JP2009036957A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suitably remove residual matter remaining on the surface of an image retaining member after transferring by a cleaning device using a plurality of brush members. <P>SOLUTION: In the cleaning device 30 for removing residual matter remaining on the surface of the image retaining member 2 after a toner image is transferred, bias voltage different in polarity is applied to a first brush member coming into contact with the surface of the image retaining member on the upstream side in the moving direction of the image retaining member, and to a second brush member 32 coming into contact with the surface of the image retaining member on the downstream side from the first brush member in the moving direction of the image retaining member, and the mechanical scraping force of a third brush member coming into contact with the surface of the image retaining member on the downstream side from the second brush member in the moving direction of the image retaining member is made larger than the mechanical scraping forces of the first brush member and the second brush member. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine of these, and in particular, after transferring a toner image from an image holding member that holds and moves the toner image, When removing residual toner such as toner on the surface with a cleaning device, a plurality of brush members are brought into contact with the surface of the moving image holding member to remove residual toner and the like on the surface of the image holding member. In this case, it is possible to prevent the residue such as toner from being filmed on the surface of the image holding member and to appropriately remove the residue such as toner from the surface of the image holding member over a long period of time. It is what has.

  In an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine of these, an image holding member that holds and moves a toner image, for example, a photoconductor on which a toner image is formed, and toner formed on the photoconductor In the intermediate transfer member to which the image is transferred, after the toner image is transferred from such an image holding member to a recording medium or the like, the toner remaining on the surface of the image holding member is removed by a cleaning device. To be done.

  Here, in order to remove residual toner and the like remaining on the surface of the image holding member after the toner image is transferred as described above, conventionally, a plate-shaped cleaning blade is generally used to hold the image. The toner is pressed against the surface of the member to remove the residue such as toner remaining on the surface of the image holding member.

  However, when the cleaning blade is brought into pressure contact with the surface of the image holding member in this way to remove toner and other residues, the cleaning blade gradually wears to deteriorate the cleaning performance, or the image holding member wears. There are problems such as shortening the service life.

  Conventionally, as disclosed in Patent Documents 1 to 3, two brush rollers are brought into contact with the surface of the moving image holding member and rotated, and the brush of the two brush rollers is used to bring the surface of the image holding member to the surface. There has been proposed one that removes residual toner and the like.

  However, when the two brush rollers are brought into contact with the surface of the moving image holding member and rotated to sufficiently remove the residual toner and the like remaining on the surface of the image holding member, the surface of the image holding member When the pressure of the brush in the two brush rollers that are brought into contact with each other is increased, the surface of the image holding member is damaged by the contact with the brush, or a residue such as toner is strongly pressed against the surface of the image holding member, thereby causing filming. There was a problem that.

  In Patent Document 1, the pressing force applied to the image holding member per brush by the first brush roller in contact with the upstream side in the movement direction of the image holding member is the second pressure in contact with the downstream side in the movement direction of the image holding member. The pressing force applied to the image holding member per brush in the brush roller is increased, and a bias voltage having a polarity opposite to the charging polarity of the toner is applied to the first brush roller, so that the normally charged toner, etc. While collecting the residue, a bias voltage having the same polarity as the charged polarity of the toner is applied to the second brush roller to collect the residue of the reversely charged toner and the like, and the surface of the image holding member is brought into contact with the brush. It has been proposed to prevent the film from being damaged or the residue such as toner from adhering to the surface of the image holding member.

  Further, in Patent Document 2, the first brush roller that contacts the upstream side of the moving direction of the image holding member scrapes off the toner of one polarity with a small residual amount on the surface of the image holding member while electrostatically sucking it. On the other hand, the second brush roller that contacts the downstream side in the moving direction of the image holding member scrapes off the toner of the other polarity that has a large residual amount on the surface of the image holding member while electrostatically sucking it, thereby holding the image. It has been proposed to prevent toner from filming on the surface of the member.

  Patent Document 3 proposes that a collecting roller is provided so as to be in contact with two brush rollers, and an alternating electric field is applied to the collecting roller to collect toner, paper dust, and the like from the two brush rollers. Has been.

