JP5323242B2 - Image forming apparatus and image forming unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To always form a toner image stably on the surface of an image carrier by effectively preventing a foreign matter such as residual toner from being accumulated at the end of the image carrier. <P>SOLUTION: The image forming apparatus includes a photoreceptor drum 121 rotating while carrying a toner image, and a developing device 122 having a developing roller 122a supplying toner to the surface of the photoreceptor drum 121, and a pair of gap rollers 122b abutting on both ends of the photoreceptor drum 121 so as to form a predetermined gap between the developing roller 122a and the surface of the photoreceptor drum 121. Then, the apparatus includes end cleaning devices 50 performing dedicated cleaning processing to portions corresponding to the gap rollers 122b at both ends of the photoreceptor drum 121. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus having an image carrier on which a toner image is formed on the surface, and in particular, an image forming process is difficult to be performed properly due to deposits deposited on the surface of the image carrier. The present invention relates to an image forming apparatus capable of effectively preventing occurrence of inconvenience and an image forming unit applicable to the image forming apparatus.

  Conventionally, an electrostatic latent image is formed on the peripheral surface of a photosensitive drum (image carrier) based on image information that has been read or transmitted from an external computer or the like, and a developing device is directed toward the electrostatic latent image. 2. Description of the Related Art An image forming apparatus applied as a copying machine, a printer, or a facsimile machine, which is configured to supply toner to form a toner image on the same peripheral surface and transfer the toner image onto a sheet is known. Yes.

  In such an image forming apparatus, the residual toner remaining on the peripheral surface of the photosensitive drum after the transfer process to the paper or the charging process at a high voltage performed before forming the electrostatic latent image on the peripheral surface is performed. The generated nitrogen oxides or the like may adhere to hinder proper image forming processing.

  Therefore, in order to eliminate such inconvenience, a cleaning blade made of an elastic material such as rubber is employed, and the front edge of the cleaning blade is brought into sliding contact with the peripheral surface of the rotating photosensitive drum, thereby the photosensitive drum. In general, the toner or the like remaining on the peripheral surface is scraped off.

  However, at both ends in the axial direction of the photosensitive drum, there is a disadvantage that a reliable cleaning process cannot be performed because it is difficult to obtain a sufficient contact pressure due to the cleaning blade rolling up.

  By the way, both end portions of the photosensitive drum are portions where the gap rollers abut so as to form a slight gap (gap) between the peripheral surface of the developing roller of the developing device and the peripheral surface of the photosensitive drum. . Accordingly, when deposits accumulate on both ends of the photosensitive drum, the gap roller gets on the deposits by the rotation of the photosensitive drum, and the developing device vibrates. The toner supply state becomes unstable, which causes a disadvantage that a stable toner image cannot be formed on the peripheral surface of the photosensitive drum.

  In order to eliminate such inconvenience, in the cleaning blade described in Patent Document 1, thick portions with increased thickness are provided at both ends of the cleaning blade, thereby preventing the both ends of the cleaning blade from rolling up. Things have been done.

JP-A-5-333753

  However, even if thick portions are formed at both ends of the cleaning blade, the side edges of the thick portions are open ends, so that it is possible to reliably prevent the cleaning blade from rolling up at both ends. Have difficulty. Therefore, even if thick portions are provided at both ends of the cleaning blade, there is a problem that it is not sufficient for reliably removing deposits such as residual toner attached to both ends of the photosensitive drum. .

  The present invention has been made in view of the above situation, and can effectively prevent deposits such as residual toner from accumulating on the edge of the image carrier. An object of the present invention is to provide an image forming apparatus improved so that a toner image can be always formed on the surface of an image carrier in a stable state, and an image forming unit applicable to the image forming apparatus.

According to a first aspect of the present invention (an image forming apparatus), an image carrier that carries and circulates a toner image, an intermediate transfer belt on which a toner image on the surface of the image carrier is transferred, and toner that is transferred to the image carrier And a developing device having a pair of gap rollers contacting both ends of the image carrier so as to form a predetermined gap between the developing roller and the surface of the image carrier. An end cleaning device that performs a cleaning process on portions corresponding to the positions of the gap rollers at both ends of the image carrier, and the end cleaning device is attached to the plate spring and the plate spring. comprising a blade member made of a felt material, the felt material of the blade member, which is in contact with the surface of the image bearing member while being biased to the leaf spring, the leaf spring A first surface located on the side of the image carrier and a second surface located on the side of the intermediate transfer belt, wherein the felt material is laminated on the first surface and the second surface, respectively. And an image forming apparatus in contact with the surface of the intermediate transfer belt .

  According to this configuration, the end cleaning device that performs the cleaning process on the portions corresponding to the gap rollers at both ends of the image carrier is employed, and the cleaning process is performed on both ends of the image carrier by the dedicated end cleaning device. Applied. For this reason, as compared with the conventional measures in which thick portions are formed at both ends of a single cleaning blade, the processing power can be concentrated exclusively on the cleaning of both ends of the image carrier. As a result, it is possible to suppress the occurrence of an inconvenience that deposits such as residual toner accumulate on both ends of the image carrier and an appropriate image forming process cannot be performed.

  In particular, according to this configuration, since the surface of the image carrier is wiped by the felt material pressed by the elastic force of the leaf spring, there is no problem such as scratching the surface of the image carrier. In addition, the surface of the image carrier is effectively cleaned by wiping with a felt material in which fibers are densely packed.

In addition, since both the image carrier and the intermediate transfer belt are simultaneously cleaned by the edge cleaning device, the number of parts can be reduced and extended compared to the case where each of them is cleaned by the dedicated edge cleaning device. This contributes to a reduction in manufacturing costs.

According to a second aspect of the present invention, in the first aspect of the present invention, the felt material has an elongated strip shape and is formed symmetrically with respect to a center line in the longitudinal direction, and the tip of the leaf spring is used as a fulcrum. It is characterized by being laminated on each surface of the leaf spring by being bent at the position of the center line.

According to a third aspect of the present invention, in the second aspect of the present invention, the housing includes a housing that supports the image carrier. The housing includes a mounting pin for fixing the blade member. A mounting hole that penetrates the leaf spring and the felt material is provided at a position on the rear side of the tip of the leaf spring, and is attached to the housing so that the attachment pin penetrates the attachment spring, and a retaining ring is attached to the attachment pin. It is characterized by being fixed to the housing by mounting.

The invention according to claim 4 is the invention according to claim 3 , wherein a positioning protrusion is formed on the housing, and a pair of locking protrusions extending in parallel with the respective surfaces are formed on the leaf spring. The blade member is fixed to the housing in a state where the positioning protrusion is sandwiched from both sides by the pair of locking protrusions.

  According to this configuration, the blade member can be positioned while preventing the blade member from turning around the mounting pin.

The invention according to claim 5 is the invention according to claim 3 or 4 , wherein the blade member is offset in the inner direction of the image carrier with respect to the mounting portion in which the mounting hole is formed, and the mounting portion. A sliding contact portion that is in contact with the surface of the image carrier and the intermediate transfer belt, and the sliding contact portion is in sliding contact with the image carrier over its entire width, while the mounting portion of the full width is Only the portion inward of the hole is in sliding contact with the intermediate transfer belt.

  According to this configuration, the sliding contact portion (felt member) can be slid to the intermediate transfer belt while avoiding the intermediate transfer belt from interfering with the mounting pin.

