JP2009175407A - Lubricant applying device, image forming device, and using method for image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant applying device, an image forming device, and an image forming method, applying a lubricant time-serially stably. <P>SOLUTION: The lubricant 82 has, in its initial state, a concave part 82a having the same curvature as that of an outer circumference of an application member 83 in a cross section perpendicular to a rotation center axis direction of the application member 83, and abutting on the outer circumference. A bottom position T of the concave part 82a in a direction perpendicular to a width direction Y1 of the lubricant 82 and a rotation center axis direction thereof is shifted to an upstream of a rotational direction C1 of the application member 83, by a distance s (0≤s≤0.12L (L: width of the lubricant 82)) from the center position of the lubricant 82 in the width direction Y1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, and the like, a lubricant coating apparatus used therefor, and a method of using such an image forming apparatus provided with the lubricant coating apparatus.

  2. Description of the Related Art Image forming apparatuses such as copying machines, facsimiles, printers, and the like are known that include an image carrier such as a photosensitive member and an intermediate transfer member, as described in, for example, [Patent Document 1]. .

  In an image forming apparatus provided with a photoconductor as an image carrier, the photoconductor is subjected to a charging process, an exposure process, and a development process in accordance with the rotation of the photoconductor in the form of a drum or a belt. An image is formed by forming a toner image thereon, further performing a transfer process, and transferring the formed toner image to another medium such as an intermediate transfer member or transfer paper.

  In an image forming apparatus provided with an intermediate transfer member as an image carrier, a toner image formed on the photosensitive member as described above as the intermediate transfer member having a drum shape, belt shape, or the like rotates. Is transferred and carried on the intermediate transfer member by the above-described transfer step, and then a transfer step is performed in which the toner image carried on the intermediate transfer member is transferred to another medium such as transfer paper.

  After these transfer steps, residual toner remaining on the image carrier such as a photoconductor and an intermediate transfer member, and other foreign matters such as paper dust are removed through a cleaning process by a cleaning means.

  As a cleaning method generally used in the cleaning process, a cleaning blade such as a rubber blade that is inexpensive, has a simple mechanism, and is excellent in cleaning properties is used. It is known to remove.

  However, due to the recent demand for higher image quality and the like, spheroidization with polymerized toner and reduction in toner particle size have progressed, and it has become increasingly difficult to clean the toner remaining on the belt.

  That is, in order to meet the demand for higher image quality, recently, polymerized toner has been used as a toner used for image formation. For example, SPR-C toner, which is one of polymerized toners, contains Since the wax component is uniformly dispersed inside the toner, there is little precipitation of the wax component to the outside when adhering to the image carrier, and the coefficient of friction of the image carrier surface tends to increase over time. Be looked at. As the coefficient of friction increases, the cleaning performance decreases.

  In recent years, in order to meet the demand for higher image quality, the toner used for image formation has become a small particle size. However, in an image forming apparatus using a small particle size toner, residual toner is The rate at which the cleaning blade and brush roller pass through increases, especially when the dimensional accuracy and assembly accuracy of the cleaning blade and brush roller are insufficient, or when the cleaning blade partially oscillates, As a result, the cleaning performance deteriorates.

  Further, in the method using the cleaning blade, the cleaning blade is pressed against the image carrier to remove residual toner and the like on the surface of the image carrier, so that stress due to friction between the image carrier surface and the cleaning blade is applied. Largely, the cleaning blade and the image carrier are worn, and their life is shortened. Further, when the friction coefficient increases as described above, there arises a problem that the cleaning blade is caught, and in the worst case, the machine is stopped or cannot be restored.

  Therefore, in order to extend the life of the image carrier and maintain high image quality over a long period of time, it is necessary to reduce the deterioration of members such as the image carrier and the cleaning blade due to friction and improve the cleaning performance. Further, filming caused by the toner adhering to the surface of the image carrier due to the contact of the cleaning blade is also a factor of deterioration in image quality, and needs to be prevented.

  Therefore, in recent image forming apparatuses, a technique of improving the cleaning performance and preventing filming by applying a lubricant to an image carrier and forming a film of the lubricant is employed.

  In the technique of applying the lubricant to the image carrier, it is important to stably apply a necessary amount of the lubricant to the image carrier. When the coating amount is large, the coefficient of friction on the surface of the image carrier becomes too low, and the amount of toner carried on the image carrier is reduced to form an abnormal image called a hollow image, worm-eaten image, etc. This is because if the amount is small, an increase in the coefficient of friction and problems due to the friction occur as described above.

  As a method of adjusting the amount of lubricant applied, in the configuration in which the lubricant is applied using a brush roller, the pressure applied to bring the lubricant into contact with the brush roller, the number of rotations of the brush roller, and the rigidity of the brush roller are determined. Although there is a method of adjustment, it has been found that the amount of application varies greatly depending on the state in which the lubricant contacts the brush roller as a factor that changes the amount of application.

  In other words, when the lubricant has corners or protrusions and this portion bites into the brush roller, the amount of consumption of the lubricant is greatly increased as compared with the state where the brush roller is in sliding contact with the surface of the lubricant. In this case, the coating amount changes over time. That is, when the corners and protrusions are scraped over time and the amount of biting is reduced, the coating amount is greatly reduced. There is an example in which the degree of this decrease is only one-tenth that of a new product in a steady state with time.

  Thus, if the lubricant has corners or protrusions and this portion bites into the brush roller, it is not preferable for stable application of the lubricant. Further, when such bite occurs, the rotational torque of the brush roller increases, and further, if the brush roller is left in a state where the lubricant has bitten in, the brush roller may fall down.

  Therefore, it is necessary to avoid a state in which the corners and protrusions of the lubricant bite into the brush roller.

  Under such circumstances, in the case where the lubricant is applied by rotating the brush roller in one direction, the lubricant is attracted to the downstream side by the rotation of the brush roller, and the angle of the lubricant is increased. In view of the possibility of being bitten, it has been devised to offset the lubricant upstream in advance as proposed in [Patent Document 2].

  Here, in [Patent Document 2], the state in which the corners and protrusions of the lubricant bite into the brush roller is attributed to the configuration holding the lubricant. Such a configuration includes a first member that supports the lubricant, a second member that guides the lubricant in a direction in which the lubricant contacts and separates from the brush roller, and the first member and the second member. And a third member that is interposed therebetween and biases the lubricant toward the brush roller.

  In such a configuration, a gap is formed between the lubricant and the first member and the second member. In consideration of the necessity of displacing the lubricant and the first member relative to the second member, the dimensional error of the lubricant and the first to third members, and ease of assembly, It is formed and is essential in such a configuration.

  When such a gap is provided, the lubricant contacts the brush roller, and when the brush roller rotates, the first member is inclined with respect to the second member, and the lubricant contacts the brush roller with an inclination. Inevitable to do.

