JP2007333844A - Counter roller cleaning device and image forming apparatus provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a counter roller cleaning device capable of removing foreign matters stuck to the counter roller, and preventing an intermediate transfer belt from meandering, and to provide an image forming apparatus equipped with the counter roller cleaning device. <P>SOLUTION: The counter roller cleaning device includes the intermediate transfer belt 203 that conveys a toner image, while holding it thereon; the counter roller 205A disposed opposite a secondary transfer roller 207 at a position where the toner image is transferred to a recording material by the secondary transfer roller 207 via the intermediate transfer belt 203; a stainless plate 206 for removing foreign matters stuck to the surface of the counter roller 205A; and a bias power source 209 for applying transfer bias, used for transferring the toner image on the intermediate transfer belt, to the recording material between the counter roller 205A and secondary transfer roller 207. The stainless plate 206 is longer than the secondary transfer roller 207; and since the secondary transfer roller 207 is shorter than the stainless plate 206, foreign matters sticking to the counter roller 205A can be removed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a counter roller cleaning device having a structure for cleaning foreign matter adhering to a counter roller, and an image forming apparatus including the same.

  Conventionally, as one of image forming apparatuses (for example, a printer, a fax machine, a copier, etc.) that forms a toner image on a recording material such as paper, a toner image formed on an image carrier is recorded via an intermediate belt. There is an intermediate transfer belt type image forming apparatus that transfers to a material. In such an image forming apparatus, the latent image on the image carrier is developed with a developing device to form a toner image, or the toner image formed on the image carrier is transferred to an intermediate transfer belt. Part of the toner is peeled off and dropped due to poor transfer, causing toner scattering.

  The scattered toner thus generated enters the inside of the intermediate transfer type image forming apparatus or adheres to the surface of the intermediate transfer belt, causing problems such as poor transfer to the recording material, contamination of the back surface, and contamination inside the image forming apparatus. was there.

  In order to solve such a problem, a roller capable of applying a transfer bias is disposed on the side opposite to the toner image transfer surface of the recording material, and means for cleaning the toner adhering to the roller capable of applying the transfer bias is provided. Those are known (for example, see Patent Document 1).

  In addition, there is also known a device that arranges a toner scattering prevention device on the back side of the intermediate transfer belt to reduce the amount of scattered toner (for example, see Patent Document 2).

Further, there is also known one provided with a cleaning means for cleaning a driving roller for driving the intermediate transfer belt (for example, see Patent Document 3).
JP 2002-214941 A (FIGS. 3 and 5) JP 2002-72706 A (FIG. 1) Japanese Patent Laying-Open No. 2005-37521 (FIG. 2)

  However, in the conventional configuration described above, the technique disclosed in Patent Document 1 aims to prevent contamination on the back surface of the recording material. However, the scattered toner inside the image forming apparatus cannot be removed, and the scattered toner is intermediate. It adheres to the back surface of the transfer belt and is conveyed to the opposing roller via the intermediate transfer belt. When a transfer bias is applied between the opposing roller and the second transfer means, a discharge phenomenon occurs between the opposing roller and the second transfer means via the intermediate transfer belt, resulting in discharge of nitrate or the like. Product adheres to the opposing roller.

  The attached discharge product plays a role of an adhesive that makes it easy to attach the scattered toner. Therefore, the scattered toner conveyed by the intermediate transfer belt adheres to the opposing roller, and the frictional force between the opposing roller and the intermediate transfer belt. Changes locally along the longitudinal direction of the opposing roller, and pushes the intermediate transfer belt in a direction perpendicular to the moving direction of the intermediate transfer belt with respect to the intermediate transfer belt (hereinafter referred to as “meandering force”). Is generated.

  The intermediate transfer belt has ribs on the left and right sides of the back side, but the intermediate transfer belt to which the meandering force is applied exerts excessive stress on the ribs on the side opposite to the direction of the meandering force, and the ribs are cut diagonally. It will be. When the rib is cut, the belt is bent on the side of the cut rib, and the belt is broken.

  That is, the above-described technique cannot remove the scattered toner inside the image forming apparatus, and thus cannot prevent toner from adhering to the opposing roller, and cannot suppress the generation of the meandering force to the intermediate transfer belt. There is a problem.

