JP2009216877A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suitably apply a lubricant to the surface of an image bearing member and obtain a satisfactory image even if the condition of an image to be formed or an environmental condition changes when the lubricant is applied to the surface of the image bearing member after residual matter remaining on the surface of the image bearing member is removed after the transfer of a toner image. <P>SOLUTION: The image forming apparatus removes residual matter on a surface of the image bearing member 10 after the transfer of a toner image by means of a cleaning device 20, then supplies the lubricant to the surface of the image bearing member by use of a lubricant supply means 30, and applies this lubricant to the surface of the image bearing member by means of a leveling member. In the image forming apparatus, the lubricant supply means is provided with: a lubricant supply member 31 that scrapes a lubricant from a solid lubricant and supplies it to the surface of the image bearing member; and a pressing-force adjusting means 60 by which pressing force for pressing the solid lubricant against the lubricant supply member is changed according to frictional force between the leveling member and the image bearing member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and a composite machine of these, and remains on the surface of an image holding member after the toner image is transferred from an image holding member that holds and moves the toner image. A cleaning device for removing residuals, lubricant supply means for supplying a lubricant to the surface of the image holding member at a position downstream of the cleaning device in the moving direction of the image holding member, and a surface of the image holding member In the image forming apparatus provided with a leveling member for applying the lubricant supplied to the surface of the image holding member, even if the state of the image to be formed and the environmental conditions change, the image is supplied by the lubricant supplying means. An appropriate amount of lubricant is supplied to the surface of the holding member, and this lubricant is appropriately applied to the surface of the image holding member by the leveling member so that good image formation can be stably performed. And those having a characteristic feature.

  In an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a combination of these, an image holding member that holds and moves a toner image, such as a photoconductor on which a toner image is formed, and toner formed on the photoconductor In an intermediate transfer member to which an image is transferred, after a toner image is transferred from such an image holding member to a transfer member such as a recording medium or an intermediate transfer member, a cleaning member such as a cleaning blade is provided on the surface of the image holding member. In order to remove the residue such as toner remaining on the surface of the image holding member.

  Here, the cleaning member is pressed against the surface of the image holding member after the toner image is transferred as described above, and the operation of removing the residual toner and the like remaining on the surface of the image holding member is lengthened. If it continues, there are problems such that the cleaning member is worn and the cleaning performance is deteriorated, and the surface of the image holding member is worn and the life of the image holding member is shortened.

  For this reason, conventionally, a lubricant such as metal soap is supplied from a lubricant supply means to the surface of an image holding member on which a toner image is transferred to a recording medium or the like, and the surface of the image holding member and the cleaning member are supplied by this lubricant. The surface of the image holding member is improved, and the toner image formed on the surface of the image holding member is appropriately transferred to the transfer member. Has been done.

  Conventionally, in supplying the lubricant from the lubricant supplying means to the surface of the image holding member having the toner image transferred to the transfer member as described above, as shown in Patent Documents 1 and 2, After scraping off the lubricant from the lubricant by a brush roll, the brush roll is brought into contact with the surface of the image holding member after transferring the toner image, and the scraped lubricant is applied to the surface of the image holding member. It has been proposed that a cleaning member is pressed against the surface of the image holding member and a lubricant is pressed by the cleaning member to apply the lubricant to the surface of the image holding member.

  However, when the cleaning member removes residual toner or the like remaining on the surface of the image holding member, the lubricant is applied by bringing the brush roll into contact with the surface of the image holding member. The toner remaining on the surface of the image holding member adheres to the brush roll and gradually accumulates, thereby gradually reducing the ability of the brush roll to scrape off the lubricant from the solid lubricant, thereby maintaining the image. There was a problem that the lubricant could not be properly applied to the surface of the member.

  Conventionally, as shown in Patent Documents 2 and 3, image holding is performed in order to prevent the toner or the like remaining on the surface of the image holding member from adhering to the brush roll as described above. After the toner and other residues remaining on the surface of the member are removed by the cleaning member, the above-described brush roll is brought into contact with the surface to supply the lubricant to the surface of the image holding member. The end of the leveling member is pressed against the surface of the image holding member in the same direction as the moving direction of the image holding member, and the lubricant supplied to the surface of the image holding member is pressed by the leveling member, There has been proposed a film in which a lubricant is applied to the surface of an image holding member.