  Therefore, in such a configuration, a state in which the corners or protrusions of the lubricant bite into the brush roller can potentially occur. Therefore, in [Patent Document 2], the entire first to third members are offset in advance to the upstream side in the rotation direction of the brush roller, so that the lubricant is also offset, and the corners and protrusions of the lubricant bite into the brush roller. This prevents the occurrence of

In addition, [Patent Document 3] describes a configuration in which the lubricant in the initial state has a shape with protrusions on the surface in order to ensure the amount of lubricant applied in the initial stage.
[Patent Document 4] shows that the portion of the lubricant contacting the brush roller has a shape along the surface of the brush roller.

Japanese Patent Laid-Open No. 5-323704 Japanese Patent Laid-Open No. 2002-268397 JP 2007-17738 A JP 2006-235563 A

However, in the configuration for offsetting the lubricant described in [Patent Document 2], since the offset amount to be set depends on the dimensional error and assembly accuracy of the lubricant and the first to third members, the lubrication is performed. There is also a possibility that the corners and protrusions of the agent bite into the brush roller, and this may change the application amount over time.
Further, even with the lubricant having the shape described in [Patent Document 3], the amount of application changes due to the absence of the protrusions over time.

  On the other hand, in the lubricant having the shape shown in FIG. 1 of [Patent Document 4], there is a possibility that the coating amount does not change greatly over time after the state shown in FIG. It is not clear whether the shape formed is the initial shape of the lubricant. Assuming that the surface shape of the lubricant in the initial stage is flat, unlike the state shown in the figure, the amount of coating also changes from the initial shape to the shape shown in the figure. Will be.

  Furthermore, even if the lubricant having the shape shown in FIG. 1 of [Patent Document 4] is used, it has not been verified whether the coating amount is stable over time after the state shown in FIG. Therefore, there is a possibility that the lubricant cannot be stably applied over time only by making the lubricant into such a shape.

  It is an object of the present invention to provide a lubricant application device, an image forming apparatus, and an image forming method that apply a lubricant stably over time.

In order to achieve the above object, the invention according to claim 1 is a coating in which a solid lubricant having a predetermined width in the width direction is applied to the image carrier by scraping the lubricant by rotation in the predetermined direction. And a biasing member that biases the lubricant so as to abut on the application member, and the lubricant and the application member are in the direction of the central axis of rotation of the application member perpendicular to the width direction. In the initial state, the lubricant has a concave portion that is in contact with the outer periphery and has the same curvature as the outer periphery of the application member in a cross section perpendicular to the rotation center axis direction. The bottom position of the recess in the direction and the direction perpendicular to the rotation center axis direction is in the lubricant application device that is shifted upstream by a distance s from the center position of the lubricant in the width direction.
0 ≦ s ≦ 0.12 L (L: width of the lubricant)

According to a second aspect of the present invention, there is provided a solid lubricant, an application member that scrapes the lubricant by rotation in a predetermined direction and applies the lubricant to the image carrier, and the lubricant so as to contact the application member. A biasing member biasing in the direction of 1, the lubricant and the application member extend in a second direction perpendicular to the first direction, the lubricant in the initial state And a concave portion that abuts against the outer periphery of the cross section perpendicular to the second direction and has the same curvature as the outer periphery of the application member, and the bottom position of the concave portion in the first direction is the first direction and the first direction The lubricant application device is shifted to the upstream side in the predetermined direction by a distance s from the center position of the width of the lubricant by a tangent at the bottom position in the third direction perpendicular to the direction of 2.
0 ≦ s ≦ 0.12 L (L: width of the lubricant)

  According to a third aspect of the present invention, in the lubricant application device according to the first or second aspect, the lubricant is applied to the application member by slidably guiding the support member that supports the lubricant and the support member. And a guide member that guides in the direction of contacting and separating.

According to a fourth aspect of the present invention, in the lubricant application device according to any one of the first to third aspects, a surface pressure between the lubricant and the application member is 0.1 N / cm ² or less. Features.

  According to a fifth aspect of the present invention, in the lubricant coating apparatus according to any one of the first to fourth aspects, the lubricant is a fatty acid metal salt.

  According to a sixth aspect of the present invention, there is provided the lubricant application device according to any one of the first to fifth aspects, and an intermediate transfer member that is an image carrier on which the lubricant is applied by the lubricant application device. An image forming apparatus having the same.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect of the present invention, the image forming apparatus includes a latent image carrier and a lubricant application unit that applies a lubricant to the latent image carrier.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the seventh aspect, the lubricant applying unit is the lubricant applying apparatus according to any one of the first to fifth aspects.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the seventh or eighth aspect, the life of the intermediate transfer member is substantially an integral multiple of the life of the latent image carrier.

  A tenth aspect of the present invention is a method of using the image forming apparatus according to any one of the seventh to ninth aspects, wherein the latent image carrier is also replaced when the intermediate transfer member is replaced. It is in usage.

  The present invention provides a solid lubricant having a predetermined width in the width direction, an application member for scraping the lubricant by rotation in a predetermined direction and applying the lubricant to an image carrier, and applying the lubricant to the application member. A biasing member that biases to abut, and the lubricant and the coating member extend in a direction of a rotation center axis of the coating member perpendicular to the width direction, and the lubricant is In the initial state, the cross-section perpendicular to the rotation center axis direction has a concave portion that has the same curvature as the outer periphery of the application member and abuts against the outer periphery, and is perpendicular to the width direction and the rotation center axis direction. The bottom position of the concave portion is shifted to the upstream side in the predetermined direction by a distance s (0 ≦ s ≦ 0.12L (L: width of the lubricant)) from the center position of the lubricant in the width direction. Since it is in the lubricant applicator, the lubricant is applied to the image carrier. Can be time stable to applied, it is possible to reduce the burden of the image bearing member, it is possible to provide a lubricant coating apparatus occurrence of an abnormal image can be suppressed or prevented.

  The present invention includes a solid lubricant, an application member that scrapes the lubricant by rotation in a predetermined direction and applies the lubricant to an image carrier, and a first direction so that the lubricant contacts the application member. A biasing member for biasing, and the lubricant and the application member extend in a second direction perpendicular to the first direction, and the lubricant is in a second state in an initial state. A cross section perpendicular to the direction has a concave portion that contacts the outer periphery of the same curvature as the outer periphery of the application member, and the bottom position of the concave portion in the first direction is in the first direction and the second direction. A distance s (0 ≦ s ≦ 0.12 L (L: width of the lubricant)) upstream of the predetermined direction from the center position of the lubricant width by a tangent at the bottom position in the vertical third direction Since there is a shifting lubricant application device, the lubricant is stably applied to the image carrier over time. Can be fabric, it is possible to reduce the burden of the image bearing member, it is possible to provide a lubricant coating apparatus occurrence of an abnormal image can be suppressed or prevented.

