JP2016080845A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suppressing the generation of abnormal noise when a levelling blade rubs the surface of an image carrier.SOLUTION: An image forming apparatus comprises: a lubricant supply member such as a coating roller 41a that coats the surface of an image carrier such as a photoreceptor 1 with a lubricant such as a solid lubricant 41b; a protective layer forming member, such as a levelling blade 41d, a tip of which contacts with the surface of the image carrier to level the lubricant applied onto the surface of the image carrier and thus form a protective layer; and an air flow generation device such as a suction fan 51 that generates an air flow for cooling the inside of the apparatus. In the apparatus, a flow channel is provided that allows the air flow generated by the air flow generation device to simultaneously cool the surfaces of the protective layer forming member on the upstream side and the downstream side in the rotation direction of the image carrier.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.

  2. Description of the Related Art An image forming apparatus having a protective layer forming apparatus that supplies a lubricant to the surface of an image carrier to form a protective layer is known for protecting and reducing friction of an image carrier such as a photoreceptor and an intermediate transfer belt. Yes. The protective layer forming apparatus includes a solid lubricant, a lubricant supply member that scrapes off the solid lubricant and supplies the solid lubricant to the surface of the image carrier, and lubricates the image carrier with the tip in contact with the surface of the image carrier. A member having a blade-like protective layer forming member that forms a protective layer by leveling the agent is known.

  Patent Document 1 describes an image forming apparatus in which an air blowing unit and an air passage are formed so that air passes along the surface of a solid lubricant in the image forming apparatus. Thereby, it is said that the rise in the temperature of the solid lubricant, which is one factor that makes the coating amount of the lubricant unstable, can be suppressed.

  In the configuration of Patent Document 1, air that passes along the surface of the solid lubricant is supplied to the surface of the protective layer forming member adjacent to the solid lubricant. Is not supplied. Therefore, the back side surface of the protective layer forming member is not sufficiently cooled. Details of the reason are unknown, but if the back side surface of the protective layer forming member is not sufficiently cooled, abnormal noise is likely to occur when the protective layer forming member rubs the surface of the image carrier. However, it became clear by the earnest research by the present inventors.

  In order to solve the above-described problems, the present invention provides a lubricant supply member that applies a lubricant to the surface of an image carrier, and a tip portion that abuts on the surface of the image carrier, and the surface of the image carrier. An image forming apparatus having a protective layer forming member that forms a protective layer by leveling the applied lubricant and an air flow generating device that generates an air flow for cooling the inside of the apparatus. A flow path is provided in which the airflow can simultaneously cool the upstream surface and the downstream surface of the protective layer forming member in the rotation direction of the image carrier.

  According to the present invention, it is possible to suppress the generation of abnormal noise when the leveling blade rubs the surface of the image carrier.

1 is a schematic configuration diagram of a copier according to an embodiment. FIG. 2 is a schematic configuration diagram of one of four image forming units in the copier. The schematic block diagram of the protective layer formation apparatus in the image formation unit. Explanatory drawing about the cell number of the foam layer in the application roller of the protective layer forming apparatus. The schematic block diagram of an example of the air flow path | route which cools the leveling blade in the protective layer forming apparatus. The schematic diagram which shows the filter insertion position in the same airflow path | route. The schematic block diagram of the other example of the airflow path | route which cools a leveling blade.

Hereinafter, an embodiment (hereinafter referred to as “embodiment 1”) of a tandem type color copying machine (hereinafter referred to as a copying machine 500) as an image forming apparatus to which the developing device according to the present invention is applied. explain.
FIG. 1 is a schematic configuration diagram of a copying machine 500 according to the present embodiment.
The copying machine 500 includes a document reading unit 4 and a document conveying unit 3 above a printer unit 100 as a main body unit of the image forming apparatus, and a sheet feeding unit 7 below the printer unit 100. The document conveying unit 3 conveys the document to the document reading unit 4, and the document reading unit 4 reads image information of the conveyed document. The paper supply unit 7 is a recording material storage unit that stores the transfer paper P, which is a recording material. The paper supply unit 26 that stores the transfer paper P, and the transfer paper P in the paper supply cassette 26 to the printer unit 100. And a paper feed roller 27 that feeds out. A one-dot chain line in FIG. 1 indicates a conveyance path of the transfer paper P in the copying machine 500.

