JP5012292B2 - 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 a residue such as toner remaining on the surface with a cleaning device, a plurality of brush rollers are brought into contact with the surface of the moving image holding member and rotated to leave a residue such as toner remaining on the surface of the image holding member. When the toner is removed, the toner residue is prevented from being filmed on the surface of the image holding member, and the toner residue can be appropriately removed from the surface of the image holding member over a long period of time. It has the characteristics.

  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.

  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 rollers are brought into contact with the surface of the moving image holding member and rotated to remove the remaining toner or the like remaining on the surface of the image holding member, the remaining toner or the like It is an object of the present invention to prevent the toner from being filmed on the surface of the image 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 for removing objects, the cleaning device includes a first brush roller that rotates in contact with the surface of the image holding member on the upstream side in the moving direction of the image holding member, and the first brush roller . a second brush roller which rotates in contact with the surface of the image holding member in the downstream side in the movement direction of the image supporting member than the brush roller, the image supporting member in the downstream side in the movement direction of the image supporting member than the second brush roller and a third brush roller rotating in contact with the surface provided, mark the charging polarity opposite the polarity of the bias voltage of the toner in the first brush roller described above in the residue in the While to, along with applying a charge having the same polarity of the bias voltage of the toner in the second brush roller of the residue in the above, the mechanical scraping force in the third brush roller described above, the above-mentioned first brush It was stronger than the mechanical scraping force of the roller and the second brush roller .

Here, in order to make the mechanical scraping force of the third brush roller stronger than the mechanical scraping force of the first brush roller and the second brush roller , for example, the brush of the third brush roller is applied to the brush. A material having higher rigidity than the brushes of the first brush roller and the second brush roller , that is, a material having a high Young's modulus is used, and the first brush roller and the second brush roller are used as the brush of the third brush roller. When using the same rigid material, the brush of the third brush roller has a larger fiber diameter or a shorter fiber length than the brushes of the first brush roller and the second brush roller . 3 fiber density of the brush in the brush roller, or to more than the fiber density of the brush of the first brush roller and a second brush roller That. Preferably, a material having higher rigidity than the brushes of the first brush roller and the second brush roller , that is, a material having a high Young's modulus, is used for the brush of the third brush roller .

In the image forming apparatus described above, since the first brush roller, the residue recovered in the second brush roller and the third brush roller is prevented from being accumulated in these brush rollers, the first brush roller a first collection member for collecting the recovered residue from the first brush roller, the residue recovered in the second brush roller and a second recovery member for recovering from the second brush roller, the third brush roller It is preferable to provide a third recovery member for recovering the recovered residue from the third brush roller .

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 while in the upstream side in the movement direction of the applying a charge opposite in polarity of the bias voltage of the toner in the first brush roller described above in the residue to be rotated in contact with the surface of the image holding member, than the first brush roller Since a bias voltage having a polarity opposite to that of the first brush roller is applied to the second brush roller that is rotated in contact with the surface of the image holding member on the downstream side in the moving direction of the image holding member, it remains on the surface of the image holding member. with many toner has become to be efficiently removed is electrically attracted to the first brush roller, said first brush Is removed by chromatography La, the amount of residue introduced into the second brush roller is reduced, in this state, the residue which has been charged to the charging polarity opposite to the toner is electrically attracted to the second brush roller As a result, the residue is efficiently removed, and the residue is reliably prevented from being filmed on the surface of the image holding member .

In the image forming apparatus of the present invention is provided with a third brush roller rotating in contact with the surface of the image holding member in the downstream side in the movement direction of the image supporting member than the second brush roller described above, the third brush Since the mechanical scraping force in the roller is stronger than the mechanical scraping force in the first brush roller and the second brush roller , the first brush roller is formed on the surface of the image holding member where a large amount of residue exists. And the brush on the second brush roller is strongly pressed to prevent the residue from filming on the surface of the image holding member, and uncharged and weakly charged residue on the surface of the image holding member after receiving the mechanical scraping force by 1 the brush roller and the second brush roller, the strength of the mechanical scraping force than the first brush roller and a second brush roller It comes to be properly recovered by the third brush roller.

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 roller , the second brush roller, and the third brush roller , 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 mechanical scraping force by the third brush roller described above, when stronger than the mechanical scraping force by the first brush roller and the second brush roller, the third brush roller brushes In addition, when a material having higher rigidity than the brushes of the first brush roller and the second brush roller is used, a material having a large fiber diameter or a short fiber length is used for the brush of the third brush roller , and its mechanical scraping is performed. As in the case of increasing the force, the amount of toner or other residue retained on the third brush roller is reduced, and the toner or other residue collected on the third brush roller is easily returned to the image holding member. There will never be. Also, by increasing the fiber density of the brush in the third brush roller, from its as in the case of stronger than the mechanical scraping force, residues such as toner collected by the third brush roller 3 brush roller Accumulation without properly discharging does not cause the residue collecting performance of the third brush roller to gradually deteriorate.