  If it has a support member that supports the lubricant, and a guide member that guides the lubricant in a direction to contact and separate from the application member by slidably guiding the support member, The contact state with the coating member can be improved, and damage to the lubricant can be suppressed or prevented, whereby the lubricant can be stably applied to the image carrier over time, and the image It is possible to provide a lubricant application device capable of reducing the burden on the carrier and suppressing or preventing the occurrence of abnormal images.

If the surface pressure between the lubricant and the application member is 0.1 N / cm ² or less, the lubricant can be more stably applied to the image carrier over time, and the load on the image carrier is reduced. It is possible to provide a lubricant application device that can reduce or reduce the occurrence of abnormal images.

  If the lubricant is a fatty acid metal salt, it is possible to stably apply an inexpensive lubricant having excellent moldability to the image carrier over time, reducing the burden on the image carrier, It is possible to provide a lubricant application device capable of suppressing or preventing the occurrence of an image.

  The present invention resides in an image forming apparatus having such a lubricant application device and an intermediate transfer member that is an image carrier to which the lubricant is applied by the lubricant application device. It is possible to provide an image forming apparatus that can be stably applied to the body, can reduce the burden on the intermediate transfer member, and can suppress or prevent the occurrence of abnormal images.

  If the latent image carrier and the lubricant applying means for applying a lubricant to the latent image carrier are provided, the lubricant can be stably applied to the intermediate transfer member over time. Image formation that can reduce the burden on the body, can apply lubricant to the latent image carrier, can reduce the burden on the latent image carrier, and can better suppress or prevent the occurrence of abnormal images An apparatus can be provided.

  If the lubricant application means is such a lubricant application device, the lubricant can be stably applied to the intermediate transfer member and the latent image carrier over time. It is possible to provide an image forming apparatus that can reduce the burden on the image forming apparatus and that can more effectively suppress or prevent the occurrence of abnormal images.

  If the life of the intermediate transfer member is approximately an integral multiple of the life of the latent image carrier, the lubricant can be stably applied to the intermediate transfer member over time, and the burden on the intermediate transfer member can be reduced. It can be reduced, and a lubricant can be applied to the latent image carrier, so that the burden on the latent image carrier can be reduced, and the occurrence of abnormal images can be more effectively suppressed or prevented. And an image forming apparatus capable of efficiently and simultaneously exchanging a latent image carrier and improving maintainability and suppressing or preventing occurrence of abnormal images due to continuing use of a deteriorated latent image carrier. Can do.

  The present invention is a method of using such an image forming apparatus, and is a method of using an image forming apparatus that also replaces the latent image carrier when the intermediate transfer member is replaced. It can be applied stably, the burden on the intermediate transfer member can be reduced, the lubricant can be applied to the latent image carrier, the burden on the latent image carrier can be reduced, and abnormal images can be generated more It is possible to satisfactorily suppress or prevent, and to improve the maintainability by exchanging the intermediate transfer member and the latent image carrier at the same time, and to maintain the use of the deteriorated latent image carrier. It is possible to provide a method of using an image forming apparatus that can suppress or prevent the occurrence.

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

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

  The photosensitive drums 20Y, 20M, 20C, and 20BK that are surface moving members are rotatably supported by a frame (not shown) of the main body 99 of the image forming apparatus 100, and are a transfer belt 11 that is an intermediate transfer member as a second image carrier. Are arranged in this order from the upstream side in the A1 direction, which is the counterclockwise direction in FIG. Y, M, C, and BK added after the numerals of the respective symbols indicate members for yellow, magenta, cyan, and black.

  Each of the photosensitive drums 20Y, 20M, 20C, and 20BK is an image forming unit for forming yellow (Y), magenta (M), cyan (C), and black (BK) images. It is provided in 60C and 60BK.

  The photoconductive drums 20Y, 20M, 20C, and 20BK are positioned on the outer peripheral surface side of the transfer belt 11 that is configured as an endless belt disposed substantially at the center inside the main body 99, that is, on the image forming surface side.

  The transfer belt 11 is movable in the direction of the arrow A1 while facing the photosensitive drums 20Y, 20M, 20C, and 20BK. Visible images, that is, toner images formed on the respective photosensitive drums 20Y, 20M, 20C, and 20BK are respectively superimposed and transferred onto the transfer belt 11 that moves in the direction of the arrow A1, and then collectively onto the transfer sheet S that is a recording medium. It is designed to be transcribed. Therefore, the image forming apparatus 100 is an intermediate transfer type image forming apparatus.

  The lower portion of the transfer belt 11 faces the photosensitive drums 20Y, 20M, 20C, and 20BK, and the opposed portions transfer the toner images on the photosensitive drums 20Y, 20M, 20C, and 20BK. A primary transfer portion 58 for transferring to the transfer belt 11 is formed.

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

  The transfer belt 11 has a multilayer structure in which the base layer is made of a material with little elongation, the surface of the base layer is covered with a smooth material, and the coat layer is formed on the base layer. Examples of the material of the base layer include a fluororesin, a PVD sheet, and a polyimide resin. Examples of the material of the coat layer include a fluorine resin.

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

  The image forming apparatus 100 is disposed in the main body 99 so as to oppose the four image forming units 60Y, 60M, 60C, and 60BK and the respective photosensitive drums 20Y, 20M, 20C, and 20BK. A transfer belt unit 10 as an intermediate transfer unit provided, a secondary transfer device 5 disposed on the right side of the transfer belt 11 in FIG. 1 so as to face the transfer belt 11, and image forming units 60Y, 60M, 60C, 60BK. And an optical scanning device 8 serving as an exposure device, which is an optical writing unit as a latent image forming means disposed facing the lower side.

  The image forming apparatus 100 also serves as a paper feed cassette capable of stacking a large number of transfer sheets S conveyed toward the secondary transfer unit 57 between the transfer belt 11 and the secondary transfer apparatus 5 in the main body 99. The sheet transfer device 61 and the recording sheet S conveyed from the sheet supply device 61 are transferred at a predetermined timing in accordance with the toner image formation timing by the image forming units 60Y, 60M, 60C, and 60BK. A registration roller pair 4 that is fed out toward the registration roller 57 and a sensor (not shown) that detects that the leading edge of the transfer sheet S has reached the registration roller pair 4 are provided.

  The image forming apparatus 100 also includes a fixing device 6 as a roller fixing type fixing unit for fixing the toner image on the transfer sheet S to which the toner image is transferred, and a fixed transfer sheet S in the main body 99. A discharge roller 7 as a discharge roller pair that is a discharge roller that discharges to the outside of the main body 99, and a toner that is disposed above the transfer belt unit 10 and is filled with toners of yellow, cyan, magenta, and black. It has bottles 9Y, 9M, 9C, and 9BK, and a paper discharge tray 17 that is disposed above the main body 99 and on which the transfer paper S discharged from the main body 99 by the discharge roller 7 is stacked.

