JP2012208240A - Cleaning device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device capable of sufficiently suppressing the scattering of toner.SOLUTION: The cleaning device includes a removal roller 201 coming into contact with the surface of an image carrier 132, to remove residual toner and foreign matter coming from a paper, a recovery roller 202 coming into contact with the surface of the removal roller 201, to recover the toner and the foreign matter, a blade 204 coming into contact with the surface of the recovery roller 202, to separate the toner and the foreign matter from the recovery roller 202, a discharge part 205 discharging the separated toner and foreign matter, and a sheet 203 which is disposed between the removal roller 201 and the discharge part 205 and whose one end comes into contact with the surface of the recovery roller 202. At least the area coming into contact with the recovery roller 202 of the sheet 203 is a roughened area having a large number of fine recessed and projecting parts, so that the toner and the foreign matter can pass through between the recovery roller 202 and the sheet 203 by the rotation of the recovery roller 202.

Description

  The present invention relates to a cleaning device and an image forming apparatus.

  An image forming apparatus using an electrophotographic system such as a copying machine, a printer, a facsimile machine, and a composite machine thereof includes a photosensitive drum, a charging device that uniformly charges the surface of the photosensitive drum, and a charged photosensitive member. An exposure device that forms an electrostatic latent image on the surface of the photosensitive drum by exposing the surface of the drum, and supplying toner to the surface of the photosensitive drum on which the electrostatic latent image is formed, A developing device that develops an electrostatic latent image as a toner image, a transfer device that transfers the toner image on the photosensitive drum to a sheet or the like directly or via an intermediate transfer belt, and the transferred toner image A fixing device or the like for fixing to paper or the like by heating and pressing is provided.

  In addition, the image forming apparatus includes a cleaning device that removes toner remaining on the image carrier, that is, so-called residual toner, after transferring a toner image on the image carrier such as a photosensitive drum or an intermediate transfer belt onto a sheet or the like. By doing so, it is possible to suppress deterioration of the image quality of the formed image due to the toner remaining on the image carrier without being transferred.

  As such a cleaning device, for example, a cleaning device described in Patent Document 1 can be cited.

  Patent Document 1 discloses a blade whose tip contacts the surface of a rotating image carrier, a casing to which the blade is attached, a developer moving direction upstream of the blade in the casing and above the gravitational direction. Provided in the developer scattering prevention portion for preventing the developer from scattering outside the casing; and provided upstream of the blade in the casing and in the direction of gravity relative to the blade of the casing; A cleaning device is described that has a developer reservoir that contacts the inner surface of the housing of the blade and stores the developer in a region including the tip of the blade.

JP 2008-145817 A

  According to Patent Document 1, it is disclosed that the developer on the surface of the image carrier can be removed satisfactorily and the developer can be smoothly moved into the housing.

  However, in the cleaning device described in Patent Document 1, if the pressure with which the blade is pressed against the image carrier (photoreceptor drum) is low, there is a risk that toner as a developer may be insufficiently removed. In addition, if the pressure for pressing the blade against the image carrier (photosensitive drum) is too high, the photosensitive drum may be damaged.

  Further, in the cleaning device described in Patent Document 1, a developer scattering prevention unit that prevents the developer from scattering outside the casing is disposed in contact with the image carrier.

  However, in some cases, the scattering of toner as a developer cannot be sufficiently suppressed.

  This is considered to be due to the following.

  First, not only residual toner but also foreign matters derived from paper such as paper dust derived from paper exist on the image carrier. Accordingly, not only the residual toner but also foreign matters derived from the paper are removed by the cleaning device.

  Then, when removing the foreign matter derived from the paper with the cleaning device, the foreign matter derived from the paper enters between the developer scatter preventing portion and the image holding body, and the developer scatter preventing portion and the image holding body are separated from each other. It is thought that there is. Therefore, it is considered that the developer scatter preventing unit separated from the image carrier cannot sufficiently exhibit the effect of suppressing the scattering of the toner as the developer.

  As a result, it is considered that the scattering of the toner as the developer may not be sufficiently suppressed.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a cleaning device that sufficiently suppresses toner scattering. Another object is to provide an image forming apparatus provided with the cleaning device.

  The present inventors contact an image carrier such as a photosensitive drum or an intermediate transfer belt to remove residual toner on the image carrier and paper-derived foreign matters, such as a fur brush instead of a blade. The use of a removal roller was considered.

  Specifically, the cleaning device using the removal roller is in contact with the surface of the removal roller, and is in contact with the recovery roller that collects the toner and foreign matter removed by the removal roller, and the surface of the recovery roller. Then, a blade having a blade for separating toner and foreign matter from the collecting roller and a discharge unit for discharging the separated toner and foreign matter to the outside of the cleaning device were examined. In such a cleaning device, the toner and foreign matter separated by the blade may return not only to the discharge portion but also to the removal roller side. Therefore, a sheet in which one end portion is in contact with the collecting roller between the discharge portion and the removing roller can be used as a sealing material for preventing scattering of toner.

  However, there is a case where toner scattering cannot be sufficiently suppressed only by providing such a sealing material. This is presumed to be due to the following.

