additive or paper dust contained in the toner slips through the gap between the cleaning blade and the image carrier, it adheres to the image carrier and forms a film. There was also.

  In response to such a problem, by applying a lubricant on the image carrier, the friction coefficient on the image carrier is reduced, so that deterioration of the cleaning blade and the image carrier is reduced. Since the removability of deposits such as untransferred toner adhering to the toner is improved, it is possible to suppress the occurrence of poor cleaning and filming over time.

Specifically, the lubricant supply device includes a brush-like rotating member (brush-like roller) that is in sliding contact with the image carrier, a solid lubricant (lubricant molding) that is in contact with the brush-like rotating member, and the like. Here, the lubricant supply device is provided in the cleaning device, and the cleaning blade is in contact with the image carrier (photoconductor) on the downstream side of the brush-like rotating member.
Then, the lubricant is gradually scraped off from the solid lubricant by the brush-like rotating member rotating in a predetermined direction, and the lubricant scraped off by the brush-like rotating member is applied (supplied) to the surface of the image carrier. Further, deposits such as untransferred toner remaining on the image carrier are removed by a cleaning blade disposed on the downstream side of the brush-like rotating member. At this time, deposits such as untransferred toner remaining on the image carrier are also removed by the brush-like rotating member.

  On the other hand, in Patent Document 1, the amount of toner input to a cleaning device (cleaning means) is adjusted for the purpose of applying a lubricant stably and quickly to an image carrier, and the linear velocity of the image carrier is adjusted. A technique for controlling the amount of lubricant applied according to the above is disclosed. Specifically, when a print job is input to the main body of the image forming apparatus and the linear velocity of the image carrier is determined by judging the content (image, paper type, etc.) of the print job, the amount of toner input to the cleaning device Is determined. As a method of controlling the toner input amount to the cleaning device, a method of changing the potential difference between the image carrier and the developing roller or turning off the transfer bias is disclosed.

  Japanese Patent Application Laid-Open No. 2003-228561 discloses a technique for varying the amount of lubricant applied to the image carrier in accordance with the state of toner input to the lubricant application device. Specifically, the solid lubricant is divided into a plurality of parts in the longitudinal direction, and each of the divided solid lubricants can be brought into contact with and separated from the brush-like rotating member. Accordingly, the number and position of the solid lubricant to be brought into contact with the brush-like rotating member are adjusted.

JP 2007-286246 A JP 2007-147917 A

In the conventional lubricant supply device described above, the amount of lubricant supplied to the image carrier has changed when the traveling speed of the image carrier is varied in the image forming process.
Specifically, the amount of lubricant supplied to the image carrier decreases when the traveling speed of the image carrier decreases due to the deceleration mode or the like, and when the traveling speed of the image carrier increases, Lubricant supply will increase. If the supply amount of the lubricant to the image carrier is insufficient, the original function as the lubricant supply device is deteriorated, resulting in deterioration of the cleaning blade, poor cleaning, and filming. . On the other hand, if the amount of lubricant supplied to the image carrier becomes excessive, the charging device may be contaminated by excessively applied lubricant, or the lubricant may be filmed on the image carrier. It will be frustrating.
Such a problem occurs when a thick recording medium (thick paper) is passed, or when the fixing temperature of the fixing member is lowered during continuous feeding. In particular, an image forming apparatus having a deceleration mode for decelerating) cannot be ignored.

On the other hand, in Patent Document 1 described above, the toner input amount to the cleaning device is adjusted by varying the potential difference between the image carrier and the developing roller or by turning off the transfer bias, so that the linear velocity of the image carrier is obtained. The amount of lubricant applied is controlled accordingly. However, since the adjustment of the toner input amount to the cleaning device changes the conditions of the normal image forming process, it cannot be performed during the normal image forming process, and before and after the image forming process ( For example, when warming up, etc.). Accordingly, the amount of lubricant supplied to the image carrier during the image forming process may change.
Further, in Patent Document 2 described above, the number and position of solid lubricants brought into contact with the brush-like rotating member are adjusted in accordance with the state of toner input to the lubricant application device, and the lubricant is applied to the image carrier. The amount is variable. Therefore, the configuration and control of the apparatus have been complicated.

  The present invention has been made in order to solve the above-described problems. Even when the traveling speed of the image carrier is varied in the image forming process, the image carrier is lubricated with a simple configuration. An object of the present invention is to provide a lubricant supply device, a cleaning device, a process cartridge, and an image forming apparatus capable of stably supplying an agent.

  The inventor of the present application has conducted research to solve the above problems, and as a result, when the amount of toner (untransferred toner) on the image carrier removed by the brush-like rotating member increases or decreases, the brush-like rotating member becomes solid lubricated. The amount of lubricant scraped off from the agent is also increased or decreased, and it has been found that the amount of lubricant supplied to the image carrier changes. Furthermore, it has been found that the amount of toner on the image carrier removed by the brush-like rotating member can be increased or decreased by controlling the magnitude of the voltage applied to the brush-like rotating member.

  The present invention is based on the above-described matters, that is, the lubricant supply device according to the first aspect of the present invention is a lubricant supply device for supplying a lubricant onto the image carrier, Brush bristles that are in sliding contact with the image carrier and the solid lubricant are provided around the image carrier and a brush-like rotating member to which a voltage is applied from a power source, and the brush from the power source according to the traveling speed of the image carrier. The voltage applied to the cylindrical rotating member is variable.

  According to a second aspect of the present invention, in the lubricant supply device according to the first aspect, the voltage applied from the power source to the brush-like rotating member has the same polarity as the polarity of the toner. The absolute value of the voltage applied to the brush-like rotating member when the running speed of the image carrier is low is applied to the brush-like rotating member when the running speed of the image carrier is fast. The voltage is controlled to be larger than the absolute value of the voltage.

Further, in the lubricant supply device according to the invention of claim 3, in the invention of claim 1 or claim 2, the brush-like rotating member has the brush hair wound around a cored bar, The brush bristles are made of low resistance fibers having an electric resistance of 10 ⁵ to 10 ¹⁰ (Ω · cm).

  A lubricant supply device according to a fourth aspect of the present invention is the invention according to any one of the first to third aspects, wherein the removing member that removes the adhering matter adhering to the brush-like rotating member, The brush-shaped rotating member is disposed downstream of the image bearing member in the rotational direction of the brush-shaped rotating member and upstream of the solid lubricant with respect to the rotational direction of the brush-shaped rotating member.