  Here, when the end of the leveling member is pressed against the surface of the image holding member in the same direction as the moving direction of the image holding member and the lubricant is applied to the surface of the image holding member, the image holding is performed. If the pressing force of the end of the leveling member against the surface of the member is weak, the lubricant supplied to the surface of the image holding member will not be sufficiently coated, and the end of the leveling member will be in a state where the lubricant is in the form of particles. To pass.

  Then, when passing through the end portion of the leveling member in the state of the lubricant, the lubricant adheres to a charging roller or the like that contacts the surface of the image holding member, and appropriately charges the surface of the image holding member. There is a problem that the toner cannot be formed or the lubricant is mixed in the developing device to cause charging failure of the toner, and various defects are generated in the formed image.

  On the other hand, when the pressure contact force of the end of the leveling member to the surface of the image holding member is increased so that the lubricant supplied to the surface of the image holding member is sufficiently coated, torque for driving the image holding member There is a problem that wear of the end of the leveling member and the surface of the image holding member increases, and the leveling member is gradually deformed to increase permanent distortion, thereby preventing stable image formation. It was.

  Further, even when the press contact force for pressing the end of the leveling member against the surface of the image holding member is set appropriately, if image formation with low image density continues, the lubricant is applied to the surface of the image holding member. The brush of the brush roll that supplies the lubricant to the surface of the image holding member even when the lubricant is further supplied and is excessively applied in the state, and when image formation is performed in a low temperature and low humidity environment. This brush roll causes an excessive lubricant to be supplied to the surface of the image holding member and applied excessively.

  If excessive lubricant is applied to the surface of the image holding member in this way, the toner image holding power on the surface of the image holding member is reduced, and toner scatters during transfer, causing the image to blur. There was a problem such as.

Conversely, when image formation with a high image density is continued or when image formation is performed in a high temperature and high humidity environment, the amount of lubricant supplied to the surface of the image holding member decreases, The lubricant is not sufficiently applied to the surface of the image holding member, the releasability of the toner image on the surface of the image holding member is deteriorated, the toner image is not properly transferred, and the line image is lost. There was a problem.
JP 2003-57996 A JP 2006-251751 A JP 2006-259450 A

  The present invention is a cleaning that removes residue remaining on the surface of an image holding member at a position downstream of the image holding member in the moving direction from the position where the toner image is transferred from the image holding member that holds and moves the toner image. An apparatus, lubricant supply means for supplying a lubricant to the surface of the image holding member at a position downstream of the cleaning device in the moving direction of the image holding member, and a lubricant supplied to the surface of the image holding member. An object of the present invention is to solve the above problems in an image forming apparatus provided with a leveling member to be applied to the surface of an image holding member.

  That is, in the present invention, even when the state of the image to be formed and the environmental conditions change, an appropriate amount of lubricant is supplied to the surface of the image holding member by the lubricant supply means, and this lubricant is It is an object of the present invention to make it possible to stably form a good image by applying an appropriate film on the surface of the image holding member by the leveling member.

  In the present invention, in order to solve the above-described problems, the image holding member is located at a position downstream of the moving direction of the image holding member from the position where the toner image is transferred from the image holding member that holds and moves the toner image. A cleaning device that removes residues remaining on the surface of the image holding member, a lubricant supply unit that supplies lubricant to the surface of the image holding member at a position downstream of the cleaning device in the moving direction of the image holding member, and an image In an image forming apparatus provided with a leveling member for applying the lubricant supplied to the surface of the holding member to the surface of the image holding member, the lubricant supply means scrapes the lubricant from the solid lubricant. A lubricant supply member that supplies the surface of the image holding member is provided, and the pressing force that presses the solid lubricant against the lubricant supply member corresponds to the frictional force between the leveling member and the image holding member. Change That provided the pressing force adjusting means.