  First, as described above, the image carrier conveys not only residual toner but also paper dust that is a foreign substance derived from paper. Such paper dust is also removed from the image carrier by the removal roller, as with the residual toner. At that time, the residual toner is considered to be charged from the paper powder. From this, it is considered that the power adhering to the collecting roller is weaker than that of the residual toner. Therefore, it is considered that paper dust is less likely to pass between the sealing material and the collection roller than the residual toner. And it is thought that such paper dust will accumulate | store gradually in the rotation direction downstream of the said collection roller of the said sealing material. As the accumulation proceeds, paper dust enters between the sealing material and the collecting roller, and it is considered that the sealing material and the collecting roller are separated from each other. It is considered that such a sealing material separated from the collection roller cannot sufficiently exhibit the effect as a sealing material and cannot sufficiently suppress toner scattering. Thus, it was speculated that the toner scattering may not be sufficiently suppressed by simply providing the sealing material.

  Accordingly, the present inventors have focused on the surface state of the area of the sheet used as the sealing material that is in contact with the collection roller, and have arrived at the present invention as follows.

  The cleaning device according to one aspect of the present invention is in contact with the surface of the image carrier, the toner remaining on the image carrier after the toner image on the image carrier is transferred to the paper, and the paper derived from the paper A removal roller that removes foreign matter, a contact with the surface of the removal roller, a recovery roller that collects the toner and foreign matter removed by the removal roller, and a surface of the recovery roller that is contacted with the recovery roller and recovered by the recovery roller A blade that separates toner and foreign matter from the collection roller, a discharge portion that discharges the toner and foreign matter separated from the collection roller, and is disposed between the removal roller and the discharge portion; A sheet to be brought into contact with the surface of the collection roller, and at least a region of the sheet that is in contact with the collection roller is rotated by the collection roller, Serial recovery roller and the sheet and between that allows passage of the toner and the foreign substance of a cleaning device, characterized in that the roughened region has a large number of fine recesses and projections.

  According to such a configuration, it is possible to provide a cleaning device that sufficiently suppresses toner scattering.

  This is considered to be due to the following.

  A cleaning device according to one embodiment of the present invention uses a sheet as described above as a sealing material for preventing toner scattering, unlike a cleaning device in which a sealing material as described above is simply provided. Specifically, at least an area in contact with the collection roller has a large number of minute recesses and projections that allow the toner and the foreign matter to pass between the collection roller and the sheet by rotation of the collection roller. A sheet which is a roughened region having a portion is used.

  By doing so, not only the residual toner easily passes between the sheet as the sealing material and the collection roller, but also foreign matters derived from paper such as paper dust easily pass. From this, it is considered that accumulation of foreign matters such as paper dust is suppressed on the downstream side of the sheet in the rotation direction of the collection roller. Therefore, it is possible to prevent foreign matter from entering between the sheet and the collection roller, and to separate the sheet and the collection roller, and the sheet preferably works as a sealing material that suppresses toner scattering. It is considered possible.

  From this, it is considered that toner scattering can be sufficiently suppressed.

  In the cleaning device, it is preferable that the roughened region includes fine concave portions and convex portions formed by performing mat processing by chemical etching or blasting.

  According to such a configuration, toner scattering can be further suppressed.

  This is considered to be due to the fact that paper-derived foreign matters such as paper dust more easily pass between the sealing material sheet and the collection roller.

  In the cleaning device, the surface roughness of the roughened region is preferably 2 to 13 μm at the maximum height Ry.

  According to such a configuration, toner scattering can be further suppressed.

  This is considered to be due to the fact that paper-derived foreign matters such as paper dust more easily pass between the sealing material sheet and the collection roller.

  In the cleaning device, it is preferable that a static friction coefficient of the roughened region is smaller than a static friction coefficient of a region other than the roughened region of the sheet.

  According to such a configuration, toner scattering can be further suppressed.

  This is considered to be due to the fact that paper-derived foreign matters such as paper dust more easily pass between the sealing material sheet and the collection roller.

  In the cleaning device, the removal roller is preferably a fur brush.

  According to such a configuration, it is possible to remove residual toner on the image carrier and foreign matters derived from paper such as paper dust from the image carrier while suppressing damage to the image carrier. .

  In the cleaning device, it is preferable that the image carrier is an intermediate transfer member to which the toner image developed by the developing device is transferred and the transferred toner image is transferred to a sheet.

  According to such a configuration, it is possible to suitably remove the residual toner on the image carrier and the foreign matters derived from the paper such as paper dust on the intermediate transfer member.

  In the cleaning device, it is preferable that the image carrier is a photoreceptor that forms a toner image developed by a developing device on the surface thereof.

  According to such a configuration, it is possible to suitably remove residual toner on the image bearing member and foreign matters derived from paper such as paper dust.

  An image forming apparatus according to another embodiment of the present invention is an image forming apparatus including the cleaning device.

  According to such a configuration, a high-quality image can be formed. This is considered to be because, first of all, it is possible to suppress deterioration in the image quality of the formed image due to the presence of residual toner and paper-derived foreign matter. Further, since the toner scattering in the cleaning device is suppressed, it is considered that the deterioration of the image quality of the formed image due to the toner scattering can be suppressed.