  The image forming apparatus 100 also controls the cleaning device 64 that cleans the secondary transfer device 5, a driving device (not shown) that rotationally drives the photosensitive drums 20 </ b> Y, 20 </ b> M, 20 </ b> C, and 20 </ b> BK, and the overall operation of the image forming device 100. And a control means (not shown) including a CPU (not shown), a memory, and the like.

  In addition to the transfer belt 11, the transfer belt unit 10 includes primary transfer rollers 12Y, 12M, 12C, and 12BK as primary transfer bias rollers, and a drive roller 72 that is a drive member around which the transfer belt 11 is wound. A counter roller 74 as a stretching roller, tension rollers 75 and 33 as support rollers for stretching the transfer belt 11 together with the driving roller 72 and the cleaning roller 74, and the transfer belt 11. And a cleaning device 13 as a belt cleaning device which is an intermediate transfer member cleaning device for cleaning the surface of the transfer belt 11.

  The transfer belt unit 10 also includes a drive system (not shown) that rotationally drives the drive roller 72, and a power source and bias control as a bias application unit (not shown) that applies a primary transfer bias to the primary transfer rollers 12Y, 12M, 12C, and 12BK. Means.

  The cleaning facing roller 74 and the stretching rollers 75 and 33 are driven rollers that rotate with the transfer belt 11 that is rotationally driven by the driving roller 72. The primary transfer rollers 12Y, 12M, 12C, and 12BK press the transfer belt 11 from the back surface thereof toward the photosensitive drums 20Y, 20M, 20C, and 20BK to form primary transfer nips. The primary transfer nip is formed at a portion of the transfer belt 11 that is stretched between the stretching rollers 75 and 33. The tension rollers 75 and 33 have a function of stabilizing the primary transfer nip.

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

The tension roller 33 is brought into contact with the secondary transfer device 5 via the transfer belt 11 to form a secondary transfer portion 57.
The cleaning counter roller 74 has a function as a tension roller as a pressure member that gives the transfer belt 11 a predetermined tension suitable for transfer.

  The life of the transfer belt 11 is substantially an integral multiple of the life of the photosensitive drums 20Y, 20M, 20C, and 20BK. When replacing the transfer belt 11 due to the life of the transfer belt 11, if the photoreceptor drums 20Y, 20M, 20C, and 20BK have also reached the end of their lives, the photoreceptor drums 20Y, 20M, 20C, and 20BK are also replaced. As described above, the transfer belt 11 and the photosensitive drums 20Y, 20M, 20C, and 20BK are replaced at the same time by setting the lifetime of the transfer belt 11 to be approximately an integral multiple of the lifetime of the photosensitive drums 20Y, 20M, 20C, and 20BK. In addition to improving the maintainability, the transfer due to the increase in the friction coefficient of the photosensitive drums 20Y, 20M, 20C, and 20BK when the photosensitive drums 20Y, 20M, 20C, and 20BK that have reached the end of their life are left unattended. The reduction in the rate and the occurrence of a hollow image are suppressed or prevented.

  However, even if the life of the transfer belt 11 is not substantially an integral multiple of the life of the photosensitive drums 20Y, 20M, 20C, and 20BK, when the transfer belt 11 is replaced due to the life of the transfer belt 11, the photosensitive drums 20Y, 20M, and 20C are replaced. If the photoconductor drums 20Y, 20M, 20C, and 20BK are also replaced when 20BK has reached the end of its life, or is approaching the end of its life, the maintenance performance is improved and the transfer rate is lowered. There is an advantage that the occurrence of a hollow image is suppressed or prevented.

  The cleaning device 13 is disposed to the left of the cleaning facing roller 74 and the stretching roller 75 in FIG. The cleaning device 13 is disposed so as to face the transfer belt 11 on the downstream side of the cleaning blade 76 in the A1 direction, and the cleaning blade 76 disposed so as to contact the transfer belt 11 at a position facing the cleaning facing roller 74. A lubricant application device 81 as a lubricant application means and a case 77 in which the cleaning blade 76 and the lubricant application device 81 are accommodated are provided.

The cleaning device 13 cleans the transfer belt 11 by scraping and removing foreign matters such as residual toner on the transfer belt 11 with a cleaning blade 76.
The remaining details of the cleaning device 13, particularly the lubricant application device 81, will be described later.

  The sheet feeding device 61 accommodates a plurality of transfer paper S in a state of a stack of transfer paper, and is arranged in a multi-stage below the optical scanning device 8 below the main body 99. The paper bank 31 is formed at the bottom of the main body 99 by the multistage sheet feeding device 61.

The sheet feeding device 61 has a feeding roller 3 as a sheet feeding roller pressed against the upper surface of the uppermost transfer sheet S, and the feeding roller 3 is driven to rotate counterclockwise at a predetermined timing. As a result, the uppermost transfer sheet S is fed toward the registration roller pair 4.
The transfer sheet S delivered from the sheet feeding device 61 reaches the registration roller pair 4 through the sheet feeding path 32 and is sandwiched between the rollers of the registration roller pair 4.

  The secondary transfer device 5 is disposed to face the stretching roller 33. The secondary transfer device 5 includes a secondary transfer belt 65 that is an endless belt disposed so as to sandwich the transfer belt 11 with the stretching roller 33, and rollers 66, 67 that span the secondary transfer belt 65. 68, 69. The roller 67 is a driving roller, and the secondary transfer belt 65 is rotationally driven in the direction of the arrow in FIG. 1 by the rotation of the roller 67 and the driven rotation of the rollers 66, 68, 69.

  The secondary transfer belt 65 is pressed against the stretching roller 33 via the transfer belt 11 at the portion stretched between the rollers 68 and 69, and the toner image on the transfer belt 11 is transferred onto the transfer paper S at this portion. It is supposed to be transferred to.

  The secondary transfer device 5 also has a sheet conveying function for conveying the transfer paper S after the toner image is transferred to the fixing device 6. As the secondary transfer device 5, the transfer roller 70 shown in FIG. 2 may be used, or a non-contact charger may be used. However, the secondary transfer device 5 is shown in FIG. A secondary transfer device 5 of the type is preferred. When the transfer roller 70 shown in FIG. 2 is used, the drive roller 72 also serves as a secondary transfer counter roller.

  The cleaning device 64 cleans the secondary transfer belt 65 by removing foreign matters such as paper dust and toner adhering to the secondary transfer belt 65 at a portion facing the roller 67.

  The fixing device 6 is disposed above the secondary transfer device 5. The fixing device 6 includes a heating roller 62 as a fixing roller having a heat source therein, and a pressure roller 63 pressed against the heating roller 62.

  The fixing device 6 passes the transfer paper S carrying the toner image in a manner to sandwich the fixing paper, which is a pressure contact portion between the heating roller 62 and the pressure roller 63, so that the toner image carried by the heat and pressure is applied. Is fixed to the surface of the transfer paper S.

  The yellow, cyan, magenta, and black toners in the toner bottles 9Y, 9M, 9C, and 9BK are polymerized toners that will be described later. The developing devices 80Y, 80M, 80C, and 80BK provided in the 60M, 60C, and 60BK are replenished.