  Here, in changing the pressing force for pressing the solid lubricant against the lubricant supply member by the pressing force adjusting means in accordance with the frictional force between the leveling member and the image holding member, for example, As a result of continuous image formation with a high image density as described above or image formation in a high-temperature and high-humidity environment, the amount of lubricant on the surface of the image-holding member decreases, and the image-holding member When the frictional force between the pressure leveling member and the leveling member becomes strong, the pressing force adjusting unit presses the solid lubricant against the lubricant supplying member to increase the pressing force. The amount of lubricant scraped off from the solid lubricant is increased so that the amount of lubricant supplied to the surface of the image holding member is increased.

  On the other hand, as a result of continuous image formation with a low image density as described above or image formation in a low-temperature and low-humidity environment, the lubricant is further applied in a state where the lubricant is applied to the surface of the image holding member. Is applied and excessively applied, and when the frictional force between the image holding member and the leveling member becomes weak, the pressing force for pressing the solid lubricant against the lubricant supplying member by the pressing force adjusting means described above The amount of lubricant scraped off from the solid lubricant by the lubricant supply member is reduced, and the amount of lubricant supplied to the surface of the image holding member is reduced.

  Here, as the pressing force adjusting means, for example, a leveling member holding portion that holds the leveling member and a solid lubricant pressing portion that presses the solid lubricant against the lubricant supply member rotate around the rotation fulcrum. A rotating member that moves can be provided.

  The leveling member is not particularly limited as long as it can apply the lubricant supplied to the surface of the image holding member to the surface of the image holding member. For example, a plate-like elastic body or roller As described above, the leveling member holding part that holds the leveling member and the solid lubricant pressing part that presses the solid lubricant against the lubricant supply member can be used as the pressing force adjusting means. Provided with a rotating member that rotates about the rotation fulcrum, the rotating member appropriately rotates with the change in the frictional force between the holding member and the leveling member, and the solid lubricant is removed. In order to properly control the pressing force applied to the lubricant supply member, a leveling member made of a plate-like elastic body is used, and the end of the leveling member made of this plate-like elastic body is imaged. It is preferable that the holding member is brought into contact with the moving direction of the holding member.

  Further, when the end of the leveling member made of a plate-like elastic body is brought into contact in the same direction as the moving direction of the image holding member, the frictional force between the holding member and the leveling member Is increased, the end of the leveling member is pulled by the moving image holding member, and the nip width between the end of the leveling member and the surface of the image holding member is slightly increased. The lubricant is sufficiently applied to the surface.

  On the other hand, when the frictional force between the holding member and the leveling member becomes low, the lubricant in the wedge-shaped space between the end of the leveling member and the surface of the image holding member is blocked by the leveling member. The amount of lubricant guided between the end of the leveling member and the surface of the image holding member is reduced, the amount of lubricant applied to the surface of the image holding member is reduced, and the surface of the image holding member is reduced. Excessive application of lubricant is prevented.

  In the image forming apparatus of the present invention, the surface of the image holding member is moved by the above-described lubricant supplying means at a position downstream of the cleaning device for removing the residue remaining on the surface of the image holding member. Since the lubricant is supplied to the surface of the image holding member, the toner remaining on the surface of the image holding member is prevented from being removed by the cleaning device and attached to the lubricant supply means. The lubricant is appropriately supplied to the surface of the image holding member.

  In the image forming apparatus of the present invention, the lubricant is scraped off from the solid lubricant by the lubricant supply member and supplied to the surface of the image holding member, and the lubricant thus supplied is held by the leveling member. Since the pressing force for pressing the solid lubricant against the lubricant supply member by the pressing force adjusting means is changed in accordance with the frictional force between the leveling member and the image holding member. When the frictional force between the image holding member and the leveling member is increased, the pressing force adjusting means presses the solid lubricant against the lubricant supply member, and the lubricant supply member causes solid lubrication. When the frictional force between the image holding member and the leveling member becomes weak while the amount of lubricant that is scraped from the agent and supplied to the surface of the image holding member is increased, solid lubrication is performed by the pressing force adjusting means. Lubricant supply member Weaken the pressing force for pressing the can to reduce the amount of lubricant supplied to the surface of the image holding member scrapes the solid lubricant by the lubricant supplying member.