  According to the present invention, it is possible to provide a cleaning device in which toner scattering is sufficiently suppressed. An image forming apparatus including the cleaning device is provided.

1 is a schematic diagram illustrating an overall configuration of an image forming apparatus to which a cleaning device according to an embodiment of the present invention is applied. It is a schematic sectional drawing which shows the structure of the cleaning apparatus which concerns on embodiment of this invention. FIG. 2 is a schematic diagram illustrating the periphery of an image forming unit of an image forming apparatus to which a cleaning device according to an embodiment of the present invention is applied.

  Hereinafter, although the embodiment concerning the present invention is described, the present invention is not limited to these.

  An image forming apparatus 10 shown in FIG. 1 will be described as an example of an image forming apparatus to which a cleaning device according to an embodiment of the present invention is applied. FIG. 1 is a schematic diagram showing the overall configuration of an image forming apparatus to which a cleaning device according to an embodiment of the present invention is applied. As an image forming apparatus 10 according to an embodiment of the present invention, an image forming process is performed based on image information transmitted from an external device such as a computer, and a so-called tandem image forming apparatus (color printer) 10 is provided. An example will be described.

  Here, a tandem image forming apparatus will be described as an example of the image forming apparatus. However, the image forming apparatus may be any image forming apparatus using an electrophotographic method, and is not limited to a tandem image forming apparatus. The type of image forming apparatus will be described by taking a color printer as an example, but it may be, for example, a copying machine, a facsimile machine, a multifunction machine, and the like, and is not limited to a color printer.

  As shown in FIG. 1, the image forming apparatus 10 includes a sheet feeding unit 12 that feeds a sheet P and is fed from the sheet feeding unit 12. While conveying the paper P, an image forming unit 13 that forms a toner image based on image information on the paper P, and an unfixed toner image formed on the paper P by the image forming unit 13 is fixed on the paper P. A fixing unit 14 for performing a fixing process is provided. Further, on the upper part of the apparatus main body 11, a paper discharge unit 15 for discharging the paper P subjected to the fixing process by the fixing unit 14 is formed.

  At an appropriate position on the upper surface of the apparatus main body 11, an operation panel (not shown) for inputting an output condition for the paper P or the like is provided. This operation panel is provided with a power key and various keys for inputting output conditions.

  Further, a sheet conveyance path 111 extending in the vertical direction is formed in the apparatus main body 11 at a position on the right side of the image forming unit 13 shown in FIG. A pair of conveyance rollers 112 is provided at an appropriate position on the sheet conveyance path 111. The paper transport path 111 transports the paper P from the paper feed unit 12 to the paper discharge unit 15 by the transport roller pair 112, and the paper P being transported passes through the transfer unit and the fixing unit 14 of the image forming unit 13. It is formed to pass.

  The paper feed unit 12 includes a paper feed tray 121, a pickup roller 122, and a paper feed roller pair 123. The sheet feeding tray 121 is detachably mounted at a position below the image forming unit 13 in the apparatus main body 11 and stores a sheet bundle P1 in which a plurality of sheets P are stacked. The pickup roller 122 is provided at an upper position on the upstream side of the paper feed tray 121 in the conveyance direction of the paper P, specifically, at an upper right position shown in FIG. The top sheet P is taken out one by one. The paper feed roller pair 123 sends the paper P taken out by the pickup roller 122 to the paper transport path 111. By doing so, the paper feeding unit 12 feeds the paper P toward the image forming unit 13.

  The paper feed unit 12 further includes a manual feed tray 124, a pickup roller 125, and a paper feed roller pair 126 attached to the left side surface of the apparatus main body 11 shown in FIG. The manual feed tray 124 is for supplying the paper P toward the image forming unit 13 by manual feed operation. The manual feed tray 124 can be stored on the side surface of the apparatus main body 11, and when the paper P is manually fed, as shown in FIG. 1, the manual feed tray 124 is pulled out from the side surface of the apparatus main body 11 to be manually fed. The pickup roller 125 takes out the paper P placed on the manual feed tray 124. The paper P taken out by the pickup roller 125 is sent out to the paper transport path 111 by a pair of paper feed rollers 123 and 126. By doing so, the paper feeding unit 12 feeds the paper P toward the image forming unit 13.

  The image forming unit 13 forms an image such as a color image on the paper P fed from the paper feeding unit 12 by predetermined image processing. The image forming unit 13 includes a plurality of image forming units 131, an intermediate transfer belt (intermediate transfer member) 132, a primary transfer roller 133, and a secondary transfer roller 133.

  As the image forming unit 131, in this embodiment, the magenta (M) color is sequentially arranged from the upstream side to the downstream side in the rotation direction of the intermediate transfer belt 132 (from the left side to the right side in FIG. 1). A magenta unit 131M using a developer, a cyan unit 131C using a cyan (C) developer, a yellow unit 131Y using a yellow (Y) developer, and a black (K) developer are used. A black unit 131K is provided. Each unit 131 includes a photosensitive drum 135 as an image carrier, and forms a toner image corresponding to each color on the photosensitive drum 135 based on image information, and performs primary transfer onto the intermediate transfer belt 132.