Further, in the image forming apparatus, residues collected by the first brush roller , the second brush roller, and the third brush roller are respectively collected from the respective brush rollers by a first collecting member, a second collecting member, and When is collected by the third collecting member is prevented from those residues recovered on each brush rollers are accumulated residue image holding member from these brush roller such as toner recovered in the brush roller 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 to 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 roller 31, a second brush roller 32, and a third brush roller 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 roller 31, the brush 32a in the second brush roller 32, and the brush 33a in the third brush roller 33 are brought into contact with the surface of the intermediate transfer belt 2. Yes.

Then, at a position where the first brush roller 31, the second brush roller 32, and the third brush roller 33 are in contact with the surface of the intermediate transfer belt 2, each brush roller 31, 32, 33 is the intermediate transfer belt 2. In order to remove the residual toner and the like remaining on the surface of the intermediate transfer belt 2, the mechanical scraping force in the third brush roller 33 is the first scraping force. The mechanical scraping force of the brush roller 31 and the second brush roller 32 is made stronger.

Here, in order to make the mechanical scraping force in the third brush roller 33 stronger than the mechanical scraping force in the first brush roller 31 and the second brush roller 32 as described above, in this embodiment, The brush 33a of the third brush roller 33 may be made of a material having higher rigidity than the brush 31a of the first brush roller 31 or the brush 32a of the second brush roller 32, or the third brush As the brush 33a in the roller 33, one having a fiber diameter larger than that of the brush 31a of the first brush roller 31 or the brush 32a of the second brush roller 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 roller 31 is provided, and the first recovery power source 35 supplies the first recovery member 34. A bias voltage having a predetermined polarity is applied to the first brush roller 31 through the one collecting member 34, and a residue such as toner having a polarity opposite to the polarity remaining on the surface of the intermediate transfer belt 2 is electrically removed. causes aspirated, the mechanical scraping force to recover the residue on the surface of the intermediate transfer belt 2 to the first brush roller 31, the residue of toner and the like collected in the first brush roller 31 in this manner, 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. That.

Also, a second recovery member 37 that is in the form of a roller that rotates in contact with the second brush roller 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 roller 32 through the second recovery member 37 to electrically attract the residue such as toner having a polarity opposite to the polarity remaining on the surface of the intermediate transfer belt 2, the residue which has not been recovered by the first brush roller 31 of the above-collected by the second brush roller 32, thus the residue of the toner and the like collected in the second brush roller 32, is further electrically attracted 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 roller 33 is provided with a third recovery member 40 in a blade shape so as to contact the brush 33a of the third brush roller 33, and the first brush roller 31 as described above. by the third brush roller 33 and the mechanical scraping force than the second brush roller 32 is increased, the residue which has not been recovered by the first brush roller 31 and the second brush roller 32 of the intermediate transfer belt 2 recovered from the surface, thus the residue of the toner and the like collected in the third brush roller 33, so as to be discharged from within the brush 33a of the third brush roller 33 by a third collection member 40 described above.

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

As a result, 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 roller 31, and is transferred to the second brush roller 32. When the amount of residue introduced is reduced and the residue is removed from the surface of the intermediate transfer belt 2 by the second brush roller 32 as described above, the residue is removed from the surface of the intermediate transfer belt 2 by the second brush roller 32. Filming is prevented.

As a result, in the image forming apparatus according to this embodiment, the residue remaining on the surface of the intermediate transfer belt 2 is intermediately transferred by the first brush roller 31, the second brush roller 32, and the third brush roller 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, using a material having high rigidity to the brush 33a of the third brush roller 33 described above, when strong mechanical scraping force by the third brush roller 33, the first brush roller 31 and the second brush roller 32 the residue which has not been recovered, it will be properly recovered by the third brush roller 33, the rigidity of the brush 33a in the third brush roller 33 is too high, the third brush roller 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 embodiment, the first brush roller , the second brush roller, and the third brush roller having brushes installed 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.

The moving speed of the intermediate transfer belt is set to 240 mm / s, the peripheral speeds of the first to third brush rollers are set to 360 mm / s, and the brush rollers are moved in the direction opposite to the intermediate transfer belt. In addition, the amount of biting into the intermediate transfer belt of each brush roller 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 roller 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 roller to the intermediate transfer belt, while the second brush roller contacting the downstream side in the moving direction of the intermediate transfer belt is supplied from the second recovery power source to the second transfer roller . 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 roller to the intermediate transfer belt.