However, in any of the above-mentioned Patent Documents 1 to 3, it is still difficult to sufficiently remove residues such as toner remaining on the surface of the image holding member. In particular, as shown in Patent Document 1 described above, when the pressing force per brush in the first brush roller that contacts the upstream side in the moving direction of the image holding member is increased, an image in which a large amount of residue exists is present. The brush of the first brush roller is strongly pressed against the surface of the holding member, and the residue is filmed on the surface of the image holding member, and uncharged and weakly charged that have not been removed by the first brush roller. There is a problem that the residue is not removed even by the second brush roller, and cleaning failure occurs.
JP 2005-17416 A JP 2005-275086 A JP-A-5-27651

  In the present invention, the toner image is transferred from the image holding member that holds and moves the toner image, and then the toner or the like remaining on the surface of the image holding member is removed by the cleaning device as described above. The problem is to solve the problem.

  In the present invention, when a plurality of brush members are brought into contact with the surface of the moving image holding member to remove the toner or the like remaining on the surface of the image holding member, the toner or the like remains in the image. An object of the present invention is to prevent filming on the surface of the holding member and to appropriately remove residues such as toner from the surface of the image holding member over a long period of time.

  In the image forming apparatus according to the present invention, in order to solve the above-described problems, after the toner image is transferred from the image holding member that holds and moves the toner image, the residue remaining on the surface of the image holding member. In the image forming apparatus provided with a cleaning device that removes an object, the cleaning device contacts the surface of the image holding member on the upstream side in the moving direction of the image holding member, and the first brush member Also, a second brush member that contacts the surface of the image holding member on the downstream side in the moving direction of the image holding member, and a third brush member that contacts the surface of the image holding member on the downstream side of the moving direction of the image holding member from the second brush member. A brush member for applying a bias voltage having a different polarity to the first brush member and the second brush member, and for applying mechanical force to the third brush member. The come-up force was stronger than the mechanical scraping force in the first brush member and the second brush member above.

  Here, in order to make the mechanical scraping force in the third brush member stronger than the mechanical scraping force in the first brush member and the second brush member, for example, a brush of the third brush member is applied. The first brush member and the second brush member are made of a material having higher rigidity than the brushes of the first brush member and the second brush member, that is, a material having a high Young's modulus. When using the same rigid material, the brush of the third brush member may have a fiber diameter larger than that of the first brush member and the second brush member or a fiber having a shorter fiber length. The fiber density of the brush in the three brush members can be made higher than the fiber density of the brushes of the first brush member and the second brush member. Preferably, a material having higher rigidity than the brushes of the first brush member and the second brush member, that is, a material having a high Young's modulus is used for the brush of the third brush member.

  In addition, in the above image forming apparatus, when the bias voltages having different polarities are applied to the first brush member and the second brush member, the polarity of the bias voltage applied to the first brush member is set to the above residue. The polarity of the bias voltage applied to the second brush member is preferably the same as the charge polarity of the toner in the residue, while the polarity is opposite to that of the toner.

  Further, in the above image forming apparatus, the first brush member is provided with the first brush member in order to prevent residues collected on the first brush member, the second brush member, and the third brush member from being accumulated on these brush members. A first collecting member that collects the collected residue from the first brush member, a second collecting member that collects the residue collected from the second brush member from the second brush member, and a third brush member It is preferable to provide a third recovery member that recovers the recovered residue from the third brush member.

  In the image forming apparatus of the present invention, when the toner remaining on the surface of the image holding member after the toner image is transferred as described above is removed by the cleaning device, the image holding member A first brush member that is brought into contact with the surface of the image holding member on the upstream side in the moving direction, and a second brush member that is brought into contact with the surface of the image holding member on the downstream side in the moving direction of the image holding member with respect to the first brush member. Since a bias voltage having a different polarity is applied, a residue charged with a polarity opposite to that of the bias voltage applied to the first brush member in the residue such as toner remaining on the surface of the holding member is the first brush member. And is efficiently removed by being electrically attracted to the second brush member and charged to a polarity opposite to the bias voltage applied to the second brush member. The residue is electrically attracted to the second brush member comes to be efficiently removed.

