JP2013242375A - Cleaning device, and image carrier unit including the same, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent, in a cleaning device that is arranged above an image carrier and cleans the image carrier, occurrence of leakage of a toner accumulated on a seal member that seals a gap between the cleaning device and the image carrier.SOLUTION: A polishing roller 353 rotatably contacts a photoreceptor drum 31 from the above. A toner seal 380 is disposed on the upstream side of the polishing roller 353 in a direction of rotation of the photoreceptor drum 31. The toner seal 380 prevents leakage of toner from a cleaning device 35. The polishing roller 353 can be moved between a first position CP1 to contact the photoreceptor drum 31 and a second position CP2 closer to the toner seal 380 than the first position CP1. The polishing roller 353 scrapes off a toner above the toner seal 380 to prevent accumulation of excessive toner on the toner seal 380.

Description

  The present invention relates to a cleaning device that cleans an image carrier that carries a toner image, an image carrier unit including the same, and an image forming apparatus.

  2. Description of the Related Art Conventionally, as an image forming apparatus that forms an image on a sheet, a technique is known in which a sheet passes from below to above through a transfer nip formed between a photosensitive drum and a transfer roller (patent) Reference 1). A toner image is formed on the photosensitive drum, and the toner image is transferred to a sheet at the transfer nip portion. The image forming apparatus further includes a fixing unit, and the sheet on which the toner image has been transferred is subjected to a fixing process in the fixing unit and then discharged.

  In the technique described in Patent Document 1, a cleaning device is disposed in the transfer nip portion so as to face the photosensitive drum in order to clean the residual toner on the photosensitive drum after the toner image is transferred. The The cleaning device is provided with a cleaning roller that comes into contact with the photosensitive drum. Toner or the like adhering to the photosensitive drum is collected by the cleaning roller. Patent Document 2 discloses a technique in which the shaft portion of the cleaning roller is movable in order to change the contact pressure of the cleaning roller to the photosensitive drum. Japanese Patent Application Laid-Open No. H10-228561 discloses a technique that enables the cleaning roller to be brought into contact with and separated from the photosensitive drum.

JP 2009-8962 A JP-A-2005-316086 JP 2005-148609 A

  As in the technique described in Patent Document 1, when the sheet passes through the transfer nip portion from below to above, the cleaning device disposed downstream of the transfer nip portion in the rotation direction of the photosensitive drum is photosensitive. Often placed above the body drum.

  When the cleaning device is disposed above the photosensitive drum, residual toner removed from the photosensitive drum may fall from the periphery of the cleaning device. Therefore, a toner seal member is brought into contact with the photosensitive drum around the cleaning device in order to prevent the residual toner from falling.

  When the cleaning device is disposed above the photosensitive drum, a large amount of toner accumulates above the toner seal member, and the toner presses the toner seal member toward the photosensitive drum. For this reason, the contact pressure of the toner seal member with respect to the photosensitive drum increases. Then, the paper dust on the sheet adheres to the cylindrical surface of the photosensitive drum at the transfer nip portion, and the paper dust moved to the tip of the toner seal member as the photosensitive drum rotates, Grown into a lump between the cylindrical surface of the photosensitive drum. As a result, the tip of the toner seal member may be lifted by the lump of paper powder, causing problems such as toner leakage.

  The present invention has been made in view of the above-described problems. In a cleaning device that is disposed above an image carrier and cleans the image carrier, and an image carrier unit including the cleaning device, or an image forming apparatus, a cleaning device is provided. An object of the present invention is to prevent toner leakage caused by toner deposited on a seal member that seals between the apparatus and the image carrier.

  A cleaning device according to one aspect of the present invention is disposed above an image carrier including a rotation shaft and a cylindrical surface that rotates in one direction around the rotation shaft and supports a toner image, and the cylindrical surface A housing and a peripheral surface that contacts the cylindrical surface at a first position above the rotation axis in a cross-sectional view orthogonal to the rotation axis, the contact position And a rotation member that is driven to rotate in the same direction as the image carrier and collects toner adhering to the image carrier, and is disposed in the housing, and is above the rotation axis in the sectional view. A sheet member provided with a tip portion that contacts the cylindrical surface on the upstream side in the rotation direction of the image carrier with respect to the rotating member, the first position, and the rotating member with respect to the first position. The peripheral surface approaches the sheet member Between 2 positions, characterized in that it comprises a moving means for moving the rotating member.

  According to this configuration, the cleaning device includes the rotating member, the sheet member, and the moving unit. The rotating member contacts the cylindrical surface of the image carrier at a first position above the rotation axis of the image carrier. The rotating member is driven to rotate and collects toner adhering to the image carrier. The sheet member includes a tip portion that is above the rotation axis of the image carrier and is in contact with a cylindrical surface on the upstream side of the rotation member in the rotation direction of the image carrier. Even when the collected toner collected from the image carrier scatters from the rotating surface of the rotating member and accumulates on the sheet member, the moving means rotates at the first position and the first position. The rotating member is moved between the second position where the peripheral surface of the member approaches the sheet member. In the second position, the peripheral surface of the rotating member can break the toner accumulated on the sheet member. For this reason, the collected toner is prevented from being excessively deposited on the sheet member. As a result, the toner deposited on the sheet member is prevented from pressing the sheet member toward the image carrier. Therefore, the contact pressure of the sheet member with respect to the image carrier is unlikely to increase, and toner leakage from the leading end of the sheet member is suppressed.

  In the above-described configuration, the rotating member includes a shaft portion that rotatably supports the peripheral surface, and the moving unit includes a shaft between the shaft portion of the rotating member and the rotation shaft of the image carrier. The rotating member is preferably moved so that the distance is constant.

  According to this configuration, the rotating member is moved between the first position and the second position so that the distance between the axes with the image carrier is constant. For this reason, the contact pressure between the rotating member and the image carrier is stably maintained. Further, it is possible to prevent the cylindrical surface of the image carrier from being damaged due to the rubbing between the rotating member and the cylindrical surface of the image carrier.

  In the above configuration, the moving means moves the rotating member between the first position and the second position in a state where the rotating member and the image carrier are rotationally driven. Is desirable.

  According to this configuration, when the rotating member is moved, the cylindrical surface of the image carrier is hardly damaged. Further, since the rotating member approaches the sheet member while being driven to rotate, the toner deposited on the sheet member is liable to collapse. Further, the broken toner is conveyed to the downstream side in the rotation direction by the image carrier and is suitably collected by the rotation member.

  In the above configuration, the rotating member is a polishing roller that polishes deposits attached to the cylindrical surface of the image carrier, and is a toner that contacts the peripheral surface of the polishing roller and adheres to the peripheral surface It is desirable to further include a regulating member that regulates the amount.

  According to this configuration, the deposit adhered to the cylindrical surface of the image carrier is effectively polished by the polishing roller. Further, the regulating member regulates the amount of toner that adheres to the rotating surface of the polishing roller. For this reason, when the toner is uniformly interposed between the polishing roller and the cylindrical surface of the image carrier, the promoted polishing effect is suppressed from being varied depending on the position on the rotating surface of the polishing roller.