Invention according to claim 6, in the invention according to any one of claims 1 to 5, that the recovery passage is provided for collecting the toner removed from the surface of the image carrier by the end cleaning device It is a feature.

  According to such a configuration, the deposits such as residual toner removed from the both ends of the image carrier by the edge cleaning device are collected through the collection passage, and thus the removed deposits are collected at the end of the image carrier. There is no inconvenience that is scattered around the part.

A seventh aspect of the present invention (an image forming unit) is an image forming unit applied to the image forming apparatus according to any one of the first to sixth aspects, wherein the image carrier has an image forming area on a peripheral surface. The photosensitive drum is rotatable about an axis and has a unit formed by at least the photosensitive drum and the cleaning device.

  According to such a configuration, by attaching / detaching the image forming unit to / from the apparatus main body of the image forming apparatus, at least the photosensitive drum and the cleaning device can be attached / detached collectively, compared with the case where they are attached / detached separately. As a result, assembly work and maintenance work become easy.

  According to the image forming apparatus of the present invention, the edge cleaning device for performing the cleaning process is provided on the portions corresponding to the position of the gap roller of the developing device at both ends of the image carrier. Compared to the one in which thick portions are formed at both ends of one cleaning blade, the cleaning process can be performed on both ends of the image carrier intensively by the dedicated end cleaning device. The vibration of the developing device does not cause the inconvenience that the toner supply from the developing device to the image bearing member becomes unstable due to the vibration caused by the gap roller getting on and off the deposit by the rotation of the image bearing member. It is possible to effectively prevent the occurrence of image defects due to.

  According to the image forming unit of the present invention, by attaching / detaching the image forming unit to / from the apparatus main body of the image forming apparatus, at least the photosensitive drum and the cleaning device can be attached / detached collectively, and these can be separated separately. The workability of the assembly work can be improved as compared with the case of attaching and detaching, and the maintenance work can be easily performed.

1 is a perspective view showing an embodiment of an image forming apparatus according to the present invention. It is explanatory drawing of front sectional view which shows one Embodiment of the internal structure of the image forming apparatus shown in FIG. It is a partially cutaway exploded perspective view as a principle view showing an embodiment of a drum unit. FIG. 4 is an assembled perspective view of the drum unit of FIG. 3. It is the VV sectional view taken on the line of FIG. It is a partially cutaway part enlarged perspective view of a drum unit for explaining an example of an end cleaning device. It is a partially cutaway part enlarged perspective view of a drum unit for explaining an example of an end cleaning device. It is an expansion perspective view which shows the edge part cleaning apparatus which concerns on this invention, (A) is an exploded perspective view, (B) is an assembly perspective view of the blade member for both. It is perspective explanatory drawing for demonstrating the mounting procedure to the top plate of a housing of an edge part cleaning apparatus, (A) is the state just before mounting a both-use blade member on the top plate of a housing, (B) is FIG. 2 shows a state in which the dual-purpose blade member is mounted on the top plate of the housing. It is a perspective view which shows the drum unit with which the edge part cleaning apparatus which concerns on this invention was mounted | worn.

  FIG. 1 is a perspective view showing an embodiment of an image forming apparatus 10 according to the present invention, and FIG. 2 is an explanatory view of a front sectional view for explaining the internal structure of the image forming apparatus 10. 1 and 2, the XX direction is referred to as the left-right direction, and the Y-Y direction is referred to as the front-rear direction. In particular, the -X direction is leftward, the + X direction is rightward, the -Y direction is frontward, and the + Y direction is rearward. That's it.

  First, an image forming apparatus 10 shown in FIG. 1 is a so-called in-cylinder discharge type copying machine. An image forming unit 12, a fixing unit 13, a sheet storage unit 14, and a discharge unit are included in an apparatus main body 11. The unit 15, the image reading unit 16, and the operation unit 17 are formed. Then, a part of the apparatus main body 11 is recessed below the image reading unit 16 to form the paper discharge unit 15, which is why the image forming apparatus 10 is referred to as an in-body paper discharge type. .

  The apparatus main body 11 includes a lower main body 111 having a rectangular parallelepiped shape in appearance, an upper main body 112 having a flat rectangular parallelepiped shape disposed above the lower main body 111, and the upper main body 112 and the lower main body 111. And a connecting body 113 interposed therebetween. The connecting body 113 is a structure for connecting the discharge body 15 between the lower main body 111 and the upper main body 112 to each other, and is erected from the left part of the lower main body 111. Yes. The upper main body 112 is supported at the upper end portion of the connecting body 113 at the left side.

  The lower main body 111 includes an image forming unit 12, a fixing unit 13, and a paper storage unit 14, and an image reading unit 16 is mounted on the upper main body 112. In the present embodiment, the operation portion 17 is provided so as to protrude forward from the front edge portion of the upper main body 112.

  The paper discharge unit 15 is formed between the lower main body 111 and the upper main body 112. The paper discharge unit 15 has a cylinder discharge tray 151 formed on the upper surface of the lower main body 111, and the paper P onto which the toner image from the image forming unit 12 has been transferred is transferred from the lower part of the coupling body 113 to the cylinder P. The paper is discharged toward the inner paper discharge tray 151.

  Hereinafter, the image forming unit 12 will be described with reference to FIG. The image forming unit 12 forms a toner image on the paper P fed from the paper storage unit 14, and is sequentially arranged from the upstream side (right side) to the downstream side as shown in FIG. A magenta image forming unit 12M, a cyan image forming unit 12C, a yellow image forming unit 12Y, and a black image forming unit 12K.

  Each of the image forming units 12M, 12C, 12Y, and 12K includes a photosensitive drum (image carrier) 121 and a developing device 122, respectively. Each photosensitive drum 121 is supplied with toner from a corresponding developing device 122 while rotating counterclockwise in FIG. Each developing device 122 is replenished with toner from a toner cartridge (not shown) disposed on the front side of the apparatus main body 11 (the front side of the paper surface of FIG. 2).

  A charging device 123 is provided immediately below each photoconductor drum 121, and an exposure device 124 is provided further below each charging device 123. Each photosensitive drum 121 is charged uniformly by the charging device 123, and laser light corresponding to each color based on image data read by the image reading unit 16 is charged from each exposure device 124. By irradiating the peripheral surface of each photoconductive drum 121, an electrostatic latent image is formed on the peripheral surface of each photoconductive drum 121. By supplying toner from the developing device 122 to the electrostatic latent image, a toner image is formed on the peripheral surface of the photosensitive drum 121.

  A transfer belt 125 is provided above the photoconductive drum 121 so as to come into contact with each photoconductive drum 121. The transfer belt 125 is wound around a driving roller 125a provided at the left position in FIG. 2 and a driven roller 125b provided at the right position.

  The transfer belt 125 is driven against a peripheral surface of the photosensitive drum 121 by a transfer roller 125c provided corresponding to each photosensitive drum 121, and is driven with a driving roller 125a and a driven roller while being synchronized with the photosensitive drum 121. Circulate between 125b.

  Accordingly, when the transfer belt 125 circulates, a magenta toner image is transferred onto the surface of the transfer belt 125 by the photosensitive drum 121 of the magenta image forming unit 12M, and then the cyan image forming unit 12C is located at the same position on the transfer belt 125. The cyan toner image is transferred on the photosensitive drum 121 in the overcoating state, and then the yellow toner image is transferred on the transfer belt 125 at the same position on the photosensitive drum 121 in the overcoating state. Then, the transfer of the black toner image by the photosensitive drum 121 of the last black image forming portion 12K is performed in the overcoating state.

