JP2008134549A - Cleaning device, and image forming apparatus mounted therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device surely removing discharge products without generating discharge breakdown on an image carrier surface, and maintaining suitable cleaning performance. <P>SOLUTION: The cleaning device 80 is provided with: a cleaning roller 82 and a cleaning blade 83 removing a matter stuck on the surface of a photoreceptor drum 21; and a toner receiving member 84 spaced from the surface of the cleaning roller 82 and storing toner removed from the photoreceptor drum 21 to a space with the cleaning roller 82. Regarding the toner receiving member 84, the length extending to the circumferential direction of the cleaning roller 8 so as to be separated from the contact part between the photoreceptor drum 21 and the cleaning roller 82 in the parts of the prescribed regions corresponding to both the edge parts in the axial direction of the cleaning roller 82 is shorter than that in the other regions. In this way, the toner stored in the toner receiving member 84 is easily discharged from both the edge parts in the axial direction of the cleaning roller 82. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cleaning device for transferring a toner image onto a sheet and then removing adhering matter such as toner remaining on the surface of an image carrier to perform cleaning. The present invention also relates to an electrophotographic image forming apparatus typified by a copying machine or a printer equipped with this cleaning device.

  In an electrophotographic image forming apparatus such as a copying machine or a printer, a photosensitive drum is widely used as an image carrier. A general image forming operation using the photosensitive drum is as follows. The surface of the photosensitive drum is uniformly charged with a predetermined potential by a charging device, and by irradiating the LED light or the like of the exposure device there, the potential is partially attenuated to form an electrostatic latent image of an original image. Is done. The electrostatic latent image is developed with a developing device, whereby a toner image is formed on the surface of the photosensitive drum. This toner image is transferred to the sheet when the sheet is inserted into a transfer region formed by bringing the photosensitive drum and the transfer member into contact with each other or close to each other.

  In such an image forming apparatus, after a toner image is transferred to a sheet, a small amount of toner may remain on the surface of the photosensitive drum without being transferred to the sheet. The residual toner adhering to the surface of the photosensitive drum becomes an obstacle to the next new image formation, so that it needs to be cleaned. As a cleaning method used for such a purpose, a method of moving and collecting residual toner on the rotating member by pressing a cleaning roller, a rotating brush, or the like that is a rotating member on the surface of the photosensitive drum, or a surface of the photosensitive drum A method of scraping residual toner by bringing a cleaning blade into contact therewith, or a cleaning method combining these methods is widely known.

  On the other hand, when an amorphous silicon photoconductor is used as the photoconductor, it is known that discharge products easily adhere to the surface of the photoconductor due to the discharge of the charging device. When this discharge product absorbs moisture, the electrical resistance on the surface of the photoreceptor is lowered, and a problem of image flow that disturbs the electrostatic latent image may occur. For this reason, a small amount of abrasive is mixed in the toner, and the cleaning roller and the cleaning blade are used in combination to remove the residual toner adhering to the surface of the photosensitive member, and a small amount of toner is carried on the surface of the cleaning roller. There is known a method of cleaning by discharging the discharge product adhering to the surface of the photoreceptor.

An example of a cleaning method for removing the discharge product adhering to the surface of the photosensitive drum using the cleaning roller and the cleaning blade as described above can be seen in Patent Document 1 and Patent Document 2.
JP-A-10-63157 (page 2-3, FIG. 1) Japanese Patent Laying-Open No. 2005-49620 (page 3-5, FIG. 1)

  An image forming apparatus described in Patent Literature 1 and Patent Literature 2 includes a cleaning roller (sliding roller) that contacts a photosensitive drum and polishes the surface thereof, and a cleaning blade provided on the downstream side in the drum rotation direction. And a cleaning roller (rubbing roller) is cleaned by polishing the surface of the photosensitive drum with toner removed directly from the surface of the photosensitive drum or moved by being removed by the cleaning blade. However, in such an image forming apparatus, the toner removed from the surface of the photosensitive drum by the cleaning roller or the cleaning blade is sent to and adhered to the surface of the cleaning roller simply by the action of gravity. However, it is easy to leave. This makes it difficult to carry an appropriate amount of toner on the surface of the cleaning roller. As a result, the surface of the photosensitive drum is not sufficiently polished by the cleaning roller, and there is a high possibility that the discharge product attached to the surface of the photosensitive member cannot be removed.