  In the above configuration, it is preferable that the moving unit moves the polishing roller and the regulating member integrally with the movement of the polishing roller.

  According to this configuration, the contact pressure between the polishing roller and the regulating member is stably maintained. For this reason, fluctuations in the amount of toner adhering to the peripheral surface of the polishing roller are suppressed.

  In the above configuration, it is preferable that the moving unit moves the rotating member so that a pressing force between the rotating member and the image carrier is constant.

  According to this configuration, the contact pressure between the rotating member and the image carrier is stably maintained. Further, it is possible to prevent the cylindrical surface of the image carrier from being damaged due to the rubbing between the rotating member and the cylindrical surface of the image carrier.

  In the above-described configuration, a support member that supports the shaft portion of the rotating member, and a length in which the shaft portion is inserted into the support member along the cylindrical surface of the image carrier in the sectional view. A first biasing member that is disposed between the hole, the housing and the support member, and biases the support member toward the image carrier, and is disposed between the housing and the shaft portion. A second urging member that urges the shaft portion from the second position toward the first position, and abutting against the shaft portion and being driven to rotate; And a cam member for pressing from the position toward the second position.

  According to this configuration, the shaft portion of the rotating member is inserted through the long hole of the support member. The rotating member is urged toward the image carrier by the first urging member. For this reason, the contact pressure between the rotating member and the image carrier is stably maintained. The shaft portion of the rotating member is urged from the second position toward the first position by the second urging member. Then, the cam member is rotationally driven, and the rotating member is moved from the first position to the second position by pressing the shaft portion from the first position to the second position.

  In the above-described configuration, it is desirable to further include a cleaning blade that contacts the cylindrical surface on the downstream side in the rotation direction of the image carrier with respect to the rotating member and removes toner adhering to the image carrier.

  According to this configuration, the cleaning blade is disposed on the downstream side in the rotation direction of the image carrier with respect to the rotation member. For this reason, the toner adhering to the image carrier is accurately removed.

  An image carrier unit according to another aspect of the present invention includes the cleaning device according to any one of the above, and the image carrier arranged to face the rotating member.

  According to this configuration, even when the collected toner collected from the image carrier is scattered from the circumferential surface of the rotating member and accumulated on the sheet member, the moving unit has the first position, the first position, The rotating member is moved between the first position and the second position where a part of the circumferential surface of the rotating member approaches the sheet member. In the second position, the peripheral surface of the rotating member can break the toner accumulated on the sheet member. For this reason, the collected toner is prevented from being excessively deposited on the sheet member. As a result, the toner deposited on the sheet member is prevented from pressing the sheet member toward the image carrier. Therefore, the contact pressure of the sheet member with respect to the image carrier is unlikely to increase, and toner leakage from the leading end of the sheet member is suppressed.

  An image forming apparatus according to another aspect of the present invention includes the cleaning device according to any one of the above, the image carrier disposed to face the rotating member, and the cylindrical surface of the image carrier. And a developing device for supplying toner.

  According to this configuration, even when the collected toner collected from the image carrier is scattered from the circumferential surface of the rotating member and accumulated on the sheet member, the moving unit has the first position, the first position, The rotating member is moved between the first position and the second position where a part of the circumferential surface of the rotating member approaches the sheet member. In the second position, the peripheral surface of the rotating member can break the toner accumulated on the sheet member. For this reason, the collected toner is prevented from being excessively deposited on the sheet member. As a result, the toner deposited on the sheet member is prevented from pressing the sheet member toward the image carrier. Therefore, the contact pressure of the sheet member with respect to the image carrier is unlikely to increase, and toner leakage from the leading end of the sheet member is suppressed. As a result, toner contamination is prevented from occurring in the image forming apparatus.

  In the above configuration, the image carrier is preferably an amorphous silicon photoconductor.

  According to this configuration, the rotating member contacts the amorphous silicon photoconductor. The rotating member polishes the discharge product adhering to the amorphous silicon photoconductor. At this time, in the amorphous silicon photoreceptor corresponding to the hard drum, the photosensitive layer is hardly polished by the rotating member. Therefore, as described above, even when the rotating member is in contact with the amorphous silicon photoconductor, the discharge product on the amorphous silicon photoconductor is suitably polished, and a toner image is formed on the amorphous silicon photoconductor. It is formed stably.

  In the above-described configuration, a sheet conveying path that conveys a sheet from below to above facing the image carrier, and abutting against the cylindrical surface of the image carrier, the toner image from the image carrier And a transfer member that forms a transfer nip portion for transferring the image to the sheet, and the image carrier is rotationally driven from below to above in the transfer nip portion. To the cylindrical surface of the image carrier between the position and the position directly above the rotation shaft.

  According to this configuration, the rotating member comes into contact with the cylindrical surface of the image carrier from the transfer nip portion to a position immediately above the rotation axis of the image carrier. The leading end of the sheet member is in contact with the cylindrical surface on the upstream side in the rotation direction of the image carrier, which is below the position where the rotating member contacts the cylindrical surface. For this reason, the toner scattered from the rotating member tends to fall on the sheet member. Even in such a case, the moving means has the rotating member between the first position and the second position where a part of the circumferential surface of the rotating member approaches the sheet member more than the first position. Move. In the second position, the peripheral surface of the rotating member can break the toner accumulated on the sheet member. For this reason, the collected toner is prevented from being excessively deposited on the sheet member. As a result, the toner deposited on the sheet member is prevented from pressing the sheet member toward the image carrier. Therefore, the contact pressure of the sheet member with respect to the image carrier is unlikely to increase, and toner leakage from the leading end of the sheet member is suppressed. As a result, toner contamination is prevented from occurring in the image forming apparatus. Further, even when the paper dust of the sheet adheres to the cylindrical surface of the image carrier at the transfer nip portion, the paper dust moved to the tip of the sheet member as the image carrier rotates is the sheet. Growing into a lump between the tip of the member and the cylindrical surface of the image carrier is suppressed. As a result, the leading edge of the sheet member is lifted by the lump of paper powder, and the toner can be prevented from leaking from the gap between the sheet member and the image carrier. Therefore, the conveyed sheet is prevented from being soiled by the leaked toner in the transfer nip portion.

  According to the present invention, in a cleaning device that is disposed above an image carrier and cleans the image carrier, and an image carrier unit or an image forming apparatus including the same, a gap between the cleaning device and the image carrier is sealed. The toner accumulated on the sealing member to be stopped is prevented from causing toner leakage.