  As a result, a color image is formed on the surface of the transfer belt 125. The color image formed on the surface of the transfer belt 125 is transferred to the paper P conveyed from the paper storage unit 14.

  A drum cleaning device 40 that removes and cleans residual toner on the peripheral surface of the photosensitive drum 121 is provided at the left position of each photosensitive drum 121 in FIG. The peripheral surface of the photosensitive drum 121 cleaned by the drum cleaning device 40 is directed to the charging device 123 for a new charging process.

  Waste toner removed from the peripheral surface of the photosensitive drum 121 by the drum cleaning device 40 is collected in a toner collection bottle (not shown) through a predetermined path.

  A sheet conveyance path 127 extending in the vertical direction is provided at the left position of the image forming unit 12. The paper transport path 127 is provided with a transport roller pair 127a at an appropriate position, and the paper P from the paper storage unit 14 is directed toward the transfer belt 125 that is wound around the drive roller 125a by the drive of the transport roller pair 127a. Be transported.

  A second transfer roller 128 that contacts the surface of the transfer belt 125 is provided in a position opposite to the driving roller 125 a in the sheet conveyance path 127, and the sheet P being conveyed through the sheet conveyance path 127 is transferred to the transfer belt 125. The toner image on the transfer belt 125 is transferred to the paper P by being pressed and clamped by the second transfer roller 128.

  A belt cleaning device 125d (not shown) for removing residual toner remaining on the surface of the transfer belt 125 is provided on the right side of the transfer belt 125. Residual toner on the surface is removed by the belt cleaning device 125d and cleaned, and circulated toward the next transfer process.

  The fixing unit 13 performs a fixing process on the toner image on the paper P transferred by the image forming unit 12. The fixing unit 13 includes a fixing roller 131 including an energization heating element such as a halogen lamp as a heating source. The pressure roller 132 disposed opposite to the fixing roller 131 is provided on the left side. Then, the transfer-processed paper P led out from the image forming unit 12 through the second transfer roller 128 is pressed and held between the fixing roller 131 and the pressure roller 132, and the toner image is heated by the fixing roller 131. Is fixed, and a stable color image is formed on the paper P.

  The color-printed paper P that has undergone the fixing process passes through a paper discharge conveyance path 129 extending from the upper part of the fixing unit 13 and is discharged toward the in-body paper discharge tray 151 through the discharge roller pair 152. .

  The paper storage unit 14 has a paper feed tray 141 that is detachably mounted at a position below the exposure device 124 in the apparatus main body 11. A sheet bundle is stored in the sheet feeding tray 141. Then, the sheet P is fed out from the sheet bundle stored in the sheet feeding tray 141 one by one by the drive of the pickup roller 142, and is introduced into the image forming unit 12 through the sheet conveying path 127.

  The image reading unit 16 presses the contact glass 161 mounted on the upper surface opening of the upper main body 112 on which the document P1 is placed with the document surface facing down, and the document placed on the contact glass 161. A document holding mat 162 that can be opened and closed with respect to the contact glass 161, and an optical system unit 163 that is built in the upper body 112 for reading a document image of the document P1 placed on the contact glass 161. I have.

  The optical system unit 163 scans a document image from the document surface by moving the light source 164 from below through the contact glass 161 in a state where the document placed on the contact glass 161 is pressed by the document pressing mat 162. It is read by a CCD (charge coupled device) 165 by the reflected light. The document image information read by the CCD 165 is output to the exposure device 124 of the image forming unit 12 after being digitized.

  The operation unit 17 is used to input various items (paper size, number of processing copies, etc.) related to image forming processing. As shown in FIG. 1, the operation unit 17 includes a start key 171, a numeric keypad 172 for inputting numerical information, and an LCD (Liquid crystal display) for displaying input information, an error message, and the like that have been actually performed. 173 etc. are provided.

  In the present embodiment, in the image forming apparatus 10 configured as described above, end portions that perform cleaning processing on both ends of the peripheral surface of the photosensitive drum 121, the charging device 123, the drum cleaning device 40, and the photosensitive drum 121 described later. A drum unit 20 is provided in which the cleaning device 50 and the like are unitized. Hereinafter, the drum unit 20 will be described with reference to FIGS.

  The drum unit 20 is provided in each of the image forming units 12M, 12C, 12Y, and 12K. These four drum units 20 are structurally identical in structure except for the type of toner employed.

  FIG. 3 is a partially cutaway exploded perspective view as a principle view showing an embodiment of the drum unit 20, and FIG. 4 is an assembled perspective view thereof. FIG. 5 is a cross-sectional view taken along line VV in FIG. 3 to 5, the direction indication by X and Y is the same as in FIG. 1 (−X: leftward, + X: rightward, −Y: forward, + Y: backward).

  As shown in these drawings, the drum unit 20 performs a cleaning process on the peripheral surfaces of both ends of the photosensitive drum 121, the charging device 123, the drum cleaning device 40, and the photosensitive drum 121 on the housing 30. This is formed by mounting an end cleaning device. As the edge cleaning device, in addition to the edge cleaning device 50 shown in FIGS. 3 to 5, the edge cleaning device 60 shown in FIG. 7 and the edge cleaning device 70 shown in FIGS. (The end cleaning device of the present invention) can also be employed.

  The housing 30 includes a pair of front and rear side plates 31 having an inverted L shape that is reversed upside down in a front view as viewed from the −Y direction, and an installation plate 32 that is installed on the left side between the pair of side plates 31. And a top plate 33 that covers the upper surface between the pair of side plates 31.

  The side plate 31 includes a vertical plate 311 extending in the vertical direction, and a horizontal plate 312 extending from the substantially upper half position of the vertical plate 311 toward the left. A drum shaft insertion hole 313 for inserting the drum shaft 121a of the photosensitive drum 121 is formed at an appropriate position on the upper right side of each side plate 31.

  In addition, on the opposing surfaces of the lateral plates 312 of the side plates 31 are formed thick portions 314 that are bulged with a predetermined thickness in the opposing direction. Each thick portion 314 is provided with a mounting recess 315 formed by cutting leftward from the right edge surface. These mounting recesses 315 are for fitting a movable bracket 44 described later so as to be movable in the left-right direction.

  In addition, a long plate 316 that is elongated in the left-right direction is formed in the lateral plate 312 in the mounting recess 315 of the thick portion 314 in the rear side plate 31. This long hole 316 is for inserting a roller shaft 411 described later so as to be slightly movable in the left-right direction.

  In addition, mounting grooves 317 extending in the vertical direction are respectively provided in the lower surface of the pair of side plates 31 facing each vertical plate 311 so as to extend substantially vertically. These mounting grooves 317 are for fitting a pair of front and rear ridges 123d of the charging device 123, which will be described later.

  In other words, the charging device 123 includes a rectangular parallelepiped casing 123a whose upper surface is opened and whose length is slightly smaller than the inner dimension between the longitudinal plates 311 of the pair of side plates 31, and the casing is protruded slightly. The charging roller 123b is provided in the 123a. The charging roller 123b is rotatably supported around a roller shaft 123c installed between the front and rear side plates of the casing 123a. The charging roller 123b is applied with a voltage from a power supply device (not shown), thereby applying a charging process to the peripheral surface of the photosensitive drum 121 in contact with the peripheral surface of the charging roller 123b.