  A lubricant supply device according to a fifth aspect of the present invention is the lubricant supply device according to any one of the first to fourth aspects, wherein the solid lubricant is zinc stearate.

  According to a sixth aspect of the present invention, there is provided the lubricant supply device according to any one of the first to fifth aspects, wherein the image carrier has a crosslinked structure and a charge transport material is dispersed. A protective layer formed of a binder resin is provided on the surface.

  According to a seventh aspect of the present invention, there is provided a cleaning device comprising the lubricant supply device according to any one of the first to sixth aspects, wherein the image carrier is mounted on the lubricant supply device. A cleaning blade for cleaning the image bearing member is disposed on the downstream side in the traveling direction.

  A process cartridge according to an eighth aspect of the present invention is a process cartridge that is detachably installed on the main body of the image forming apparatus, and the lubrication according to any one of the first to sixth aspects. The agent supply device and the image carrier are integrated.

  An image forming apparatus according to a ninth aspect of the present invention includes the lubricant supply device according to any one of the first to sixth aspects and the image carrier.

  An image forming apparatus according to a tenth aspect of the present invention is the image forming apparatus according to the ninth aspect, wherein the image forming apparatus has a deceleration mode in which a traveling speed of the image carrier is reduced, and the image carrier is rotated in the brush shape. A drive unit that is driven together with the member is provided.

  In the present application, “process cartridge” means a charging device (charging unit) for charging an image carrier, a developing device (developing unit) for developing a latent image formed on the image carrier, and an image carrier. It is defined as a unit in which at least one of the cleaning devices (cleaning units) for cleaning the top and the image carrier are integrated and detachably installed on the image forming apparatus main body.

  The present invention varies the voltage applied to the brush-like rotating member according to the traveling speed of the image carrier even when the traveling speed of the image carrier is varied in the image forming process. It is possible to provide a lubricant supply device, a cleaning device, a process cartridge, and an image forming apparatus in which the lubricant is stably supplied onto the image carrier with a simple configuration.

Embodiment.
Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

First, the configuration and operation of the entire image forming apparatus will be described with reference to FIG.
In FIG. 1, 1 is an apparatus main body of a color copying machine as an image forming apparatus, 2 is a writing section (exposure section) that emits laser light based on input image information, and 20Y, 20M, 20C, and 20BK are colors (yellow, magenta). , Cyan, and black), 21 is a photosensitive drum as an image carrier accommodated in each of the process cartridges 20Y, 20M, 20C, and 20BK, 22 is a charging unit that charges the photosensitive drum 21, Reference numerals 23Y, 23M, 23C, and 23BK denote developing devices (developing units) that develop the electrostatic latent image formed on the photosensitive drum 21, and 24 denotes a toner image formed on the photosensitive drum 21 to the intermediate transfer belt 27. A transfer bias roller 25 for transferring, a cleaning device (cleaning unit) for collecting untransferred toner on the photosensitive drum 21, Show.

  In addition, 27 is an intermediate transfer belt on which toner images of a plurality of colors are transferred in an overlapping manner, 28 is a second transfer bias roller for transferring the toner image formed on the intermediate transfer belt 27 to the recording medium P, and 29 is an intermediate transfer belt. 27 is an intermediate transfer belt cleaning unit that collects untransferred toner, 30 is a conveyance belt that conveys a recording medium P on which a four-color toner image is transferred, and 32Y, 32M, 32C, and 32BK are developing devices 23Y and 23M. , 23C and 23BK, a toner replenishing unit for replenishing toner of each color, 51 a document conveying unit for conveying the document D to the document reading unit 55, 55 for a document reading unit for reading image information of the document D, 61 for transfer paper, etc. A paper feed unit for storing the recording medium P, and a fixing unit 66 for fixing an unfixed image on the recording medium P are shown.

Here, each of the process cartridges 20Y, 20M, 20C, and 20BK is a unit in which the photosensitive drum 21, the charging unit 22, and the cleaning device 25 (with a lubricant supply device installed therein) are integrated. is there. The process cartridges 20Y, 20M, 20C, and 20BK are exchanged with respect to the apparatus main body 1 in a predetermined exchange cycle. Similarly, the developing devices 23Y, 23M, 23C, and 23BK are also exchanged with respect to the apparatus main body 1 in a predetermined exchange cycle.
Image formation of each color (yellow, magenta, cyan, black) is performed on the photosensitive drum 21 in each of the process cartridges 20Y, 20M, 20C, and 20BK.

Hereinafter, an operation during normal color image formation in the image forming apparatus will be described.
First, the document D is transported from the document table in the direction of the arrow in the drawing by the transport roller of the document transport unit 51 and placed on the contact glass 53 of the document reading unit 55. Then, the document reading unit 55 optically reads the image information of the document D placed on the contact glass 53.

  Specifically, the document reading unit 55 scans the image of the document D on the contact glass 53 while irradiating light emitted from the illumination lamp. Then, the light reflected by the document D is imaged on the color sensor via the mirror group and the lens. The color image information of the document D is read for each RGB (red, green, blue) color separation light by the color sensor, and then converted into an electrical image signal. Further, an image processing unit (not shown) performs color conversion processing, color correction processing, spatial frequency correction processing, and the like on the basis of RGB color separation image signals, so that yellow, magenta, cyan, and black are processed. Get color image information.

  Then, the image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 2. Then, laser light (exposure light) based on the image information of each color is emitted from the writing unit 2 toward the photosensitive drums 21 of the corresponding process cartridges 20Y, 20M, 20C, and 20BK.

On the other hand, the four photosensitive drums 21 rotate in the clockwise direction in FIG. First, the surface of the photosensitive drum 21 is uniformly charged at a position facing the charging unit 22 (a charging process). Thus, a charged potential is formed on the photosensitive drum 21. Thereafter, the surface of the charged photosensitive drum 21 reaches the irradiation position of each laser beam.
In the writing unit 2, laser light corresponding to the image signal is emitted from the light source corresponding to each color. The laser light is incident on the polygon mirror 3 and reflected, and then passes through the lenses 4 and 5. The laser light after passing through the lenses 4 and 5 passes through different optical paths for each of the yellow, magenta, cyan, and black color components (this is an exposure process).

  The laser beam corresponding to the yellow component is reflected by the mirrors 6 to 8 and then irradiated onto the surface of the photosensitive drum 21 of the first process cartridge 20Y from the left side of the drawing. At this time, the yellow component laser light is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 21 by the polygon mirror 3 that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 21 charged by the charging unit 22.