  An upper portion of the printer unit 100 is a paper discharge tray 30 on which transfer paper P on which an output image is formed is stacked. The printer unit 100 includes four image forming units 6Y, 6M, 6C, and 6K as image forming units that form toner images of respective colors (yellow, magenta, cyan, and black), and an intermediate transfer unit 10. Each of the image forming units 6Y, 6M, 6C, and 6K is formed on a drum-shaped photoreceptor 1Y, 1M, 1C, and 1K as a latent image carrier on which each color toner image is formed, and on the surface of each photoreceptor. And developing devices 5Y, 5M, 5C, and 5K for developing the electrostatic latent image.

  The intermediate transfer unit 10 includes an intermediate transfer belt 8 and primary transfer bias rollers 9Y, 9M, 9C, and 9K. The intermediate transfer belt 8 is an intermediate transfer body serving as a transfer body on which the color toner images formed on the surfaces of the photoreceptors 1Y, 1M, 1C, and 1K are transferred in a superimposed manner, and a color toner image is formed on the surface. It is. The primary transfer bias rollers 9Y, 9M, 9C, and 9K are primary transfer units that transfer the toner images formed on the surfaces of the photoreceptors 1Y, 1M, 1C, and 1K to the intermediate transfer belt 8.

  The printer unit 100 includes a secondary transfer bias roller 19 for transferring the color toner image on the intermediate transfer belt 8 onto the transfer paper P. Also, the transfer of the transfer paper P sent out by the paper feed roller 27 is stopped once, and the registration roller pair 28 that adjusts the timing at which the intermediate transfer belt 8 and the secondary transfer bias roller 19 are transported to the opposing secondary transfer nip. Is provided. Further, the printer unit 100 includes a fixing device 20 that fixes an unfixed toner image on the transfer paper P above the secondary transfer nip.

  In addition, toner containers 11Y, 1M, 1C, and 1K for the respective colors are disposed below the paper discharge tray 30 and above the intermediate transfer unit 10 in the printer unit 100. The toner containers 11Y, 1M, 1C, and 1K for the respective colors store the respective color toners supplied to the developing devices 5Y, 5M, 5C, and 5K.

FIG. 2 is an enlarged explanatory diagram of one of the four image forming units 6Y, 6M, 6C, and 6K.
The four image forming units 6Y, 6M, 6C, and 6K have substantially the same configuration and operation except for the color of the toner used in the image forming process. Therefore, in the following description, reference numerals indicating the corresponding colors are used. In the description, Y, M, C, and K are omitted as appropriate.

  As shown in FIG. 2, the image forming unit 6 is a process cartridge that integrally supports the photosensitive member 1 and the developing device 5, and this process cartridge is detachable from the copying machine 500 main body. . This facilitates exchange of the developing device 5 in the main body of the copying machine 500 provided with the developing device 5, and improves the maintainability of the copying machine 500.

  The image forming unit 6 includes a photoconductor cleaning device 2, a protective layer forming device 41, and a charging device 40 in addition to the developing device 5 around the photoconductor 1. In the image forming unit 6 of the present embodiment, the photoreceptor cleaning device 2 is configured to be cleaned by the cleaning blade 2a, and the charging device 40 is configured to be charged by the charging roller 4a.

Hereinafter, an operation during normal color image formation in the copier 500 of the present embodiment will be described.
First, when a start button (not shown) is pressed in a state where the document is set on the document table of the document conveyance unit 3, the document is conveyed from the document table by the conveyance roller of the document conveyance unit 3, and the document reading unit 4. Placed on the contact glass. Then, the document reading unit 4 optically reads the image information of the document placed on the contact glass.

  Specifically, the document reading unit 4 scans an image of a document on the contact glass while irradiating light emitted from an illumination lamp. Then, the light reflected from the original is imaged on the color sensor via the mirror group and the lens. The color image information of the original is read for each color separation light of RGB (red, green, blue) by the color sensor, and then converted into an electrical image signal. Further, color conversion processing, color correction processing, spatial frequency correction processing, and the like are performed by the image processing unit based on the RGB color separation image signals to obtain yellow, magenta, cyan, and black color image information.

  Then, image information of each color of yellow, magenta, cyan, and black is transmitted to a writing unit (not shown). Then, laser light L based on the image information of each color is emitted from the writing unit toward the corresponding photoreceptors 1Y, 1M, 1C, and 1K.

  On the other hand, the four photoconductors 1Y, 1M, 1C, and 1K rotate in the clockwise direction in FIGS. 1 and 2, respectively. First, the surfaces of the photoreceptors 1Y, 1M, 1C, and 1K are uniformly charged at a portion facing the charging roller 4a of the charging device 40 (charging process). Laser beams L corresponding to image signals are emitted from the four light sources onto the surfaces of the charged photoreceptors 1Y, 1M, 1C, and 1K from the writing unit. Each laser beam L passes through a different optical path for each color component of yellow, magenta, cyan, and black, and is irradiated on the surface of each of the photoreceptors 1Y, 1M, 1C, and 1K (exposure process).