1 is a perspective view illustrating an appearance of an image forming apparatus 1 according to an embodiment of the present disclosure. 1 is a cross-sectional view illustrating an internal structure of an image forming apparatus 1 according to an embodiment of the present invention. It is a sectional side view which shows the internal structure of the image carrier unit 31H which concerns on one Embodiment of this invention. FIG. 4 is a schematic diagram for explaining a state where toner is accumulated on a toner seal. FIG. 4 is a schematic diagram for explaining a state in which a front end portion of a toner seal is lifted by a lump of paper powder. It is typical sectional drawing of the cleaning apparatus 35 which concerns on one Embodiment of this invention. It is a perspective view which shows the moving means of the grinding | polishing roller which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an appearance of an image forming apparatus 1 according to an embodiment of the present invention. FIG. 2 is a side sectional view showing the internal structure of the image forming apparatus 1 according to the embodiment of the present invention. Here, a monochrome printer is illustrated as the image forming apparatus 1, but the image forming apparatus may be a copying machine, a facsimile machine, or a multifunction machine having these functions, and an image forming apparatus that forms a color image. It may be.

  The image forming apparatus 1 includes a main body housing 10 having a substantially rectangular parallelepiped housing structure, and a paper feeding unit 20, an image forming unit 30, a fixing unit 40, and a toner container 50 housed in the main body housing 10. .

  A front cover 11 is provided on the front side of the main body housing 10, and a rear cover 12 is provided on the rear side. When the front cover 11 is opened, the toner container 50 is exposed to the front side. Thereby, the user can take out the toner container 50 from the front side of the main body housing 10 when the toner runs out. The rear cover 12 is a cover that is opened at the time of sheet jam or maintenance. The units of the image forming unit 30 and the fixing unit 40 can be taken out from the rear side of the main body housing 10 by opening the rear cover 12. Further, on the side surface of the main body housing 10, a left cover 12L (FIG. 1) and a right cover 12R (not shown in FIG. 1) opposite to the left cover 12L extend in the vertical direction. It is arranged. An intake port 12La for taking in air into the main body housing 10 is disposed at the front portion of the left cover 12L. Further, on the upper surface of the main body housing 10, a paper discharge unit 13 for discharging the sheet after image formation is provided. Various devices for executing image formation are installed in an internal space S (FIG. 2) defined by the front cover 11, the rear cover 12, the left cover 12L, the right cover 12R, and the paper discharge unit 13. The

  The paper feed unit 20 includes a paper feed cassette 21 that accommodates sheets to be subjected to image forming processing (FIG. 2). A part of the sheet feeding cassette 21 protrudes further forward from the front surface of the main body housing 10. An upper surface of a portion of the sheet cassette 21 accommodated in the main body housing 10 is covered with a sheet cassette top plate 21U. The sheet feeding cassette 21 is provided with a sheet accommodating space for accommodating the bundle of sheets, a lift plate for lifting the bundle of sheets for feeding. A sheet feeding portion 21 </ b> A is provided at an upper portion on the rear end side of the sheet feeding cassette 21. The sheet feeding unit 21A is provided with a sheet feeding roller 21B for feeding the uppermost sheet of the sheet bundle in the sheet feeding cassette 21 one by one.

  The image forming unit 30 performs an image forming process for forming a toner image on a sheet fed from the paper feeding unit 20. The image forming unit 30 includes a photosensitive drum 31 (image carrier), a charging device 32, an exposure device (not shown in FIG. 2), a developing device 33, a transfer device, which are arranged around the photosensitive drum 31. A roller 34 and a cleaning device 35. The image forming unit 30 is disposed between the left cover 12L and the right cover 12R.

  The photosensitive drum 31 includes a rotation shaft 31A and a cylindrical surface 31B that rotates around the rotation shaft 31A (see FIG. 3). An electrostatic latent image is formed on the cylindrical surface 31B, and a toner image corresponding to the electrostatic latent image is carried on the cylindrical surface 31B. As the photosensitive drum 31, a photosensitive drum using an amorphous silicon (a-Si) material can be used.

  The charging device 32 uniformly charges the surface of the photosensitive drum 31, and includes a charging roller that contacts the photosensitive drum 31.

  The cleaning device 35 has a cleaning blade 351 (FIG. 3), cleans the toner adhering to the peripheral surface of the photosensitive drum 31 after the toner image is transferred, and conveys the toner to a collecting device (not shown). Further, the photosensitive drum 31, the charging device 32, and the cleaning device 35 are integrally configured as a drum unit 31H (see FIG. 3) (image carrier unit). The cleaning device 35 and the drum unit 31H will be described in detail later.

  The exposure apparatus has a laser light source and optical equipment such as a mirror and a lens, and irradiates the peripheral surface of the photosensitive drum 31 with light modulated based on image data given from an external device such as a personal computer. An electrostatic latent image is formed. The developing device 33 supplies toner to the peripheral surface of the photosensitive drum 31 in order to develop the electrostatic latent image on the photosensitive drum 31 to form a toner image. The developing device 33 includes a developing roller 331 that carries toner to be supplied to the photosensitive drum 31, a first conveying screw 332 and a second conveying screw 333 that circulate and convey the developer inside a developing housing (not shown). including.

  The transfer roller 34 is a roller for transferring a toner image formed on the peripheral surface of the photosensitive drum 31 onto a sheet. The transfer roller 34 is in contact with the cylindrical surface 31B of the photosensitive drum 31 to form a transfer nip portion TP (FIG. 3). The transfer roller 34 is given a transfer bias having a polarity opposite to that of the toner.

  The fixing unit 40 performs a fixing process for fixing the transferred toner image on the sheet. The fixing unit 40 includes a fixing roller 41 having a heating source therein, and a pressure roller 42 that is pressed against the fixing roller 41 and forms a fixing nip portion with the fixing roller 41. When the sheet on which the toner image has been transferred is passed through the fixing nip portion, the toner image is fixed on the sheet by heating by the fixing roller 41 and pressing by the pressure roller 42.

  The toner container 50 stores toner to be supplied to the developing device 33. The toner container 50 includes a container main body 51 serving as a main storage location of toner, a cylindrical portion 52 projecting from a lower portion on one side surface of the container main body 51, and a lid member 53 covering the other side surface of the container main body 51. And a rotating member 54 that is contained in the container and conveys toner. The toner stored in the toner container 50 is supplied into the developing device 33 from the toner discharge port 521 provided on the lower surface of the front end of the cylindrical portion 52 when the rotating member 54 is driven to rotate. Further, the container top plate 50H covering the upper side of the toner container 50 is located below the paper discharge unit 13 (see FIG. 2).

  In the main body housing 10, a main conveyance path 22F and a reverse conveyance path 22B are provided to convey the sheet. The main conveyance path 22 </ b> F passes through the image feeding unit 21 and the fixing unit 40 from the sheet feeding unit 21 </ b> A of the paper feeding unit 20, and the paper discharge port 14 provided to face the paper discharge unit 13 on the upper surface of the main body housing 10. It extends to. The reverse conveyance path 22B is a conveyance path for returning a sheet printed on one side to the upstream side of the image forming unit 30 in the main conveyance path 22F when performing duplex printing on the sheet.