  Similarly, the laser beam corresponding to the magenta component is reflected by the mirrors 9 to 11 and then irradiated to the surface of the photosensitive drum 21 of the second process cartridge 20M from the left side of the paper, thereby causing an electrostatic latent image corresponding to the magenta component. An image is formed. The cyan component laser light is reflected by the mirrors 12 to 14 and then irradiated onto the surface of the photosensitive drum 212 of the third process cartridge 20C from the left side of the drawing to form a cyan component electrostatic latent image. The black component laser light is reflected by the mirror 15 and then irradiated on the surface of the photosensitive drum 21 of the fourth process cartridge 20BK from the left side of the paper, thereby forming an electrostatic latent image of black component.

Thereafter, the surface of the photosensitive drum 21 on which the electrostatic latent images of the respective colors are formed reaches positions facing the developing devices 23Y, 23M, 23C, and 23BK, respectively. Then, the respective color toners are supplied from the developing devices 23Y, 23M, 23C, and 23BK onto the photosensitive drum 21, and the latent image on the photosensitive drum 21 is developed (this is a developing step).
Thereafter, the surface of the photosensitive drum 21 after the development process reaches the position facing the intermediate transfer belt 27 after passing the position facing the photosensor 41 (see FIG. 2). Here, the transfer bias roller 24 is installed at each facing position so as to contact the inner peripheral surface of the intermediate transfer belt 27. Then, at the position of the transfer bias roller 24, the images of the respective colors formed on the photosensitive drum 21 are sequentially superimposed and transferred onto the intermediate transfer belt 27 (first transfer step).

Then, the surface of the photosensitive drum 21 after the first transfer process reaches a position facing the cleaning device 25. Then, the untransferred toner remaining on the photosensitive drum 21 is collected by the cleaning device 25 (this is a cleaning process).
Thereafter, the surface of the photosensitive drum 21 passes through a static elimination unit (not shown), and a series of image forming processes on the photosensitive drum 21 is completed.

On the other hand, the surface of the intermediate transfer belt 27 on which the images of the respective colors on the photosensitive drum 21 are transferred in an overlapping manner travels in the direction of the arrow in the drawing and reaches the position of the second transfer bias roller 28. Then, the full-color image on the intermediate transfer belt 27 is secondarily transferred onto the recording medium P at the position of the second transfer bias roller 28 (second transfer step).
Thereafter, the surface of the intermediate transfer belt 27 reaches the position of the intermediate transfer belt cleaning unit 29. Then, the untransferred toner on the intermediate transfer belt 27 is collected by the intermediate transfer belt cleaning unit 29, and a series of transfer processes on the intermediate transfer belt 27 is completed.

Here, the recording medium P at the position of the second transfer bias roller 28 is transported from the paper feeding unit 61 via the transport guide 63, the registration roller 64, and the like.
Specifically, the recording medium P fed by the paper feeding roller 62 from the paper feeding unit 61 that stores the recording medium P passes through the conveyance guide 63 and is guided to the registration roller 64. The recording medium P that has reached the registration roller 64 is conveyed toward the position of the second transfer bias roller 28 in synchronization with the toner image on the intermediate transfer belt 27.

Thereafter, the recording medium P on which the full-color image is transferred is guided to the fixing unit 66 by the conveyance belt 30. In the fixing unit 66, the color image is fixed on the recording medium P at the nip between the heating roller 67 and the pressure roller 68.
Then, the recording medium P after the fixing process is discharged as an output image outside the apparatus main body 1 by the paper discharge roller 69, and a series of image forming processes is completed.

Note that the image forming apparatus according to the present embodiment is configured such that a deceleration mode for decelerating the process linear velocity (conveying speed of the recording medium P) is automatically and manually selected. Specifically, when passing a thick recording medium P (thick paper), the user manually operates the “thick paper mode” button on the operation panel (not shown) of the image forming apparatus main body 1. As a result, the deceleration mode is selected, and the fixing property to the thick paper is sufficiently secured. In addition, when the temperature (fixing temperature) on the heating roller 67 of the fixing unit 66 detected by a temperature sensor (not shown) during continuous paper feeding becomes equal to or lower than a predetermined value, the control by the control unit. The deceleration mode is automatically selected, and the fixing property of the output image is ensured as the heating time of the heating roller 67 is ensured. The selection of the deceleration mode is not limited to the specific example described above.
When the deceleration mode is selected, the conveyance speed of the recording medium P is lowered by the low-speed driving of the conveyance motor, and the drive unit (not shown) for performing the image forming process is low-speed as compared with the normal mode. The rotational speed (running speed) of the photosensitive drum 21, the developing roller 23a, the brush-like roller 25b (brush-like rotating member), and the like is reduced by driving.

Next, the image forming unit of the image forming apparatus will be described in detail with reference to FIG.
FIG. 2 is a cross-sectional view showing the image forming unit. The four image forming units installed in the apparatus main body 1 have substantially the same structure except that the color of the toner T used in the image forming process is different. Therefore, the alphabet of reference numerals in the process cartridge, the developing device, and the toner supply unit (Y, M, C, BK) is omitted for illustration.
As shown in FIG. 2, the process cartridge 20 mainly contains a photosensitive drum 21 as an image carrier, a charging unit 22, and a cleaning device 25 integrally in a case 26.

Here, the photosensitive drum 21 as an image bearing member is a negatively charged organic photosensitive member, in which a photosensitive layer or the like is provided on a drum-shaped conductive support.
Although not shown, the photosensitive drum 21 has a conductive support as a base layer, an undercoat layer as an insulating layer, a charge generation layer and a charge transport layer as a photosensitive layer, and a protective layer (surface layer) sequentially. Are stacked.
As the conductive support (base layer) of the photosensitive drum 21, a conductive material having a volume resistance of 10 ¹⁰ Ωcm or less can be used.

The photosensitive layer of the photosensitive drum 21 can have a laminated structure or a single layer structure.
First, a case where the photosensitive layer has a laminated structure including a charge generation layer and a charge transport layer will be described.
The charge generation layer is a layer mainly composed of a charge generation material. A known charge generation material can be used for the charge generation layer. Specifically, as a charge generating substance, monoazo pigment, disazo pigment, trisazo pigment, perylene pigment, perinone pigment, quinacridone pigment, quinone condensed polycyclic compound, squalic acid dye, other phthalocyanine pigment, na A phthalocyanine pigment, an azulenium salt dye, or the like can be used. These charge generation materials can be used alone or in combination of two or more.
In the charge generation layer, the charge generation material is dispersed in a suitable solvent together with a binder resin as necessary using a ball mill, attritor, sand mill, ultrasonic wave, etc., and this is dispersed on the conductive support (or below). It is formed by applying on the pulling layer and drying. As a coating method of the coating solution, methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, and the like can be used. The thickness of the charge generation layer is suitably about 0.01 to 5 μm (more preferably about 0.1 to 2 μm).