  The laser beam L corresponding to the yellow component is applied to the surface of the first yellow photoreceptor 1Y from the left side of the drawing in FIG. At this time, the yellow component laser light L is scanned in the rotational axis direction (main scanning direction) of the yellow photoconductor 1Y by a polygon mirror that rotates at high speed. By scanning the laser beam L in this manner, an electrostatic latent image corresponding to the yellow component is formed on the surface of the yellow photoreceptor 1Y after being charged by the charging device 40.

  Similarly, the laser light L corresponding to the magenta component is irradiated on the surface of the second magenta photosensitive member 1M from the left in FIG. 1, and an electrostatic latent image corresponding to the magenta component is formed. The cyan component laser light L is applied to the surface of the third cyan photoreceptor 1C from the left in FIG. 1 to form an electrostatic latent image of the cyan component. The black component laser beam L is applied to the surface of the black photoconductor 1K from the left in FIG. 1 to form a black component electrostatic latent image.

  Thereafter, the surfaces of the photoreceptors 1Y, 1M, 1C, and 1K on which the electrostatic latent images of the respective colors are formed reach positions facing the developing device 5, respectively. Then, the respective color toners are supplied onto the surfaces of the photoreceptors 1Y, 1M, 1C, and 1K from the developing devices 5Y, 5M, 5C, and 5K that store the developer including the toners and magnetic carriers, and the photoreceptors 1Y and 1M. , 1C, 1K are developed (development process).

  The surfaces of the photoreceptors 1Y, 1M, 1C, and 1K after passing through the portion facing the developing device 5 (development region) reach the portion facing the intermediate transfer belt 8 (primary transfer region). Here, in each primary transfer region, primary transfer bias rollers 9Y, 9M, 9C, and 9K are installed so as to be in contact with the inner peripheral surface of the intermediate transfer belt 8. The photosensitive drums 1Y, 1M, 1C, and 1K and the primary transfer bias rollers 9Y, 9M, 9C, and 9K face each other with the intermediate transfer belt 8 interposed therebetween, thereby forming a primary transfer nip. In the primary transfer nip, the toner images of the respective colors formed on the photoreceptors 1Y, 1M, 1C, and 1K are sequentially transferred onto the intermediate transfer belt 8 (primary transfer process).

  The surfaces of the photoconductors 1Y, 1M, 1C, and 1K after passing through the primary transfer nip reach positions facing the photoconductor cleaning device 2, respectively. Then, untransferred toner remaining on the photoconductor is scraped and collected by the cleaning blade 2a at a position facing the photoconductor cleaning device 2 (photoconductor cleaning process).

  The surfaces of the photoconductors 1Y, 1M, 1C, and 1K that have passed through the portion facing the photoconductor cleaning device 2 pass through a charge removal unit that is opposed to a charge removal unit (not shown), and residual charges are discharged. The image forming process is completed, and the next image forming operation is prepared.

  The color toner images on the four photoconductors 1Y, 1M, 1C, and 1K are superimposed and transferred, and the intermediate transfer belt 8 that carries the color toner images moves in the counterclockwise direction in FIG. It reaches the secondary transfer nip which is a position facing the bias roller 19. On the other hand, the transfer paper P fed by the paper feed roller 27 from the paper feed cassette 26 containing the transfer paper P is guided to the registration roller pair 28 after passing through the conveyance guide, and hits the registration roller pair 28. Stop once. The transfer paper P that has struck the registration roller pair 28 is conveyed toward the secondary transfer nip in accordance with the timing at which the color toner image formed on the intermediate transfer belt 8 is directed to the secondary transfer nip. Then, the color toner image carried on the intermediate transfer belt 8 at the secondary transfer nip is transferred onto the transfer paper P (secondary transfer step).

  The surface of the intermediate transfer belt 8 that has passed through the secondary transfer nip reaches a portion facing an intermediate transfer belt cleaning device (not shown). At this facing portion, the transfer residual toner adhering to the intermediate transfer belt 8 is collected by an intermediate transfer belt cleaning device (not shown), and a series of transfer processes in the intermediate transfer belt 8 is completed.

  The transfer paper P on which the color toner image is transferred at the secondary transfer nip is guided to the fixing device 20. In the fixing device 20, a color image is fixed on the transfer paper P by heat and pressure at a fixing nip formed by a fixing roller and a pressure roller (fixing step). The transfer paper P that has passed through the fixing device 20 is discharged as an output image outside the printer unit 100 by the paper discharge roller pair 25 and stacked on the paper discharge tray 30 to complete a series of image forming processes.