  The main conveyance path 22F (sheet conveyance path) is extended so as to pass through a transfer nip portion TP formed by the photosensitive drum 31 and the transfer roller 34 from below to above. In addition, a registration roller pair 23 is disposed on the upstream side of the transfer nip portion TP in the main conveyance path 22F. After the sheet is temporarily stopped by the registration roller pair 23 and skew correction is performed, the sheet is sent out to the transfer nip portion at a predetermined timing for image transfer. A plurality of transport rollers for transporting the sheet are disposed at appropriate positions on the main transport path 22F and the reverse transport path 22B. For example, a pair of paper discharge rollers 24 is disposed in the vicinity of the paper discharge port 14.

  The reverse conveyance path 22 </ b> B is formed between the outer side surface of the reverse unit 25 and the inner surface of the rear cover 12 of the main body housing 10. Note that one roller of the transfer roller 34 and the registration roller pair 23 is mounted on the inner surface of the reversing unit 25. The rear cover 12 and the reversing unit 25 can be rotated about the axis of the fulcrum 121 provided at the lower end thereof. When a sheet jam occurs in the reverse conveyance path 22B, the rear cover 12 is opened. When a sheet jam occurs in the main conveyance path 22F, or when the unit of the photosensitive drum 31 and the developing device 33 are taken out, the reversing unit 25 is opened in addition to the rear cover 12.

  Next, the configuration of the drum unit 31H according to the present embodiment will be described in detail with reference to FIG. FIG. 3 is an enlarged cross-sectional view of the drum unit 31H according to the present embodiment. Note that FIG. 3 is a diagram in which the horizontal direction on the paper surface (the front-rear direction of the image forming apparatus 1) is reversed in FIG.

  With reference to FIG. 3, the drum unit 31 </ b> H includes a photosensitive drum 31, a charging device 32, and a cleaning device 35. The drum unit 31H includes a pair of side plates (not shown) at both ends in the left-right direction (a direction orthogonal to the paper surface of FIG. 3). The photosensitive drum 31 is rotatably supported by the pair of side plates. Further, the charging device 32 and the cleaning device 35 are supported by the pair of side plates so as to face the photosensitive drum 31. The photosensitive drum 31 is rotationally driven in the direction of arrow DP in FIG. The drum unit 31H includes a fixing part (not shown) disposed on the side plate. When the drum unit 31 </ b> H is attached to the main body housing 10 of the image forming apparatus 1, the fixing portion is fixed to the main body housing 10 of the image forming apparatus 1. As a result, in the image forming apparatus 1, the position of the drum unit 31H is fixed. The fixing part is configured by a fastening hole to which a screw is fastened.

  The charging device 32 is disposed in front of the photosensitive drum 31. The charging device 32 includes a charging roller 321, a cleaning roller 322, and a charging housing 32H. The charging housing 32 </ b> H has a substantially U-shaped shape in a cross-sectional view orthogonal to the rotation axis of the photosensitive drum 31. A charging roller 321 and a cleaning roller 322 are rotatably supported in the charging housing 32H.

  The charging roller 321 is a roll member whose surface is made of a rubber material. A charging voltage is applied to the charging roller 321 from a bias applying unit (not shown). The charging roller 321 is rotated while being driven by the photosensitive drum 31 by contacting the circumferential surface of the photosensitive drum 31. The peripheral surface of the photosensitive drum 31 is uniformly charged by the charging roller 321 to which the charging voltage is applied.

  The cleaning roller 322 contacts the charging roller 321 and rotates with the charging roller 321 with a linear velocity difference. The cleaning roller 322 is a brush roller formed of conductive nylon fibers. When the charging roller 321 comes into contact with the surface of the photosensitive drum 31, toner, foreign matter, or the like adheres to the surface of the charging roller 321. The cleaning roller 322 is rotated with a linear velocity difference while being in contact with the charging roller 321, so that toner, foreign matter, and the like attached to the surface of the charging roller 321 are preferably removed.

  The cleaning device 35 is disposed above the photosensitive drum 31. The cleaning device 35 includes a cleaner housing 35H (housing), a cleaning blade 351, a conveying screw 352, and a polishing roller 353 (rotating member). The cleaning device 35 includes a scraper 354, a scraper holder 355, and an upper seal 356. Further, the cleaning device 35 includes a first plate 357, a second plate 358, a cover seal 359, and a toner seal 380.

  The cleaner housing 35 </ b> H is a housing that supports each member in the cleaning device 35. The cleaning device 35 is disposed so as to cover the photosensitive drum 31 and the charging device 32 upward. In particular, the front portion of the cleaner housing 35H is disposed above the charging roller 321. Further, in the cross-sectional view orthogonal to the rotation axis of the photosensitive drum 31, the central portion in the front-rear direction of the cleaner housing 35H has a shape protruding upward in an arc shape. Further, the rear portion of the cleaner housing 35H is defined by the housing rear wall 35H1. The housing rear wall 35H1 is a wall portion extending in the vertical direction. The housing rear wall 35H1 is disposed to face a polishing roller 353 described later. The lower end of the housing rear wall 35 </ b> H <b> 1 is disposed with a space on the peripheral surface of the photosensitive drum 31.

  The cleaning blade 351 is disposed in the horizontal direction along the bottom of the cleaner housing 35H. The cleaning blade 351 is a plate-like member made of a rubber material. The cleaning blade 351 is supported by the blade holder 351H. The blade holder 351H is a sheet metal member having an L-shape in the cross-sectional view. A central portion of the blade holder 351H is fixed to the cleaner housing 35H by the first fixing screw 351B. The cleaning blade 351 and the blade holder 351H are fixed with an adhesive. As a result, a fixed end of the cleaning blade 351 is formed. On the other hand, the front end of the cleaning blade 351 is a free end and is in contact with the peripheral surface of the photosensitive drum 31. The tip of the cleaning blade 351 is in contact with the cylindrical surface 31B on the downstream side in the rotation direction (arrow DP direction) of the photosensitive drum 31 with respect to a later-described polishing roller 353. As a result, toner remaining (attached) on the peripheral surface of the photosensitive drum 31 is removed by the tip of the cleaning blade 351.

  The conveying screw 352 is rotatably supported by the cleaner housing 35H above the cleaning blade 351. The conveying screw 352 includes a shaft portion and a spiral blade member disposed around the shaft portion. The conveying screw 352 is scraped off by the cleaning blade 351 and conveys the collected toner PT accumulated on the cleaning blade 351 in the axial direction of the rotating shaft 31 </ b> A of the photosensitive drum 31.