  The charge transport layer can be formed by dissolving or dispersing the charge transport material and the binder resin in a suitable solvent, and applying and drying the solution on the charge generation layer. If necessary, one or more plasticizers, leveling agents, antioxidants and the like can be added. The amount of the charge transport material is suitably 20 to 300 parts by weight (preferably 40 to 150 parts by weight) with respect to 100 parts by weight of the binder resin. The thickness of the charge transport layer is preferably 25 μm or less from the viewpoint of resolution and responsiveness. The lower limit varies depending on the image forming process (particularly, charging potential), but is preferably 5 μm or more.

Next, a case where the photosensitive layer has a single layer structure will be described.
The photosensitive layer having a single-layer structure is obtained by dissolving or dispersing the above-described charge generating substance, charge transporting substance, binder resin, etc. in an appropriate solvent and coating it on a conductive support (or undercoat layer). It can be formed by drying. You may comprise from a charge generation material and binder resin, without containing a charge transport material. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
As the binder resin, in addition to the binder resin used when the charge transport layer is formed, a binder resin used when the charge generation layer is formed may be mixed and used. Furthermore, polymer charge transport materials can also be used favorably. The amount of the charge generating material is preferably 5 to 40 parts by weight with respect to 100 parts by weight of the binder resin, and the amount of the charge transporting material is preferably 0 to 190 parts by weight (more preferably 50 to 150 parts by weight).
The photosensitive layer with a single-layer structure is a dip coating method or spray coating method in which a coating solution in which a charge generating material and a binder resin are dispersed together with a charge transporting material using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane by a dispersing machine. It can be formed by coating with bead coat, ring coat or the like. The film thickness of the photosensitive layer is suitably about 5 to 25 μm.

  The undercoat layer of the photosensitive drum 21 is generally composed mainly of a resin. However, considering that the photosensitive layer is applied with a solvent on these resins, it has a high solvent resistance with respect to a general organic solvent. A resin is desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. A fine powder pigment of metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide may be added to the undercoat layer in order to prevent moire and reduce residual potential. In addition, these undercoat layers can be formed using an appropriate solvent and coating method in the same manner as the photosensitive layer described above. The thickness of the undercoat layer is suitably about 0 to 5 μm.

The protective layer of the photosensitive drum 21 is for reducing mechanical wear on the surface of the photosensitive drum 21.
The protective layer in the present embodiment is formed of a binder resin having a crosslinked structure. The crosslinked structure is a three-dimensional network structure formed by using a reactive monomer having a plurality of crosslinking functional groups in one molecule and causing a crosslinking reaction using light or thermal energy. The binder resin having this network structure exhibits high wear resistance. From the viewpoint of electrical stability, printing durability, and life, a monomer having a charge transporting ability can be used in whole or in part as the reactive monomer. By using such a monomer, a charge transport site is formed in the network structure, and the function as a protective layer is sufficiently exhibited.

Examples of the reactive monomer having charge transporting ability include a compound containing at least one charge transporting component and a silicon atom having a hydrolyzable substituent in the same molecule, and a charge transporting component in the same molecule. A compound containing a hydroxyl group, a compound containing a charge transporting component and a carboxyl group in the same molecule, a compound containing a charge transporting component and an epoxy group in the same molecule, a charge transporting component in the same molecule And a compound containing an isocyanate group can be used. These charge transport materials having a reactive group may be used alone or in combination of two or more.
A reactive monomer having a triarylamine structure can also be used as the monomer having a charge transporting ability because of its high electrical and chemical stability and high carrier mobility.
In addition, monofunctional and bifunctional polymerizable monomers and polymerizable oligomers are used in combination for viscosity adjustment during coating, stress relaxation of the cross-linked charge transport layer, low surface energy, friction coefficient reduction, and other functions. You can also. As these polymerizable monomers and oligomers, known ones can be used.

  The protective layer is formed by polymerizing or crosslinking the hole transporting compound using heat or light. When performing the polymerization reaction by heat, there are cases where the polymerization reaction proceeds only with thermal energy and a polymerization initiator is required, but in order to advance the reaction efficiently at a lower temperature, the initiator Is preferably added. In the case of polymerization by light, it is preferable to use ultraviolet light as light, but the reaction rarely proceeds only by light energy, and a photopolymerization initiator is generally used in combination. The polymerization initiator in this case mainly absorbs ultraviolet rays having a wavelength of 400 nm or less, generates active species such as radicals and ions, and initiates polymerization. In addition, it is also possible to use together the heat | fever and photoinitiator mentioned above.

The protective layer having a network structure formed in this manner has high wear resistance, but has a large volume shrinkage during the crosslinking reaction, and may become cracked if it is too thick. In such a case, the protective layer has a laminated structure, a protective layer made of a low molecular weight dispersion polymer is formed on the lower layer (photosensitive layer side), and a protective layer having a crosslinked structure is formed on the upper layer (surface side). You may do it.
As described above, in this embodiment, since the hard protective layer formed of the binder resin having a crosslinked structure is provided on the surface of the photosensitive drum 21, the function as the photosensitive drum 21 is not impaired. In addition, it is possible to prevent the photoconductor film from being scraped by the cleaning blade 25a and the first brush-like roller 25b.

  Referring to FIG. 2, the charging unit 22 is a charging roller formed by covering an outer periphery of a conductive metal core with an intermediate resistance elastic layer. A predetermined voltage is applied to the charging roller 22 from a power supply unit (not shown), thereby uniformly charging the surface of the opposing photosensitive drum 21.

  The developing device (developing unit) 23 mainly faces the first conveying screw 23b via the developing roller 23a facing the photosensitive drum 21, the first conveying screw 23b facing the developing roller 23a, and the partition member 23e. The second conveying screw 23c and a doctor blade 23d facing the developing roller 23a are configured. The developing roller 23a includes a magnet that is fixed inside and forms a magnetic pole on the circumferential surface of the roller, and a sleeve that rotates around the magnet. A plurality of magnetic poles are formed on the developing roller 23a (sleeve) by the magnet, and the developer G is carried on the developing roller 23a.