  On the other hand, even when an appropriate amount of toner is carried on the surface of the cleaning roller, a smooth flow of toner in the vicinity of the surface must be ensured in the entire axial direction and the design must be devised so that the toner can be carried easily. Don't be. If neglected, the inner wall of the housing of the cleaning device may block the flow of toner at both ends in the axial direction of the cleaning roller, and the toner may stay. As a result, when the staying toner is peeled from the surface of the photoconductor, a peeling discharge with a very large amount of charge may occur, and the surface of the photoconductor may be destroyed by discharge.

  The present invention has been made in view of the above points, and includes a polishing agent in a cleaning device that removes deposits such as toner remaining on the surface of an image carrier and cleans them after transferring a toner image onto a sheet. While taking care that the toner can move smoothly in the vicinity of the surface of the cleaning roller that removes the adhering matter adhered to the surface of the image carrier by the toner to be applied, an appropriate amount of toner can be reliably carried on the surface of the image bearing member. An object of the present invention is to provide a cleaning device capable of maintaining a suitable cleaning performance for the body surface. Another object of the present invention is to provide a high-performance image forming apparatus equipped with such a cleaning device.

  In order to solve the above-mentioned problems, the present invention is provided with a cleaning roller that removes deposits on the surface of the image carrier while rotating in contact with the image carrier, and is provided downstream of the cleaning roller in the image carrier rotation direction. In a cleaning device comprising a cleaning blade that contacts the carrier and scrapes off the toner on the surface, the toner is disposed with a gap with respect to the surface of the cleaning roller, and the toner removed from the image carrier is removed from the cleaning roller. The toner receiving member is provided between the image bearing member and the cleaning roller at a predetermined area corresponding to both ends of the cleaning roller in the axial direction of the cleaning roller. The length of the cleaning roller extending in the circumferential direction so as to be separated from the length of other regions It was shorter.

  In the cleaning device having the above-described configuration, the toner receiving member is a bowl-shaped member along the peripheral surface of the cleaning roller.

  In the cleaning device having the above-described configuration, the cleaning blade is disposed on the lower side in the vertical direction with respect to the cleaning roller.

  In the present invention, the cleaning device is mounted on the image forming apparatus.

  According to the configuration of the present invention, the cleaning roller that rotates in contact with the image carrier and removes deposits on the surface thereof is provided on the downstream side of the cleaning roller in the rotation direction of the image carrier, and contacts the image carrier. And a cleaning blade that scrapes off the toner on the surface of the cleaning roller. The toner is disposed with a gap with respect to the surface of the cleaning roller and stores the toner removed from the image carrier between the cleaning roller and the cleaning roller. The toner receiving member includes a receiving member, and the toner receiving member is separated from a contact portion between the image carrier and the cleaning roller at a predetermined region corresponding to both ends of the cleaning roller in the axial direction of the cleaning roller. The length extending in the circumferential direction is shorter than the length of other areas. The toner removed from the surface of the image carrier by the cleaning roller or the cleaning blade is stored in the toner receiving member, so that pressure can be applied from the periphery of the cleaning roller to adhere to the cleaning roller. The stored toner is easily discharged from both ends in the cleaning roller axial direction. Thereby, in addition to preventing the toner from being easily separated from the surface of the cleaning roller, it is possible to smoothly move the toner at both ends of the cleaning roller in the axial direction. Accordingly, it is possible to form a suitable toner layer on the surface of the cleaning roller without causing discharge breakdown on the surface of the photoreceptor, and it is effective to polish the surface of the image carrier using the toner containing the abrasive by the cleaning roller. Can be accomplished. As a result, the discharge product adhering to the surface of the image carrier can be surely removed, and a cleaning device capable of maintaining a suitable cleaning performance for the surface of the image carrier can be obtained.

  In addition, since the toner receiving member is a bowl-shaped member along the peripheral surface of the cleaning roller, the space for storing the toner is further reduced, and pressure is applied from the periphery of the cleaning roller to apply the surface of the image carrier. The toner removed from the toner can be adhered to the surface of the cleaning roller. As a result, it is possible to make it difficult for the toner to be separated from the surface of the cleaning roller, and the effect of carrying an appropriate amount of toner is enhanced. Therefore, it is possible to improve the cleaning performance for the surface of the image carrier. Further, since the space for storing the toner is further reduced, the effect of smoothly discharging unnecessary toner can be enhanced. Therefore, aggregation of the toner in the toner receiving member can be prevented, and the effect of preventing the occurrence of problems such as discharge breakdown on the surface of the photoreceptor can be further improved. Furthermore, the space occupied by the toner receiving member can be reduced, and the cleaning device can be made compact.