  Further, the front and rear side plates of the casing 123a are provided with ridges 123d that are fitted in the respective mounting grooves 317 recessed in the opposing surfaces of the longitudinal plates 311 of the housing 30 in a sliding contact state. Therefore, the charging device 123 can move up and down while the protrusions 123d are guided by the attachment grooves 317 by fitting the protrusions 123d into the corresponding attachment grooves 317.

  A predetermined number of coil springs 123e are interposed between the bottom plate 321 of the housing 30 and the bottom plate of the casing 123a of the charging device 123 in a compressed state. Accordingly, with the charging device 123 mounted between the front and rear side plates 31, the peripheral surface of the charging roller 123b is pressed against the peripheral surface of the photosensitive drum 121 by the biasing force of the coil spring 123e.

  The erection plate 32 connects the pair of side plates 31 to each other and closes the left surface side and the lower surface side between the pair of side plates 31. The construction plate 32 is formed in a step shape so as to follow the left edge portion and the lower edge portion of the side plate 31 in a front view as viewed from the −Y direction.

  Specifically, a bottom plate 321 corresponding to the lower edge portion of the vertical plate 311 of the side plate 31 and a lower portion corresponding to a portion below the horizontal plate 312 in the vertical plate 311 erected from the left edge portion of the bottom plate 321. A left side plate 322, a middle bottom plate 323 extending leftward along the lower edge portion of the lateral plate 312 in the side plate 31 of the lower left side plate 322, and a left edge portion of the middle step bottom plate 323 from the left edge portion to the side plate 31. An erection plate 32 is formed from an inclined plate 324 along an inclined portion on the left side of the lateral plate 312 and an upper left plate 325 extending upward from the upper edge of the inclined plate 324. .

  Such an erection plate 32 is fixed to the left surface side between the pair of side plates 31 by screwing or the like, and the top plate 33 is erected between the upper edge portions of the thick portions 314 of the lateral plates 312 in the pair of side plates 31. Then, a housing 30 as shown in FIG. 4 is formed by fixing with screws or the like.

  The drum cleaning device 40 is generated when a residual toner remaining on the circumferential surface of the photosensitive drum 121 after the transfer process to the paper P or a high voltage is applied to the circumferential surface of the photosensitive drum 121 by the charging device 123. This is for removing deposits such as nitrogen oxides attached to the surface and subjecting the image forming area on the peripheral surface of the photosensitive drum 121 to a cleaning process.

  The drum cleaning device 40 includes a cleaning roller 41 provided between the thick portions 314 of the pair of side plates 31, a blade 42 provided immediately below the cleaning roller 41, and the blade 42 and the installation plate 32. A toner conveying screw 43 disposed between the inclined plate 324 and immediately above the middle bottom plate 323, a pair of front and rear movable brackets 44 functioning as bearings for a roller shaft 411 described later, and each movable bracket 44 The side seal member 45 is attached to the right end edge surface, and the coil spring 46 biases the movable bracket 44 toward the photosensitive drum 121.

  The cleaning roller 41 is rotated forward at a higher speed than the photosensitive drum 121 in a state in which the peripheral surface is in sliding contact with the peripheral surface of the photosensitive drum 121, thereby removing the deposits attached to the peripheral surface of the photosensitive drum 121. It is something to remove. The cleaning roller 41 includes a roller shaft 411 and a roller main body 412 that is concentrically mounted on the roller shaft 411 so as to be integrally rotatable. In such a cleaning roller 41, the front end of the roller shaft 411 is supported by the front movable bracket 44 mounted in the front mounting recess 315, and the rear end of the roller shaft 411 is mounted in the rear mounting recess 315. It is attached to the housing 30 so as to penetrate through the rear movable bracket 44 and through the long hole 316.

  In the cleaning roller 41, a pair of front and rear movable brackets 44 fitted in the front and rear mounting recesses 315 are urged rightward by a coil spring 46 described later, so that the peripheral surface of the roller body 412 is exposed to light. The outer peripheral surface of the photosensitive drum 121 is pressed and brought into contact with the peripheral surface of the photosensitive drum 121, thereby removing the deposits on the peripheral surface of the photosensitive drum 121 more effectively. The deposits removed from the peripheral surface of the photosensitive drum 121 are collected in the deposit collection space 34 surrounded by the lateral plates 312, the middle bottom plate 323, the inclined plate 324 and the blade 42 of the pair of side plates 31.

  The blade 42 is provided immediately below the cleaning roller 41 in order to scrape off deposits in the image forming area on the peripheral surface of the photosensitive drum 121 that could not be removed even by the drum cleaning device 40. The blade 42 is set to have a long length in the front-rear direction (specifically, set to be the same as the inner dimension between the front and rear thick portions 314), and the base end edge portion is the middle bottom plate 323 of the installation plate 32. As shown in FIG. 5, the front end edge portion is inclined upwardly toward the right so as to come into contact with the peripheral surface of the photosensitive drum 121.

  Therefore, the photosensitive drum 121 is attached to the image forming area on the peripheral surface of the photosensitive drum 121 that cannot be removed by the cleaning roller 41 by rotating counterclockwise in FIG. 5 around the drum shaft 121a. Deposits such as residual toner and nitrogen oxide are scraped off by the tip (upper end) of the blade 42, thereby cleaning the image forming area of the photosensitive drum 121. The deposits scraped from the peripheral surface of the photosensitive drum 121 are collected in the deposit collection space 34.

  The toner conveying screw 43 is for discharging collected matter such as residual toner collected in the deposit collecting space 34 to the outside. The toner conveying screw 43 has a screw shaft 431 penetrating between the thick portions 314 of the pair of side plates 31 and a rotation around the screw shaft 431 concentrically and externally fitted to the screw shaft 431. And a helical screw fin 432 for carrying out the recovered material.

  On the other hand, the thick portion 314 of the rear side plate 31 is provided with an insertion hole 318 for inserting the rear end side of the roller shaft 411, and the thick portion 314 of the front side plate 31 has A discharge cylinder 35 for discharging the collected material is provided on the outer surface side (front surface side). A front end side of the toner conveying screw 43 is inserted into the discharge cylinder 35, and a discharge port 351 is provided at an appropriate position on the lower surface.

  A predetermined shutter member 36 formed by combining a shutter mechanism, a spring, and the like is attached to the discharge cylinder 35. When the drum unit 20 is mounted in the apparatus main body 11, the shutter member 36 operates while interfering with a predetermined member in the apparatus main body 11 to open the discharge port 351, while the shutter member 36 is The discharge port 351 is closed by releasing the interference with a predetermined member in the apparatus main body 11 by being pulled out from the apparatus main body 11.

  The photosensitive drum 121, the cleaning roller 41, and the toner conveying screw 43 are configured to be able to interlock with each other via unillustrated gears provided between the drum shaft 121a, the roller shaft 411, and the screw shaft 431, respectively. ing.

  Therefore, when the driving force of a driving motor (not shown) is transmitted to, for example, the drum shaft 121a and the photosensitive drum 121 rotates counterclockwise in FIG. 5, the rotation speed is higher than that of the photosensitive drum 121. This is transmitted to the clockwise rotation of the cleaning roller 41 set so as to be faster, and to the rotation of the toner conveying screw 43 toward the predetermined direction.

  Each of the movable brackets 44 is fitted into a mounting recess 315 provided in the thick portion 314 of each side plate 31 so as to be movable in the left-right direction in a sliding contact state. A coil spring 46 is interposed between the left edge portion of the movable bracket 44 and the left back portion of the mounting recess 315. The movable bracket 44 is pressed rightward by the urging force of the coil spring 46 (see FIG. 5).