  In the image forming apparatus of the present invention, a third brush member is provided to be brought into contact with the surface of the image holding member on the downstream side in the moving direction of the image holding member with respect to the second brush member. Since the mechanical scraping force is made stronger than the mechanical scraping force of the first brush member and the second brush member, the first brush member and the second brush member are formed on the surface of the image holding member where a large amount of residue exists. The brush on the brush member is strongly pressed to prevent the residue from being filmed on the surface of the image holding member, and the non-charged and weakly charged residue on the surface of the image holding member is the first brush member. And the third brush member having a mechanical scraping force stronger than that of the first brush member and the second brush member, after receiving the mechanical scraping force by the second brush member. It comes to be.

  As a result, in the image forming apparatus of the present invention, when the residue such as toner remaining on the surface of the image holding member is removed by the first brush member, the second brush member, and the third brush member, It is possible to prevent the residue such as toner from being filmed on the surface of the image holding member and to appropriately remove the residue such as toner from the surface of the image holding member over a long period of time.

  In the image forming apparatus of the present invention, the brush of the third brush member is used to make the mechanical scraping force by the third brush member stronger than the mechanical scraping force by the first brush member and the second brush member. In addition, when a material having higher rigidity than the brushes of the first brush member and the second brush member is used, a material having a large fiber diameter or a short fiber length is used for the brush of the third brush member, and its mechanical scraping is performed. As in the case where the force is increased, the amount of toner or other residue retained on the third brush member is reduced, and the toner or other residue collected on the third brush member is easily returned to the image retaining member. There will never be. Further, as in the case where the fiber density of the brush in the third brush member is increased to make it stronger than the mechanical scraping force, residues such as toner collected on the third brush member are removed from the third brush member. Accumulation without proper discharge does not cause the residue collection performance of the third brush member to gradually decline.

  Further, in the image forming apparatus of the present invention, when the bias voltages having different polarities are applied to the first brush member and the second brush member, the first brush member is opposite to the charging polarity of the toner in the residue. When a bias voltage having a polarity is applied while a bias voltage having a polarity opposite to that of the first brush member is applied to the second brush member, a large amount of toner remaining on the surface of the image holding member is removed from the first brush. The amount of the residue that is removed by the member and guided to the second brush member is reduced, and the residue is removed from the surface of the image holding member when the second brush member removes the residue from the surface of the image holding member. Filming is further prevented.

  Further, in the above image forming apparatus, residues collected by the first brush member, the second brush member, and the third brush member are transferred from the brush members to the first collection member, the second collection member, and the second collection member, respectively. When collected by the third collection member, the collected residue is prevented from being accumulated on each of the brush members, and the residue such as toner collected on each of the brush members is transferred from these brush members to the image holding member. It is possible to further prevent the occurrence of poor cleaning.

  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 of this embodiment, as shown in FIG. 1, four imaging cartridges 10 </ b> A to 10 </ b> D are mounted in the apparatus main body 1.

  Here, in each of the imaging cartridges 10 </ b> A to 10 </ b> D, the rotating drum-shaped photoconductor 11, the charging device 12 that charges the surface of the photoconductor 11, and the image information on the surface of the charged photoconductor 11 are displayed. An exposure apparatus 13 that forms an electrostatic latent image on the surface of the photoconductor 11 by performing appropriate exposure, and supplies toner to the electrostatic latent image formed on the surface of the photoconductor 11 to form a toner image. Toner remaining on the surface of the photoconductor 11 by pressing the cleaning blade 15a against the surface of the photoconductor 11 after the toner image formed on the surface of the photoconductor 11 and the developing device 14 is transferred to the intermediate transfer belt 2 A first cleaning device 15 is provided to remove the residue.

  In the image forming apparatus according to this embodiment, when full color image formation is performed, each developing device 14 in each of the imaging cartridges 10A to 10D has different colors of black, yellow, magenta, and cyan. Toner is accommodated, and a toner image of each color is formed on the surface of each photoconductor 11 in each of the imaging cartridges 10A to 10D.