  In the image forming unit 131, a photosensitive drum 135 as an image carrier is disposed at a central position so as to be rotatable in the direction of an arrow (clockwise in FIG. 1). Then, around the photosensitive drum 135, when the transfer (primary transfer) position by the primary transfer roller 133 is the most upstream side in the rotation direction of the photosensitive drum 135, the position is shifted from there to the downstream side. The neutralization device 24, the charging device 21, the exposure device 22, the development device 23, and the like are arranged in order so as to be a neutralization position, a charging position, an exposure position, and a development position, respectively. .

  The photosensitive drum 135 is for forming a toner image corresponding to each color on the peripheral surface based on image information. The charging device 21 is for charging the peripheral surface of the photosensitive drum 135 rotated in the direction of the arrow. The exposure device 22 irradiates the peripheral surface of the photosensitive drum 135 whose peripheral surface is charged by the charging device 21 with laser light based on image information, and electrostatically based on the image information on the peripheral surface of the photosensitive drum 135. This is for forming a latent image. Examples of the exposure device 22 include an LED head unit and a laser scanning unit (LSU). The developing device 23 is for developing the electrostatic latent image formed on the peripheral surface of the photosensitive drum 135 into a toner image.

  The intermediate transfer belt 132 is for transferring (primary transfer) a toner image based on image information to the peripheral surface (contact surface) of the plurality of image forming units 131. That is, in the present embodiment, the intermediate transfer belt 132 is an image carrier that is sandwiched between the photosensitive drum 135 and the primary transfer roller 133 and has a peripheral surface to which a toner image is transferred from the photosensitive drum 135. .

  The intermediate transfer belt 132 is an endless belt-like rotator, and is stretched around the driving roller 136 and the driven roller 137 so that the circumferential surface side thereof abuts on the circumferential surface of each photosensitive drum 135. ing. Further, the intermediate transfer belt 132 is pressed against each photoconductive drum 135 by each primary transfer roller 133 disposed at a position facing each photoconductive drum 135 via the intermediate transfer belt 132, and the driving roller 136. It is comprised so that it may rotate endlessly by rotational drive. The driving roller 136 is rotationally driven by a driving source such as a stepping motor, and gives a driving force for rotating the intermediate transfer belt 132 endlessly. The driven roller 137 is rotatably provided and rotates following the endless rotation of the intermediate transfer belt 132 by the driving roller 136.

  The intermediate transfer belt 132 is not particularly limited. Specifically, for example, the surface of a seamless belt made of a resin such as polyimide, polycarbonate, or polyvinylidene fluoride is coated with a synthetic rubber such as silicone rubber or fluorine rubber. Examples thereof include a belt formed of a layer. As an example of a preferable intermediate transfer belt 132, for example, a CR (chloroprene) rubber layer is provided on a PVDF (polyvinylidene fluoride) underlayer, and a PTFE (polytetrafluoroethylene) coating layer is formed thereon. This is a belt. In some cases, a conductive filler such as carbon black is added to the coating layer in order to impart conductivity.

  The primary transfer roller 133 is for primary transfer of the toner image formed on the photosensitive drum 135 to the intermediate transfer belt 132. That is, in the present embodiment, the primary transfer roller 133 is a transfer unit that sandwiches the intermediate transfer belt 132 and primarily transfers the toner image on the circumferential surface of the photosensitive drum 135 to the intermediate transfer belt 132.

  Further, the primary transfer roller 133 is disposed at a position facing each photosensitive drum 135 with the intermediate transfer belt 132 interposed therebetween. The primary transfer roller 133 is provided for each photosensitive drum 135 of each image forming unit 131. Further, as described above, the primary transfer roller 133 is in contact with the intermediate transfer belt 132 so that the intermediate transfer belt 132 is pressed against the photosensitive drum 135. In addition, the primary transfer roller 133 rotates depending on the endless rotation of the intermediate transfer belt 132 while being in contact with the intermediate transfer belt 132. At that time, by applying a primary transfer bias voltage having a polarity opposite to the charging polarity of the toner to each primary transfer roller 133, the toner image formed on each photoconductor drum 135 is changed to each photoconductor drum. Primary transfer is performed on the intermediate transfer belt 132 between the 135 and the corresponding primary transfer rollers 133. As a result, the toner images formed on the respective photosensitive drums 135 are sequentially primary-transferred sequentially in an overcoated state on the intermediate transfer belt 132 that rotates in the direction of the arrow (counterclockwise in FIG. 1).

  The secondary transfer roller 134 is for transferring (secondary transfer) the toner image on the intermediate transfer belt 132 onto the paper P fed from the paper feeding unit 12. That is, in the present embodiment, the secondary transfer roller 134 contacts the peripheral surface of the intermediate transfer belt 132 to form a nip portion, and the intermediate transfer belt 132 is formed on a sheet P that is a recording medium passing through the nip portion. 2 is a secondary transfer portion for secondary transfer of the toner image on the peripheral surface of the toner.