In the developing device 23, a two-component developer G composed of carrier C and toner T is accommodated.
As the toner T, a spherical toner having a circularity of 0.980 or more is used to improve the image quality. The “circularity” is an average circularity measured by a flow type particle image analyzer “FPIA-2000” (manufactured by Toa Medical Electronics Co., Ltd.). Specifically, 0.1 to 0.5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance. Further, about 0.1 to 0.5 g of a measurement sample (toner) is added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the dispersion liquid concentration is set to 3000 to 10000 / μl in the above-described analyzer. Then, the shape and distribution of the toner are measured.

As the spherical toner, it is possible to use an irregularly shaped toner (pulverized toner) whose shape is distorted by a pulverization method that has been widely used so far, which is spheroidized by heat treatment or the like, or a toner manufactured by a polymerization method. it can.
When such a spherical toner is used, conventionally, there is a case where a slight gap between the cleaning blade 25a and the photosensitive drum 21 enters the gap and eventually passes through the gap, resulting in poor cleaning. However, in the present embodiment, the lubricant Q is applied to the surface of the photosensitive drum 21 by the lubricant supply devices 25b and 45 to 49 to improve the toner peelability (removability) on the photosensitive drum 21. The occurrence of defective cleaning is suppressed.

  The cleaning device 25 has a function as a lubricant supply device that supplies a lubricant onto the photosensitive drum 21, as well as an original function of removing deposits such as untransferred toner attached on the photosensitive drum 21. ing. The cleaning device 25 (lubricant supply device) includes a cleaning blade 25a (blade member) that comes into contact with the photosensitive drum 21 (image carrier) and a brush-like rotating member that is provided with brush bristles 25b1 that slide in contact with the photosensitive drum 21. As a brush-like roller 25b, a solid lubricant 45 slidably contacting the brush-like roller 25b, a compression spring 46 urging the solid lubricant 45 toward the brush-like roller 25b, and a removal slidingly contacting the brush bristles 25b1 of the brush-like roller 25b It is comprised by the flicker 47 (plate-shaped member) etc. as a member.

The cleaning blade 25a is made of a rubber material such as polyurethane rubber, silicone rubber, nitrile rubber, or chloroprene rubber, and is in contact with the surface of the photosensitive drum 21 at a predetermined angle and a predetermined pressure. The cleaning blade 25a preferably has an elastic modulus of about 20 to 80 (%) and a thickness of about 1 to 6 (mm). The cleaning blade 25a mechanically scrapes off deposits such as untransferred toner adhering to the photosensitive drum 21 and collects them in the cleaning device 25. Here, as the deposits adhered to the photosensitive drum 21, in addition to the untransferred toner, paper dust generated from the recording medium P (paper), discharge products generated on the photosensitive drum 21 during discharge by the charging unit 22. And additives added to the toner.
In the present embodiment, the cleaning blade 25 a is in contact with the rotation direction of the photosensitive drum 21 in the counter direction, but the photosensitive member is arranged in the trailing direction with respect to the rotation direction of the photosensitive drum 21. The drum 21 may be contacted.
In addition to the above-described cleaning function, the cleaning blade 25a also has a function as a thinning blade for thinning the lubricant supplied onto the photosensitive drum 21 by the brush roller 25b.

The brush-like roller 25b serving as the brush-like rotating member is a brush-like roller 25b having a length (hair foot) of 0.2 to 20 mm (preferably 0.5 to 10 mm) in which brush hair 25b1 is planted on the base fabric. It is wound around a metal core in a spiral shape, and rotates in the counterclockwise direction of FIG. 2 in a state where the brush bristles 25b1 are in contact with the surface of the photosensitive drum 21.
The brush bristles 25b1 of the brush-like roller 25b (brush-like rotating member) are formed of low resistance fibers having an electric resistance (brush resistance) of 10 ⁵ to 10 ¹⁰ (Ω · cm). Specifically, the brush bristles 25b1 can be formed by adding a conductivity-imparting agent such as carbon to resin fibers such as PET (polyethylene terephthalate), nylon, rayon, acrylic, vinylon, polyester, and vinyl chloride. The brush bristles 25b1 preferably have a brush density of 1 to 50 (10,000 / inch ² ). In this embodiment, the brush length is 5 (mm), the brush density is 10 (10,000 / inch ² ), and the brush A resistor with a resistance of 10 ⁵ (Ω · cm) is used. The brush-like roller 25b functions as a cleaning brush that assists in scraping off deposits such as untransferred toner that adhere to the photosensitive drum 21. More specifically, deposits such as untransferred toner adhering to the photosensitive drum 21 are scraped off by the brush-like roller 25b, removed to some extent by the flicker 47, and then collected in the cleaning device 25.
The configuration and operation of the lubricant supply devices 25b and 45 to 47 will be described in detail later.

The image forming process described above will be described in more detail with reference to FIG.
The developing roller 23a rotates in the direction of the arrow in FIG. The developer G in the developing device 23 is supplied from the toner replenishing portion 32 to the toner replenishing port by the rotation of the first conveying screw 23b and the second conveying screw 23c arranged with the partition member 23e interposed therebetween. It circulates in the longitudinal direction while being agitated and mixed with the toner T replenished through 23f (in the direction perpendicular to the paper surface of FIG. 2).

  Then, the toner T that is frictionally charged and adsorbed on the carrier C is carried on the developing roller 23 a together with the carrier C. The developer G carried on the developing roller 23a then reaches the position of the doctor blade 23d. The developer G on the developing roller 23a is adjusted to an appropriate amount at the position of the doctor blade 23d, and then reaches a position facing the photosensitive drum 21 (developing area).

  Thereafter, in the development area, the toner T in the developer G adheres to the electrostatic latent image formed on the surface of the photosensitive drum 21. Specifically, the toner T is latently exposed by the electric field formed by the potential difference (development potential) between the latent image potential (exposure potential) of the image area irradiated with the laser light L and the development bias applied to the development roller 23a. Adhere to the image.

  Thereafter, most of the toner T adhering to the photosensitive drum 21 in the developing process is transferred onto the intermediate transfer belt 27. The untransferred toner T remaining on the photosensitive drum 21 is collected in the cleaning device 25 by the cleaning blade 25a and the brush-like roller 25b.