  Further, in the technique disclosed in Patent Document 2, since the scattered toner floating at the tip of the toner scattering prevention device cannot be removed, the scattered toner floating at the tip of the toner scattering prevention device adheres to the back surface of the intermediate transfer belt, and the intermediate transfer belt It is conveyed to the opposing roller disposed inside the intermediate transfer belt via the belt and adheres to the opposing roller, and the frictional force between the opposing roller and the intermediate transfer belt also changes locally along the longitudinal direction of the opposing roller. To generate a meandering force.

  Accordingly, even with the technique disclosed in Patent Document 2, as in the above case, the scattered toner inside the image forming apparatus cannot be completely removed, so that the toner is prevented from adhering to the opposing roller disposed inside the intermediate transfer belt. There is a problem that the generation of the meandering force on the intermediate transfer belt cannot be suppressed.

  Further, the technique disclosed in Patent Document 3 does not consider the cleaning of the counter roller, and thus cannot prevent the toner from adhering to the counter roller disposed inside the intermediate transfer belt. Due to the scattered toner, the frictional force between the opposing roller and the belt changes locally along the longitudinal direction of the opposing roller, and there is a problem that the generation of the meandering force to the intermediate transfer belt cannot be suppressed.

  The present invention solves the above-described conventional problems, and is a counter roller disposed inside the intermediate transfer belt, which removes foreign matters adhering to the counter roller and prevents the meandering force from being generated in the intermediate transfer belt. An object of the present invention is to provide a counter roller cleaning device and an image forming apparatus including the same.

  The counter roller cleaning device of the present invention includes a transfer belt that carries and conveys a toner image, a counter roller that is disposed opposite to the transfer unit at a position where the toner image on the transfer belt is transferred to a recording material by the transfer unit, Removing means for removing foreign matter adhering to the surface, and bias power supply means for applying a transfer bias for transferring the toner image on the transfer belt to the recording material between the opposing roller and the transfer means. The length is longer than the length of the transfer means, and the transfer means is arranged within the length of the removal means.

  With this configuration, all foreign matters such as nitrate adhering to the opposing roller due to the discharge phenomenon generated between the opposing roller and the transferring means via the transfer belt can be scraped off by the removing means pressed against the opposing roller. .

  In the counter roller cleaning device of the present invention, the removing means is configured such that the length thereof is shorter than the length of the counter roller and is disposed within the length of the counter roller.

  With this configuration, when the counter roller is rotated and cleaned, it is possible to prevent the burr at the end of the counter roller from being deformed or partially worn on a part of the removing means.

  In the counter roller cleaning device of the present invention, the removing means is configured such that its length is longer than the length of the other transfer means for transferring the toner image formed on the image carrier to the transfer belt, The other transfer means is arranged within the length of the removing means.

  With this configuration, it is possible to scrape off all foreign matters conveyed from the other transfer means to the opposing roller via the transfer belt.

  Moreover, in the opposing roller cleaning apparatus of this invention, the opposing roller is comprised with an electroconductive material, and has the structure by which the abrasion prevention process was performed to the surface.

  With this configuration, the surface of the opposing roller is less likely to be worn, so that the wear of the opposing roller due to the pressing of the removing means can be reduced.

  Furthermore, the image forming apparatus of the present invention has a configuration including any of the above-described counter roller cleaning devices.

  With this configuration, foreign matter adhering to the opposing roller is removed, and no meandering force is generated on the transfer belt, so that a stable and high-quality image can be obtained.

  The roller cleaning device of the present invention has a configuration in which the length of the removing means for removing foreign matters adhering to the surface of the opposing roller is longer than the length of the transferring means, and the transferring means is arranged within the length of the removing means. Therefore, the foreign matter adhering to the opposing roller can be removed, the generation of the meandering force of the transfer belt can be suppressed, and the belt can be prevented from tearing.

Hereinafter, a roller cleaning device according to an embodiment of the present invention will be described with reference to the drawings.
(Embodiment)
FIG. 1 is a diagram showing a configuration of a color image forming apparatus using an intermediate transfer system to which a roller cleaning apparatus according to an embodiment of the present invention is applied.

  In FIG. 1, the color image forming apparatus according to the present embodiment is called a tandem type full-color copying machine, and includes a plurality of sets of image forming units 101Y, 101M, 101C, and 101K, an intermediate transfer unit 102, and a plurality of supply units. It consists of a paper cassette 103 and fixing means 104. A document image reading device 20 is disposed on the upper portion of the main body 10 of the image forming apparatus.