  The image forming units 60Y, 60M, 60C, and 60BK have the same configuration. The image forming units 60Y, 60M, 60C, and 60BK are respectively arranged around the photosensitive drums 20Y, 20M, 20C, and 20BK along the rotation direction B1, which is the clockwise direction in FIG. 12C, 12BK, cleaning devices 71Y, 71M, 71C, 71BK as cleaning means, static elimination devices 78Y, 78M, 78C, 78BK as static elimination means, and charging devices 79Y, 79M, 79C as charging means for performing AC charging 79BK, developing devices 80Y, 80M, 80C, 80BK as developing means for performing development with a two-component developer, and a lubricant coating device (not shown) having the same configuration as the lubricant coating device 81. Note that the lubricant application device is located between the cleaning devices 71Y, 71M, 71C, and 71BK and the charge eliminating devices 78Y, 78M, 78C, and 78BK in the B1 direction.

  In the image forming apparatus 100 having such a configuration, when a signal indicating that a color image should be formed is input, the driving roller 72 is driven, and the transfer belt 11, the cleaning facing roller 74, and the stretching rollers 75 and 33 are driven. At the same time, the photosensitive drums 20Y, 20M, 20C, and 20BK are driven to rotate in the B1 direction.

  The photosensitive drums 20Y, 20M, 20C, and 20BK are uniformly charged on the surface by the charging devices 79Y, 79M, 79C, and 79BK as the B1 rotates, and the laser beam exposure scanning from the optical scanning device 8 is performed. To form an electrostatic latent image corresponding to each color of yellow, magenta, cyan, and black, and the electrostatic latent image is developed with toners of yellow, magenta, cyan, and black by developing devices 80Y, 80M, 80C, and 80BK. As a result, a single-color image constituted by magenta, cyan, and black toner images is formed.

  The yellow, magenta, cyan, and black toner images obtained by development are sequentially transferred to the same position on the transfer belt 11 rotating in the A1 direction by the primary transfer rollers 12Y, 12M, 12C, and 12BK. As a result, a composite color image is formed on the transfer belt 11.

  On the other hand, when a signal indicating that a color image should be formed is input, one of the sheet feeding devices 61 provided in the paper bank 31 is selected, and a feeding roller provided in the selected sheet feeding device 61 is selected. 3 is rotated to feed out the transfer paper S and separated one by one and fed to the paper feed path 32. The transfer paper S fed into the paper feed path 32 is further conveyed by a conveyance roller (not shown) and hits the registration roller pair 4. Stop in the hit state.

  The registration roller pair 4 rotates in accordance with the timing at which the composite color image superimposed on the transfer belt 11 moves to the secondary transfer unit 57 as the transfer belt 11 rotates in the A1 direction. The composite color image is in close contact with the transfer sheet S sent to the secondary transfer unit 57, and is secondarily transferred and recorded on the transfer sheet S by the action of the nip pressure.

  The transfer sheet S is sent to the fixing device 6 by the secondary transfer device 5 and is carried by the action of heat and pressure when passing through the fixing portion between the heating roller 62 and the pressure roller 63 in the fixing device 6. A toner image, that is, a composite color image is fixed.

  The transfer sheet S on which the composite color image has been fixed, which has passed through the fixing device 6, is discharged out of the main body 99 through the discharge roller 7 and stacked on the discharge tray 17 at the top of the main body 99.

  In the photosensitive drums 20Y, 20M, 20C, and 20BK, the transfer residual toner remaining after the transfer is removed by the cleaning devices 71Y, 71M, 71C, and 71BK, the charges are discharged by the charge removing devices 78Y, 78M, 78C, and 78BK, and the charging devices 79Y, It is subjected to the next charging by 79M, 79C, 79BK.

  The surface of the transfer belt 11 that has passed the secondary transfer portion 57 after the secondary transfer is cleaned by a cleaning blade 76 provided in the cleaning device 13 to prepare for the next transfer.

  As described above, a cleaning method using a cleaning blade is conventionally known as a cleaning method generally used for a cleaning device, but the toner used in the image forming apparatus 100 due to the recent demand for higher image quality and the like. As is the case, spheroidization with polymerized toner and reduction in toner particle size have progressed, and it has become difficult to clean the residual toner remaining on the image carrier.

  In addition, as in the image forming apparatus 100, in the configuration using the cleaning blade in the image carrier cleaning apparatus, stress due to friction between the surface of the image carrier and the cleaning blade is large. There is a problem that the wear of the image carrier occurs and the life of the image carrier is shortened, and the problem that the cleaning blade is involved, so that in order to extend the life of the image carrier and maintain high image quality over a long period of time, It is necessary to reduce the deterioration of members such as the image bearing member and the cleaning blade due to friction and improve the cleaning performance. Filming caused by the toner adhering to the surface of the image bearing member due to the contact of the cleaning blade is also of high image quality. It was necessary to prevent it because it was a factor of decline.

  Therefore, in recent image forming apparatuses, a technique for improving the cleaning performance and preventing filming by applying a lubricant to an image carrier and forming a film of the lubricant is employed. Also in the forming apparatus 100, the cleaning device 13 includes a lubricant application device 81.

  As shown in FIG. 3, the lubricant application device 81 scrapes the lubricant material 82 in contact with the lubricant material 82, the lubricant material 82 and the transfer belt 11, and transfers the lubricant material 82. A brush roller 83 serving as an application member that supplies and applies to the belt 11, a holding member 84 that holds the lubricating material 82, and a drive unit (not shown) that rotationally drives the brush roller 83 in the C1 direction.

  The holding member 84 supports a support member 85 that supports the bottom side of the lubricating material 82 opposite to the surface side facing the brush roller 83, and guides that guide the support member 85 in a direction in which the support member 85 contacts and separates from the brush roller 83. It has a member 86 and a spring 87 which is a compression spring as an elastic member which is a biasing member that biases the lubricating substance 82 toward the brush roller 83. In FIG. 3A, the support member 85 is not shown for the sake of illustration.

  The brush roller 83 is disposed so as to extend in the width direction of the transfer belt 11, in other words, the X1 direction corresponding to the main scanning direction, and is disposed so as to be in sliding contact with the surface of the transfer belt 11 over the same direction. Yes. The C1 direction is a direction along the A1 direction at a position facing the transfer belt 11.

The brush material constituting the brush roller 83 is polyester, nylon, etc., 3 to 6 denier, 30 to 120 × 1000 [f / inch ² (f: abbreviation for filament, minimum unit as a fibrous body)] It is.

  The lubricating substance 82 is disposed so as to extend in the direction of the rotation center axis of the brush roller 83 that coincides with the X1 direction, and the brush roller 83 has a uniform surface pressure by the biasing force of the spring 87 throughout the same direction. Abut.