  Accordingly, the peripheral surface of the roller body 412 is pressed against the image forming area on the peripheral surface of the photosensitive drum 121 via the roller shaft 411 supported by the movable bracket 44, and the side seal member is interposed via the movable bracket 44. 45 is pressed against and brought into contact with the peripheral surfaces at both ends of the photosensitive drum 121, thereby preventing the toner removed from the peripheral surface of the photosensitive drum 121 from leaking.

  Incidentally, in the present embodiment, the side seal member 45 is a state in which a plurality of acrylic pile seal materials (sheet-like seal materials made of acrylic resin) are laminated in the left-right direction via a predetermined adhesive, It is formed by cutting while being pressed by a predetermined mold. On the right edge surface of the side seal member 45, an arc edge surface is formed for sliding contact with the peripheral surface of the photosensitive drum 121 by surface contact.

  The edge cleaning device 50 is for subjecting a part of the circumferential surface of the photosensitive drum 121 that is out of the image forming area to the abutment of the gap roller 122b, particularly for this part. It is. The reason why such a cleaning process is performed is as follows.

  That is, the peripheral surfaces of both end portions of the photosensitive drum 121 are out of the image forming area, and therefore, it is difficult for the residual toner to be attached, so that the cleaning process of the peripheral surface by the cleaning roller 41 is not performed.

  However, as shown in FIGS. 4 and 5, there is a predetermined gap (gap) between the peripheral surface of the developing roller 122 a and the peripheral surface of the photosensitive drum 121 at both ends of the photosensitive drum 121. The gap rollers 122b provided to form the gaps are in contact with each other. Therefore, if residual toner, nitrogen oxides, etc. that are generated in other parts and scattered on both ends of the photosensitive drum 121 adhere to and accumulate on both ends of the photosensitive drum 121, the gap is increased according to the rotation of the photosensitive drum 121. The developing device 122 swings as the roller 122b rides on the attached deposit and descends from the deposited matter.

  When the developing device 122 is swung, the gap dimension between the circumferential surface of the photosensitive drum 121 and the circumferential surface of the developing roller 122a, which are strictly dimensioned, varies. When the gap size fluctuates, it becomes impossible to stably supply toner from the peripheral surface of the developing roller 122a toward the peripheral surface of the photosensitive drum 121. As a result, an appropriate toner image is applied to the peripheral surface of the photosensitive drum 121. This causes a so-called image defect in which the image is not formed.

  In the present invention, in order to eliminate such an image defect, a particularly careful cleaning process is performed on the peripheral surfaces of both end portions of the photosensitive drum 121, so that toner, nitrogen oxides, and the like are applied to this portion. Even if it adheres, it is immediately removed and cleaned.

  Hereinafter, the edge cleaning device 50 will be described with reference to FIG. 6 and other drawings as necessary. FIG. 6 is a partially cutaway enlarged perspective view of the drum unit 20 for explaining the end cleaning device 50. The direction display by X and Y in FIG. 6 is the same as in FIG. 1 (−X: leftward, + X: rightward, −Y: forward, + Y: backward).

  First, as shown in FIG. 3, the end cleaning device 50 is installed such that the cleaning shaft 51 is installed between the lateral plates 312 of the pair of side plates 31 and is concentrically and integrally rotated on both sides of the cleaning shaft 51. A cylindrical brush member 52 that wipes the peripheral surface of the photosensitive drum 121 with the brushed brush, a drive motor 53 that drives and rotates the cylindrical brush member 52, and the cylindrical brush member 52 around the photosensitive drum 121. A collection passage 54 is provided for guiding deposits such as toner removed from the surface to the deposit collection space 34.

  On the other hand, a through hole 319 for penetrating the cleaning shaft 51 is formed in the upper left position of the drum shaft fitting insertion hole 313 in each lateral plate 312 of the pair of side plates 31. The cleaning shaft 51 is set to be slightly longer than the outer dimension between the pair of side plates 31, and has a length such that the front end portion protrudes outward from the front side plate 31 in a state where the cleaning shaft 51 penetrates each side plate 31. Is set. Further, the diameter of the cleaning shaft 51 is set so that the tip of the bristles of the cylindrical brush member 52 abuts on the peripheral surface of the photosensitive drum 121 in a state where the cleaning shaft 51 is inserted into each through hole 319. ing.

  As shown in FIG. 4, a cleaning gear 511 is fitted on the front end of the cleaning shaft 51 so as to be concentric and integrally rotatable. The driving force of the driving motor 53 is transmitted to the cleaning gear 511 through a gear mechanism indicated by an arrow, whereby the cylindrical brush member 52 rotates integrally around the cleaning shaft 51 in the counterclockwise direction and is photosensitive. A wiping process can be performed on the peripheral surfaces of both ends of the body drum 121.

  As shown in FIG. 6, the collection passage 54 is formed at the right and left right edges (only the front one is shown in FIG. 6) of the top plate 33. The collection passage 54 is hung from the rear side of the top plate 33 at an inner position of each of the outer hanging plates 541 and the outer hanging plate 541 hanging downward from the right and left right and left edges of the top plate 33. Vertically along the circumferential surface of the photosensitive drum 121 surrounded by the inner hanging plate 542 and the left surface plate 543 (FIG. 5) installed between the outer hanging plate 541 and the left edge of the inner hanging plate 542. It is formed by an extended space.

  The inner hanging plate 542 is provided with an arc edge surface formed in an arc shape along the circumferential surface of the photosensitive drum 121, and the inner hanging plate 542 is also arranged along the circumferential surface of the photosensitive drum 121. Is provided with an arc edge surface formed in an arc shape. The inner dimension between the outer hanging plate 541 and the inner hanging plate 542 is set so that the cylindrical brush member 52 can be accommodated with a slight margin.

  The outer hanging plate 541 and the inner hanging plate 542 are provided with relief grooves at portions corresponding to the cleaning shaft 51, respectively. When the top plate 33 is mounted between the side plates 31 from above, these relief grooves are formed on the cleaning shaft. 51 is externally fitted.

  According to the collection passage 54, the deposits such as toner and nitrogen oxides removed from the peripheral surface of the end portion of the photosensitive drum 121 by the driving rotation of the cylindrical brush member 52 are once directed in the radial direction by centrifugal force. The blown-off deposits are captured by the recovery passage 54 surrounded by the outer hanging plate 541, the inner hanging plate 542 and the top plate 33, and the deposit collection space 34 is along the collection passage 54. Therefore, it is possible to effectively prevent the occurrence of inconveniences such as adhesion of toner or the like to the outside.

  Next, the end cleaning device 60 will be described with reference to FIG. FIG. 7 is a partially cutaway enlarged perspective view of the drum unit 20 for explaining the end cleaning device 60. In addition, the direction display by X and Y in FIG. 7 is the same as in FIG. 1 (−X: leftward, + X: rightward, −Y: forward, + Y: backward).

  As shown in FIG. 7, the end cleaning device 60 includes an end dedicated blade member 61 whose tip edge abuts on the peripheral surface of the photosensitive drum 121 in an elastically deformed state, and the end dedicated blade member 61. A screw 62 for fixing to the top plate 33 is provided in the collection passage 54.