  The secondary transfer roller 134 is disposed at a position facing the drive roller 136 with the intermediate transfer belt 132 interposed therebetween. Further, the secondary transfer roller 134 is rotated in accordance with the endless rotation of the intermediate transfer belt 132 while being in contact with the intermediate transfer belt 132. At this time, a secondary transfer bias voltage having a polarity opposite to the charging polarity of the toner is applied to the secondary transfer roller 134 so that the toner image primarily transferred onto the intermediate transfer belt 132 is transferred to the secondary transfer roller 132. Secondary transfer is performed between the sheet 134 and the driving roller 136 on the sheet P fed from the sheet feeding unit 12. As a result, the toner image based on the image information is transferred onto the paper P in an unfixed state.

  In addition, the image forming unit 13 further includes a cleaning device 200 at a position downstream of the secondary transfer position in the rotation direction from the secondary transfer position and upstream of the primary transfer position in the rotation direction. The cleaning device 200 is for removing and cleaning the toner remaining on the peripheral surface of the intermediate transfer belt 132 after the secondary transfer. The peripheral surface of the intermediate transfer belt 132 cleaned by the cleaning device 200 goes to the primary transfer position for a new primary transfer process. The waste toner removed by the cleaning device 200 is collected in a toner collection bottle (not shown) through a predetermined path and stored. The configuration of the cleaning device 200 will be described later.

  The fixing unit 14 performs a fixing process on the toner image on the paper P transferred by the image forming unit 13. The fixing unit 14 is stretched between a heating roller 141 including an energization heating element as a heating source therein, a fixing roller 142 oriented with the heating roller 141, and the fixing roller 142 and the heating roller 141. A fixing belt 143 and a pressure roller 144 disposed to face the fixing roller 142 with the fixing belt 143 interposed therebetween are provided.

  The paper P supplied to the fixing unit 14 is heated and pressed by passing through a fixing nip formed between the fixing belt 143 and the pressure roller 144. As a result, the toner image transferred to the paper P by the image forming unit 13 is fixed to the paper P. The sheet P that has been subjected to the fixing process is discharged toward the sheet discharge tray 151 of the sheet discharge unit 15 provided at the top of the apparatus main body 11 through the sheet conveyance path 111 extending from the upper part of the fixing unit 14. Paper.

  The paper discharge unit 15 is formed by recessing the top of the apparatus main body 11, and a paper discharge tray 151 for receiving the discharged paper P is formed at the bottom of the concave portion.

  Hereinafter, the cleaning device 200 will be described. FIG. 2 is a schematic cross-sectional view showing the configuration of the cleaning device 200 according to the embodiment of the present invention, and shows an enlarged peripheral portion of the cleaning device 200 provided in the image forming apparatus 10 shown in FIG. is there.

  The cleaning device 200 includes a removal roller 201, a collection roller 202, a blade 204, a discharge unit 205, a sheet 203, and the like.

  The removal roller 201 removes residual toner on the intermediate transfer belt 132 by rotating while contacting the surface of the intermediate transfer belt 132 that is an image carrier. At that time, during the secondary transfer, the paper is pressed against the intermediate transfer belt 132 by the secondary transfer roller 134, so that paper-derived foreign matters such as paper dust generated from the paper are also removed from the intermediate transfer belt 132. The

  The removal roller 132 is not particularly limited as long as it can remove residual toner and paper-derived foreign matter from the intermediate transfer belt 132. For example, a fur brush etc. are mentioned. By using a fur brush as the removal roller, it is possible to remove residual toner on the intermediate transfer belt 132 and foreign matters derived from the paper while suppressing damage to the intermediate transfer belt 132 as an image carrier. Moreover, as a fur brush, the brush etc. which made the fur brush shape etc. which wound the bundle which bundled the several filament yarn and made it pile shape are mentioned, for example.

  The collection roller 202 collects the toner and foreign matter removed by the removal roller 201 by rotating while contacting the surface of the removal roller 201. The collection roller 202 is not particularly limited as long as it can collect residual toner and paper-derived foreign matter from the removal roller 201. Specifically, a metal roller having a voltage application unit that applies a voltage to the metal roller can be used. By applying a voltage to the metal roller, residual toner and paper-derived foreign matter can be collected from the removal roller 201. This is because the residual toner is considered to be charged, for example, positively charged. Then, it is considered that the toner is adsorbed by applying a voltage so that the metal roller is charged with a polarity opposite to that of the toner. At that time, it is considered that the paper powder is weaker than the toner and is attracted to the collection roller, but the paper powder is also collected by the collection roller.

  The blade 204 comes into contact with the surface of the collection roller 202 and separates toner and foreign matter collected by the collection roller 202 from the collection roller 202. The separated toner and paper dust move to the discharge unit 205 positioned in the lower direction of the blade 204.

  The blade 204 is not particularly limited as long as it can separate toner and foreign matter from the collection roller 202. For example, a resin plate-like member can be used. One end of the plate member is in contact with the surface of the collection roller 202. The plate-like member is in contact so that the direction from the other end toward the end in contact with the surface of the collection roller 202 is opposite to the rotation direction of the collection roller 200. ing. By doing so, the toner and foreign matter collected by the collection roller 202 are separated from the collection roller 202 so as to be scraped by the blade 204.