  Here, a toner replenishing unit 32 provided in the apparatus main body 1 includes a toner bottle 33 configured to be replaceable, and a toner hopper unit 34 that holds and rotates the toner bottle 33 and replenishes the developing device 23 with new toner T. And is composed of. Also, a new toner T (any one of yellow, magenta, cyan, and black) is accommodated in the toner bottle 33. In addition, a spiral protrusion is formed on the inner peripheral surface of the toner bottle 33.

  The new toner T in the toner bottle 33 is appropriately replenished into the developing device 23 from the toner replenishing port 23f as the toner T (existing toner) in the developing device 23 is consumed. . The toner T in the developing device 23 is consumed indirectly or directly by the reflective photosensor 41 facing the photosensitive drum 21 and the magnetic sensor 40 installed below the second conveying screw 23c of the developing device 23. Detected.

  Here, in the present embodiment, the toner density (TC) is controlled to be within a predetermined range. Specifically, toner replenishment is performed so that the detection results of the magnetic sensor 40 and the reflection type photosensor 41 have an output value corresponding to the above-described toner density range (the ratio of the toner T in the developer G). The toner is supplied from the unit 32 to the developing device 23 through the toner supply port 23f.

Hereinafter, the configuration and operation of the lubricant supply device, which is characteristic in the present embodiment, will be described in detail.
Referring to FIG. 2, the lubricant supply device is installed integrally with the cleaning device 25. The lubricant supply device includes a cleaning blade 25a that contacts the photosensitive drum 21, a brush-like roller 25b as a brush-like rotating member around which brush bristles 25b1 that slide in contact with the photosensitive drum 21 and the solid lubricant 45 are provided, a solid roller Consists of a lubricant 45, a compression spring 46 that urges the solid lubricant 45 toward the brush-like roller 25b, a flicker 47 (plate-like member) as a removal member that removes deposits adhering to the brush-like roller 25b, etc. Is done.
In addition to the original cleaning function, the cleaning blade 25a also has a function of thinning the lubricant supplied to the photosensitive drum 21 by the brush roller 25b.

The brush-like roller 25b is disposed on the upstream side in the rotation direction (traveling direction) of the photosensitive drum 21 with respect to the cleaning blade 25a.
The brush-like roller 25b has a spiral shape on a metal core, which is obtained by planting brush hairs 25b1 having a length (hair feet) in the range of 0.2 to 20 mm (preferably 0.5 to 10 mm) on a base fabric. It is wrapped around. The brush-like roller 25b is arranged so that the brush bristles 25b1 bite into the photosensitive drum 21 by a predetermined amount.
When the length of the brush bristles 25b1 exceeds 20 mm, the brush bristles 25b1 fall down in a predetermined direction due to repeated rubbing with the photosensitive drum 21, the solid lubricant 45, and the flicker 47 over time. Scraping ability is reduced. On the other hand, if the length of the brush bristles 25b1 is less than 0.2 mm, the physical contact force with respect to the solid lubricant 45 will be insufficient. Therefore, the length of the brush bristles 25b1 is preferably in the above range.

The brush roller 25b rotates in the opposite direction to the photosensitive drum 21 rotating in the clockwise direction in FIG. 2 (rotation in the counterclockwise direction in FIG. 2). The brush-like roller 25b is disposed so as to be in sliding contact with the solid lubricant 45, and the lubricant Q is scraped off from the solid lubricant 45 as the brush-like roller 25b rotates (see FIG. 3 as well). ), Applying the lubricant Q onto the photosensitive drum 21.
A compression spring 46 is disposed behind the solid lubricant 45 in order to eliminate contact unevenness between the brush-like roller 25b and the solid lubricant 45, and urges the solid lubricant 45 to the brush-like roller 25b. Yes.

In the present embodiment, the solid lubricant 45 is formed of zinc stearate. Specifically, the solid lubricant 45 is preferably prepared by dissolving a lubricating oil additive mainly composed of zinc stearate, having no side effects due to overcoating and having sufficient lubricity.
Zinc stearate is a typical lamellar crystal powder. A lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal breaks along the layers and is slippery. Therefore, the surface of the photosensitive drum 21 can be made low in friction. That is, the surface of the photosensitive drum 21 can be effectively covered with a small amount of lubricant by the lamellar crystal that uniformly receives the shearing force and covers the surface of the photosensitive drum 21.

  In addition to the zinc stearate, the solid lubricant 45 includes stearic acid groups such as barium stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, and calcium stearate. The thing which has can be used. In addition, the same fatty acid group zinc oleate, barium oleate, lead oleate, the same compound as stearic acid, zinc palmitate, barium palmitate, lead palmitate, the following compound similar to stearic acid May be used. In addition, caprylic acid, linolenic acid, corinolenic acid and the like can be used as the fatty acid group. In addition, waxes such as candelilla wax, canrunauba wax, rice wax, wax, coconut oil, beeswax, and lanolin can also be used. These easily become organic solid lubricants and have good compatibility with the toner.

Referring to FIG. 3, flicker 47 as a removing member is a plate-like member made of stainless steel or the like that is in sliding contact with brush bristles 25b1 of brush-like roller 25b, and brush bristles 25b1 toward the rotation center of brush-like roller 25b. It is arrange | positioned so that it may bite into. The flicker 47 is on the downstream side in the rotation direction of the brush roller 25 b with respect to the position where the brush roller 25 b and the photosensitive drum 21 face each other, and the flicker 47 is brushed with respect to the position where the brush roller 25 b and the solid lubricant 45 face each other. It is arrange | positioned in the rotation direction upstream of the roller 25b. The flicker 47 removes, to some extent, deposits such as toner T collected from the photosensitive drum 21 by the brush roller 25b from the brush roller 25b.
As described above, the brush-like roller 25b removes deposits such as toner T (untransferred toner) adhered on the photosensitive drum 21 in addition to the function of supplying the lubricant Q onto the photosensitive drum 21. It has a function. Then, the brush bristles 25b1 of the brush-like roller 25b to which the toner T is adhered are bent in the direction opposite to the rotation direction at the position of the flicker 47 (after falling down) and then slip through the position of the flicker 47 and vigorously. It will be restored (standing up). At this time, an energizing force is generated when the brush bristles 25b1 are restored, and a part of the toner T (adhered matter) carried on the brush-like roller 25b flies, and the toner T (adhered matter) is ejected from the brush-like roller 25b. A part of will be removed. As will be described later, the toner T necessary for the scraping property (polishing effect) of the solid lubricant 45 remains without being removed from the brush roller 25b.