  The end-only blade member 61 is formed of a leaf spring material, and its front-rear width dimension is set slightly smaller than the inner dimension of the front-rear width of the collection passage 54, while the left and right length dimensions are the upper end of the collection passage 54. This is set to be slightly shorter than the left and right dimensions, and is formed into a strip shape in plan view.

  The end-only blade member 61 has a base end 611 fixed to the left end of the top surface of the collection passage 54, and extends downward from the base end 611 toward the right, and is elastically deformed. In this state, the front end (right end) edge portion is composed of an elastic deformation portion 612 that contacts the peripheral surface of the photosensitive drum 121. A screw hole into which the screw 62 is screwed is screwed at the center of the base end portion 611. On the other hand, an insertion hole through which the screw 62 is passed is formed in a portion of the top plate 33 corresponding to the screw hole.

  The end-only blade member 61 has the base end 611 positioned at the left end of the top surface of the collection passage 54 (that is, the back surface side of the top plate 33) and the screw 62 is inserted into the insertion hole of the top plate 33. The screw is fitted into the collection passage 54 by being screwed into the screw hole of the base end portion 611 and fastened.

  The elastic deformation portion 612 is elastically deformed in a state where the end dedicated blade member 61 is screwed to the top surface of the recovery passage 54 so that the right end edge thereof is brought into contact with the peripheral surface of the photosensitive drum 121. The length is set.

  According to the end cleaning device 60, since the leading edge of the end-only blade member 61 is pressed against the peripheral surface of the end of the photosensitive drum 121 in a state where the elastic deforming portion 612 is elastically deformed, When the body drum 121 rotates around the drum shaft 121 a, deposits such as toner and nitrogen oxide attached to the peripheral surface of the end portion of the photosensitive drum 121 are scraped by the end edge of the end-only blade member 61. As a result, the peripheral surface of the end of the photosensitive drum 121 is cleaned.

  Then, the scraped deposits are guided to the recovery passage 54 through the clearance between the elastic deformation portion 612 and the recovery passage 54 and the clearance between the elastic deformation portion 612 and the inner hanging plate 542. It is collected in the deposit collection space 34 in the drum unit 20.

  Next, the end cleaning device 70 according to the present invention will be described with reference to FIGS. 8 is an enlarged perspective view showing the end cleaning device 70 according to the present invention, FIG. 8 (A) is an exploded perspective view, and FIG. 8 (B) is an assembled perspective view of the dual-purpose blade member 71.

  FIG. 9 is an explanatory perspective view for explaining the mounting procedure of the edge cleaning device 70 to the top plate 33 of the housing 30. FIG. 9A shows the dual blade member 71 mounted to the top plate 33. FIG. 9B shows a state immediately before the operation is performed, in which the dual blade member 71 is mounted on the top plate 33.

  Further, FIG. 10 is an overall perspective view of the drum unit 20 showing a state in which a pair of dual-purpose blade members 71 are mounted on the top plate 33.

  In addition, the direction display by X and Y in FIGS. 8-10 is the same as that of FIG. 1 (-X: leftward, + X: rightward, -Y: forward, + Y: backward).

  The edge cleaning device 70 according to the present invention is intended for the photosensitive drum 121 and the transfer belt 125 that are pressed against the circumferential surface of the photosensitive drum 121 and also slidably contacted with the surface of the transfer belt 125. A dual blade member 71 is employed.

  As shown in FIG. 8, the end cleaning device 70 includes a dual blade member 71 and a mounting pin projecting upward from the top plate 33 of the housing 30 to which the dual blade member 71 is externally fitted. 74, a retaining ring 75 for retaining the mounting pin 74 in a state where the both-purpose blade member 71 is externally fitted to the mounting pin 74, and a dual-purpose blade member 71 externally fitted to the mounting pin 74 to prevent rotation. And a positioning projection piece 76 to be provided.

  Note that the dual blade member 71 shown in FIGS. 8 and 9 is mounted on the front side of the top plate 33 of the housing 30. When the dual-purpose blade member 71 is mounted at the rear position, the one shown in FIG. 8B is reversed and used.

  As shown in FIG. 8A, the dual blade member 71 includes a leaf spring piece (leaf spring) 72 and a felt material 73 that covers the front and back surfaces of the leaf spring piece 72. The leaf spring piece 72 has a spring-side mounting portion 721 having a rectangular shape in a plan view in which the length in the left-right direction is set slightly longer than the length in the front-rear direction, and slightly rearward from the right edge of the spring-side mounting portion 721. And a spring-side sliding contact portion 722 that has a rectangular shape in plan view and extends in a shifted state.

  The spring side mounting portion 721 is a portion that is externally fitted to the mounting pin 74 and is mounted on the top plate 33, and the spring side sliding contact portion 722 is an end peripheral surface of the photosensitive drum 121 through the felt material 73. And a portion that is slidably contacted with the end surface of the transfer belt 125 in the width direction for cleaning processing. A spring-side mounting hole 723 is formed in the center position of the spring-side mounting portion 721 so as to be fitted on the mounting pin 74, and the left edge of the spring-side mounting portion 721 is directed leftward. A pair of projecting protrusions 724 parallel to each other are provided. A locking gap 724 a is formed between these locking protrusions 724. The leaf spring piece 72 in which the spring-side attachment hole 723 is externally fitted to the attachment pin 74 is positioned by being prevented from rotating by the engagement gap 724a being externally fitted to the positioning protrusion 76.

  The dual-purpose blade member 71 provided on the front side of the top plate 33 is provided with the spring-side sliding contact portion 722 of the leaf spring piece 72 closer to the rear side than the spring-side mounting portion 721 and provided on the rear side of the top plate 33. The blade member 71 is provided with the spring-side sliding contact portion 722 closer to the front than the spring-side mounting portion 721. In this state, in the state where the dual-purpose blade member 71 is mounted on the mounting pin 74, the transfer belt 125 is prevented from interfering with the mounting pin 74 and contacts the spring-side sliding contact portion 722 via the felt material 73. This is to make contact.

  In such a leaf spring piece 72, a felt material 73 for cleaning the peripheral surface of the photosensitive drum 121 is attached to the lower surface (first surface) side. A felt material 73 for cleaning the surface of the transfer belt 125 is attached to the upper surface (second surface) side.

  As shown in FIG. 8A, the felt material 73 is shaped so as to be vertically symmetric with respect to a center line O extending in the left-right direction in a state extending in the up-down direction. The felt material 73 is formed with a pair of felt side mounting portions 731 formed on the upper and lower side portions corresponding to the spring side mounting portions 721 of the leaf spring piece 72 and a center line O therebetween. A pair of felt side sliding contact portions 732 formed respectively corresponding to the spring side sliding contact portions 722 are provided at the upper and lower positions.

  In the pair of felt side mounting portions 731 of the felt material 73, felt side mounting holes 733 are formed at positions corresponding to the spring side mounting holes 723 of the leaf spring pieces 72, respectively. An adhesive layer 734 is laminated on one side of the felt material 73 (left side in FIG. 8A).

  The leaf spring piece 72 is sandwiched between the upper and lower felt members 73 in a state where the upper and lower portions in FIG. 8A are bent leftward with the center line O of the felt member 73 as a boundary. It adheres to the front and back of the leaf spring piece 72 through the agent layer 734. As a result, as shown in FIG. 8 (B), the dual blade member 71 in which the upper and lower surfaces of the leaf spring piece 72 are covered with the felt material 73 is completed.