  Further, since the cleaning blade is disposed on the lower side in the vertical direction with respect to the cleaning roller, the toner removed from the surface of the image carrier falls immediately below without adhering to the cleaning roller. This can be prevented by providing a toner receiving member. Therefore, even when the cleaning roller is provided in the upper part of the housing of the cleaning device and the cleaning blade is provided below the cleaning roller, the surface of the image carrier is polished by the cleaning roller by the action of the toner receiving member. The discharge product adhering to the surface of the image carrier can be surely removed.

  In the present invention, since the cleaning device is mounted on the image forming apparatus, an appropriate amount of toner is reliably supported on the surface of the cleaning roller while considering that the toner can smoothly move in the vicinity of the surface of the cleaning roller. And a high-performance image forming apparatus capable of maintaining a suitable cleaning performance for the surface of the image carrier.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  First, an image output operation of an image forming apparatus equipped with a cleaning device according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic vertical sectional front view of an image forming apparatus. This image forming apparatus is of a color printing type in which a toner image is transferred onto a sheet using an intermediate transfer belt.

  As shown in FIG. 1, a paper feed cassette 3 is disposed below the inside of the main body 2 of the image forming apparatus 1. The paper feed cassette 3 stores and accommodates paper P such as cut paper before printing. The sheets P are separated and sent one by one toward the upper left of the sheet cassette 3 in FIG. The paper feed cassette 3 can be pulled out horizontally from the front side of the main body 2.

  A first paper transport unit 4 is provided inside the main body 2 and to the left of the paper feed cassette 3. The first paper transport unit 4 is formed substantially vertically along the left side surface of the main body 2. The first paper transport unit 4 receives the paper P sent out from the paper feed cassette 3 and transports the paper P vertically upward along the left side surface of the main body 2 to the secondary transfer unit 40.

  A manual paper feed unit 5 is provided above the paper feed cassette 3 at a location on the right side which is the side opposite to the left side of the main body 2 where the first paper transport unit 4 is formed. Yes. In the manual sheet feeder 5, paper P of a size that is not contained in the paper cassette 3, thick paper, and OHP sheets that are to be fed one by one are placed.

  A second paper transport unit 6 is provided on the left side of the manual paper feed unit 5. The second paper transport unit 6 is located immediately above the paper feed cassette 3, extends substantially horizontally from the manual paper feed unit 5 to the first paper transport unit 4, and joins the first paper transport unit 4. Then, the second paper transport unit 6 receives the paper P or the like sent from the manual paper feed unit 5 and transports it to the first paper transport unit 4 substantially horizontally.

  On the other hand, the image forming apparatus 1 receives document image data from an external computer (not shown). The information of the image data is sent to a laser irradiation unit 7 that is an exposure unit disposed above the second paper transport unit 6. The laser irradiation unit 7 irradiates the image forming unit 20 with laser light L controlled based on the image data.

  A total of four image forming units 20 are provided above the laser irradiation unit 7, and an intermediate transfer belt 8 using an intermediate transfer member in the form of an endless belt is provided above each image forming unit 20. The intermediate transfer belt 8 is supported by being wound around a plurality of rollers, and is rotated clockwise in FIG. 1 by a driving mechanism (not shown).

  As shown in FIG. 1, the four image forming units 20 are of a so-called tandem system that are arranged in a line from the upstream side to the downstream side in the rotational direction along the rotational direction of the intermediate transfer belt 8. The four image forming units 20 are, in order from the upstream side, a magenta image forming unit 20M, a cyan image forming unit 20C, a yellow image forming unit 20Y, and a black image forming unit 20B. These image forming units 20 are replenished with a developer (toner) by a developer supply container and a conveying unit (not shown) corresponding to each color. In the following description, the identification symbols “M”, “C”, “Y”, and “B” are omitted unless particularly limited.