  The polishing roller 353 is disposed behind the conveying screw 352. The polishing roller 353 includes a rotation surface (circumferential surface) that comes into contact with the cylindrical surface 31B above the rotation shaft 31A of the photosensitive drum 31. Further, the polishing roller 353 contacts the cylindrical surface 31B of the photosensitive drum 31 from the transfer nip portion TP to a position directly above the rotation shaft 31A of the photosensitive drum 31. More specifically, the polishing roller 353 contacts the cylindrical surface 31B directly above the rotation shaft 31A of the photosensitive drum 31 or slightly upstream of the photosensitive drum 31 in the rotation direction. The position where the polishing roller 353 contacts on the cylindrical surface 31B is defined as a contact position CP. The polishing roller 353 is a rubber roller having a roughened peripheral surface. In this embodiment, a shaft having a diameter of 12 mm and an EPDM rubber (ethylene propylene rubber) having a thickness of 1.75 mm are used. Is done. The polishing roller 353 is rotated following the photosensitive drum 31 while being in contact with the peripheral surface of the photosensitive drum 31 (arrow DC in FIG. 3). The polishing roller 353 collects the toner attached to the cylindrical surface 31B of the photosensitive drum 31. Further, the polishing roller 353 polishes deposits such as a discharge product attached to the surface of the photosensitive drum 31. At this time, a predetermined amount of toner adheres to the peripheral surface of the polishing roller 353, so that the discharge product removal performance (polishing performance) is improved.

  The scraper 354 (regulating member) is a plate-like member extending in the vertical direction (vertical direction). In the present embodiment, the scraper 354 is composed of a 0.05 mm SUS plate. The lower end of the scraper 354 is in contact with the rotating surface of the polishing roller 353. The lower end of the scraper 354 is in contact with the rotation surface of the polishing roller 353 so as to face the rotation direction (arrow DC direction) of the polishing roller 353. When the scraper 354 comes into contact with the rotating surface of the polishing roller 353 with a predetermined elastic force, the amount of toner attached to the rotating surface of the polishing roller 353 is regulated. As a result, since the amount of toner adhering to the rotating surface of the polishing roller 353 becomes uniform, variation in the discharge product removal performance by the polishing roller 353 is suppressed.

  The scraper holder 355 is disposed so as to cover the upper part of the polishing roller 353. The scraper holder 355 is composed of a bent sheet metal member. The central portion of the scraper holder 355 extends in the horizontal direction. A front portion of the scraper holder 355 is bent downward to support the scraper 354. Further, the rear portion of the scraper holder 355 is bent rearward and downward.

  The upper seal 356 is fixed on the scraper holder 355. One end of the upper seal 356 is supported at the center of the scraper holder 355, and the other end of the upper seal 356 is disposed so as to protrude forward from the scraper holder 355. The upper seal 356 has a function of blocking the toner that has jumped upward when the toner attached to the rotating surface of the polishing roller 353 is scraped off by the scraper 354.

  The first plate 357 is disposed to face the housing rear wall 35H1 of the cleaner housing 35H. The first plate 357 is a sheet metal member extending in the vertical direction. A central portion in the vertical direction of the first plate 357 is fixed to the housing rear wall 35H1 by the second fixing screw 357B. The first plate upper portion 357T, which is the upper end portion of the first plate 357, is bent rearward. Further, the first plate lower portion 357S, which is the lower end portion of the first plate 357, is bent forward. At this time, the first plate lower portion 357 </ b> S is disposed so as to enter the space between the lower end of the housing rear wall 35 </ b> H <b> 1 and the peripheral surface of the photosensitive drum 31 so as to face the lower end of the housing rear wall 35 </ b> H <b> 1.

  The second plate 358 is disposed behind the first plate 357 so as to face the first plate 357. The second plate 358 is a sheet metal member extending in the vertical direction. The second plate upper portion 358T, which is the upper end portion of the second plate 358, is bent backward so as to be bent upward. The second plate 358 is fixed to the cleaner housing 35H by a fixing screw outside the sheet passing area. A lower end portion of the second plate 358 extends to a lower side than the first plate lower portion 357S.

  The cover seal 359 extends in the vertical direction along the second plate 358. The upper portion of the cover seal 359 is bonded and fixed to the second plate 358 to form a fixed end of the cover seal 359. The lower portion of the cover seal 359 is disposed so as to protrude downward from the second plate 358, and forms a free end of the cover seal 359. The lower end portion (free end) of the cover seal 359 is disposed close to the peripheral surface of the photosensitive drum 31.

  The toner seal 380 (sheet member) extends in the horizontal direction along the first plate lower portion 357S of the first plate 357. The toner seal 380 is a urethane sheet having a thickness of 100 μm. The rear side portion of the toner seal 380 is bonded and fixed to the first plate lower portion 357S to form a fixed end of the toner seal 380. On the other hand, the front portion (tip portion) of the toner seal 380 forms a free end of the toner seal 380 and abuts on the peripheral surface of the photosensitive drum 31. The front portion of the toner seal 380 is located on the upstream side in the rotation direction of the photosensitive drum 31 toward the contact portion between the polishing roller 353 and the photosensitive drum 31 in a cross-sectional view orthogonal to the rotation shaft 31A of the photosensitive drum 31. It contacts the cylindrical surface 31B. In other words, the toner seal 380 is cylindrical in a direction approaching the reference straight line RL connecting the rotation shaft 31A and the contact position CP of the polishing roller 353 in a cross-sectional view orthogonal to the rotation shaft 31A of the photosensitive drum 31. Abuts on the surface 31B. The toner seal 380 may be composed of a thin sheet member other than the urethane sheet. To prevent the cylindrical surface 31B of the photosensitive drum 31 from being damaged, the toner seal 380 is preferably a soft and deformable member.

  On the photosensitive drum 31 whose cylindrical surface 31B is uniformly charged by the charging roller 321 of the charging device 32, an electrostatic latent image is formed by an exposure device (not shown) on the downstream side of the charging device 32 in the rotation direction. . Then, the electrostatic latent image is visualized as a toner image by the developing device 33 (FIG. 2) disposed below the photosensitive drum 31. The photosensitive drum 31 is rotated from below to above in the transfer nip portion TP. The toner image formed on the photoconductive drum 31 is transferred to a sheet conveyed from the lower side to the upper side of the transfer nip portion TP.

  In the transfer nip portion TP, a part of the toner image transferred to the sheet remains on the photosensitive drum 31 as residual toner. Residual toner on the photoconductive drum 31 is conveyed from the lower side to the upper side with the rotation of the photoconductive drum 31 to a region where the cleaning device 35 faces the photoconductive drum 31.

  Part of the residual toner transported to the area facing the cleaning device 35 adheres to the rotating surface of the polishing roller 353. Residual toner that has not adhered to the rotating surface of the polishing roller 353 is scraped off by the cleaning blade 351.

  Next, the problem of the toner seal member disposed in the cleaning device 35 will be described. Part of the toner adhering to the rotating surface of the polishing roller 353 is scraped off by the scraper 354. The toner that passes through the tip of the scraper 354 and remains on the rotating surface of the polishing roller 353 is circulated on the polishing roller 353 while passing through a region facing the scraper holder 355 and the housing rear wall 35H1. At this time, the toner attached to the rotating surface of the polishing roller 353 is separated from the polishing roller 353 by the centrifugal force of the polishing roller 353. The toner released from the polishing roller 353 is scattered in a region surrounded by the scraper holder 355, the housing rear wall 35H1, and the cylindrical surface 31B of the photosensitive drum 31.