  As a result, image formation with a high image density is continuously performed, or image formation is performed in an environment of high temperature and high humidity. As a result, the amount of lubricant on the surface of the image holding member is reduced, so When the frictional force between the first and second members is increased, the above-described pressing force adjusting means increases the pressing force that presses the solid lubricant against the lubricant supplying member and supplies the lubricant to the surface of the image holding member. As a result of increasing the amount of the agent while continuously performing image formation with a low image density or performing image formation in a low temperature and low humidity environment, the amount of lubricant on the surface of the image holding member increases, When the frictional force between the image holding member and the leveling member becomes weak, the pressing force for pressing the solid lubricant against the lubricant supply member by the pressing force adjusting means is weakened, and the image holding member By reducing the amount of lubricant supplied to the surface, State of image to be formed, even when the environmental conditions change, become suitable amount of lubricant on the surface of the image holding member is properly applied, good image formation is allow stable.

  Next, an image forming apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. Note that the image forming apparatus according to the present invention is not limited to those shown in the following embodiments, and can be implemented with appropriate modifications within a range not changing the gist thereof.

  In the image forming apparatus according to this embodiment, as shown in FIG. 1, an image holding member corresponding to four developing devices 11 containing toners of different colors of yellow, magenta, cyan, and black. Four photoconductor drums 10 are provided.

  Here, in this image forming apparatus, when full-color image formation is performed, the respective photosensitive drums 10 are rotated, and the surface of each photosensitive drum 10 is charged by the charging device 12 including a charging roller. Each of the photosensitive drums 10 charged in this way is exposed according to image data by the exposure device 13 to form an electrostatic latent image on the surface of each photosensitive drum 10.

  Then, toner of a predetermined color is supplied from each developing device 11 corresponding to each photosensitive drum 10 on which the electrostatic latent image is formed in this manner to the electrostatic latent image on each photosensitive drum 10 and developed. The toner images of the respective colors are formed on the surface of each photosensitive drum 10.

  Next, the toner images of the respective colors formed on the respective photosensitive drums 10 are respectively transferred to the intermediate transfer body 15 in the form of an endless belt that is driven around the roller 14 and transferred in the form of a roller. A primary transfer is sequentially performed by the device 16 to form a full-color toner image on the intermediate transfer member 15.

  Residues such as toner remaining on the surface of each photosensitive drum 10 after transfer are guided to the first cleaning device 20, and elasticity of a plate-like urethane rubber or the like provided in the first cleaning device 20 is obtained. A cleaning blade 21 made of a body is brought into pressure contact with the surface of the photosensitive drum 10 to remove residues such as toner from the surface of each photosensitive drum 10.

  Next, a lubricant is supplied by the lubricant supply means 30 to the surface of each photoconductor drum 10 from which the residue such as toner has been removed in this manner, and the photoconductor drum 10 thus supplied with the lubricant is supplied. The end of a plate-like leveling member 40 made of an elastic material such as urethane rubber is pressed against the surface in the same direction as the movement direction of the photosensitive drum 10, and each leveling member 40 causes each photosensitive drum 10 to be in contact with the end. The lubricant supplied to the surface of the photosensitive drum 10 is uniformly applied to the surface of each photosensitive drum 10.

  On the other hand, the full-color toner image formed on the intermediate transfer member 15 as described above is guided to a position facing the secondary transfer device 17 formed into a roller shape by the intermediate transfer member 15, and the image forming apparatus. The sheet-like recording medium S accommodated in the lower part of the sheet is guided between the intermediate transfer member 15 and the secondary transfer device 17 by the feed roller 18 and formed on the intermediate transfer member 15 by the secondary transfer device 17. The resulting full-color toner image is secondarily transferred to the recording medium S.

  After that, the recording medium S to which the full-color toner image is transferred in this way is guided to the fixing device 19, and the transferred full-color toner image is fixed on the recording medium S. The fixed recording medium S is discharged.

  Further, the toner or the like remaining on the intermediate transfer body 15 without being transferred to the recording medium S is guided to the second cleaning device 50, and a plate-like urethane rubber or the like provided in the second cleaning device 50 is used. A cleaning blade 51 made of an elastic body is brought into pressure contact with the surface of the intermediate transfer member 15 to remove residues such as toner remaining on the intermediate transfer member 15 from the intermediate transfer member 15.