Here, with reference to FIG. 2 and FIG. 4, in the lubricant supply device in the present embodiment, a voltage is supplied from the power source 50 (voltage variable type power source) to the brush-like roller 25b (brush-like rotating member). It is comprised so that it may be applied. The voltage applied from the power source 50 to the brush roller 25b is varied according to the rotational speed (traveling speed) of the photosensitive drum 21.
Specifically, the voltage applied from the power supply 50 to the brush roller 25b has the same polarity as that of the toner T (new toner) (in this embodiment, it is a negative polarity). Is set to When the deceleration mode is selected and the rotational speed (traveling speed) of the photosensitive drum 21 is low, the absolute value of the voltage applied to the brush roller 25b is the rotational speed of the photosensitive drum 21 when the normal mode is selected. Control is performed so that the absolute value of the voltage applied to the brush-like roller 25b is larger when (traveling speed) is faster (when the traveling speed is normal).
Specifically, when the normal mode is selected, the switch of the power source 50 is set as shown in FIG. 4A, and the voltage Va is applied to the brush roller 25b. On the other hand, when the deceleration mode is selected, the switch of the power supply 50 is switched as shown in FIG. 4B, and the voltage Vb (| Vb |> | Va |) is applied to the brush roller 25b. ) Is applied.

  As described above, even when the deceleration mode is selected, the voltage applied to the brush-like roller 25b is largely controlled. Therefore, the photosensitive member removed by the brush-like roller 25 that is driven to decelerate by the same drive unit as the photosensitive drum 21. The amount of the toner (untransferred toner) on the body drum 21 does not decrease, and the amount of the lubricant Q that the brush roller 25b scrapes off from the solid lubricant 45 does not decrease. Therefore, a problem that the amount of lubricant supplied onto the photosensitive drum 21 by the lubricant supply device when the deceleration mode is selected is suppressed.

Hereinafter, the above-described contents will be described in more detail.
Referring to FIG. 3, the solid roller 45 is scraped off when the brush roller 25b rotates in the direction of the arrow, and the powdery lubricant Q is carried on the brush roller 25b. At this time, when the toner T does not adhere to the brush-like roller 25b as shown in FIG. 3A, the toner T adheres to the brush-like roller 25b as shown in FIG. 3B. In comparison, the polishing effect on the solid lubricant 45 is reduced, and the amount of the lubricant Q applied to the photosensitive drum 21 by the brush roller 25b is reduced.
Since the brush roller 25b is in contact with the photosensitive drum 21 by a certain amount, the brush roller 25b applies the lubricant Q to the photosensitive drum 21 and collects the untransferred toner T on the photosensitive drum 21. It has a function to do. Therefore, toner adheres to the brush bristles 25b1 of the brush-like roller 25b. The toner T adhering to the brush roller 25b greatly contributes to the polishing of the solid lubricant 45. That is, if a large amount of toner T adheres to the brush-like roller 25b, a lot of the lubricant Q is scraped off from the solid lubricant 45.
This is because additives such as silica and titanium oxide are added to the toner T, and these contribute greatly to the polishing of the solid lubricant 45. The size of an additive such as silica or titanium oxide is 10 to 100 (nm), and is very small compared to a toner having a particle size of 5 to 10 (μm).
Even if the amount of the toner T adhering to the brush roller 25b is too large, the polishing effect on the solid lubricant 45 is lowered. On the other hand, in the present embodiment, since the flicker (removal member) 47 is provided, the above-described problems are prevented from occurring without the toner T exceeding a certain amount adhering to the brush roller 25b. can do.

FIG. 5 is a graph showing the relationship between the conventional travel distance of the photosensitive drum 21 and the consumption amount of the lubricant Q, and shows the relationship when the core metal of the brush roller 25b is grounded. FIG. 6 is a graph showing a conventional lubricant consumption rate in the normal mode and a lubricant consumption rate in the deceleration mode.
5 and 6, in the deceleration mode in which the rotation speed of the photosensitive drum 21 and the brush-like roller 25b is slow, the consumption amount and consumption rate of the lubricant Q (approximately equal to the amount of lubricant applied to the photosensitive drum 21). .) Is decreasing.
This is because the photosensitive drum 21 and the brush-like roller 25b are driven by the same drive unit (drive source), so when the photosensitive drum 21 rotates at a low speed, the brush-like roller 25b also rotates at a low speed, and the solid lubricant This is because the polishing effect of 45 is reduced. Therefore, in the deceleration mode in which the photosensitive drum 21 rotates at a low speed, the lubricant Q is not sufficiently applied to the photosensitive drum 21, and problems such as defective cleaning occur.
In order to eliminate such problems, if the deceleration mode is set as a reference so that the lubricant consumption rate in the deceleration mode becomes an appropriate value, the polishing effect on the solid lubricant 45 becomes too large in the normal mode. As a result, the amount of lubricant applied to the photosensitive drum 21 increases, causing problems such as contamination of the charging unit 22.

On the other hand, in the present embodiment, in order to keep the consumption rate of the lubricant constant, the voltage applied to the metal core of the brush roller 25b by the power source 50 is varied. By controlling the toner adhesion amount, the polishing efficiency for the solid lubricant 45 can be controlled.
The toner used in the present embodiment is charged with a negative polarity to perform the development process. Therefore, in order to transfer the toner from the photosensitive drum 21 to the intermediate transfer belt 27, a positive voltage is applied to the transfer bias roller 24 to form an electric field between the photosensitive drum 21 and the negatively charged toner. Is transferred to the intermediate transfer belt 27. At this time, all of the toner on the photosensitive drum 21 is not transferred to the intermediate transfer belt 27, and a part of the toner remains on the photosensitive drum 21 as untransferred toner having strong adhesion to the photosensitive drum 21. To do. Since the untransferred toner on the photosensitive drum 21 is affected by the transfer current, the charging polarity is changed from the negative polarity which is the normal charging polarity to the positive polarity. Therefore, the toner (untransferred toner) can be positively attached to the brush-like roller 25b by applying a negative polarity (same polarity as the toner polarity) voltage from the power source 50 to the brush-like roller 25b. it can.