  Since the space exists above the toner seal 380, the toner scattered from the rotating surface of the polishing roller 353 accumulates on the toner seal 380 and forms a toner reservoir TN. 4 and 5 are views showing the surroundings of the toner seal 380 at this time. Referring to FIG. 4, toner reservoir TN accumulated on toner seal 380 is piled up so as to form a mountain shape. Generally, the angle of repose of toner collected by the cleaning device 35 is 30 degrees to 40 degrees. However, the collected toner is likely to adhere to a member made of a resin material or a rubber material located around it with static electricity. For this reason, in the region where the polishing roller 353 and the housing rear wall 35H1 are close to each other, the angle of repose of the collected toner may be 60 degrees to 70 degrees. Therefore, the toner reservoir TN is unlikely to collapse and a large amount of toner accumulates on the toner seal 380.

  On the other hand, when the toner image is transferred to the sheet P at the transfer nip portion TP, the paper dust attached to the surface of the sheet P may be moved to the cylindrical surface 31B of the photosensitive drum 31 in some cases. The paper dust attached to the cylindrical surface 31 </ b> B of the photosensitive drum 31 is conveyed toward the tip of the toner seal 380 as the photosensitive drum 31 rotates. When the toner reservoir TN is not formed on the toner seal 380, the tip of the toner seal 380 is in contact with the cylindrical surface 31B of the photosensitive drum 31 with a low contact pressure. In this case, the paper dust conveyed on the photosensitive drum 31 passes between the tip of the toner seal 380 and the cylindrical surface 31B of the photosensitive drum 31 and is collected by the cleaning blade 351.

  However, when the front end of the toner seal 380 is strongly in contact with the cylindrical surface 31B of the photosensitive drum 31 due to the toner reservoir TN accumulated on the toner seal 380, the paper dust is exposed to the front end of the toner seal 380. It cannot pass between the cylindrical surface 31B of the body drum 31. As a result, as shown in FIG. 4, a lump PD of paper dust is formed between the tip of the toner seal 380 and the cylindrical surface 31B of the photosensitive drum 31.

  When the paper powder lump PD is grown, the toner seal 380 is lifted from the cylindrical surface 31B of the photoconductive drum 31 in the axial direction of the rotating shaft 31A of the photoconductive drum 31 corresponding to the portion where the lump PD is present. (FIG. 5). As a result, the toner TN1 starts to leak from the toner reservoir TN. The toner TN1 falls along the cylindrical surface 31B of the photosensitive drum 31 according to gravity (arrow DT). Then, the toner TN1 reaching the transfer nip portion TP adheres to the sheet P conveyed to the transfer nip portion TP. As a result, toner contamination occurs on the sheet P.

  As described above, the toner scattered from the polishing roller 353 is deposited above the toner seal 380 of the cleaning device 35. A paper powder lump PD is generated between the toner seal 380 and the photosensitive drum 31. As a result, the toner stain on the sheet P may be caused. The cleaning device 35 according to the present embodiment is characterized by a support structure for the polishing roller 353 in order to solve the above-described problems.

  FIG. 6 is a schematic enlarged sectional view of the cleaning device 35 according to the present embodiment. FIG. 7 is a perspective view for explaining the moving part 390 of the polishing roller 353.

  Referring to FIG. 6, the polishing roller 353 has a first position CP1 for collecting toner from the photosensitive drum 31, and a part of the peripheral surface of the polishing roller 353 from the first position CP1. Between the second position CP2 and the second position CP2. More specifically, the polishing roller 353 is moved so that the peripheral surface of the polishing roller 353 approaches a corner where the housing rear wall 35H1 and the toner seal 380 intersect.

  Referring to FIG. 7, the cleaning device 35 includes a moving unit 390 (moving unit). The moving unit 390 moves the polishing roller 353 of the cleaning device 35 in the circumferential direction of the photosensitive drum 31.

  The moving unit 390 includes a holder 385 (support member), a cam 386 (cam member), a first spring SP1 (first biasing member), and a second spring SP2 (second biasing member). The moving unit 390 moves the polishing roller 353 between the first position CP1 and the second position CP2.

  The holders 385 are support members that are disposed as a pair at both ends of the polishing roller 353 in the axial direction. The holder 385 supports the polishing roller 353 so as to be movable. The holder 385 is a plate-like member having a slight thickness in the left-right direction and extending in the front-rear direction. The holder 385 is disposed below the housing top plate 35H2 corresponding to the top plate of the cleaner housing 35H and in front of the housing rear wall 35H1. The holder 385 includes a guide portion 385H (a long hole) at the center in the front-rear direction.

  The guide portion 385H is a hole portion penetrating in the left-right direction in the holder 385. The guide portion 385H extends in an arc shape along the cylindrical surface 31B of the photosensitive drum 31 in a cross-sectional view that intersects the axial direction of the polishing roller 353 (the axial direction of the rotation shaft 31A of the photosensitive drum 31). It is a hole. A roller shaft 353S that is a rotation shaft of the polishing roller 353 is inserted through the guide portion 385H. The polishing roller 353 is movable along the guide portion 385H. At this time, the interaxial distance between the roller shaft 353S of the polishing roller 353 and the rotation shaft 31A of the photosensitive drum 31 is maintained constant.

  The cam 386 is a cam member having an elliptical shape in the sectional view. The circumferential surface of the cam 386 is in contact with the roller shaft 353S of the polishing roller 353. The cam 386 is connected to a motor (not shown) disposed in the image forming apparatus 1 and is driven to rotate. The cam 386 presses the roller shaft 353S from the first position CP1 toward the second position CP2.

  The first spring SP1 is a spring member disposed between the housing rear wall 35H1 and the roller shaft 353S. The first spring SP1 biases the roller shaft 353S in the direction from the second position CP2 toward the first position CP1.

  The second spring SP2 is disposed between the housing top plate 35H2 and the upper end surface of the holder 385. The second spring SP2 biases the holder 385 toward the photosensitive drum 31. Since the roller shaft 353S is inserted into the guide portion 385H of the holder 385, the polishing roller 353 is urged toward the photosensitive drum 31 by the second spring SP2.

  When the minor axis portion of the elliptical outer periphery of the cam 386 is in contact with the roller shaft 353S, the roller shaft 353S is urged forward by the first spring SP1. For this reason, the polishing roller 353 is disposed at the first position CP1. On the other hand, when the cam 386 is rotationally driven by a motor (not shown) and the portion of the outer periphery of the cam 386 that contacts the roller shaft 353S is changed from the short diameter portion to the long diameter portion of the cam 386, the first spring SP1 Are compressed backwards. Then, the roller shaft 353S is moved backward following the shape of the guide portion 385H of the holder 385. As a result, the polishing roller 353 moves from the first position CP1 to the second position CP2 on the circumferential surface of the photosensitive drum 31. In the present embodiment, the polishing roller 353 is moved in a distance of about 2 to 3 mm from the first position CP1 to the second position CP2 in about 10 seconds.