  Next, the toner images of the respective colors formed on the surfaces of the respective photoreceptors 11 in the respective imaging cartridges 10A to 10D in this way are sequentially transferred to the intermediate transfer belt 2 which is laid over the roller 2a and rotates. A full-color toner image is formed on the intermediate transfer belt 2, while residues such as toner remaining on the surface of each photoconductor 11 are removed by the first cleaning device 15.

  Then, the recording medium S is fed by the paper feed roller 3, and the recording medium S is guided by the timing roller 4 between the intermediate transfer belt 2 and the transfer roller 5 at an appropriate timing, and is placed on the intermediate transfer belt 2. The formed full-color toner image is transferred to the recording medium S, and the recording medium S on which the full-color toner image is transferred is guided to the fixing device 6, and the full-color toner image is transferred to the recording medium S. After fixing, the recording medium S is discharged by the discharge roller 7.

  In addition, when the above-described full-color toner image formed on the intermediate transfer belt 2 as described above is transferred to the recording medium S, the toner remaining on the surface of the intermediate transfer belt 2 without being transferred to the recording medium S And the like are removed from the intermediate transfer belt 2 by the second cleaning device 30.

  Here, in this embodiment, as shown in FIG. 1, the second cleaning device 30 removes residues such as toner remaining on the surface of the intermediate transfer belt 2 without being transferred to the recording medium S as described above. In addition, a first brush member 31, a second brush member 32, and a third brush member 33 in which brushes 31a, 32a, and 33a are implanted are provided on the outer circumferences of the rollers 31b, 32b, and 33b. In order from the upstream side in the direction, the brush 31a in the first brush member 31, the brush 32a in the second brush member 32, and the brush 33a in the third brush member 33 are brought into contact with the surface of the intermediate transfer belt 2. Yes.

  At the position where the first brush member 31, the second brush member 32, and the third brush member 33 are in contact with the surface of the intermediate transfer belt 2, the brush members 31, 32, 33 are connected to the intermediate transfer belt 2. In order to remove the residual toner such as toner remaining on the surface of the intermediate transfer belt 2 by rotating it so as to move in the opposite direction, the mechanical scraping force in the third brush member 33 is the first scraping force. The mechanical scraping force of the brush member 31 and the second brush member 32 is made stronger.

  Here, in order to make the mechanical scraping force in the third brush member 33 stronger than the mechanical scraping force in the first brush member 31 and the second brush member 32 as described above, in this embodiment, The brush 33a of the third brush member 33 may be made of a material having higher rigidity than the brush 31a of the first brush member 31 or the brush 32a of the second brush member 32, or the third brush. As the brush 33a of the member 33, one having a fiber diameter larger than that of the brush 31a of the first brush member 31 or the brush 32a of the second brush member 32 or one having a short fiber length is used.

  Further, in this embodiment, as shown in FIG. 2, a first recovery member 34 in the form of a roller that rotates in contact with the first brush member 31 is provided. A bias voltage having a predetermined polarity is applied to the first brush member 31 through the first recovery member 34, and a residue such as a toner having a polarity opposite to the polarity remaining on the surface of the intermediate transfer belt 2 is electrically removed. At the same time, the mechanical scraping force collects the residue on the surface of the intermediate transfer belt 2 on the first brush member 31, and thus the toner and other residues collected on the first brush member 31 are collected. Further, it is electrically sucked and collected in the first collecting member 34, and the residue collected in the first collecting member 34 is removed from the surface of the first collecting member 34 by the blade 36.

  Also, a second recovery member 37 in the form of a roller that rotates in contact with the second brush member 32 is provided, and a bias voltage having a reverse polarity from the second recovery power source 38 to the first recovery power source 35 is provided. Is applied to the second brush member 32 through the second recovery member 37 to electrically suck the residue of toner having the opposite polarity to the polarity remaining on the surface of the intermediate transfer belt 2, and Residues that have not been collected by the first brush member 31 are collected by the second brush member 32, and the toner and other residues thus collected by the second brush member 32 are further electrically sucked. The second recovery member 37 collects the residue, and the residue recovered by the second recovery member 37 is removed from the surface of the second recovery member 37 by the blade 39.