  The discharge unit 205 discharges the toner and foreign matter separated from the collection roller 202 from the cleaning device 200. The discharge unit 205 includes, for example, a discharge roller in parallel with the collection roller 202 and the like, and the rotation of the discharge roller removes toner and foreign matter in a direction in which the discharge roller extends (perpendicular to the paper surface in FIG. 2). And the like and the like discharged from the cleaning device 200. The waste toner removed by the cleaning device 200 is collected in a toner collection bottle (not shown) through a predetermined path and stored.

  The sheet 203 is disposed between the removal roller 201 and the discharge unit 205, and one end thereof is brought into contact with the surface of the collection roller 202. The sheet 203 is in contact so that the direction from the other end toward the end in contact with the surface of the collection roller 202 is the same as the rotation direction of the collection roller 200. That is, it is installed so as to face the blade 204, and the sheet 203 and the blade 204 partition the removal roller 201 side and the discharge unit 205 side.

  Without such a sheet 203, the toner and foreign matter separated from the collection roller 202 by the blade 203 are left to free fall, so that not only the discharge unit 205 located below the blade 204 but also the removal is removed. It is considered that the toner also scatters by moving to the roller 201 side. The sheet 203 is for suppressing the toner scattering.

  In addition, at least an area of the sheet 203 that is in contact with the collection roller 202 can have a large number of fine particles such that toner and foreign matter can pass between the collection roller 202 and the sheet 203 by the rotation of the collection roller 202. This is a roughened region having a concave portion and a convex portion. By using the sheet 203 having such a roughened area so that the roughened area is in contact with the collecting roller 202, toner scattering as described later can be suppressed.

  The sheet 203 preferably allows the toner and foreign matter on the collection roller 202 to pass therethrough. Since the sheet 203 is installed in the same direction as the rotation direction of the collection roller 202, it is considered that the toner strongly adhered to the collection roller 202 passes. On the other hand, paper dust tends to accumulate on the downstream side of the sheet 203 in the rotation direction of the collection roller 202. This is presumably because, as described above, the power adhering to the collection roller 202 is weaker with paper powder than with toner. When such accumulation of paper powder proceeds, it is considered that paper powder enters between the sheet 203 and the collection roller 202, and the sheet 203 and the collection roller 202 are separated from each other. Therefore, the toner is scattered from between the sheet 203 and the collection roller 202, and the toner scattering may not be sufficiently suppressed.

  Therefore, by using the sheet as described above so that the roughened area is in contact with the collection roller 202, a cleaning device in which toner scattering is sufficiently suppressed can be obtained.

  Further, the roughened region has a large number of fine concave portions and convex portions that allow toner and foreign matter to pass between the collection roller 202 and the sheet 203 as described above. There is no particular limitation. Specifically, for example, the roughened region is preferably a region subjected to mat processing. That is, it is preferable that the region is subjected to a so-called processing called “texture processing”. Moreover, it is preferable that the said roughening area | region is equipped with the fine convex part and recessed part which were formed by performing a mat | matte process by chemical etching or a blast process. By doing so, toner scattering can be further suppressed. This is considered because it becomes easy for foreign matters derived from paper such as paper dust to pass between the sheet 203 and the collection roller 202.

  Moreover, the surface roughness of the roughened region is preferably 2 to 13 μm, more preferably 5 to 10 μm, and further preferably 8 to 10 μm in terms of the maximum height Ry. If the unevenness of the roughened area is too small and smooth, paper powder tends to accumulate on the downstream side of the sheet 203 in the rotation direction of the collection roller 202. This is considered to be due to the fact that the sheet 203 has high adhesion to the collection roller 202 and paper dust does not easily pass between the sheet 203 and the collection roller 202. Further, even when the unevenness of the roughened region is too large and rough, paper powder tends to accumulate on the downstream side of the sheet 203 in the rotation direction of the collection roller 202. This means that the entire sheet 203 does not have high adhesion to the collection roller 202, but the convex portion of the roughened area strongly hits the collection roller 202. This is considered to be due to the phenomenon that paper dust hardly passes between 203 and the collection roller 202. Therefore, the scattering of the toner can be further suppressed by making the roughened region whose surface roughness is 2 to 13 μm at the maximum height Ry come into contact with the collection roller 202. This is considered because it becomes easy for foreign matters derived from paper such as paper dust to pass between the sheet 203 and the collection roller 202.

  The maximum height Ry is a value measured by a method according to JIS B 0601: 2001. For example, the surface roughness can be measured using a surface roughness measuring machine, specifically, Surfcom 570A manufactured by Tokyo Seimitsu Co., Ltd.

  Further, the roughened region preferably has a static friction coefficient smaller than that of the region of the sheet 203 other than the roughened region. In the case where the entire surface of the sheet 203 is subjected to a roughening process, the roughened region preferably has a static friction coefficient smaller than that of the sheet 203 before the roughening process.

  If the coefficient of static friction in the roughened area is too large compared to other areas, paper dust tends to accumulate on the downstream side of the sheet 203 in the rotation direction of the collection roller 202. This is presumably because paper dust hardly passes between the sheet 203 and the collection roller 202. Therefore, toner scattering can be further suppressed by reducing the static friction coefficient of the roughened region as described above.