FIG. 3 is a diagram showing a schematic configuration of the protective layer forming apparatus 41.
As shown in FIG. 3, the protective layer forming device 41 is disposed downstream of the cleaning device 2 with respect to the rotation direction of the photosensitive member 1 (arrow C in the drawing). The protective layer forming apparatus 41 includes an application roller 41a as a lubricant application means, a solid lubricant 41b as a lubricant accommodated in a fixed case, a leveling blade 41d as a lubricant leveling member, and the like. The application roller 41 a scrapes off the powdery lubricant from the solid lubricant 41 b and applies it to the surface of the photoreceptor 1. The lubricant applied to the surface of the photoconductor 1 is stretched by the leveling blade 41d that rubs the surface of the photoconductor 1 so that the coating unevenness is roughly leveled. As a result, the coefficient of friction on the surface of the photoreceptor 1 is reduced, and the deterioration of the cleaning blade 2a and the photoreceptor 1 is reduced. In addition, the detachability of deposits such as untransferred toner deposited on the photoreceptor 1 is improved.

  As the application roller 41a, a brush roller, a foam roller, or the like can be used, but a foam roller is preferably used. The foam roller as the application roller 41a is manufactured as follows. First, a polyurethane foam to be an elastic layer is formed in advance from a polyurethane foam raw material into a block shape, cut into a necessary shape, the surface is polished, and a core material is inserted. Thereafter, the polyurethane foam into which the core material is inserted is rotated, a polishing blade is applied to the surface, and the polishing blade is moved parallel to the axial direction to cut to a predetermined thickness (traverse grinding). The method of manufacturing the foam roller is not limited to this, and for example, a polyurethane foam raw material may be injected into a foam roller molding die containing a core material and foamed and cured.

  As the polyurethane foam raw material, those added with auxiliary agents such as polyol, polyisocyanate, catalyst, foaming agent, foam stabilizer and the like are used. In the polyurethane foam raw material, components other than the polyisocyanate are usually mixed in advance, and the polyisocyanate component is mixed immediately before molding.

  As the polyol component of the polyurethane foam raw material, polyether polyol is preferable because it is easy to process and the hardness of the polyurethane foam can be easily adjusted, but is not limited thereto. The polyether polyol can also be used by appropriately selecting from various polyether polyols. Since polyether polyether polyols, polyester polyether polyols, polymer polyether polyols, and the like are generally used in the production of flexible polyurethane foams, such a material may be selected. These materials may be used alone or in combination of two or more. Furthermore, it is said that the moldability of the polyurethane foam is improved by using a polyether polyol in which ethylene oxide is bonded to 5 [mol%] or more terminals.

  As the polyisocyanate component of the polyurethane foam raw material, various polyisocyanates can be appropriately selected and used. For example, 2,4-tolylene diisocyanate (TDI), 2,6-TDI, tolidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), 4-diphenylmethane diisocyanate (MDI), 4'- MDI, carbodiimide modified MDI, polymethylene polyphenyl polyisocyanate, polymeric polyisocyanate and the like can be mentioned. These materials may be used alone or in combination of two or more.

  The catalyst for the polyurethane foam raw material can be appropriately selected from catalysts generally used for the urethanization reaction. Examples thereof include amine catalysts such as triethylenediamine, dimethylethanolamine and bis (dimethylamino) ethyl ether, organometallic catalysts such as dioctyltin and distearyltin dibutyrate, and modified catalysts thereof. A reactive catalyst such as dimethylaminoethanol containing active hydrogen may be used. By adjusting the type of catalyst used and the amount of catalyst used, the cell wall width, open cell diameter, hardness, air flow rate, etc. of the polyurethane foam can be controlled.

  As the foam stabilizer used for the polyurethane foam raw material, any of those generally used for the production of polyurethane foam can be used, but a silicone surfactant is preferred. Moreover, as a foaming agent, although well-known foaming agents, such as water, a low boiling point thing, and a gas body, can be used, It is preferable to use water with easy handling as a foaming agent. These materials may be used alone or in combination of two or more. By adjusting the use amount and conditions of the foaming agent, the cell wall width, cell diameter, hardness, air flow rate and the like of the polyurethane foam can be controlled.

  The polyurethane foam raw material may be blended with a crosslinking agent, a foam breaker and the like so as to control the closed cell and open cell properties of the cells of the polyurethane foam, and the conductive agent for imparting desired conductivity. Further, an antistatic agent or the like may be added. Examples of the crosslinking agent include conventionally known ones such as triethanolamine and diethanolamine. Other additives such as conductive agents, flame retardants, thickeners, pigments, stabilizers, colorants, anti-aging agents, UV absorbers, antioxidants, antioxidants, etc. Can be blended.