  In each image forming unit 20, an electrostatic latent image of a document image is formed by the laser light L irradiated by the laser irradiation unit 7 serving as an exposure unit, and the toner image is developed from the electrostatic latent image. The toner image is primarily transferred onto the surface of the intermediate transfer belt 8 by a primary transfer unit 30 provided above each image forming unit 20. As the intermediate transfer belt 8 rotates, the toner image of each image forming unit 20 is transferred to the intermediate transfer belt 8 at a predetermined timing. A color toner image is formed by superimposing the color toner images.

  A secondary transfer unit 40 including a secondary transfer roller 41 is disposed at a position where the intermediate transfer belt 8 is suspended on the sheet conveyance path. The color toner image on the surface of the intermediate transfer belt 8 is a secondary formed by the intermediate transfer belt 8 and the secondary transfer roller 41 being pressed against the paper P sent in synchronization by the first paper transport unit 4. Transferred at the transfer nip.

  After the secondary transfer, deposits such as toner remaining on the surface of the intermediate transfer belt 8 are cleaned for the intermediate transfer belt 8 provided upstream of the intermediate transfer belt 8 in the rotation direction of the magenta image forming unit 20M. It is cleaned and collected by the device 9.

  A fixing unit 10 is provided above the secondary transfer unit 40. The paper P carrying the unfixed toner image in the secondary transfer unit 40 is sent to the fixing unit 10 where the toner image is heated and pressed by the heat roller and the pressure roller to be fixed.

  A branch portion 11 is provided above the fixing portion 10. The sheet P discharged from the fixing unit 10 is discharged from the branching unit 11 to the sheet discharging unit 12 provided on the upper part of the image forming apparatus 1 when double-sided printing is not performed.

  The discharge port portion from which the paper P is discharged from the branch portion 11 toward the paper discharge portion 12 functions as the switchback portion 13. When performing duplex printing, the switchback unit 13 switches the transport direction of the paper P discharged from the fixing unit 10. Then, the sheet P is sent downward through the branching unit 11, the left side of the fixing unit 10, and the left side of the secondary transfer unit 40, and again passes through the first sheet transport unit 4 to the secondary transfer unit 40. Sent.

  Next, a detailed configuration around the image forming unit 20 of the image forming apparatus 1 will be described with reference to FIGS. 2 is a partially enlarged vertical sectional view showing the periphery of the image forming unit, FIG. 3 is a perspective view showing the photosensitive drum and the inside of the cleaning device, FIG. 4 is a perspective view of a toner receiving member of the cleaning device, and FIG. It is a partial expansion perspective view which shows the edge part of a member. Since the four color image forming units 20 have the same structure, the identification symbols “M”, “C”, “Y”, and “B” are omitted as described above.

  As shown in FIG. 2, the image forming unit 20 includes a photosensitive drum 21 as an image carrier at the center thereof. In the vicinity of the photosensitive drum 21, a charging device 50, a developing device 60, a charge removal device 70, and a drum cleaning device 80 are arranged in this order along the rotation direction. The primary transfer unit 30 is provided between the developing device 60 and the charge removal device 70 along the rotation direction of the photosensitive drum 21.

  The photosensitive drum 21 extends in the paper width direction perpendicular to the paper conveyance direction in the image forming apparatus 1, that is, the depth direction of the paper surface in FIG. The photosensitive drum 21 is an inorganic photosensitive drum in which an amorphous silicon photosensitive layer, which is an inorganic photoconductive material, is provided on the outside of a conductive roller-shaped substrate made of aluminum or the like by vacuum deposition or the like, and has a diameter of 30 mm. It is. The photosensitive drum 21 is rotated by a driving mechanism (not shown) so that the peripheral speed thereof is substantially the same as the paper transport speed (147 mm / s).

  The charging device 50 includes a charging roller 52 in contact with the photosensitive drum 21 inside the housing 51. The charging roller 52 is in pressure contact with the photosensitive drum 21 with a predetermined pressure, and rotates according to the rotation of the photosensitive drum 21. By this charging roller 52, the surface of the photosensitive drum 21 is uniformly charged with a predetermined polarity and potential. The charging potential at this time is usually about 200 to 1000V. In the housing 51, a cleaning brush 53 is provided at a position separating the charging roller 52 from the photosensitive drum 21, and the surface of the charging roller 52 is cleaned by the cleaning brush 53.