  An image forming unit 101Y that forms a yellow image includes a drum-shaped photosensitive member 202Y as a first image carrier, a charging unit, an exposing unit, and a developing unit (not shown) arranged around the photosensitive unit 202Y. A transfer roller 204Y for transferring the toner image formed on the photoconductor 202Y to the intermediate transfer belt 203, and a cleaning unit 210Y for cleaning the toner remaining on the photoconductor 202Y. In order to transfer the toner image formed on the photoreceptor 202Y to the intermediate transfer belt 203, a transfer bias is applied between the photoreceptor 202Y and the transfer roller 204Y.

  Similarly, the image forming units 101M, 101C, and 101K that form magenta, cyan, and black images respectively have drum-shaped photoconductors 202M, 202C, and 202K, and photoconductors 202M as first image carriers. Charging means, exposure means, and developing means (not shown) arranged around 202C and 202K, primary transfer rollers 204M, 204C, and 204K as first transfer means, and cleaning means 210M, 210C, and 210K, respectively. Have

  The intermediate transfer unit 102 is disposed opposite to an intermediate transfer belt 203 that is an endless belt-like second image carrier, a plurality of support rollers 205 that suspend the intermediate transfer belt 203, and a secondary transfer roller 207 that will be described later. A counter roller 205A and a driving roller 205B for driving the intermediate transfer belt 203 are provided.

  The images of the respective colors formed by the image forming units 101Y, 101M, 101C, and 101K are transferred onto a primary transfer roller 204Y, 204M, 204C as a first transfer unit on an intermediate transfer belt 203 driven by a driving roller 205B. The combined color image is formed by sequentially transferring images by 204K.

  A sheet 30 as a recording material accommodated in the sheet cassette 103 is conveyed from the sheet cassette 103 and passes through a plurality of conveyance rollers 105A, 105B, and 105C to a secondary transfer roller 207 as a second transfer unit. The color image is transferred onto the paper 30 by secondary transfer. The sheet 30 on which the color image has been transferred is subjected to fixing processing by the fixing unit 104 and is discharged onto a discharge tray 107 outside the apparatus by a discharge roller 106.

  In addition, when it is desired to transfer not only on one side of the sheet 30 but also on both sides, the sheet discharge switching lever 109 is switched after the one side is fixed, and the sheet 30 is conveyed to the sheet reversing unit 108. The sheet 30 stored in the sheet reversing unit 108 is switched back, the sheet discharge switching lever 109 is switched, and the sheet is conveyed to the conveying roller 110A. Then, the toner is conveyed again to the intermediate transfer unit 102 via the conveyance rollers 110A, 110B, 110C, 110D, and 105C.

  The sheet 30 conveyed to the intermediate transfer unit 102 is conveyed to the secondary transfer roller 207, and is secondarily transferred onto the back surface of the sheet 30 to collectively transfer color images. The sheet 30 on which the color image has been transferred is subjected to fixing processing by the fixing unit 104 and is discharged onto a discharge tray 107 outside the apparatus by a discharge roller 106.

  FIG. 2 is a diagram showing a configuration of an intermediate transfer unit to which the counter roller cleaning device according to the embodiment of the present invention is applied.

  In FIG. 2, the intermediate transfer unit 102 according to the present exemplary embodiment uses a plurality of photoconductors 202Y, 202M, 202C, and 202K that carry a toner image formed from the toner 201 and a photoconductor 202Y, 202M, 202C, and 202K. An intermediate transfer belt 203 for transferring an image and performing secondary transfer onto the paper 30 and a first transfer bias for transferring a toner image from the photoconductors 202Y, 202M, 202C, and 202K to the intermediate transfer belt 203 are applied. Primary transfer rollers 204Y, 204M, 204C, and 204K, a plurality of support rollers 205 that suspend the intermediate transfer belt 203, and one of a plurality of support rollers, with the intermediate transfer belt 203 interposed therebetween. Thus, the toner image is transferred to the paper 30 at a position where the toner image is transferred to the secondary transfer roller 207. The direction roller 205A, a driving roller 205B for driving the intermediate transfer belt 203, a stainless plate 206 as a removing means for removing scattered toner that is a foreign matter adhering to the surface of the opposing roller 205A, and the intermediate transfer belt 203 are interposed. A secondary transfer roller 207 as a second transfer means disposed opposite to the opposing roller 205A, a collection box 208 for collecting the toner removed by the stainless steel plate 206, an opposing roller 205A and the secondary transfer roller 207, A bias power source 209 that applies a transfer bias for transferring the toner image to the paper 30 and a cleaning unit 211 that cleans residual toner on the intermediate transfer belt 203 are provided.