Specifically, a negative polarity voltage Vb (see FIG. 4B) applied from the power source 50 to the brush roller 25b in the deceleration mode is applied from the power source 50 to the brush roller 25b in the normal mode. The voltage is set to be larger than the negative polarity voltage Va (see FIG. 4A). As a result, the amount of lubricant supplied to the photosensitive drum 21 can be optimized in the deceleration mode as in the normal mode. As a result, problems such as poor cleaning and filming of the photosensitive drum 21 can be prevented.
FIG. 7 is a graph showing the lubricant consumption rate in the normal mode and the lubricant consumption rate in the deceleration mode when the lubricant supply device in the present embodiment is used. It can be seen from FIG. 7 that the lubricant consumption rate in the normal mode and the lubricant consumption rate in the deceleration mode are substantially equal by performing variable control of the voltage applied to the brush roller 25b.

The brush bristles 25b1 of the brush-like roller 25b are preferably formed of low resistance fibers having an electric resistance of 10 ⁵ to 10 ¹⁰ (Ω · cm). When the electric resistance of the brush bristles 25b1 is high, an electric field is hardly formed between the bristles 25b1 and the photosensitive drum 21 even when a voltage is applied to the core of the brush-like roller 25b, and the toner with polarity is brushed. It becomes difficult to adhere to the roller 25b. Further, when the electric resistance of the brush bristles 25b1 is high, the brush-like roller 25b is frictionally charged by sliding contact with the photosensitive drum 21, and the brush bristles 25b1 are in a state of holding electric charge, so that the polar toner However, it is difficult to control by applying voltage.

  As described above, according to the present embodiment, even when the rotational speed (running speed) of the photosensitive drum 21 (image carrier) is varied in the image forming process, the rotation of the photosensitive drum 21 is performed. Since the voltage applied to the brush roller 25b (brush rotating member) is varied according to the speed, the lubricant Q can be stably supplied onto the photosensitive drum 21 with a simple configuration. .

In the present embodiment, the cleaning device 25 (lubricant supply device) is integrated with the photosensitive drum 21 and the charging unit 22 to form the process cartridge 20 so that the image forming unit can be made compact and maintenance workability can be improved. We are trying to improve. Thus, in a compact process cartridge, a lubricant supply device having a small number of parts and a simple configuration as in the present embodiment is particularly useful.
In addition, the cleaning device 25 (lubricant supply device) can be configured to be replaceable in the apparatus main body 1 as a single unit without being a component of the process cartridge. Even in such a case, the same effect as the present embodiment can be obtained.
In the present embodiment, the present invention is applied to an image forming apparatus equipped with a two-component developing type developing device 23 using a two-component developer. However, a one-component developing type using a one-component developer is used. Of course, the present invention can also be applied to an image forming apparatus equipped with the developing device 23.
Further, in the present embodiment, the present invention is applied to a lubricant supply device that supplies a lubricant to the photosensitive drum 21 as an image carrier. However, the present invention is applied to a photosensitive belt or an intermediate transfer belt as an image carrier. Naturally, the present invention can also be applied to a lubricant supply device that supplies a lubricant.

  It should be noted that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be modified as appropriate within the scope of the technical idea of the present invention, other than suggested in the present embodiment. is there. In addition, the number, position, shape, and the like of the constituent members are not limited to the present embodiment, and the number, position, shape, and the like suitable for implementing the present invention can be achieved.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. It is sectional drawing which shows an image formation part. They are (A) an enlarged view showing a state when the amount of toner collected on the brush roller is small, and (B) an enlarged view showing a state when the amount of toner collected is large. (A) It is sectional drawing which shows the lubricant supply apparatus at the time of normal mode, (B) It is sectional drawing which shows the lubricant supply apparatus at the time of deceleration mode. It is the graph which shows the relationship between the travel distance of the conventional image carrier, and the consumption of a lubricant. It is a graph which shows the conventional lubricant consumption rate in the normal mode and the lubricant consumption rate in the deceleration mode. It is a graph which shows the lubricant consumption rate at the time of normal mode, and the lubricant consumption rate at the time of deceleration mode.

Explanation of symbols

1 image forming apparatus body (apparatus body),
20, 20Y, 20M, 20C, 20BK Process cartridge,
21 photosensitive drum (image carrier), 22 charging unit,
23, 23Y, 23M, 23C, 23BK Developing device (developing unit),
25 Cleaning device (lubricant supply device),
25a Cleaning blade,
25b brush-like roller (brush-like rotating member),
25b1 brush hair,
45 solid lubricant,
46 compression spring,
47 Flicker (removal member),
50 power supply, Q lubricant,
G Two-component developer (developer), T toner, C carrier.

Claims (10)

A lubricant supply device for supplying a lubricant onto an image carrier,
The brush bristles that are in sliding contact with the image carrier and the solid lubricant are provided around, and a brush-like rotating member to which a voltage is applied from a power source is provided.
The lubricant supply device, wherein a voltage applied from the power source to the brush-like rotating member is varied according to a traveling speed of the image carrier. The voltage applied to the brush-like rotating member from the power source has the same polarity as the polarity of the toner,
The absolute value of the voltage applied to the brush-like rotating member when the running speed of the image carrier is low is the absolute value of the voltage applied to the brush-like rotating member when the running speed of the image carrier is high. The lubricant supply device according to claim 1, wherein the lubricant supply device is controlled so as to be larger than the lubricant. The brush-like rotating member has the brush hair wound around a cored bar,
The lubricant supply device according to claim 1, wherein the brush bristles are made of low resistance fibers having an electric resistance of 10 ⁵ to 10 ¹⁰ (Ω · cm).   A removing member that removes deposits adhering to the brush-like rotating member is downstream of the image-bearing member in the rotation direction of the brush-like rotating member, and the brush-like rotating member is disposed on the solid lubricant. The lubricant supply device according to any one of claims 1 to 3, wherein the lubricant supply device is disposed upstream in the rotation direction.   The lubricant supply device according to claim 1, wherein the solid lubricant is zinc stearate.   6. The image bearing member according to claim 1, wherein the surface of the image bearing member includes a protective layer formed of a binder resin having a crosslinked structure and having a charge transporting material dispersed therein. Lubricant supply device. Comprising the lubricant supply device according to any one of claims 1 to 6,
A cleaning apparatus comprising a cleaning blade for cleaning the image carrier on the downstream side in the running direction of the image carrier relative to the lubricant supply device. A process cartridge that is detachably attached to the image forming apparatus main body,
7. A process cartridge in which the lubricant supply device according to claim 1 and the image carrier are integrated.   An image forming apparatus comprising the lubricant supply device according to claim 1 and the image carrier. A deceleration mode for decelerating the traveling speed of the image carrier,
The image forming apparatus according to claim 9, further comprising a drive unit that drives the image carrier together with the brush-like rotating member.

Images