  As shown in FIG. 8B, the dual blade member 71 includes a mounting portion 701 in which a spring side mounting portion 721 and a felt side mounting portion 731 are stacked, a spring side sliding contact portion 722, and a felt side sliding contact portion. 732 are stacked, and the lower surface side is in sliding contact with the peripheral surface of the photosensitive drum 121, and the upper surface side includes a sliding contact portion 702 in sliding contact with the surface of the transfer belt 125. A mounting hole 703 formed by combining the spring side mounting hole 723 and the felt side mounting hole 733 is formed at the center of the mounting portion 701.

  The mounting pin 74 is erected on the front and rear right corners (the front right corner in the example shown in FIG. 8A) of the top plate 33 of the housing 30. As shown in FIG. 8A, an annular groove 741 is recessed in the mounting pin 74 at a position spaced upward from the top plate 33 by the thickness dimension of the dual blade member 71 shown in FIG. 8B. Has been. With the mounting hole 703 of the mounting portion 701 of the dual-purpose blade member 71 fitted on the mounting pin 74, the retaining ring 75 is mounted in the annular groove 741, so that the dual-purpose blade member 71 comes out of the mounting pin 74. Is prevented.

  The retaining ring 75 has an inner diameter set slightly larger than the outer diameter of the mounting pin 74. The retaining ring 75 is provided with a plurality (four in the example shown in FIG. 8A) of locking claw pieces 752 protruding from the inner peripheral surface of the ring hole 751 toward the hole center. Yes. These locking claw pieces 752 are set so that the protruding amount from the inner peripheral surface of the ring hole 751 is shorter than the groove depth of the annular groove 741 after being fitted into the annular groove 741.

  Therefore, when the retaining ring 75 is press-fitted into the mounting pin 74 in a state where the dual-purpose blade member 71 is externally fitted to the mounting pin 74 via the spring-side mounting hole 723, the retaining ring 75 When the claw piece 752 is bent upward, the spring side mounting hole 723 is fitted into the mounting pin 74 while being elastically deformed, and when the locking claw piece 752 reaches the annular groove 741 of the mounting pin 74, The locking claw piece 752 is restored to its original state after the elastic deformation is eliminated. As a result, the tip of each locking claw piece 752 is fitted into the annular groove 741, so that the retaining ring 75 is in a retaining state. Therefore, once the dual-purpose blade member 71 is fitted onto the annular groove 741 and is prevented from being removed by the retaining ring 75, it is not detached from the mounting pin 74.

  The positioning protrusion 76 is used for positioning the dual-purpose blade member 71 mounted on the mounting pin 74 in the circumferential direction and preventing the dual-purpose blade member 71 from rotating. The positioning protrusion 76 is provided at a position separated from the axis of the mounting pin 74 by a distance between the hole center of the spring-side mounting hole 723 and the edge where the locking protrusion 724 is provided.

  The positioning protrusion 76 is set to have a front-rear width dimension slightly smaller than a dimension of the locking gap 724 a between the pair of locking protrusions 724. Accordingly, when the dual blade member 71 is mounted on the mounting pin 74, the locking gap 724a between the locking protrusions 724 is externally fitted to the positioning protrusion 76 as shown in FIG. The dual-purpose blade member 71 is positioned.

  Subsequently, the retaining ring 75 is press-fitted into the mounting pin 74, and each of the locking claw pieces 752 is fitted into the annular groove 741, so that the blade member 71 for both uses the mounting pin as shown in FIG. 9B. 74 is attached.

  Then, in a state where the dual-use blade member 71 is mounted on the mounting pin 74, the sliding contact portion 702 protrudes outward from the right end portion of the top plate 33, and the lower surface side is the end of the photosensitive drum 121. The size and shape of the transfer belt 125 are set such that the upper surface is in contact with the end surface in the width direction of the surface of the transfer belt 125.

  According to the end cleaning device 70 of the present invention configured as described above, the sliding contact portion 702 of the dual-purpose blade member 71 includes the peripheral surface of the end of the photosensitive drum 121 and the transfer belt as shown in FIG. 125 is sandwiched between the surfaces of the end portions in the width direction of 125, so that not only the peripheral surface of the end portion of the photosensitive drum 121 but also the surface of the end portion of the transfer belt 125 can be cleaned. As a result, it is possible to prevent the occurrence of image defects such that the edge of the paper is contaminated with toner.

  The sliding contact portion 702 of the dual blade member 71 has a felt side sliding contact portion 732 of the felt material 73 laminated on both surfaces of the spring side sliding contact portion 722 of the leaf spring piece 72. Accordingly, since the spring is softer than the case where the spring is directly brought into contact with the peripheral surface of the photosensitive drum 121 and the surface of the transfer belt 125 and has a large wiping effect, the spring is superior to the photosensitive drum 121 and the transfer belt 125. A cleaning effect can be obtained.

  As described above in detail, the image forming apparatus 10 according to the present invention includes a photosensitive drum 121 that carries and circulates a toner image, a developing roller 122a that supplies toner to the surface of the photosensitive drum 121, and the developing roller 122a. And a developing device 122 having a pair of gap rollers 122b in contact with both ends of the photosensitive drum 121 so as to form a predetermined gap between the photosensitive drum 121 and the surface of the photosensitive drum 121.

  Since the end cleaning devices 50, 60, and 70 for performing a dedicated cleaning process are provided at portions corresponding to the gap roller 122b at both ends of the photosensitive drum 121, the dedicated end cleaning devices 50, 60, and 70 are provided. 70, cleaning processing can be performed on both ends of the photosensitive drum 121. Therefore, it is possible to effectively suppress the occurrence of inconvenience that deposits such as residual toner accumulate on both ends of the photosensitive drum 121 and the proper image forming process cannot be performed.

  The end cleaning device 50 shown in FIGS. 3 to 6 includes the columnar brush member 52 that wipes the surface of the photoconductor drum 121 with brush bristles. By rotating the columnar brush member 52 around the axis, it is wiped intensively with the brush bristles, and thereby it is possible to always keep the state of being cleaned.

  Further, since the end cleaning device 60 shown in FIG. 7 includes the end-only blade member 61 made of an elastic body whose front end edge abuts on the surface of the photoconductive drum 121 in a state of being elastically deformed, the photoconductive drum Both end portions of 121 are intensively scraped while being pressed by the end-dedicated blade member 61 that is elastically deformed by the end-dedicated blade member 61, and thus the state where the cleaning is always performed can be maintained. it can.

  Also, the end-only blade member 61 is a very simple member made of a leaf spring, and can be completed with only one of them, which can contribute to a reduction in component costs and assembly costs.

  Further, the end cleaning device 70 according to the present invention includes a leaf spring piece 72 and a felt material 73 attached to the leaf spring piece 72, and the felt material 73 is urged by the leaf spring piece 72. Therefore, the surface of the photosensitive drum 121 is wiped off by the felt material 73 pressed by the elastic force of the leaf spring piece 72, thereby the photosensitive drum 121. In addition, the peripheral surface of the photosensitive drum 121 can be effectively cleaned by wiping with the felt material 73 in which fibers are densely packed.

  The peripheral surface of the photosensitive drum 121 is cleaned by the felt side sliding contact portion 732 of the felt material 73 attached to the lower surface (first surface) of the leaf spring piece 72 and the upper surface ( Since the surface of the transfer belt 125 is subjected to the cleaning process by the second surface), the number of parts can be reduced and the manufacturing cost can be reduced as compared with the case where the cleaning process is performed by a dedicated edge cleaning device. It can contribute to reduction.