  Here, in this embodiment, after the toner remaining on the surface of the photosensitive drum 10 after the transfer is removed by the first cleaning device 20 as described above, the surface of the photosensitive drum 10 is removed. When supplying the lubricant by the lubricant supply means 30, as shown in FIGS. 1 and 2, the lubricant supply member 31 scrapes the lubricant from the solid lubricant 32 and supplies it to the surface of the photosensitive drum 10. A rotating roller-shaped brush member 31 is used.

  Then, the roller-shaped brush member 31 is brought into contact with the surface of the photosensitive drum 10 and rotated, and the pressing force adjusting means is adapted to correspond to the frictional force between the leveling member 40 and the photosensitive drum 10. 60, the pressing force of the solid lubricant 32 pressed against the brush member 31 is adjusted, and the lubricant is scraped off from the solid lubricant 32 by the brush member 31 and supplied to the surface of the photosensitive drum 10. I have to.

  Here, as said lubricant, fatty acid metal salts, such as zinc stearate, magnesium stearate, lithium stearate, can be used, for example.

  Further, as the brush of the brush member 31, for example, a conductive or insulating brush made of synthetic fiber such as nylon, rayon, or acrylic, or metal fiber can be used.

  Here, as this brush member 31, while using what was comprised with the brush whose fiber thickness is the range of 5-15 micrometers, the pressing force which presses this brush member 31 to said solid lubricant 32 is 2-6 N /. In the range of m, when the lubricant is scraped off from the solid lubricant 32 by the brush member 31, a uniform lubricant having a small particle diameter is scraped off and supplied to the surface of the photosensitive drum 10. It becomes like this.

  In this embodiment, as the pressing force adjusting means 60, the leveling member holding part 61 that holds the leveling member 40 and the solid lubricant pressing part 62 that presses the solid lubricant 32 against the brush member 31. Is provided with a rotation member 60 that rotates around a rotation fulcrum 63.

  In the image forming apparatus according to this embodiment, as a result of continuously performing image formation with a high image density or performing image formation in a high-temperature and high-humidity environment, the amount of lubricant on the surface of the photosensitive drum 10 is increased. When the frictional force between the photosensitive drum 10 and the leveling member 40 is increased and the end of the leveling member 40 is pulled by the moving photosensitive drum 10, The force by which the leveling member holding portion 61 is urged downward is increased, whereby the solid lubricant 32 is brushed by the solid lubricant pressing portion 62 on the opposite side of the leveling member holding portion 61 via the rotation fulcrum 63. The pressing force pressed by 31 increases.

  As a result, the amount of lubricant scraped off from the solid lubricant 32 by the brush member 31 increases, the amount of lubricant supplied to the surface of the photosensitive drum 10 increases, and the leveling member 40 When the end portion is pulled by the moving photosensitive drum 10, the nip width between the end portion of the leveling member 40 and the surface of the photosensitive drum 10 is slightly increased, and the lubricant is sufficiently applied to the surface of the photosensitive drum 10. As a result, the toner image on the surface of the photosensitive drum 10 is appropriately transferred to the intermediate transfer member 15 to prevent the line image from being lost and a good image can be obtained. Become

  On the other hand, as a result of continuous image formation with a low image density or image formation in a low-temperature and low-humidity environment, the amount of lubricant on the surface of the photosensitive drum 10 increases, and the photosensitive drum 10 and When the frictional force with the leveling member 40 decreases, the force pulled by the photosensitive drum 10 at which the end of the leveling member 40 moves becomes weak, and the leveling member holding portion in the rotating member 60 described above. The force by which 61 is urged downward is reduced, whereby the solid lubricant 32 is pressed against the brush member 31 by the solid lubricant pressing portion 62 on the side opposite to the leveling member holding portion 61 via the rotation fulcrum 63. Pressure decreases.

  As a result, the amount of lubricant scraped off from the solid lubricant 32 by the brush member 31 is reduced, the amount of lubricant supplied to the surface of the photosensitive drum 10 is reduced, and the leveling member 40 Lubricant in the wedge-shaped space between the end and the surface of the photosensitive drum 10 is blocked by the leveling member 40, and excessive application of the lubricant to the surface of the photosensitive drum 10 is suppressed. Thus, when the toner image on the surface of the photosensitive drum 10 is transferred to the intermediate transfer member 15, the toner is prevented from scattering, and the formed image does not blur and a good image can be obtained. become.