  The foam roller needs to supply a uniform protective agent particle having a relatively small particle diameter to the photoreceptor 1. For this reason, in the foam layer, the number of cells is preferably 20 to 300/25 mm (particularly 40 to 100/25 mm), and the hardness is preferably 40 to 430 N (particularly 100 to 350 N). Further, when a block-shaped molded body is used as the protective agent, the particle size of the protective agent particles supplied to the surface of the photoreceptor can be controlled by adjusting the number of cells and the hardness of the foam layer. For example, when the number of cells is increased or the hardness is reduced, the particle diameter of the protective agent particles is reduced, and a more uniform protective layer can be formed. The hardness of the foam layer is an average value of values measured based on JIS K 6400 at arbitrary points on the surface of the foam layer.

As the number of cells in the foam layer, an average value of values measured by the following method is used.
FIG. 4 is a diagram illustrating the number of cells in the foam layer in the application roller 41a.
First, as shown in FIG. 4A, at the both ends and the center of the surface of the foam layer, three measurement points are selected on a line parallel to the axial direction (in the figure, R and T are the ends of the ends). Measurement location, S is the measurement location in the center). Three lines parallel to the axial direction in which such three measurement points are selected are selected at equal intervals in the circumferential direction. That is, there are nine measurement points in total.

  Next, the photograph screen of each measurement location is observed using a microscope. At each measurement point, as shown in FIG. 4B, a line having a length corresponding to the actual size 1 [inch] (about 25 [mm]) is drawn at the center of the photographic screen, and the line is within the line. Count how many cells there are. A cell that touches even a 25 mm line is counted as one. The average value of the number of cells counted at each measurement location is taken as the number of cells. For example, in FIG. 3B, the number of cells is twelve.

  The solid lubricant 41b is formed in a rectangular parallelepiped shape and is pressed toward the application roller 41a by a pressing mechanism 3c described later. As the lubricant for the solid lubricant 41b, a lubricant containing at least a fatty acid metal salt is used. As the fatty acid metal salt, for example, a fatty acid metal salt having a lamellar crystal structure such as fluorine resin, zinc stearate, calcium stearate, barium stearate, aluminum stearate, magnesium stearate, or the like can be used. Moreover, substances such as lauroyllysine, monocetyl phosphate sodium zinc salt, lauroyl taurine calcium and the like can be used. Of these fatty acid metal salts, it is particularly preferable to use zinc stearate. This is because zinc stearate has very good extensibility on the surface of the photoreceptor 1 and has low hygroscopicity, and even when the humidity changes, the lubricity is not easily lost. .

  Therefore, it is possible to form a coating layer of a lubricant having a high ability to protect the surface of the photoconductor which is not easily affected by environmental changes, and the surface of the photoconductor can be well protected. Moreover, since it has the characteristic that lubricity is hard to be impaired, the effect of reducing cleaning defects can be obtained satisfactorily. In addition to these fatty acid metal salts, liquid materials such as silicone oil, fluorine oil, and natural wax, and gaseous materials can be added as an external addition method.

  The lubricant of the solid lubricant 41b preferably contains boron nitride which is an inorganic lubricant. Examples of the crystal structure of boron nitride include a hexagonal low-pressure phase (h-BN) and a cubic high-pressure phase (c-BN). Among these boron nitrides, hexagonal low-pressure phase boron nitride crystals have a layered structure and are easily cleaved. Therefore, the coefficient of friction can be maintained at about 0.2 or less until close to 400 ° C., and the characteristics are not easily changed by discharge, and the lubricity is not lost as compared with other lubricants even when discharged.

  By adding such boron nitride, the lubricant supplied to the surface of the photoreceptor 1 and thinned does not deteriorate early due to discharge generated when the charging device 40 or the primary transfer bias roller 9 operates. . Boron nitride does not easily change its characteristics due to discharge, and even when subjected to discharge, lubricity is not lost compared to other lubricants. Moreover, it is possible to prevent the photosensitive layer of the photosensitive member 1 from being oxidized and evaporated by discharge. Further, since boron nitride can exhibit its lubricity even with a slight addition amount, it is effective for troubles caused by adhesion of lubricant to the charging roller 4a and the like, and blade noise of the cleaning blade 2a.