  The housing 30 of the drum unit 20 is provided with a collection passage 54 for collecting the toner removed from the surface of the photosensitive drum 121 by the edge cleaning devices 50, 60, 70. , 60, and 70, the adhered matter such as residual toner removed from both ends of the photosensitive drum 121 is collected through the collection passage 54 so that the removed adhered matter is scattered around the end of the photosensitive drum 121. Such an inconvenience can be effectively prevented.

  The present invention is not limited to the above embodiment, and includes the following contents.

  (1) In the above embodiment, a copying machine has been described as an example of the image forming apparatus 10 to which the edge cleaning devices 50, 60, and 70 are applied. However, the image forming apparatus 10 is not limited to a copying machine, and may be a printer. Alternatively, it may be a facsimile machine.

  (2) Although the columnar brush member 52 is employed in the end cleaning device 50 shown in FIGS. 3 to 6, the brush is not limited to the end cleaning device 50, and is not a flat plate. You may employ | adopt the normal brush which planted the bristle on one side of the board | substrate. In this case, the peripheral surface is wiped with a normal brush by the rotation of the photosensitive drum 121.

  (3) In the above embodiment, the photosensitive drum 121 is described as an example of the image carrier, but the present invention is not limited to the photosensitive drum 121 as the image carrier. An endless belt different from the transfer belt 125 in the above-described embodiment, which is stretched between a pair of rollers so as to be able to rotate and has a toner image formed on the surface thereof, may be employed as the image carrier.

  (4) In the above embodiment, the side seal member 45 is formed of an acrylic pile seal material, but instead of the acrylic pile seal material, for example, a non-woven fabric or sponge, a felt material, a foaming synthetic resin, or the like is employed. May be.

  (5) Although the side seal member 45 is mounted on the movable bracket 44 in the above embodiment, it may be mounted on both ends of the blade 42 instead.

  (6) In the above-described embodiment, the charging device 123 using the charging roller 123b is used. Instead, the peripheral surface of the photosensitive drum 121 is charged by corona discharge from a charging wire. You may make it give.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Apparatus main body 111 Lower main body 112 Upper main body 113 Connection body 12 Image forming part 12M Magenta image forming part 12C Cyan image forming part 12Y Yellow image forming part 12K Black image forming part 121 Photosensitive drum (image) Carrier)
121a drum shaft 122 developing device 122a developing roller 122b gap roller 123 charging device 123a casing 123b charging roller 123c roller shaft 123d ridge 123e coil spring 124 exposure device 125 transfer belt 125a driving roller 125b driven roller 125c transfer roller 125d belt cleaning device 127 paper Conveying path 127a Conveying roller pair 128 Transfer roller 129 Discharge conveying path 13 Fixing part 131 Fixing roller 132 Pressure roller 14 Paper storage part 141 Paper feed tray 142 Pickup roller 15 Paper discharging part 151 In-body paper discharging tray 152 Discharge roller pair 16 Image reading unit 161 Contact glass 162 Document holding mat 163 Optical system unit 164 Light source 17 Operation unit 171 Start key 172 Numeric keypad 2 Drum unit 30 Housing 31 Side plate 311 Vertical plate 312 Horizontal plate 313 Drum shaft insertion hole 314 Thick portion 315 Mounting recess 316 Long hole 317 Mounting groove 318 Insertion hole 319 Through hole 32 Construction plate 321 Bottom plate 322 Lower left plate 323 Middle bottom plate 324 Inclined plate 325 Upper left plate 33 Top plate 34 Deposit collection space 35 Discharge cylinder 351 Discharge port 36 Shutter member 40 Drum cleaning device 41 Cleaning roller 411 Roller shaft 412 Roller body 42 Blade 43 Toner transport screw 431 Screw shaft 432 Screw Fin 44 Movable bracket 45 Side seal member 46 Coil spring 50 End cleaning device 51 Cleaning shaft 511 Cleaning gear 52 Cylindrical brush member 53 Drive motor 54 Collection passage 54 DESCRIPTION OF SYMBOLS 1 Outer side drooping board 542 Inner drooping board 543 Left side board 60 End part cleaning apparatus 61 End part blade member 611 Base end part 612 Elastic deformation part 62 Screw 70 End part cleaning apparatus 71 Both-use blade member 701 Mounting part 702 Sliding part 72 Plate Spring piece (plate spring) 72 721 Spring side mounting portion 722 Spring side sliding contact portion 723 Spring side mounting hole 724 Locking protrusion 724a Locking gap 73 Felt material 731 Felt side mounting portion 732 Felt side sliding contact portion 733 Felt side mounting Hole 734 Adhesive layer 74 Mounting pin 741 Annular groove 75 Retaining ring 751 Ring hole 752 Locking claw piece 76 Positioning protrusion P Paper P1 Document O Center line

Claims (7)

An image carrier that carries and circulates a toner image;
An intermediate transfer belt to which a toner image on the surface of the image carrier is transferred;
A developing roller that supplies toner to the surface of the image carrier, and a pair of gap rollers that abut against both ends of the image carrier to form a predetermined gap between the developing roller and the surface of the image carrier. A developing device having
An end cleaning device that performs a cleaning process on a portion corresponding to an arrangement position of the gap roller at both ends of the image carrier,
The edge cleaning device includes a blade member composed of a leaf spring and a felt material attached to the leaf spring, and the felt material of the blade member is urged by the leaf spring in an image bearing member state. Which is in contact with the surface ,
The leaf spring includes a first surface located on the image carrier side and a second surface located on the intermediate transfer belt side, and the felt material is laminated on the first surface and the second surface, respectively. An image forming apparatus being in contact with surfaces of the image carrier and the intermediate transfer belt . The felt material has an elongated strip shape and is formed symmetrically with respect to a center line in the longitudinal direction, and is bent at the position of the center line with the front end of the leaf spring as a fulcrum, thereby each surface of the leaf spring. The image forming apparatus according to claim 1 , wherein the image forming apparatus is laminated. A housing for supporting the image carrier,
The housing includes a mounting pin for fixing the blade member,
The blade member includes a mounting hole that penetrates the leaf spring and the felt material at a position rearward of the tip of the leaf spring, and is attached to the housing so that the mounting pin passes through the mounting hole. The image forming apparatus according to claim 2 , wherein the retaining pin is fixed to the housing by being mounted on the mounting pin. A positioning protrusion is formed on the housing, and a pair of locking protrusions extending in parallel with the surfaces are formed on the leaf spring, and the blade member is positioned by the pair of locking protrusions. The image forming apparatus according to claim 3 , wherein the housing is fixed in a state where a protrusion is sandwiched from both sides. The blade member includes a mounting portion in which the mounting hole is formed, and a sliding contact that is offset inward of the image carrier relative to the mounting portion and contacts the surface of the image carrier and the intermediate transfer belt. The sliding contact portion is in sliding contact with the image carrier over its entire width, and only the portion in the inner direction of the mounting hole in the full width is in sliding contact with the intermediate transfer belt. the image forming apparatus according to claim 3 or 4, wherein. The image forming apparatus according to any one of claims 1 to 5, characterized in that recovery passage for recovering toner removed from the surface of the image carrier by the end cleaning device is provided. An image forming unit applied to an image forming apparatus according to any one of claims 1 to 6,
The image carrier is a photosensitive drum that is rotatable about an axis having an image forming region on a peripheral surface, and is unitized by at least the photosensitive drum and the cleaning device. unit.

Images