  In the image forming apparatus of this embodiment, the end of the leveling member 40 made of a plate-like elastic body is pressed against the surface of the photosensitive drum 10 in the same direction as the moving direction of the photosensitive drum 10. However, the leveling member 40 brought into pressure contact with the surface of the photosensitive drum 10 is not limited to this, and although not shown, for example, the end portion of the leveling member made of the plate-like elastic body is used. May be pressed against the surface of the photosensitive drum in a direction opposite to the moving direction of the photosensitive drum, or a leveling member made of a roller-like elastic body may be pressed against the surface of the photosensitive drum. Is possible.

  In the image forming apparatus of this embodiment, the roller-like brush member 31 is used as the lubricant supply member 31 that supplies the lubricant scraped from the solid lubricant 32 to the surface of the photosensitive drum 10. However, instead of the brush member 31 described above, it is also possible to use a solid type or foam type roller member made of urethane rubber, silicon rubber, or the like.

1 is a schematic explanatory view showing an image forming apparatus according to an embodiment of the present invention. In the image forming apparatus according to the embodiment, the first cleaning device removes the residue remaining on the surface of the photosensitive drum at a position downstream of the position where the toner image is transferred from the photosensitive drum in the moving direction of the photosensitive drum. A lubricant supplying means for supplying a lubricant to the surface of the photosensitive drum, a leveling member for applying the lubricant supplied to the surface of the photosensitive drum to the surface of the photosensitive drum, and a brush member for applying the solid lubricant FIG. 6 is a schematic explanatory view showing a state in which a rotating member that changes a pressing force to be pressed in accordance with a frictional force between a leveling member and an image holding member is provided.

Explanation of symbols

10 Photosensitive drum (image holding member)
DESCRIPTION OF SYMBOLS 11 Developing device 12 Charging device 13 Exposure device 14 Roller 15 Intermediate transfer body 16 Primary transfer device 17 Secondary transfer device 18 Feeding roller 19 Fixing device 20 First cleaning device 21 Cleaning blade 30 Lubricant supply means 31 Brush member (lubricant supply) Element)
32 solid lubricant 33 pressing member 40 leveling member 50 second cleaning device 51 cleaning blade 60 rotating member (pressing force adjusting means)
61 Leveling member holding part 62 Solid lubricant pressing part 63 Rotating fulcrum S Recording medium

Claims (4)

  A cleaning device that removes residue remaining on the surface of the image holding member at a position downstream of the image holding member in the moving direction from the position where the toner image is transferred from the image holding member that holds and moves the toner image; Lubricant supply means for supplying lubricant to the surface of the image holding member at a position downstream of the cleaning device in the moving direction of the image holding member, and lubricant supplied to the surface of the image holding member. In the image forming apparatus provided with the leveling member to be applied to the surface, the lubricant supply means is provided with a lubricant supply member that scrapes off the lubricant from the solid lubricant and supplies the lubricant to the surface of the image holding member. And a pressing force adjusting means for changing the pressing force for pressing the solid lubricant against the lubricant supply member in accordance with the frictional force between the leveling member and the image holding member. Image formation Location.   2. The image forming apparatus according to claim 1, wherein when the frictional force between the leveling member and the image holding member becomes strong, the solid lubricant is pressed against the lubricant supply member by the pressing force adjusting means. An image forming apparatus characterized in that the pressing force is increased.   3. The image forming apparatus according to claim 1, wherein the leveling member holding unit that holds the leveling member and the solid lubricant are pressed against the lubricant supply member as the pressing force adjusting unit. An image forming apparatus, comprising: a solid lubricant pressing portion provided with a rotating member that rotates about a rotation fulcrum.   4. The image forming apparatus according to claim 1, wherein the leveling member is formed of a plate-like elastic body, and an end of the leveling member is defined as a moving direction of the image holding member. An image forming apparatus, wherein the image forming apparatus is contacted in the same direction.

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