  As the solid lubricant 41b of this embodiment, a material obtained by compression molding a lubricant material containing zinc stearate and boron nitride was used. The molding method of the solid lubricant 41b is not limited to this, and other molding methods such as melt molding may be adopted. Thereby, the effect of the zinc stearate mentioned above and the effect of the boron nitride nitrogen mentioned above can be acquired.

  The solid lubricant 41b is scraped off and consumed by the application roller 41a, and the thickness thereof decreases with time. However, since the solid lubricant 41b is pressed by the pressing mechanism 41c, the solid lubricant 41b is always in contact with the application roller 3a. The application roller 41a applies the lubricant scraped off while rotating to the surface of the photoreceptor. Thereafter, the applied lubricant is spread by contact between the surface of the photoconductor 1 and the cleaning blade 2a to form a thin film. As a result, the coefficient of friction of the surface of the photoreceptor 1 is reduced. Note that the lubricant film adhered to the surface of the photoreceptor 1 is very thin and does not hinder charging by the charging roller 4a.

  The core metal in the foam roller is, for example, a cylindrical body made of a metal such as iron, aluminum, stainless steel, or a non-metal such as resin, but is not limited thereto. An adhesive layer may be provided in advance on the core material. In the above-described manufacturing method using the molding die of the foam roller containing the core material, it is preferable to provide a release layer such as a fluororesin coating agent or a release agent on the inner surface of the molding die. By doing in this way, the polyurethane foam layer which has openability can be formed easily.

  The leveling blade 41d is formed in a plate shape by an elastic material made of urethane rubber, hydrin rubber, silicone rubber, fluorine rubber, or the like alone or in combination. Another method for forming the leveling blade 41d is to form a layer of resin, rubber, elastomer or the like on the surface of an elastic metal blade such as a spring plate by a method such as coating or dipping, and then subjecting it to heat curing or the like. There may be. A base such as a coupling agent or a primer component may be provided on the surface of the elastic metal blade as necessary. Further, after the heat effect treatment, surface polishing or the like may be performed as necessary.

  The leveling blade 41d is fixed to the blade support by an arbitrary method such as adhesion or fusion so that the tip is pressed against the surface of the photoreceptor 1. The force (pressing force) by which the leveling blade 41d presses the surface of the photosensitive member 1 is sufficient as the image carrier protecting agent spreads to form a protective layer or a protective film, and the linear pressure is 5 [gf / cm] or more and 80 [gf / cm] or less, more preferably 10 [gf / cm] or more and 60 [gf / cm] or less.

  The thickness of the leveling blade 41d cannot be uniquely defined in consideration of the pressing force, but is preferably about 0.5 to 5 [mm], preferably about 1 to 3 [mm]. More preferable. When the elastic metal blade is used for the leveling blade 41d, the thickness of the elastic metal blade is preferably about 0.05 to 3 [mm], more preferably about 0.1 to 1 [mm]. . The protruding length (free length) of the leveling blade 41d from the blade support is not uniquely defined in consideration of the pressing force, but is preferably about 1 to 15 [mm], More preferably, it is about 2 to 10 [mm]. Moreover, in an elastic metal blade, in order to suppress the twist of a braid | blade, you may perform processes, such as a bending process, in the direction substantially parallel to a spindle after attachment.

  The contact portion of the leveling blade 41d with the photoreceptor 1 may be coated with a material having a low coefficient of friction or impregnated. A filler such as an inorganic / organic filler for adjusting the hardness may be dispersed in the elastic material. As a material for forming the surface layer, fluorine resin such as PFA, PTFE, FEP, PVdF, silicone elastomer such as fluorine rubber, methylphenyl silicone elastomer, and the like can be used together with a filler, if necessary. It is not limited to this.

  As shown in FIG. 3, an application roller 41a is disposed on the upstream side and a charging roller 4a is disposed on the downstream side of the leveling blade 41d in the rotation direction of the photosensitive member 1. Since the space P between the leveling blade 41d and the application roller 41a and the space Q between the leveling blade 41d and the charging roller 4a are relatively narrow, the sliding between the photoreceptor 1 and the leveling blade 41d during image formation. Heat generated by rubbing tends to remain in these spaces. Once the temperature of the leveling blade 41d rises due to this heat, abnormal noise is likely to occur when the leveling blade 41d rubs on the surface of the photoreceptor 1.

Here, the air flow path for cooling the leveling blade 41d, which is a feature of the present invention, will be described.
FIG. 5 is a schematic configuration diagram illustrating an example of an air flow path for cooling the leveling blade 41d. In the image forming apparatus, if the temperature in the apparatus rises, the developer in the developing apparatus may be fixed and the image quality may be deteriorated. Therefore, a plurality of airflow generators (fans) are installed for cooling in the apparatus. It is common. In the present embodiment, the air flow generated by these fans is leveled and used to cool the blade 41d.