  The static friction coefficient can be measured using a portable friction meter (Tribogear Muse 94i-II) manufactured by Shinto Kagaku Co., Ltd.

  Such a cleaning device can sufficiently suppress toner scattering.

  This is considered to be due to the following.

  Such a cleaning device is different from a cleaning device in which a sheet is simply provided between the removing roller and the discharge unit as a sealing material, and the above-described sheet as a sealing material for preventing toner scattering. Is used. Specifically, at least an area in contact with the collection roller has a large number of minute recesses and projections that allow the toner and the foreign matter to pass between the collection roller and the sheet by rotation of the collection roller. A sheet which is a roughened region having a portion is used. By doing so, not only the residual toner easily passes between the sheet as the sealing material and the collection roller, but also foreign matters derived from paper such as paper dust easily pass. From this, it is considered that accumulation of foreign matters such as paper dust is suppressed on the downstream side of the sheet in the rotation direction of the collection roller. Therefore, it is possible to prevent foreign matter from entering between the sheet and the collection roller, and to separate the sheet and the collection roller, and the sheet preferably works as a sealing material that suppresses toner scattering. It is considered possible.

  Therefore, the image forming apparatus provided with the cleaning device as described above can form a high-quality image. This is considered to be because, first of all, it is possible to suppress deterioration in the image quality of the formed image due to the presence of residual toner and paper-derived foreign matter. Further, since the toner scattering in the cleaning device is suppressed, it is considered that the deterioration of the image quality of the formed image due to the toner scattering can be suppressed.

  In the above-described image forming apparatus, the cleaning device according to the present embodiment transfers the toner image developed by the developing device and transfers the transferred toner image onto a sheet. It is provided for removing residual toner and foreign matters on the transfer belt, that is, provided as a belt cleaning device. The cleaning device according to the present embodiment is not limited to use as such a belt cleaning device, and can be used for removing toner. For example, as shown in FIG. 3, a photosensitive member that forms a toner image developed by a developing device on its surface, specifically, used to remove residual toner and foreign matter on the photosensitive drum. it can. That is, it can be used as a cleaning device for cleaning the photoreceptor, such as a drum cleaning device. Therefore, the cleaning device according to the present embodiment can be used as a belt cleaning device or a cleaning device for cleaning a photoreceptor such as a drum cleaning device.

  Hereinafter, a case where the cleaning device according to the present embodiment is used as a drum cleaning device will be described.

  FIG. 3 is a schematic diagram showing the periphery of the image forming unit of the image forming apparatus 300 to which the cleaning device according to the embodiment of the present invention is applied. The image forming apparatus 300 is an apparatus that forms a predetermined image on a sheet 330 that is a recording medium by an electrophotographic method. Further, as shown in FIG. 3, the image forming apparatus 300 is arranged around a photosensitive drum 331 that is an image carrier in order along the rotation direction A of the photosensitive drum 331, in order, a charging device 332, an exposure device 333, and a developing device. A device 334, a transfer roller 336, a cleaning device 200, a static eliminator 338, and the like are provided. Note that the cleaning device 200 and the static eliminator 338 may be reversely arranged.

  In the present embodiment, the photosensitive drum 331 is described by taking a photosensitive drum as a drum-shaped photosensitive member as an example. However, the photosensitive drum 331 is not limited thereto, and is not limited to this, and a belt-shaped photosensitive member and a sheet-shaped photosensitive member. It can also be applied to the body. The charging device 332 charges the surface of the photosensitive drum 331. The exposure device 333 forms an electrostatic latent image by selectively attenuating the surface potential of the photosensitive drum 331 by irradiating light based on image data. The developing device 334 forms a toner image by developing the electrostatic latent image formed on the surface of the photosensitive drum 31 with toner. The transfer roller 336 transfers the toner image formed on the photosensitive drum 331 onto the paper 330. The cleaning device 200 is a device for removing toner remaining on the surface of the photosensitive drum 331. The cleaning device 200 is the same as the cleaning device except that the removal roller 201 provided is changed from the intermediate transfer belt to the photosensitive drum. The neutralization device 338 neutralizes the surface charge of the photosensitive drum 331 with lamp light.

  Further, the image forming apparatus 300 includes a fixing device 341 (a heating roller 342 and a pressure roller 343) on the downstream side in the conveyance direction of the paper 330. The fixing device 341 applies heat and pressure to the paper 330 on which the toner image is transferred to fix the toner image, thereby forming a predetermined image on the paper 330. According to such an image forming apparatus, a high-quality image can be formed. This is presumably because toner scattering in the cleaning device is suppressed and the photosensitive drum is preferably cleaned.

  The sheet was examined using an image forming apparatus as shown in FIG.

Example 1
First, as a sheet of a cleaning device (cleaning device shown in FIG. 2) provided in the image forming apparatus, at least an area in contact with the collecting roller is rotated between the collecting roller and the sheet by the rotation of the collecting roller. A sheet which is a roughened region having a large number of fine concave portions and convex portions so that foreign substances can pass therethrough was used.