  In the present embodiment, the scraper holder 355 disposed above the polishing roller 353 is integrally disposed with the polishing roller 353 by a housing (not shown). When the moving unit 390 moves the polishing roller 353, the scraper holder 355 is moved integrally with the polishing roller 353. As a result, the scraper 354 that contacts the polishing roller 353 is also moved integrally with the polishing roller 353. Therefore, the contact pressure between the polishing roller 353 and the scraper 354 is unlikely to change.

  When the polishing roller 353 moves to the second position CP2, the peripheral surface of the polishing roller 353 comes into contact with the toner reservoir TN deposited above the toner seal 380 (FIG. 6). For this reason, the toner deposited above the toner seal 380 is broken and falls onto the cylindrical surface 31 </ b> B of the photosensitive drum 31. The toner adheres again to the peripheral surface of the polishing roller 353 as the cylindrical surface 31B rotates. Alternatively, the toner is suitably scraped off from the cylindrical surface 31B by the cleaning blade 351 disposed on the downstream side in the rotation direction of the polishing roller 353. As the toner in the toner reservoir TN adheres again to the peripheral surface of the polishing roller 353, the toner adheres abundantly to the peripheral surface of the polishing roller 353. As a result, the polishing effect of the cylindrical surface 31B of the photosensitive drum 31 by the polishing roller 353 is promoted. Further, when the polishing roller 353 is moved from the first position CP1 to the second position CP2, the polishing roller 353 and the photosensitive drum 31 are rotationally driven. Therefore, with the movement of the polishing roller 353, the collection of the toner constituting the toner reservoir TN and the polishing of the cylindrical surface 31B of the photosensitive drum 31 by the polishing roller 353 are simultaneously performed.

  According to the above embodiment, the cleaning device 35 includes the polishing roller 353, the toner seal 380, and the moving unit 390. The polishing roller 353 contacts the cylindrical surface 31B of the photosensitive drum 31 at the first position CP1 above the cylindrical surface 31B of the photosensitive drum 31. The polishing roller 353 is driven to rotate and collects the toner attached on the photosensitive drum 31. The toner seal 380 includes a front end portion that is above the rotation shaft 31A of the photosensitive drum 31 and contacts the cylindrical surface 31B on the upstream side of the polishing roller 353 in the rotation direction of the photosensitive drum 31. Even when the collected toner collected from the photosensitive drum 31 scatters from the peripheral surface of the polishing roller 353 and accumulates on the toner seal 380, the moving unit 390 moves the polishing roller 353 to the first position. It is moved between CP1 and the second position CP2 where a part of the peripheral surface of the polishing roller 353 is closer to the toner seal 380 than the first position CP1. At the second position CP2, the peripheral surface of the polishing roller 353 can collect the toner deposited on the toner seal 380. For this reason, the collected toner is prevented from being excessively deposited on the toner seal 380. As a result, the toner deposited on the toner seal 380 is prevented from pressing the toner seal 380 toward the photosensitive drum 31. Therefore, the contact pressure of the toner seal 380 with respect to the photosensitive drum 31 is unlikely to be high, and the occurrence of toner leakage from the front end portion of the toner seal 380 is suppressed.

  In the above embodiment, the polishing roller 353 is moved between the first position CP1 and the second position CP2 so that the distance between the axes with the photosensitive drum 31 is constant. For this reason, the contact pressure between the polishing roller 353 and the photosensitive drum 31 is stably maintained. Further, it is possible to prevent the cylindrical surface 31B of the photosensitive drum 31 from being damaged by the strong sliding friction between the polishing roller 353 and the cylindrical surface 31B of the photosensitive drum 31.

  In the above embodiment, the moving unit 390 moves the polishing roller 353 between the first position CP1 and the second position CP2 in a state where the polishing roller 353 and the photosensitive drum 31 are rotationally driven. Move. For this reason, when the polishing roller 353 is moved, the cylindrical surface 31B of the photosensitive drum 31 is less likely to be damaged. Further, since the polishing roller 353 approaches the toner seal 380 while being driven to rotate, the toner deposited on the toner seal 380 tends to collapse. Further, the broken toner is conveyed to the downstream side in the rotation direction by the photosensitive drum 31 and is suitably collected by the polishing roller 353.

  Further, according to the above embodiment, the adhering matter attached to the cylindrical surface 31 </ b> B of the photosensitive drum 31 is effectively polished by the polishing roller 353. Further, the scraper 354 regulates the amount of toner that adheres to the rotating surface of the polishing roller 353. For this reason, when the toner is uniformly interposed between the polishing roller 353 and the cylindrical surface 31 </ b> B of the photosensitive drum 31, the promoted polishing effect is prevented from being varied depending on the position on the rotation surface of the polishing roller 353. Is done.

  Further, according to the above embodiment, the moving unit 390 moves the polishing roller 353 and the scraper 354 integrally with the movement of the polishing roller 353. For this reason, the contact pressure between the polishing roller 353 and the scraper 354 is stably maintained. As a result, the toner amount adhering to the peripheral surface of the polishing roller 353 is suppressed from fluctuating.

  Further, according to the above embodiment, the moving unit 390 moves the polishing roller 353 so that the pressure contact force between the polishing roller 353 and the photosensitive drum 31 is constant. For this reason, the contact pressure between the polishing roller 353 and the photosensitive drum 31 is stably maintained. Further, the cylindrical surface 31B of the photosensitive drum 31 is further prevented from being damaged by the strong rubbing between the polishing roller 353 and the cylindrical surface 31B of the photosensitive drum 31.

  Further, according to the above embodiment, the photosensitive drum 31 is an amorphous silicon photosensitive member. That is, the polishing roller 353 contacts the amorphous silicon photoconductor. The polishing roller 353 polishes the discharge product attached on the amorphous silicon photoconductor. At this time, in the amorphous silicon photoreceptor corresponding to the hard drum, the photosensitive layer is hardly polished by the polishing roller 353. Therefore, as described above, when the polishing roller 353 comes into contact with the photosensitive drum 31, the discharge product on the photosensitive drum 31 is suitably polished, and the toner image is stably formed on the photosensitive drum 31. It is formed.