  In an image forming apparatus, heat generated in a driving unit such as motor driving heat and frictional heat between gears is a major factor that raises the temperature in the apparatus. In consideration of the convenience of the user, the drive unit that generates heat is generally arranged on the side (front side) opposite to the side operated by the user (back side). When outside air is allowed to flow in from the back side of the device having the drive unit, the outside air is heated by the heat generated from the drive unit, and cooling efficiency decreases. Therefore, as shown in FIG. 5A, the airflow generated by the intake fan 51 provided at the intake port 50 on the front side of the copying machine 500 is guided to the leveling blade 41d, and the rear surface of the copying machine 500 is displayed. It is desirable to configure the flow path so as to be discharged from the side exhaust port 52.

  FIG. 5B is a perspective view showing the inflow of airflow into the leveling blade 41d. FIG. 5C is an enlarged view of a region indicated by a dotted line V in FIG. As shown in FIG. 5C, inlets 60 and 61 are provided at one end of the leveling blade 41d in the longitudinal direction. The inflow ports 60 and 61 are in communication with the air flow passages shown in FIG. The air flow indicated by the arrow A in the figure is from the inlet 60 to the space P between the leveling blade 41d and the application roller 41a, and the air current indicated by the arrow B in the figure is from the level inlet blade 61d and the charging roller 4a. Respectively flows into the space Q between them.

  FIG.5 (d) is sectional drawing in the DD cross section of FIG.5 (b). As shown in FIG. 5 (d), outlets 62 and 63 are provided at the end of the leveling blade 41d opposite to the inlets 60 and 61, respectively. Outflow ports 62 and 63 communicate with the airflow passage shown in FIG. The airflow flowing in from the inflow port 60 (arrow A in the figure) flows to the outflow port 62 along the surface of the leveling blade 41d. Further, the airflow (arrow B in the figure) flowing in from the inflow port 61 flows to the outflow port 63 along the surface of the leveling blade 41d. Thereby, the surface in contact with the space P of the leveling blade 41d and the surface in contact with the space Q can be simultaneously cooled. If the surface in contact with the space P of the leveling blade 41d and the surface in contact with the space Q are simultaneously cooled, the leveling blade 41d is sufficiently cooled. As a result, it is possible to prevent noise generated when the leveling blade 41d is not sufficiently cooled.

In the copying machine 500, a filter is generally installed at an exhaust port or the like so that scattered toner generated inside the apparatus is not released to the outside.
FIG. 6 is a schematic diagram showing the insertion position of the filter 53 in the airflow path.
FIG. 6A shows an example in which the filter 53 is inserted only into the exhaust port 52. FIG. 6B shows an example in which a filter 53 is inserted into the exhaust port 52 and the outflow port 62. The space P is near the application roller 41a. When the application roller 41a scrapes off the solid lubricant 41b, the powdery lubricant is scattered in the space P. A filter 53 is inserted in the outlet 62 to trap the scattered solid lubricant.

  When the filter 53 is inserted into the outlet 62 as shown in FIG. 6B, the flow velocity of the airflow is reduced due to the pressure loss caused by the filter 53. When the flow velocity of the airflow decreases, the efficiency of cooling the leveling blade 41d decreases. In order to suppress a decrease in the flow velocity of the air flow, a material having a small pressure loss is selected as a material of the filter 53, such as a relatively coarse fiber filter, in a range where powder does not pass. Further, as shown in FIG. 6C, an exhaust fan 54 may be provided.

[Modification]
Next, a modified example of the air flow path for cooling the leveling blade 41d in the present embodiment will be described.
FIG. 7 is a diagram showing a schematic configuration of a modified example of the air flow path for cooling the leveling blade 41d. As shown in FIG. 7, an impeller 55 is installed at the shaft end of the charging roller 4a, and an impeller 56 is installed at the shaft end of the application roller 41a. When the impellers 55 and 56 rotate together with the rotation of the shaft, a pressure difference is generated before and after the impellers 55 and 56. As a result, airflow (arrows A and B in the figure) passing through the spaces P and Q is generated. In this configuration, there is no need to separately provide a drive motor and wiring for rotating the impellers 55 and 56, so that installation in a relatively small space is possible. In this modification, the impellers 55 and 56 are provided on the upstream side of the airflow, but may be provided on the downstream side of the airflow.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A lubricant supply member such as an application roller 41a for applying a lubricant such as a solid lubricant 41b to the surface of the image carrier such as the photosensitive member 1 and a tip part abut against the surface of the image carrier, and the image carrier A protective layer forming member such as a leveling blade 41d for leveling the lubricant applied to the surface of the device to form a protective layer, and an airflow generating device such as an intake fan 51 for generating an airflow for cooling the inside of the device. In the image forming apparatus, the airflow generated by the airflow generating device has a flow path that can simultaneously cool the upstream surface and the downstream surface of the protective layer forming member in the rotation direction of the image carrier. Provided.
By using the flow path, both surfaces of the protective layer forming member can be simultaneously cooled by the air flow from the air flow generation device. As a result, it is possible to suppress abnormal noise generated when the protective layer forming member rubs the surface of the image carrier when cooling of one surface of the protective layer forming member is not sufficient.