  The lubricating material 82 reduces the coefficient of friction between the surface of the transfer belt 11 and the toner of each color that contacts the surface or a material such as a magnetic carrier contained in the developer together with the toner or the cleaning blade 76. The component is a fatty acid metal salt, specifically zinc stearate, but other fatty acid metal salts can be used.

  The support member 85 extends in the X1 direction, and as shown in FIG. 3 (b), the cross section of the plane perpendicular to the same direction has a U-shape and supports the bottom side of the lubricant 82 on the surface side. The bottom portion 85a and side edge portions 85b and 85b which are located on both side edges of the bottom portion 85a and are bent at a right angle downward with respect to the bottom portion 85a. One end of the spring 87 is in contact with the back side of the bottom 85a.

  The guide member 86 extends in the X1 direction, and a cross section formed by a plane perpendicular to the same direction has a U-shaped cross section. The other end side of the spring 87 abuts to support the spring 87, and both side edges of the bottom portion 86a. The side edge portions 86b and 86b are respectively formed in a manner of being bent at a right angle upward with respect to the bottom portion 86a and facing the side edge portions 85b and 85b, respectively.

  Each side edge portion 86b is opposed to the inner surface thereof in such a manner that the outer surface of each side edge portion 85b is in contact with or close to the inner surface, and the support member 85 moves up and down in the D1 direction by the elasticity of the spring 87. I am guiding you.

  In this way, the guide member 86 guides the support member 85 in the direction in which the support member 85 is brought into contact with and separated from the brush roller 83. The direction D1 includes a direction toward the rotation center O of the brush roller 83. That is, it is not always necessary to guide the support member 85 toward the rotation center O at the shortest distance.

  For the support member 85 and the guide member 86, steel, aluminum, resin, or the like can be selected as the material from the viewpoint of strength, weight, and cost. However, if the clearance with the guide member 86 is taken into consideration, the support member 85 and the guide member 86 are supported. It is not preferable to use both the member 85 and the guide member 86 as resin members. However, by configuring the support member 85 and the guide member 86 to be less affected by bending and warping, both of them can be resin members.

  3B is illustrated so as to occupy the position facing the brush roller 83, the actual position of the brush roller 83 is shown in FIG. As described above, the E1 direction is perpendicular to the D1 direction and the X1 direction, and is shifted to the downstream side in the C1 direction at the position where the lubricating material 82 and the brush roller 83 face each other. Accordingly, as shown in FIG. 4, the lubricating material 82 is in contact with the brush roller 83 in a manner inclined in the counterclockwise direction as compared with FIG. 3B.

  The lubricant application device 81 rotates the brush roller 83 in the C1 direction to scrape off the lubricant material 82, and supplies the scraped lubricant material 82 to the surface of the transfer belt 11. Specifically, the brush roller 83 scrapes the solid lubricating material 82 by rubbing. As a result, the lubricating substance 82 in the form of fine powder adheres to the brush roller 83. Then, the adhering fine powdery lubricating substance 82 is conveyed to a region facing the surface of the transfer belt 11 as the brush roller 83 rotates, and is supplied to the surface of the transfer belt 11.

  By attaching the lubricating substance 82 to the surface of the transfer belt 11, mechanical stress applied to the transfer belt 11 and the cleaning blade 76 during the above-described image forming process is greatly reduced, and transfer is also performed from discharge received by AC charging. The belt 11 is protected, and the life of the transfer belt 11 and the cleaning blade 76 is extended. Thereby, the cleaning performance is good over time, and filming is prevented or suppressed.

  Since the lubricant application device 81 is located on the downstream side of the cleaning blade 76 and the upstream side of the primary transfer portion 58 in the A1 direction, the transfer belt 11 in a state where the lubricant material 82 is applied is cleaned. It has become. Therefore, the lubricating substance 82 is uniformly applied to the transfer belt 11 regardless of the image area of the toner image transferred to the transfer belt 11 during image formation, so that the action of the lubricating substance is exhibited well.

  Note that the lubricating substance 82 applied to the transfer belt 11 is stretched by the cleaning blade 76 when the cleaning blade 76 removes residual toner, thereby forming a lubricant film on the transfer belt 11. However, a dedicated blade for extending the lubricating material 82 applied to the transfer belt 11 on the transfer belt 11 may be disposed immediately downstream of the brush roller 83 in the A1 direction.

  Here, as described above, in the technique of applying the lubricating substance to the image carrier, it is important to stably apply a necessary amount of the lubricating substance to the image carrier. When the coating amount is large, the coefficient of friction on the surface of the image carrier becomes too low, and the amount of toner carried on the image carrier is reduced to form an abnormal image called a hollow image, worm-eaten image, etc. This is because if the amount is small, an increase in the coefficient of friction and problems due to the friction occur as described above.

  As a method of adjusting the application amount of the lubricating substance, in the configuration in which the lubricating substance is applied using a brush roller as in the image forming apparatus 100, the pressure applied to bring the lubricating substance into contact with the brush roller, There is a method of adjusting the rotation speed of the brush roller and the rigidity of the brush roller, and this is also adopted in the image forming apparatus 100.

On the other hand, another factor that causes the change in the coating amount is a state in which the lubricating substance contacts the brush roller.
That is, as shown in FIG. 8, when the lubrication material 82 'has corners or protrusions and this portion bites into the brush roller 83', the brush roller is in surface contact with the surface of the lubrication material (for example, From FIG. 4, it is clear from the curve shown in FIG. 9 that when the consumption amount of the lubricating material is greatly increased as shown by the hatched portion in FIG. As a result, the coating amount is greatly reduced.

  As described above, if the lubricating material has corners or protrusions and this portion bites into the brush roller, it is not preferable for stable application of the lubricating material. In addition, when such biting occurs, the rotational torque of the brush roller increases, and further, if the brush roller is left in a state where the lubricating material is biting in, it may cause the brush roller to fall down.

  Therefore, it must be avoided that the corners and protrusions of the lubricating material are bitten into the brush roller. For example, as shown in FIG. 8, the brush roller 83 ′ rotates in the C1 ′ direction and rubs against the lubricating material 82 ′, so that the lubricating material 82 ′ is downstream in the C1 ′ direction. It is caused by tilting towards the side.

  Such a tilt is unavoidable in the lubricant application device 81 due to its structure. In the lubricant application device 81, the outer width of the support member 85 in the E1 direction, that is, the length between the outer surfaces of the side edge portions 85b and 85b is set so that the support member 85 is freely displaced in the D1 direction. This is because the design mounting backlash is set by making the inner width of 86 in the E1 direction, that is, the length between the inner surfaces of the side edge portions 86b and 86b shorter. Due to the backlash, the lubricating material 82 pressed against the brush roller 83 is inclined with respect to the guide member 86 together with the support member 85 as shown in FIG.

  Therefore, if the lubricating material 82 has a simple quadrangular prism shape like the lubricating material 82 'as shown in FIG. 8, the corners of the lubricating material 82 are bitten into the brush roller 83' by inclination. .