  Further, according to the above-described embodiment, the image forming apparatus 1 faces the photosensitive drum 31, the main conveyance path 22 </ b> F that conveys the sheet from the lower side to the upper side, and the cylindrical surface 31 </ b> B of the photosensitive drum 31. And a transfer roller 34 that forms a transfer nip portion TP that abuts and transfers a toner image from the photosensitive drum 31 to a sheet. The photosensitive drum 31 is rotationally driven from below to above in the transfer nip portion TP, and the polishing roller 353 extends from the transfer nip portion TP to a position immediately above the rotation shaft 31A of the photosensitive drum 31. It contacts the cylindrical surface 31B of the photosensitive drum 31. The tip of the toner seal 380 is in contact with the cylindrical surface 31B on the upstream side in the rotation direction of the photosensitive drum 31 below the position where the polishing roller 353 contacts the cylindrical surface 31B. For this reason, the toner scattered from the polishing roller 353 easily falls on the toner seal 380. Even in such a case, the moving unit 390 moves the polishing roller 353 between the first position CP1 and the second position CP2. For this reason, at the second position CP2, the peripheral surface of the polishing roller 353 can break the toner deposited on the toner seal 380. Furthermore, even when the paper dust of the sheet adheres to the cylindrical surface 31B of the photosensitive drum 31 at the transfer nip portion TP, the sheet is moved to the tip of the toner seal 380 as the photosensitive drum 31 rotates. The paper dust is prevented from growing into a lump between the tip of the toner seal 380 and the cylindrical surface 31B of the photosensitive drum 31. As a result, the tip of the toner seal 380 is lifted by the lump of paper dust, and the toner can be prevented from leaking from the gap between the toner seal 380 and the cylindrical surface 31B of the photosensitive drum 31. Therefore, the conveyed sheet in the transfer nip portion TP is prevented from being soiled by the leaked toner.

  The cleaning device 35, the drum unit 31H including the cleaning device 35, and the image forming apparatus 1 according to the embodiment of the present invention have been described above. However, the present invention is not limited to this, and for example, the following modified embodiment is provided. Can be taken.

  (1) In the above embodiment, the embodiment has been described in which the polishing roller 353 and the cleaning blade 351 are disposed downstream of the toner seal 380 in the rotation direction of the photosensitive drum 31, but the present invention is not limited thereto. It is not limited. The polishing roller 353 may be a cleaning roller that cleans the surface of the photosensitive drum 31. In this case, the cleaning blade 351 may be disposed downstream of the cleaning roller in the rotation direction of the photosensitive drum 31, or the cleaning blade 351 may not be disposed.

  (2) In the above embodiment, the polishing roller 353 is moved so that the distance between the roller shaft 353S of the polishing roller 353 and the rotation shaft 31A of the photosensitive drum 31 is constant. Although described, the present invention is not limited to this. After the peripheral surface of the polishing roller 353 is separated from the cylindrical surface 31 </ b> B of the photosensitive drum 31, the polishing roller 353 may be moved so as to approach the toner seal 380.

  (3) In the above-described embodiment, the cleaning device 35 including the polishing roller 353 and the toner seal 380 has been described as being disposed in the drum unit 31H. However, the present invention is not limited to this. Absent. The cleaning device 35 including the polishing roller 353 and the toner seal 380 may be individually attached to the image forming apparatus 1.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 30 Image forming part 31 Photosensitive drum (image carrier)
31H drum unit (image carrier unit)
32 Charging device 321 Charging roller 322 Cleaning roller 32H Charging housing 33 Development device 34 Transfer roller (transfer member)
35 Cleaning device 35H Cleaner housing (housing)
35H1 Housing rear wall 35H2 Housing top plate 351 Cleaning blade 351H Blade holder 351B First fixed screw 352 Conveying screw 353 Polishing roller (rotating member)
353S Roller shaft 354 Scraper (Regulator)
355 Scraper holder 356 Upper seal 357 First plate 357T First plate upper 357S First plate lower 357B Second fixing screw 358 Second plate 358T Second plate upper 380 Toner seal 385 Holder (supporting member)
385H Guide part (long hole)
386 Cam (Cam member)
390 Moving part (moving means)
SP1 first spring (first biasing member)
SP2 second spring (second biasing member)

Claims (12)

A cleaning device that is disposed above an image carrier having a rotation shaft and a cylindrical surface that rotates in one direction around the rotation shaft and carries a toner image, and that cleans the cylindrical surface,
A housing,
In a cross-sectional view orthogonal to the rotation axis, a circumferential surface that comes into contact with the cylindrical surface at a first position above the rotation axis is driven to rotate in the same direction as the image carrier at the contact position. A rotating member that collects toner adhering to the image carrier;
A sheet that is provided in the housing and includes a tip portion that is above the rotation shaft and is in contact with the cylindrical surface on the upstream side in the rotation direction of the image carrier in the sectional view. Members,
A moving means for moving the rotating member between the first position and a second position where the circumferential surface of the rotating member is closer to the sheet member than the first position;
A cleaning device comprising: The rotating member includes a shaft portion that rotatably supports the peripheral surface,
The said moving means moves the said rotation member so that the center distance between the said axial part of the said rotation member and the said rotating shaft of the said image carrier may become fixed. Cleaning device.   The moving means moves the rotating member between the first position and the second position in a state where the rotating member and the image carrier are rotationally driven. Item 3. The cleaning device according to Item 1 or 2. The rotating member is a polishing roller that polishes deposits attached to the cylindrical surface of the image carrier,
The cleaning apparatus according to claim 1, further comprising a regulating member that abuts on the circumferential surface of the polishing roller and regulates an amount of toner adhering to the circumferential surface.   The cleaning apparatus according to claim 4, wherein the moving unit moves the polishing roller and the regulating member integrally with the movement of the polishing roller.   The cleaning apparatus according to claim 1, wherein the moving unit moves the rotating member such that a pressing force between the rotating member and the image carrier is constant. A support member that supports the shaft portion of the rotating member;
In the cross-sectional view, the support member is opened along the cylindrical surface of the image carrier, and an elongated hole through which the shaft portion is inserted;
A first biasing member disposed between the housing and the support member and biasing the support member toward the image carrier;
A second biasing member that is disposed between the housing and the shaft portion and biases the shaft portion from the second position toward the first position;
A cam member that is in contact with the shaft portion, is rotationally driven, and presses the shaft portion from the first position toward the second position;
The cleaning apparatus according to claim 2, further comprising:   8. The apparatus according to claim 1, further comprising a cleaning blade that contacts the cylindrical surface on the downstream side in the rotation direction of the image carrier with respect to the rotating member and removes toner adhering to the image carrier. The cleaning device according to any one of the above. A cleaning device according to any one of claims 1 to 8,
An image carrier unit comprising: the image carrier arranged to face the rotating member. A cleaning device according to any one of claims 1 to 8,
The image carrier disposed to face the rotating member;
A developing device for supplying toner to the cylindrical surface of the image carrier;
An image forming apparatus comprising:   The image forming apparatus according to claim 10, wherein the image carrier is an amorphous silicon photoconductor. A sheet conveying path that conveys a sheet from the lower side to the upper side, facing the image carrier,
A transfer member that is in contact with the cylindrical surface of the image carrier and forms a transfer nip portion for transferring the toner image from the image carrier to the sheet;
The image carrier is rotationally driven from below to above in the transfer nip portion,
The image forming apparatus according to claim 10, wherein the rotating member is in contact with the cylindrical surface of the image carrier between the transfer nip portion and a position immediately above the rotation shaft.

Images