(Aspect B)
In the aspect A, the flow path is formed so that the air flow generated by the air flow generation device flows in a direction in which a contact portion of the protective layer forming member with the image carrier extends.

(Aspect C)
In the aspect A or B, the flow path is formed so that the airflow generated by the airflow generation device passes through a drive source for an image forming operation after the protective layer forming member is cooled.
The temperature of the airflow after passing through the drive source which is a heating element is rising. The airflow after the temperature rise cannot sufficiently cool the protective layer forming member. By forming the flow path so as to allow the drive source to pass after cooling the protective layer forming member, the protective layer forming member can be sufficiently cooled.

(Aspect D)
In Aspects A to C, a filter such as the filter 53 is installed on the downstream side of the flow path through which the airflow for cooling the surface on the upstream side of the image carrier in the protective layer forming member passes.
When the application roller 41a is adjacent to the upstream surface, the powdery lubricant is scattered when the application roller 41a scrapes off the solid lubricant 41b. The scattered lubricant can be captured by a filter inserted on the downstream side of the flow path through which the airflow for cooling the surface passes.

(Aspect E)
In aspects A to D, an auxiliary air flow generation device such as an exhaust fan 54 is disposed in the vicinity of the air flow outflow side of the filter.
If a filter is inserted in the downstream side of the flow path through which the airflow for cooling the upstream surface passes, the flow velocity of the airflow is reduced due to the pressure loss of the filter, and the cooling efficiency of the protective layer forming member is reduced. By arranging the auxiliary airflow generation device in the vicinity of the airflow outflow side of the filter, it is possible to suppress a decrease in the flow velocity of the airflow.

(Aspect F)
In Aspects A to E, the charging member for charging the image carrier and the lubricant supply member are driven to rotate, and impellers 55 and 56 and the like are provided at the ends of the rotation shafts of the charging member and the lubricant supply member. The impeller was installed.
In an image forming apparatus, the protective layer forming member generally has a structure in which a charging member is adjacent to one surface and a lubricant supply member is adjacent to the other surface. In such an image forming apparatus, an impeller is provided at the shaft end portions of the charging member and the lubricant supply member, thereby constituting a mechanism for simultaneously cooling both surfaces of the protective layer forming member in a relatively small space. can do.

1 Photoconductor 41a Coating roller 41b Solid lubricant 41d Leveling blade 51 Intake fan

JP2013-003239A

Claims (6)

A lubricant supply member for applying a lubricant to the surface of the image carrier;
A protective layer forming member that abuts on the surface of the image carrier and forms a protective layer by leveling the lubricant applied to the surface of the image carrier;
In an image forming apparatus having an airflow generating device that generates an airflow for cooling the inside of the device,
The airflow generated by the airflow generator is provided with a flow path capable of simultaneously cooling the upstream surface and the downstream surface of the protective layer forming member in the rotation direction of the image carrier. Image forming apparatus. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the flow path is formed such that an air flow generated by the air flow generating device flows in a direction in which a contact portion of the protective layer forming member with the image carrier extends. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein the flow path is formed so that an air flow generated by the air flow generating apparatus passes through a driving source for an image forming operation after cooling the protective layer forming member. The image forming apparatus according to any one of claims 1 to 3,
An image forming apparatus, wherein a filter is installed on the downstream side of a flow path through which an airflow for cooling the surface on the upstream side in the rotation direction of the image carrier in the protective layer forming member passes. The image forming apparatus according to claim 1,
An image forming apparatus, wherein an auxiliary airflow generation device is disposed in the vicinity of the airflow outflow side of the filter. The image forming apparatus according to any one of claims 1 to 5,
An image forming apparatus characterized in that a charging member for charging the image carrier and the lubricant supply member are rotationally driven, and an impeller is provided at an end of a rotating shaft of the charging member and the lubricant supply member. apparatus.

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