  In such a state, as shown in FIG. 9, the coating amount greatly changes between the initial time and the elapsed time because the surface pressure, which is the pressure at which the lubricating material 82 ′ and the brush roller 83 ′ are in surface contact with each other. This is because it decreases with time. That is, since the initial surface pressure is large, the amount of application is large, and as the corner of the lubricating material 82 'is scraped over time, the surface pressure decreases and the amount of application decreases.

  In view of such circumstances, in the lubricant application device 81, as shown in FIG. 4, the surface of the lubricating material 82 facing the brush roller 83 is initially a cross section perpendicular to the X1 direction in the initial state. Are provided as concave portions 82a having the same curvature as the outer periphery of the brush roller 83, and the lubricating material 82 is in contact with the brush roller 83 in the entire arc-shaped concave portion 82a. The lubricating material 82 and the brush roller 83 are arranged so that the brush roller 83 is fitted in the recess 82a when the brush roller 83 is rotated in the C1 direction.

  Such a shape of the lubricating material 82 may be solidified by using a mold corresponding to the shape when the lubricating material 82 is molded, or the corner portion of the shape that has been previously formed into a quadrangular prism shape becomes such a shape. You may form by shaving.

  Here, as shown in FIG. 5, the width direction of the lubricating material 82 is Y1, and the direction perpendicular to the Y1 direction and the X1 direction is the Z1 direction. The Z1 direction is a direction in which the lubricating substance 82 faces the brush roller 83 out of the components in the D1 direction in which the support member 85 is guided by the guide member 86, and the spring 87 causes the lubricating substance 82 to move to the brush roller 83. This is the direction in which they are energized to face each other. The spring 87 is originally provided to urge the lubricating substance 82 in the Z1 direction. Note that the width of the lubricating substance 82 in the Y1 direction is L and uniform.

  Let T be the bottom position of the recess 82a in the direction Z1, and let s be the distance from the center of the lubricating substance 82 in the Y1 direction to the bottom position T, which is indicated by a one-dot chain line. At this time, when the distance s was changed and the application amount of the lubricating material 82, in other words, the consumption amount was examined over time, the decrease rate was as shown in FIG.

  In the figure, the shaving center position of the brush is the percentage that the distance s occupies in the width L. As shown in FIG. 5, the rotation center O and the bottom position T are in the same position in the Y1 direction, and both the rotation center O and the bottom position T are indicated by a two-dot chain line parallel to the Z1 direction. Located on a straight line.

  From FIG. 6, when the distance s is in the range of 0 ≦ s ≦ 0.12L, that is, the bottom position T is opposed to the lubricating material 82 and the brush roller 83 from the center position of the lubricating material 82 in the Y1 direction. If the region is shifted to the upstream side in the C1 direction within this range, in other words, the bottom position T extends in the Y1 direction from the center position of the lubricating substance 82 by the tangent t at the bottom position T. It has been found that the rate of change in the application amount of the lubricating substance 82 with time is suppressed when the region 82 and the brush roller 83 are shifted in the above-mentioned range upstream in the C1 direction.

  In view of this, in the initial state, the lubricating substance 82 is formed so that the recess 82a is within the range where the distance s is applied. Even if the lubricating substance 82 is scraped over time by the brush roller 83, the size and shape of each member constituting the holding member 84, the biasing force of the spring 87, the rigidity of the brush roller 83, etc. By appropriately setting, the shape of the recess 82a is maintained within the range where the distance s is required.

  As shown in FIG. 6, the rate of change of the lubricating material 82 over time is suppressed to approximately 30% when the distance s is in such a range, but this is the limit. This is due to the deterioration over time of the brush roller 83 and other tolerances related to the size and shape of each member constituting the holding member 84, the biasing force of the spring 87, the rigidity of the brush roller 83, the hardness of the lubricating material 82, and the like. However, considering these factors, the range of 0 ≦ s ≦ 0.12L that suppresses the rate of change to approximately 30% is an optimal range, which is a very good value.

Further, by setting the range of 0 ≦ s ≦ 0.12L, a phenomenon in which the consumption amount of the lubricating material 82 greatly increases in the initial stage as shown by the hatched portion in FIG. The surface pressure between the lubricating material 82 and the brush roller 83, particularly the initial surface pressure, is set to 0.1 N / cm ² or less.

As described above, the initial contact pressure between the lubricating substance 82 and the brush roller 83 is set to 0.1 N / cm ² or less, as shown in FIG. This is because is further suppressed. In the figure, the lubricant consumption is a value obtained by dividing the consumption of the lubricating substance 82 by the movement distance of the peripheral surface of the brush roller 83. From the figure, the initial contact pressure is 0.1 N / cm ² or less. If so, it can be seen that the variation in the amount of lubricant consumption is extremely small, and the lubricant 82 is stably applied to the transfer belt 11. As described above, in the shape of the recess 82a, the distance s is maintained within the above-mentioned range over time, but the surface pressure is also maintained at 0.1 N / cm ² or less over time. Maintaining the shape of the recess 82a also contributes to maintaining the surface pressure.

  As described above, the guide member 86 extends in the X1 direction, and the cross section of the plane perpendicular to the same direction has a U-shaped cross section. However, the guide member 86 is formed of the lubricant 82 in the X1 direction. It suffices if the lubricating material 82 or the support member 85 is guided by the central portion in the direction and at least two portions symmetrical to the central portion in the same direction.

  This is because when the lubricating substance 82 is inclined, the lubricating substance 82 may come into contact with the side edge portion 86b of the guide member 86 and protrude from the side edge portion 86b. However, if the guide member 86 is not in such a shape, when the lubricating material 82 contacts the side edge 86b, the lubricating material 82 exerts an asymmetric force from the side edge 86b with respect to the center in the X1 direction. As a result, it is inclined with respect to the X1 direction, the protrusion from the side edge portion 86b becomes asymmetric with respect to the same center, and the amount of application to the transfer belt 11 in the X1 direction becomes non-uniform.

  However, since the guide member 86 has such a shape, even if the lubricating substance 82 abuts on the side edge portion 86b and protrudes from the side edge portion 86b, the protrusion is symmetric with respect to the center in the X1 direction. The amount applied to the transfer belt 11 is uniform.

  Accordingly, the cleaning performance and the like are uniformly stabilized in the X1 direction, and the consumption amount of the lubricating substance 82 in the X1 direction is also uniform, so that the intended purpose such as stabilization of the lubricating substance consumption amount can be achieved to a higher degree.

  If the side edge portion 86b is symmetrical in the X1 direction, the lubricating material 82 or the support member 85 may be supported at a total of three locations, that is, a central portion in the X1 direction and two symmetrical locations in the central portion. The lubricating material 82 or the supporting member 85 may be supported at the above-described locations, or the lubricating material 82 or the supporting member 85 may be supported throughout the X1 direction as in this embodiment.