  As a normal operation, the toner images of the respective colors formed on the photoreceptors 202Y, 202M, 202C, and 202K are transferred to the intermediate transfer belt 203 driven by the driving roller 205B, and a color image is formed on the intermediate transfer belt 203. To do. The color image formed on the intermediate transfer belt 203 is conveyed to the opposing roller 205A by the intermediate transfer belt 203.

  The color image conveyed to the counter roller 205A via the intermediate transfer belt 203 is applied with a transfer bias between the counter roller 205A and the secondary transfer roller 207 by the bias power source 209, and is conveyed to the counter roller 205A. 30 from the intermediate transfer belt 203.

  After the color image is transferred to the paper 30, the residual toner is removed from the intermediate transfer belt 203 from which the paper 30 is separated by the cleaning unit 211.

  However, when the toner image is transferred from the photoconductors 202Y, 202M, 202C, and 202K to the intermediate transfer belt 203, a part of the toner is peeled off and dropped due to transfer failure, and the toner is scattered. It adheres like toner 301. Then, the scattered toner is conveyed to the opposing roller 205A via the intermediate transfer belt 203, and adheres to the opposing roller 205A there.

  Further, when a transfer bias is applied between the opposing roller 205A and the secondary transfer roller 207 by the bias power source 209, a discharge phenomenon occurs between the opposing roller 205A and the secondary transfer roller 207 via the intermediate transfer belt 203. As a result, a discharge product 302 such as nitrate adheres to the opposing roller 205A.

  The attached discharge product 302 plays a role of an adhesive that makes it easy to attach scattered toner, so that the scattered toner conveyed by the intermediate transfer belt 203 further adheres to the opposing roller 205A.

  In this embodiment, the opposing roller 205A and the intermediate transfer belt 203 are pressed by pressing the stainless steel plate 206 against the opposing roller 205A with a uniform pressure and evenly scraping off the toner 301 and the discharge product 302 adhering to the opposing roller 205A. Can be prevented from locally changing along the longitudinal direction of the opposing roller 205A, and the generation of the meandering force of the belt can be suppressed. Therefore, there is no problem that the intermediate transfer belt 203 is not bent due to the meandering force, and the belt is torn.

  The toner scraped off as described above is collected in the collection box 208 in order to prevent new scattering. As described above, in this embodiment, the stainless steel plate 206 and the collection box 208 constitute a removing unit.

  Therefore, in the present embodiment, there is no problem that the intermediate transfer belt 203 is not bent due to the meandering force, and the belt is torn.

  In the present embodiment, the opposing roller 205A is made of aluminum, which is a conductive material, and electroless nickel plating is applied to the surface as an anti-abrasion treatment. Since electroless nickel plating has a higher hardness than stainless steel, it is possible to reduce wear caused by pressing the stainless plate 206 against the opposing roller 205A with a uniform pressure.

  FIG. 3 is a partially cut-out top view of the intermediate transfer unit to which the roller cleaning device according to the embodiment of the present invention is applied, and shows a top view seen from the direction of arrow Z in FIG.

  In FIG. 3, the adhesion range of the toner adhering to the opposing roller 205A is that when the transfer bias is applied between the opposing roller 205A and the secondary transfer roller 207, the opposing roller 205A and the secondary transfer via the intermediate transfer belt 203 are applied. This is a range of discharge products such as nitrate adhering to the facing roller 205A due to a discharge phenomenon generated between the roller 207 and the roller 207. Since this is within the length L3 of the secondary transfer roller 207, the length L3 of the secondary transfer roller 207 is made shorter than the length L2 of the stainless plate 206, and the secondary transfer roller 207 is moved to the stainless plate 206. By disposing within the length L2, it is possible to scrape off all the toner adhering to the facing roller 205A.