  The third brush member 33 is provided with a blade-like third recovery member 40 in contact with the brush 33a of the third brush member 33. As described above, the first brush member 31 is provided. The third brush member 33 having a mechanical scraping force larger than that of the second brush member 32 removes the residue not collected by the first brush member 31 and the second brush member 32 of the intermediate transfer belt 2. Residues such as toner collected from the surface and thus collected by the third brush member 33 are discharged from the brush 33a of the third brush member 33 by the third collection member 40 described above.

  Here, the bias voltage applied to the first brush member 31 from the first recovery power source 35 through the first recovery member 34 and the second brush member 32 from the second recovery power source 38 through the second recovery member 37 as described above. In this embodiment, in order to make the bias voltage to be applied to the reverse polarity, in this embodiment, the first brush member 31 is applied with a bias voltage having a polarity opposite to the charging polarity of the toner in the residue, while the second brush member 32 is applied with the reverse polarity. A bias voltage having a polarity opposite to that of the first brush member 31 is applied.

  In this way, a large amount of toner remaining on the surface of the intermediate transfer belt 2 as described above is removed from the surface of the intermediate transfer belt 2 by the first brush member 31, and is transferred to the second brush member 32. When the amount of the introduced residue is reduced and the residue is removed from the surface of the intermediate transfer belt 2 by the second brush member 32 as described above, the residue is removed from the surface of the intermediate transfer belt 2 by the second brush member 32. Filming is prevented.

  As a result, in the image forming apparatus of this embodiment, the residue remaining on the surface of the intermediate transfer belt 2 is transferred intermediately by the first brush member 31, the second brush member 32, and the third brush member 33. The toner is appropriately collected from the surface of the belt 2 and the residue such as toner is prevented from being filmed on the surface of the intermediate transfer belt 2.

  Here, when a high-stiffness material is used for the brush 33a of the third brush member 33 and the mechanical scraping force by the third brush member 33 is increased, the first brush member 31 and the second brush member 32 Residues that have not been collected will be properly collected by the third brush member 33. However, if the rigidity of the brush 33a in the third brush member 33 becomes too high, the residual with the third brush member 33 Since the wear of the intermediate transfer belt 2 due to contact increases, it is preferable to use a material having an appropriate rigidity in consideration of the wear resistance of the intermediate transfer belt 2 and the like.

  In this embodiment, only the second cleaning device 30 that removes toner and other residues remaining on the surface of the intermediate transfer belt 2 is configured as described above. However, it remains on the surface of each of the photoreceptors 11. Each of the first cleaning devices 15 that removes residual toner and the like can also be configured in the same manner as the second cleaning device 30 described above.

  Next, in a commercially available copying machine using negatively charged toner (manufactured by Konica Minolta, Inc .: Bizhub C450), a second cleaning device that removes residual toner and the like remaining on the surface of the intermediate transfer belt after transfer is provided. As shown in the above-described embodiment, the first brush member, the second brush member, and the third brush member in which brushes are implanted on the outer periphery of the roller are brought into contact with the surface of the intermediate transfer belt.

Here, as the negatively chargeable toner, toner having an average particle diameter of 7.2 μm manufactured by a polymerization method using styrene-acrylic resin as a binder is used, and the surface resistance of the intermediate transfer belt is 5 ×. An intermediate transfer belt made of 10 ¹¹ Ω conductive polyimide resin was used.

  Then, the moving speed of the intermediate transfer belt is set to 240 mm / s, the peripheral speeds of the first to third brush members are set to 360 mm / s, and the brush members are moved in the direction opposite to the intermediate transfer belt. The amount of biting of each brush member with respect to the intermediate transfer belt was set to 1 mm.