  The developing device 60 includes a developing roller 62 and a supply screw 63 inside the housing 61. The developing roller 62 is in contact or non-contact with the developing system, and is provided in the vicinity of the photosensitive drum 21. A bias having the same polarity as the charging polarity of the photosensitive drum 21 is applied to the developing roller 62. The developing roller 62 charges the toner, which is a developer, and moves it to the electrostatic latent image on the surface of the photosensitive drum 21 to develop the electrostatic latent image.

  The developing device 60 uses a two-component toner obtained by mixing a magnetic carrier and a non-magnetic toner as a developer, but may be of a type using a magnetic or non-magnetic one-component toner. Absent. Further, in order to clean the surface of the photosensitive drum 21 by polishing, a small amount of powder of titanium oxide, alumina or the like is mixed in the toner as an abrasive. The toner is accommodated in a toner supply container (not shown), conveyed to a location of the developing device 60 by a conveying means (not shown), and replenished inside the housing 61 by a supply screw 63.

  The primary transfer unit 30 is provided with a primary transfer roller 31 that comes into contact with the photosensitive drum 21 via the intermediate transfer belt 8. The primary transfer roller 31 rotates according to the rotation of the intermediate transfer belt 8 by contacting the intermediate transfer belt 8 without having a driving mechanism. The primary transfer roller 31 is applied with a primary transfer bias of minus 500 to minus 1000 V, which has a polarity different from the charging polarity of the photosensitive drum 21 or toner, as necessary.

  As shown in FIG. 1, the intermediate transfer belt 8 is wound around and supported by a plurality of rollers. The intermediate transfer belt 8 is constituted by an elastic belt in which a rubber layer is laminated on the surface of a base layer made of a synthetic resin. As materials, polyvinylidene fluoride (PVDF) and chloroprene rubber (CR) are used for the base layer, silicon and urethane, and polytetrafluoroethylene (PTFE) and urethane are used for the coating.

  The neutralization device 70 is disposed on the downstream side of the primary transfer unit 30 along the rotation direction of the photosensitive drum 21. The static eliminator 70 includes an LED (light emitting diode) 71 and a reflector 72. The LED 71 is attached to the upper surface of the housing 81 of the cleaning device 80. Instead of the LED 71, an EL (electroluminescence) light source, a fluorescent lamp, or the like can be used. The reflector 72 is provided above the LED 71 so as to cover the LED 71. The neutralization device 70 irradiates the photosensitive drum 21 with the neutralization light of the LED 71, thereby removing the charged charge on the surface and preparing for the charging process in the next image forming operation.

  The cleaning device 80 is disposed further downstream of the primary transfer unit 30 and the charge removal device 70 along the rotation direction of the photosensitive drum 21. As shown in FIGS. 2 and 3, the cleaning device 80 includes a cleaning roller 82 that is a rotating member, a cleaning blade 83, a toner receiving member 84, a transport paddle 85, and a discharge screw 86 inside a housing 81. Yes.

  The cleaning roller 82 is provided in the upper part of the housing 81 so as to be pressed against the photosensitive drum 21 with a predetermined force by urging means (not shown) provided at both ends of the shaft portion. The cleaning roller 82 is configured by providing ethylene propylene rubber (EPDM) with a thickness of 2 mm around the core, has a diameter of 16 mm, and has substantially the same axial length as the photosensitive drum 21. (See FIG. 3).

  The cleaning roller 82 is rotated by a driving mechanism (not shown) constituted by a motor or the like. In order to efficiently polish the surface of the photosensitive drum 21, it is necessary to rotate the cleaning roller 82 at a predetermined peripheral speed. As a result, the cleaning roller 82 is rotated in such a direction that the surface at the contact point with the photosensitive drum 21 moves in the same direction as the surface of the photosensitive drum 21, and the peripheral speed of the cleaning roller 82 is one of that of the photosensitive drum 21. .2x is set. The cleaning roller 82 collects deposits such as residual toner from the surface of the photosensitive drum 21 and also cleans the surface of the photosensitive drum 21 with the toner containing the abrasive adhered to the surface of the cleaning roller 82. Fulfill.