  When the side edge portion 86b is discontinuously provided in the X1 direction, each portion may be provided separately, or may be a comb tooth shape in which only the side facing the brush roller 83 is discontinuous. Non-continuous is advantageous in terms of weight reduction.

  The contact with the side edge portion 86b when the lubricating material 82 is inclined tends to occur at the side edge portion 86b located on the downstream side in the C1 direction among the side edge portions 86b. It is good also considering the shape of the part 86b as this shape.

  The configuration, operation, and the like of the lubricant application device 81 described above are the same in the lubricant application devices provided in the image forming units 60Y, 60M, 60C, and 60BK. In the image forming units 60Y, 60M, 60C, and 60BK, the same applies. A good image is provided stably.

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

For example, the shape of the lubricant may not be a rectangular parallelepiped like the above-described lubricating substance 82, but may change in the Z1 direction so that the width L increases, for example, with increasing distance from the application member. However, the distance s is kept within the above range. Furthermore, it is preferable to keep the surface pressure within the above range.
The biasing member that biases the lubricant to the application member is not limited to an elastic body, and may be one using an actuator.

  Regardless of whether the image bearing member is an intermediate transfer member or a photosensitive member, the lubricant coating device is not provided as a part of the cleaning device, but may be provided as an independent configuration outside the cleaning device. good. Further, instead of the image carrier, a lubricant may be applied to the secondary transfer belt of the secondary transfer device 5 in this embodiment.

  The lubricant application device may include a position adjusting unit that adjusts the position of the lubricant with respect to the application member in consideration of the inclination of the lubricant. In this case, the position adjusting means adjusts the position of the holding member, for example, so that the lubricant occupies a preferable position on the upstream side in the rotation direction of the application member and the use efficiency of the lubricant from the position facing the application member. By adjusting, the position of the lubricant is adjusted.

  In the embodiment described above, a two-component developer is used, but the developer may be a one-component developer. In addition, the present invention is not a so-called tandem image forming apparatus such as the image forming apparatus 100, but sequentially forms toner images of each color on a single photosensitive drum and sequentially superimposes the color toner images to form a color image. The present invention can be similarly applied to a so-called one-drum type image forming apparatus, and can be applied not only to a color image forming apparatus but also to a monochrome image forming apparatus. In any type of image forming apparatus, the toner image of each color may be directly transferred onto a transfer sheet or the like without using an intermediate transfer member.

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

1 is a schematic front view of an image forming apparatus to which the present invention is applied. FIG. 10 is a schematic front view showing a modification of the secondary transfer device provided in the image forming apparatus shown in FIG. 1. 1A and 1B show a lubricant application device provided in the image forming apparatus shown in FIG. 1, wherein FIG. FIG. 4 is a front sectional view showing a state where the lubricant is tilted in the lubricant application device shown in FIG. 3. FIG. 4 is a schematic front view showing that the concave portion of the lubricant is shifted in the width direction in the lubricant application device shown in FIG. 3. FIG. 4 is a correlation diagram showing the correlation between the amount of shift of the concave portion of the lubricant in the width direction and the reduction rate of the consumption amount of the lubricant in the lubricant application device shown in FIG. 3. FIG. 4 is a correlation diagram showing a correlation between an initial surface pressure between the lubricant and the application member and a consumption amount of the lubricant in the lubricant application device shown in FIG. 3. It is a front sectional view showing a state in which the lubricant bites into the brush roller. FIG. 5 is a correlation diagram showing that the amount of lubricant consumption changes greatly over time when the lubricant bites into the brush roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Image carrier, intermediate transfer body 20Y, 20M, 20C, 20BK Image carrier, latent image carrier 81 Lubricant application device, lubricant application means 82 Lubricant 82a Recessed portion of lubricant 83 Application member 85 Support member 86 Guide member 87 Biasing member 100 Image forming apparatus C1 Predetermined direction of rotation of application member D1 Direction of guide of holding member by guide member t Tangent line at bottom of concave portion of lubricant T Bottom position of concave portion of lubricant X1 Rotation of application member Central axis direction, second direction Y1 Lubricant width direction, third direction Z1 Direction of rotation central axis of application member and direction perpendicular to lubricant width direction, first direction

Claims (10)

A solid lubricant having a predetermined width in the width direction;
An application member that scrapes off the lubricant by rotation in a predetermined direction and applies the lubricant to the image carrier;
An urging member that urges the lubricant to abut against the application member;
The lubricant and the application member extend in the direction of the rotation center axis of the application member perpendicular to the width direction,
In the initial state, the lubricant has a concave portion that is in contact with the outer periphery, having the same curvature as the outer periphery of the application member in a cross section perpendicular to the rotation center axis direction.
The lubricant application device, wherein a bottom position of the concave portion in a direction perpendicular to the width direction and the rotation central axis direction is shifted to the upstream side in the predetermined direction by a distance s from a center position of the lubricant in the width direction.
0 ≦ s ≦ 0.12L
(L: width of the lubricant) A solid lubricant,
An application member that scrapes off the lubricant by rotation in a predetermined direction and applies the lubricant to the image carrier;
A biasing member that biases the lubricant in a first direction so as to contact the application member;
The lubricant and the application member extend in a second direction perpendicular to the first direction,
In the initial state, the lubricant has a concave portion that is in contact with the outer periphery of the cross section perpendicular to the second direction and has the same curvature as the outer periphery of the application member.
The bottom position of the recess in the first direction is the predetermined distance from the center position of the width of the lubricant by a tangent at the bottom position in a third direction perpendicular to the first direction and the second direction. Lubricant application device that is shifted upstream in the direction.
0 ≦ s ≦ 0.12L
(L: width of the lubricant) In the lubricant application device according to claim 1 or 2,
A support member for supporting the lubricant;
And a guide member that guides the lubricant in a direction in which the lubricant comes in contact with and separates from the application member by slidably guiding the support member. In the lubricant application device according to any one of claims 1 to 3,
A lubricant application device, wherein a surface pressure between the lubricant and the application member is 0.1 N / cm ² or less. In the lubricant application device according to any one of claims 1 to 4,
The lubricant application apparatus, wherein the lubricant is a fatty acid metal salt.   6. An image forming apparatus comprising: the lubricant application device according to claim 1; and an intermediate transfer member that is an image carrier on which the lubricant is applied by the lubricant application device. The image forming apparatus according to claim 6.
An image forming apparatus comprising: a latent image carrier; and a lubricant application unit that applies a lubricant to the latent image carrier.   8. The image forming apparatus according to claim 7, wherein the lubricant applying unit is the lubricant applying apparatus according to any one of claims 1 to 5. The image forming apparatus according to claim 7 or 8,
An image forming apparatus, wherein the life of the intermediate transfer member is substantially an integral multiple of the life of the latent image carrier.   10. The method of using the image forming apparatus according to claim 7, wherein the latent image carrier is also replaced when the intermediate transfer member is replaced.

Images