  Further, a positive bias voltage having a polarity opposite to the charging polarity of the toner is applied from the first recovery power source through the first recovery member to the first brush member that contacts the upstream side in the moving direction of the intermediate transfer belt. Thus, a current of +50 μA flows from the first brush member to the intermediate transfer belt, while the second brush power source contacts the second brush member that contacts the downstream side in the moving direction of the intermediate transfer belt from the second recovery power source. A negative bias voltage having the same polarity as the charging polarity of the toner was applied through the collecting member so that a current of −50 μA flowed from the second brush member to the intermediate transfer belt.

  And it experimented by changing the kind of said 1st brush member, 2nd brush member, and 3rd brush member.

Here, as the first brush member, the second brush member, and the third brush member, a roller having a diameter of 7 mm, a Young's modulus of 1.2 × 10 ⁹ N / m ² , a fiber thickness of 2 dtex, and a fiber length Is a brush member A1 provided with a conductive nylon fiber brush having a fiber density of 372 fibers / mm ² , a roller having a diameter of 7 mm, a Young's modulus of 1.2 × 10 ⁹ N / m ² , a fiber Brush member A2 provided with a conductive nylon fiber brush having a thickness of 3 dtex, a fiber length of 4 mm, and a fiber density of 372 fibers / mm ² , and a roller having a diameter of 9 mm and a Young's modulus of 1.2 × 10 ⁹ N / m ² , fiber thickness is 2 dtex, fiber length is 3 mm, fiber density is 372 fibers / mm ² and a brush member A3 provided with a brush of conductive nylon fiber and a roller having a diameter of 7 mm Young's modulus is 5 ^{0 × 10 9 N / m 2} , fiber thickness is 2 dtex, fiber length of 4 mm, and a brush member B which the brush of the conductive polyester fibers became fiber density 372 present / mm ² is provided, the diameter is 7mm of A brush provided with a conductive acrylic fiber brush having a Young's modulus of 9.0 × 10 ⁹ N / m ² , a fiber thickness of 2 dtex, a fiber length of 4 mm, and a fiber density of 372 fibers / mm ² The member C was used.

  As shown in Table 1 below, in Experiment 1, the brush member A1 is used for the first brush member, the second brush member, and the third brush member, and in Experiment 2, the first brush member and the second brush member are used. Brush member A1 is used for the brush member, brush member B is used for the third brush member, and in experiment 3, brush member A1 is used for the first brush member and the second brush member, and brush member C is used for the third brush member. In the experiment 4, the brush member A1 is used for the first brush member and the second brush member, the brush member A2 is used for the third brush member, and in the experiment 5, the first brush member and the second brush member are used. In the experiment 6, the brush member A1 was used as the third brush member, the brush member B was used as the first brush member and the second brush member, and the brush member A1 was used as the third brush member. In Thus, the brush member B is used for the first brush member, the second brush member, and the third brush member. In Experiment 8, the brush member B is used for the first brush member and the second brush member, and the third brush member is used. The brush member C was used.

  Here, in said brush member A1, B, C, the Young's modulus which shows the rigidity of a brush is order of brush member A1 <brush member B <brush member C, and fiber thickness and fiber of other conditions Since the length and the fiber density are the same, the mechanical scraping force is in the order of brush member A1 <brush member B <brush member C.

  In the brush members A1 and A2, the brush fiber A2 is thicker than the brush member A1 in the brush fiber thickness. Therefore, the mechanical scraping force is higher than that of the brush member A1. Is stronger.

  Further, in the brush members A1 and A3, the brush fiber A3 is shorter than the brush member A1 in the fiber length of the brush. Therefore, the mechanical scraping force is higher than that of the brush member A1. Is stronger.

  In Experiments 1 to 8, a solid image was printed on each A4 sheet, and the filming state on the surface of the intermediate transfer belt at the printing end point of 200,000 sheets and the printing end point of 400,000 sheets, respectively. The cleaning state of the residue such as toner on the surface of the intermediate transfer belt was examined.

  Here, regarding the filming state on the surface of the intermediate transfer belt, after forming five blank paper images, the state of the residue adhered to the surface of each intermediate transfer belt was visually observed to confirm that the residue adhered. The case where there was no residue was marked with ◯, the case where there was a slight sticking of the residue but no problem in practical use, and the case where there was a lot of sticking of the residue causing a practical problem.