  The cleaning blade 83 is disposed on the downstream side of the cleaning roller 82 in the rotation direction of the photosensitive drum 21 and on the lower side in the vertical direction with respect to the cleaning roller 82 in the housing 81. The cleaning blade 83 is provided by being pressed with a predetermined force against the photosensitive drum 21 by an urging means (not shown). The cleaning blade 83 is a rectangular parallelepiped member such as a 2.2 mm thick plate made of polyurethane rubber and extending in the drum axial direction, and has substantially the same axial length as the photosensitive drum 21. is doing. The cleaning blade 83 plays a role of cleaning so as to scrape off deposits such as toner remaining on the surface of the photosensitive drum 21.

  As shown in FIGS. 2 and 3, the toner receiving member 84 is disposed immediately below the cleaning roller 82 and between the cleaning roller 82, the cleaning blade 83, and the discharge screw 86. The toner receiving member 84 is configured by bending a thin plate-like member made of stainless steel (SUS) as shown in FIG. The toner receiving member 84 extends in the circumferential direction of the cleaning roller 82 so as to be away from the contact point between the photosensitive drum 21 and the cleaning roller 82, that is, from the vicinity of the cleaning blade 83 toward the downstream side in the rotation direction of the cleaning roller 82. It has a bowl shape extending along the peripheral surface of the cleaning roller 82 and has a length substantially the same as the axial length of the cleaning roller 82.

  As shown in FIGS. 3 and 4, support portions 84 a are provided at both ends of the toner receiving member 84 in the axial direction of the cleaning roller 82. The support portion 84 a is shaped to be hooked on the shaft portion of the cleaning roller 82. As shown in FIGS. 3 to 5, a toner discharge portion 84 b is provided immediately inside the support portion 84 a of the toner receiving member 84. The toner discharge portion 84 b of the toner receiving member 84 is a region 3 mm inward from the position corresponding to both ends in the axial direction of the cleaning roller 82 in the axial direction of the cleaning roller 82, and the contact between the photosensitive drum 21 and the cleaning roller 82. The length extending in the circumferential direction of the cleaning roller 82 so as to be away from the portion is provided so as to be shorter than the length of other regions.

  The toner receiving member 84 is left in a space where the cleaning roller 82 and the cleaning blade 83 are disposed in the housing 81, and a space where the discharge screw 86 is provided, with the upper portion and the toner discharge portion 84b remaining. And the toner removed from the surface of the photosensitive drum 21 is provided so as to be easily stored in the space near the peripheral surface of the cleaning roller 82.

  The transport paddle 85 is disposed below the upper end portion of the toner receiving member 84 and in the vicinity of the inner wall of the housing 81. The transport paddle 85 has substantially the same axial length as the cleaning roller 82 and is rotated by a drive mechanism (not shown). The transport paddle 85 plays a role of preventing toner overflowing from the toner receiving member 84 from staying in the vicinity of the inner wall of the housing 81 and transporting it toward the discharge screw 86.

  The discharge screw 86 is provided below the cleaning roller 82 in the housing 81. The discharge screw 86 extends from the inside of the housing 81 to a waste toner collection container (not shown) provided outside the image forming unit 20. The discharge screw 86 serves to discharge waste toner or the like in the housing 81 that has been removed from the surface of the photosensitive drum 21 and used for cleaning out of the housing 81, that is, to a waste toner collection container.

  The cleaning device 80 as described above uses the cleaning roller 82 and the cleaning blade 83 after the toner image on the surface of the photosensitive drum 21 is transferred to the intermediate transfer belt 8, and the toner remaining on the surface of the photosensitive drum 21. Remove deposits and clean.

  Next, the operation of removing the deposits such as toner remaining on the surface of the photosensitive drum 21 by the cleaning device 80 will be described with reference to FIG. 6 in addition to FIG. FIG. 6 is a partial perspective view showing the toner moving state inside the toner receiving member.

  In FIG. 2, the toner removed from the surface of the photosensitive drum 21 by the cleaning roller 82 and the cleaning blade 83 tends to move below the cleaning roller 82 and the cleaning blade 83 by the action of gravity. However, the movement of the toner is blocked by the toner receiving member 84 and stored in a space near the peripheral surface of the cleaning roller 82 constituted by the toner receiving member 84. When the toner is stored in this space, pressure is applied to the cleaning roller 82 and adheres to the surface of the cleaning roller 82 from below.

  Then, the cleaning roller 82 polishes the surface of the photosensitive drum 21 with toner containing an abrasive attached to the surface.