  Further, the length L2 of the stainless steel plate 206 is shorter than the length L1 of the opposing roller 205A, and the stainless steel plate 206 is disposed within the length of the opposing roller 205A. This is because when the length L2 of the stainless plate 206 is longer than the length L1 of the opposed roller 205A, the opposed roller 205A is pressed against the opposed roller 205A with a uniform pressure, and the opposed roller 205A is rotated to rotate the opposed roller 205A. This is because, when cleaning 205A, the burr at the end of the opposed roller 205A causes deformation or partial wear on a part of the stainless steel plate.

  On the other hand, the length L2 of the stainless steel plate 206 is shorter than the length L1 of the opposing roller 205A and is disposed within the length of the opposing roller 205A, thereby pressing the stainless steel plate 206 against the opposing roller 205A with a uniform pressure. When the counter roller 205A is cleaned by rotating the counter roller 205A, it is possible to prevent the burr at the end of the counter roller 205A from being deformed or partially worn on the stainless plate.

  Further, scattered toner scattered due to transfer failure from the photoconductors 202Y, 202M, 202C, and 202K adheres to the primary transfer rollers 204Y, 204M, 204C, and 204K, and reaches the opposing roller 205A via the back surface of the intermediate transfer belt 203. Since the toner adheres, the toner conveyed from the primary transfer rollers 204Y, 204M, 204C, and 204K to the opposing roller 205A is within the length L4 of the primary transfer rollers 204Y, 204M, 204C, and 204K. By making the length L4 of the rollers 204Y, 204M, 204C, and 204K shorter than the length L2 of the stainless steel plate 206 and disposing it within the length L2 of the stainless steel plate 206, all the toner adhering to the opposing roller 205A is scraped off. be able to.

  On the other hand, the facing roller 205A is made of a conductive material and has a surface subjected to wear prevention treatment. As a result, the surface of the facing roller 205A is less likely to be worn, and thus the wear of the facing roller 205A due to the pressing of the stainless steel plate 206 can be reduced.

  As described above, the counter roller cleaning device and the image forming apparatus including the counter roller cleaning device according to the present invention can remove foreign matters adhering to the counter roller, thereby suppressing the generation of the meandering force of the transfer belt and preventing the belt from tearing. Therefore, the image forming apparatus is useful as an image forming apparatus such as a printer, a fax machine, a copying machine, or a complex machine of which high quality is required.

1 is a configuration diagram of a color image forming apparatus including a counter roller cleaning device according to an embodiment of the present invention. The block diagram of the intermediate transfer unit provided with the counter roller cleaning apparatus of one embodiment of this invention 1 is a partially cut-out top view of an intermediate transfer unit according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Apparatus main body 20 Original image reading apparatus 30 Paper 101Y, 101M, 101C, 101K Image formation part 102 Intermediate transfer unit 103 Paper feed cassette 104 Fixing means 105A, 105B, 105C Conveyance roller 106 Discharge roller 110A, 110B, 110C, 110D Conveyance roller 201, 301 Toner 202Y, 202M, 202C, 202K Photoconductor 203 Intermediate transfer belt 204Y, 204M, 204C, 204K Primary transfer roller 205 Support roller 205A Opposed roller 205B Drive roller 206 Stainless steel plate 207 Secondary transfer roller 208 Collection box 209 Bias Power supply 210Y, 210M, 210C, 210K Cleaning means 211 Cleaning means 302 Discharge product

Claims (5)

A transfer belt that carries and conveys a toner image; a counter roller disposed opposite to the transfer unit at a position where the toner image on the transfer belt is transferred to a recording material by the transfer unit; and a foreign matter attached to the surface of the counter roller. Removing means for removing, and bias power supply means for applying a transfer bias for transferring the toner image on the transfer belt to the recording material between the opposing roller and the transfer means, The counter roller cleaning device, wherein the length is longer than the length of the transfer means, and the transfer means is disposed within the length of the removal means. The counter roller cleaning device according to claim 1, wherein the removing unit has a length shorter than that of the counter roller, and is disposed within the length of the counter roller. The removal means is configured such that its length is longer than the length of another transfer means for transferring the toner image formed on the image carrier to the transfer belt, and the other transfer means is the removal means. The counter roller cleaning device according to claim 1, wherein the counter roller cleaning device is disposed within a length of the counter roller. 4. The counter roller cleaning device according to claim 1, wherein the counter roller is made of a conductive material, and the surface thereof is subjected to wear prevention treatment. An image forming apparatus comprising the counter roller cleaning device according to claim 1.

Images