  Further, regarding the cleaning state of the toner and other residues on the surface of the intermediate transfer belt, a solid image of 5 cm in length and 3 cm in width is printed, and the surface of the intermediate transfer belt after passing through the second cleaning device is visually observed. When no residue such as toner was confirmed, the case where the residue such as toner was confirmed was indicated with x.

  As a result, the mechanical scraping force of the third brush member that is in contact with the most downstream side in the moving direction of the intermediate transfer belt is less than the first brush member that is in contact with the upstream side of the moving direction of the intermediate transfer belt. In Experiments 2 to 5 and 8 where the mechanical scraping force of the second brush member is stronger than that of the second brush member, filming does not occur on the surface of the intermediate transfer belt even after printing of 400,000 sheets, and the intermediate transfer The cleaning state of the residue such as toner on the surface of the belt was also good.

  On the other hand, those in Experiments 1 and 7 in which the mechanical scraping force in the first brush member, the second brush member, and the third brush member are the same, and the mechanical scraping force in the third brush member In Experiment 6, in which the mechanical scraping force of the first brush member and the second brush member was weakened, filming and cleaning failure were likely to occur.

When the intermediate transfer belt made of conductive polyimide resin is used as described above, the Young's modulus of the first brush member, the second brush member, or the third brush member is 2.0 × 10 ^10. When a brush member provided with a brush of conductive rayon fibers exceeding N / m ² was used, the surface of the intermediate transfer belt was abraded due to contact with the brush.

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, a state in which toner and other residues remaining on the surface of the intermediate transfer belt after transfer is removed from the intermediate transfer belt by the second cleaning device provided with three brush members is shown. It is a schematic explanatory drawing.

Explanation of symbols

1 Device body 2 Intermediate transfer belt (image holding member)
2a roller 3 paper feed roller 4 timing roller 5 transfer roller 6 fixing device 7 paper discharge roller 10A to 10D imaging cartridge 11 photoconductor 12 charging device 13 exposure device 14 developing device 15 first cleaning device 15a cleaning blade 30 second cleaning device 31 First brush member 31a Brush 31b Roller 32 Second brush member 32a Brush 32b Roller 33 Third brush member 33a Brush 33b Roller 34 First collection member 35 First collection power source 36 Blade 37 Second collection member 38 Second collection power source 39 Blade 40 Third recovery member S Recording medium

Claims (4)

  In the image forming apparatus provided with a cleaning device for removing the residue remaining on the surface of the image holding member after the toner image is transferred from the image holding member that holds and moves the toner image, the above-mentioned cleaning device is used. A first brush member that is brought into contact with the surface of the image holding member on the upstream side in the moving direction of the image holding member, and a second brush that is brought into contact with the surface of the image holding member on the downstream side in the moving direction of the image holding member with respect to the first brush member. A brush member and a third brush member that is brought into contact with the surface of the image holding member on the downstream side in the moving direction of the image holding member with respect to the second brush member are provided, and the first brush member and the second brush member are different from each other. A bias voltage having a polarity is applied, and the mechanical scraping force of the third brush member is mechanically applied to the first brush member and the second brush member. Image forming apparatus characterized by strongly than can up force.   The image forming apparatus according to claim 1, wherein a material having higher rigidity than the brushes of the first brush member and the second brush member is used for the brush of the third brush member.   3. The image forming apparatus according to claim 1, wherein a polarity of a bias voltage applied to the first brush member is opposite to a charging polarity of toner in the residue, while the first voltage is applied to the first brush member. 2. An image forming apparatus, wherein the polarity of a bias voltage applied to the two brush members is the same as the charging polarity of the toner in the residue.   4. The image forming apparatus according to claim 1, wherein the first collection member that collects the residue collected on the first brush member from the first brush member, and the first collection member. A second collection member that collects the residue collected on the second brush member from the second brush member; and a third collection member that collects the residue collected on the third brush member from the third brush member; An image forming apparatus comprising:

Images