  The toner that is stored inside the toner receiving member 84 and does not adhere to the surface of the cleaning roller 82 moves as indicated by arrows in FIG. That is, in other areas of the toner receiving member 84 excluding the toner discharge portion 84 b, for example, an area corresponding to the substantially central portion in the axial direction of the cleaning roller 82, the toner is 1 from below the cleaning roller 82 as the cleaning roller 82 rotates. About / 4 rotation (see FIG. 2), the toner receiving member 84 moves to the upper part along the inner wall. At the same time, a part of the toner moves outward in the axial direction, that is, toward the toner discharge portion 84b.

  On the other hand, at the location of the toner discharge portion 84b of the toner receiving member 84, the length extending in the circumferential direction of the cleaning roller 82 so as to be away from the contact location between the photosensitive drum 21 and the cleaning roller 82, as shown in FIG. Since the toner is shorter than the other region, the toner immediately falls from below the cleaning roller 82 toward the discharge screw 86 without moving to the upper portion of the toner receiving member 84 as the cleaning roller 82 rotates.

  Then, the toner overflowing from the space near the peripheral surface of the cleaning roller 82 at the upper portion of the toner receiving member 84 spills downward along the inner wall of the housing 81 and reaches the location of the discharge screw 86 via the transport paddle 85. To do. In addition, the toner dropped from the toner discharge portion 84 b of the toner receiving member 84 almost directly reaches the discharge screw 86. The toner that reaches the location of the discharge screw 86 is conveyed to the outside of the housing 81 by the discharge screw 86.

  In this way, the cleaning roller 82 that rotates in contact with the photosensitive drum 21 that is an image bearing member and removes deposits on the surface of the photosensitive drum 21 and the downstream side of the cleaning roller 82 in the rotational direction of the photosensitive drum 21 are provided. In the cleaning device 80 provided with the cleaning blade 83 that contacts the photosensitive drum 21 and scrapes off the toner on the surface, the cleaning roller 80 is disposed with a gap with respect to the surface of the cleaning roller 82 and removed from the photosensitive drum 21. A toner receiving member 84 that stores toner between the cleaning roller 82 and the toner receiving member 84 is provided at a predetermined region corresponding to both ends of the cleaning roller 82 in the axial direction in the axial direction of the cleaning roller 82. Away from the contact point between the photosensitive drum 21 and the cleaning roller 82 Since the length of the cleaning roller 82 extending in the circumferential direction is shorter than the length of other regions, the toner removed from the surface of the photosensitive drum 21 by the cleaning roller 82 or the cleaning blade 83 is transferred to the toner receiving member 84. By storing the toner, pressure can be applied from the periphery of the cleaning roller 82 to adhere to the cleaning roller 82, and the toner stored in the toner receiving member 84 can be easily discharged from both ends in the axial direction of the cleaning roller 82. . Thereby, in addition to preventing the toner from being easily separated from the surface of the cleaning roller 82, the toner can be smoothly moved at both ends in the axial direction of the cleaning roller 82. Therefore, a suitable toner layer can be formed on the surface of the cleaning roller 82 without causing discharge breakdown on the surface of the photoconductor, and the surface of the photoconductor drum 21 is polished by the cleaning roller 82 using toner containing an abrasive. Can be carried out effectively. As a result, it is possible to surely remove the discharge product adhering to the surface of the photosensitive drum 21 and obtain the cleaning device 80 capable of maintaining a suitable cleaning performance for the surface of the photosensitive drum 21. it can.

  Further, since the toner receiving member 84 is a bowl-shaped member along the peripheral surface of the cleaning roller 82, the space for storing the toner is further reduced, and pressure is applied from the periphery of the cleaning roller 82 to apply the surface of the photosensitive drum 21. The toner removed from the toner can adhere to the surface of the cleaning roller 82. As a result, it is possible to make it difficult for the toner to be separated from the surface of the cleaning roller 82, and the action of carrying an appropriate amount of toner is enhanced. Therefore, the cleaning performance for the surface of the photosensitive drum 21 can be improved. Further, since the space for storing the toner is further reduced, the effect of smoothly discharging unnecessary toner can be enhanced. Therefore, toner aggregation in the toner receiving member 84 can be prevented, and the effect of preventing the occurrence of problems such as discharge breakdown on the surface of the photoreceptor can be further improved. Furthermore, the space occupied by the toner receiving member 84 can be reduced, and the cleaning device 80 can be made compact.