  Specifically, the region in contact with the collection roller was subjected to mat processing (texture processing) by chemical etching, and a sheet was provided so that the region was in contact with the collection roller. The surface roughness of this roughened region was 13 μm at the maximum height Ry. The maximum height Ry was measured using a surface roughness measuring machine (Surfcom 570A manufactured by Tokyo Seimitsu Co., Ltd.). In the roughened region, the static friction coefficient is smaller than the static friction coefficient in the region other than the roughened region of the sheet. The relationship between the static friction coefficient and the static friction coefficient of the roughened area of the sheet using a portable friction meter (Tribogear Muse 94i-II) manufactured by Shinto Kagaku Co., Ltd. It was determined by measuring the static friction coefficient.

(Example 2)
The surface roughness of the roughened region is the same as in Example 1 except that a sheet having a maximum height Ry of 3 μm was used.

(Example 3)
The surface roughness of the roughened region is the same as in Example 1 except that a sheet having a maximum height Ry of 7 μm was used.

Example 4
The surface roughness of the roughened region is the same as in Example 1 except that a sheet having a maximum height Ry of 9 μm was used.

(Comparative Example 1)
Example 2 is the same as Example 1 except that a sheet not subjected to surface roughening such as mat processing is used as a sheet of a cleaning device (cleaning device shown in FIG. 2) provided in the image forming apparatus.

  And the surface roughness of the area | region which contacts a collection | recovery roller of this sheet | seat was 1 micrometer by the maximum height Ry. In this sheet, since the area that contacts the collection roller and the other area are not subjected to the roughening treatment, their static friction coefficients are approximately the same.

(Comparative Example 2)
As a sheet of the cleaning device (cleaning device shown in FIG. 2) provided in the image forming apparatus, at least an area in contact with the recovery roller cannot pass foreign matter between the recovery roller and the sheet due to rotation of the recovery roller. Example 1 is the same as Example 1 except that a sheet that is a roughened region having a large number of fine concave portions and convex portions is used.

  Specifically, the sheet from which the foreign substance cannot pass is a sheet having a roughened region with a surface roughness of 100 μm at the maximum height Ry.

  Image formation was performed using the image forming apparatus provided with the cleaning apparatuses according to Examples 1 to 4 and Comparative Examples 1 and 2. As a result, in Examples 1 to 4, the amount of paper dust collected in the interior of the removing roller side from the sheet was smaller in the cleaning device than in Comparative Examples 1 and 2. This is considered to indicate that the accumulation of paper dust on the downstream side of the collection roller of the sheet is suppressed. In Examples 1 to 4, since accumulation of paper dust is suppressed as compared with Comparative Examples 1 and 2, toner scattering in the cleaning device is suppressed. Therefore, it was found that the image forming apparatuses according to Examples 1 to 4 can form high-quality images as compared with Comparative Examples 1 and 2.

  Further, in Example 4 where Ry was 9 μm, the amount of paper dust accumulated inside the removal roller side of the sheet was less in the cleaning device than in Examples 1 to 3. Further, in Example 3 where Ry was 7 μm, the amount of paper dust accumulated in the interior of the removal roller side from the sheet was smaller in the cleaning device than in Example 1 and Example 2. From these, it is understood that Ry is preferably 2 to 13 μm, more preferably 5 to 10 μm, and further preferably 8 to 10 μm.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 132 Intermediate transfer belt (image carrier)
200 Cleaning Device 201 Removal Roller 202 Recovery Roller 203 Sheet 204 Blade 205 Discharge Portion

Claims (8)

A removal roller that contacts the surface of the image carrier and removes toner remaining on the image carrier after the toner image on the image carrier is transferred to paper and foreign matters derived from the paper;
A collection roller that contacts the surface of the removal roller and collects the toner and foreign matter removed by the removal roller;
A blade that contacts the surface of the collection roller and separates the toner and foreign matter collected by the collection roller from the collection roller;
A discharge section for discharging toner and foreign matter separated from the collection roller;
A sheet disposed between the removal roller and the discharge unit, and having one end in contact with the surface of the collection roller;
A number of fine recesses and protrusions in which at least an area of the sheet that contacts the recovery roller can pass the toner and the foreign matter between the recovery roller and the sheet by rotation of the recovery roller. A cleaning device characterized by being a roughened region.   The cleaning apparatus according to claim 1, wherein the roughened region includes fine concave portions and convex portions formed by performing mat processing by chemical etching or blasting.   The cleaning device according to claim 1, wherein the roughened region has a surface roughness of 2 to 13 μm at a maximum height Ry.   The cleaning device according to claim 1, wherein a static friction coefficient of the roughened region is smaller than a static friction coefficient of a region other than the roughened region of the sheet.   The cleaning device according to claim 1, wherein the removing roller is a fur brush.   The cleaning device according to claim 1, wherein the image carrier is an intermediate transfer member to which a toner image developed by a developing device is transferred, and the transferred toner image is transferred to a sheet.   The cleaning device according to claim 1, wherein the image bearing member is a photosensitive member that forms a toner image developed by a developing device on the surface thereof.   An image forming apparatus comprising the cleaning device according to claim 1.

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