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

Here, as the first brush roller , the second brush roller, and the third brush roller , 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 roller 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 A brush roller 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 , a fiber thickness of 2 dtex, a fiber length of 3 mm, a brush roller A3 provided with a conductive nylon fiber brush having a fiber density of 372 fibers / mm ² , and a roller having a diameter of 7 mm , 'S modulus is ^{5.0 × 10 9 N / m 2} , fiber thickness is 2 dtex, fiber length of 4 mm, and the brush roller B provided the brush conductive polyester fibers became fiber density 372 present / mm ² A conductive acrylic fiber brush with a roller having a diameter of 7 mm, 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 brush roller C provided with

As shown in Table 1 below, in Experiment 1, the brush roller A1 is used as the first brush roller , the second brush roller, and the third brush roller, and in Experiment 2, the first brush roller and the second brush roller are used. the brush roller A1 in the brush roller, a brush roller B to the third brush roller, in experiment 3, the brush roller A1 in the first brush roller and the second brush roller, the brush roller C to the third brush roller used in the experiment 4, the brush roller A1 in the first brush roller and the second brush roller, a brush roller A2 on the third brush roller, in experiment 5, in a first brush roller and a second brush roller the brush rollers A1, using a brush roller A3 third brush roller in experiment 6, the first brush roller and the brush roller and a second brush roller The, using a brush roller A1 in the third brush roller in Experiment 7 using a brush roller B to the first brush roller and a second brush roller and the third brush roller in Experiment 8, a first brush roller the brush roller B and a second brush roller was to use a brush roller C to the third brush roller.

Here, in the above-described brush rollers A1, B, and C, the Young's modulus indicating the rigidity of the brush is in the order of brush roller A1 < brush roller B < brush roller C, and the fiber thickness and fiber under other conditions. Since the length and the fiber density are the same, the mechanical scraping force is in the order of brush roller A1 < brush roller B < brush roller C.

In the above brush roller A1, A2, fiber thickness of the brush, since the direction of the brush roller A2 is thicker than the brush roller A1, a brush than the mechanical scraping force the brush roller A1 roller A2 Is stronger.

In the above brush roller A1, A3, fiber length of the brush, since the direction of the brush roller A3 is shorter than the brush roller A1, a brush roller than the mechanical scraping force the brush roller A1 A3 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 brushing force of the third brush roller that contacts at the most downstream side in the moving direction of the intermediate transfer belt has a first brush roller that contacts at the upstream side in the moving direction of the intermediate transfer belt from the third brush roller; In Experiments 2 to 5 and 8 where the mechanical scraping force of the second brush roller was stronger than that of the second brush roller , there was no filming on the surface of the intermediate transfer belt even after printing of 400,000 sheets. The cleaning state of the residue such as toner on the surface of the belt was also good.

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

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

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 a residue such as toner remaining on the surface of the intermediate transfer belt after transfer is removed from the intermediate transfer belt by a second cleaning device provided with three brush rollers is shown. It is a schematic explanatory drawing.

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 roller 31a Brush 31b Roller 32 Second brush roller 32a Brush 32b Roller 33 Third brush roller 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 (3)

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. , contact with the surface of the first brush roller and an image holding member in the downstream side in the movement direction of the image supporting member than the first brush roller which rotates in contact with the surface of the image holding member in the upstream side in the movement direction of the image supporting member and a second brush roller which is rotated, and a third brush roller rotating in contact with the surface of the image holding member in the downstream side in the movement direction of the image supporting member than the second brush roller provided above the first brush A bias voltage having a polarity opposite to the charging polarity of the toner in the residue is applied to the roller, while the toner in the residue is applied to the second brush roller. With applying a polarity of the same polarity of the bias voltage, that the mechanical scraping force, was stronger than the mechanical scraping force in the first brush roller and the second brush roller described above for the third brush roller of the An image forming apparatus. 2. The image forming apparatus according to claim 1, wherein a material having higher rigidity than the brushes of the first brush roller and the second brush roller is used for the brush of the third brush roller . The image forming apparatus according to claim 1 or claim 2, a first collection member for collecting the residues collected in the first brush roller of the from the first brush roller, the recovery in the second brush roller of the a second collection member for collecting the by residue from the second brush roller, in that a third collecting member for collecting the residues collected in the third brush roller of the from the third brush roller An image forming apparatus.

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