  Since the cleaning blade 83 is disposed on the lower side in the vertical direction with respect to the cleaning roller 82, the toner removed from the surface of the photosensitive drum 21 falls immediately without adhering to the cleaning roller 82. This can be prevented by providing the toner receiving member 84. Therefore, even if the cleaning roller 82 is provided in the upper part of the housing 81 of the cleaning device 80 and the cleaning blade 83 is provided below the cleaning roller 82, the cleaning roller 82 is operated by the action of the toner receiving member 84. Thus, the surface of the photosensitive drum 21 can be effectively polished, and the discharge product adhering to the surface of the photosensitive drum 21 can be reliably removed.

  In the present invention, since the cleaning device 80 is mounted on the image forming apparatus 1, an appropriate amount of toner is reliably supported on the surface of the cleaning roller 82 while considering that the toner can move smoothly in the vicinity of the surface. Therefore, it is possible to obtain the high-performance image forming apparatus 1 capable of maintaining a suitable cleaning performance for the surface of the photosensitive drum 21.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  For example, the embodiment of the present invention has a structure in which the cleaning blade 83 is disposed on the lower side in the vertical direction with respect to the cleaning roller 82, but is disposed on the upper side in the vertical direction with respect to the cleaning roller 82. It doesn't matter. Even in such a structure, there is provided a toner receiving member 84 that is disposed with a gap with respect to the surface of the cleaning roller 82 and stores the toner removed from the photosensitive drum 21 between the cleaning roller 82 and The length of the toner receiving member 84 extending in the circumferential direction of the cleaning roller 82 so as to be away from the contact point between the photosensitive drum 21 and the cleaning roller 82 at a predetermined region corresponding to both axial ends of the cleaning roller 82. By providing the toner discharge portion 84b that is shorter than other regions, the same operation and effect as in the present embodiment can be obtained.

  Further, the region length of the toner discharge portion 84b of the toner receiving member 84 is not limited to the numerical value shown in the present embodiment, and may be another region length.

  The present invention can be used in general cleaning apparatuses that transfer a toner image onto a sheet and then remove the adhering matter such as toner remaining on the surface of the image carrier to perform cleaning.

1 is a schematic vertical sectional front view of an image forming apparatus equipped with a cleaning device according to an embodiment of the present invention. FIG. 2 is a partially enlarged vertical sectional view showing the periphery of an image forming unit of the image forming apparatus of FIG. FIG. 3 is a perspective view showing the photosensitive drum of FIG. 2 and the inside of a cleaning device. FIG. 6 is a perspective view of a toner receiving member of the cleaning device. FIG. 4 is a partially enlarged perspective view showing an end portion of a toner receiving member. FIG. 6 is a partial perspective view showing a toner moving state inside a toner receiving member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 8 Intermediate transfer belt 20 Image forming part 21 Photosensitive drum (image carrier)
DESCRIPTION OF SYMBOLS 30 Primary transfer part 50 Charging apparatus 60 Developing apparatus 70 Static elimination apparatus 80 Cleaning apparatus 81 Housing 82 Cleaning roller 83 Cleaning blade 84 Toner receiving member 84b Toner discharging part 85 Conveying paddle 86 Discharging screw

Claims (4)

A cleaning roller that rotates in contact with the image carrier and removes deposits on the surface thereof, and is provided downstream of the cleaning roller in the image carrier rotation direction, and contacts the image carrier and scrapes the toner on the surface. In a cleaning device comprising a cleaning blade to take
The toner receiving member is disposed with a gap with respect to the surface of the cleaning roller, and stores toner removed from the image carrier between the cleaning roller and the toner receiving member in the axial direction of the cleaning roller. The length of the predetermined region corresponding to both ends of the cleaning roller in the axial direction extends in the circumferential direction of the cleaning roller so as to be away from the contact point between the image carrier and the cleaning roller, than the length of other regions. A cleaning device characterized by being short.   The cleaning device according to claim 1, wherein the toner receiving member is a bowl-shaped member along a peripheral surface of the cleaning roller.   The cleaning apparatus according to claim 1, wherein the cleaning blade is disposed on the lower side in the vertical direction with respect to the cleaning roller.   An image forming apparatus comprising the cleaning device according to claim 1.

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