JP5948285B2 - Cleaning device and image forming apparatus - Google Patents

Description

  The present invention relates to a cleaning device that removes toner remaining on the surface of a photosensitive drum, and an image forming apparatus including the cleaning device.

  In the electrophotographic image forming apparatus, in order to remove the toner remaining on the surface of the photosensitive drum after the toner is transferred, the cleaning blade is brought into contact with the surface of the photosensitive drum in the counter direction and remains. A method of scraping off the toner is widely put into practical use. Since the cleaning blade is generally formed of an elastic material such as urethane rubber, the Young's modulus of the elastic material is reduced when the environmental temperature is high, and the pressure contact force of the cleaning blade to the photosensitive drum is reduced. Therefore, there is a problem that the toner cannot be completely scraped off and an image defect occurs.

  Therefore, Patent Document 1 proposes a cleaning device including means for changing the pressure contact force of the cleaning blade according to a change in environmental temperature. In this cleaning device, a rib is formed in a space in which the toner scraped off by the cleaning blade is temporarily stored so as to extend in a direction substantially perpendicular to the surface of the photosensitive drum. When the environmental temperature rises, the rib presses the mounting surface of the cleaning blade support member, and presses the cleaning blade against the photosensitive drum.

  Further, this document also proposes a method of attaching a cleaning blade support member to the surface of the housing on the side of the photosensitive drum via a temperature correction member. The temperature correction member is formed of a thin plate material having a thermal expansion coefficient larger than that of the housing, and is attached to the attachment surface of the support member of the cleaning blade of the housing. When the environmental temperature rises, the temperature correction member expands thermally, presses the supporting member of the cleaning blade toward the photosensitive drum, and presses the cleaning blade against the photosensitive drum.

Japanese Patent Laid-Open No. 3-44977

  However, as described in Patent Document 1 described above, the method of pressing the support member of the cleaning blade with the rib is effective for the housing in which the rib is provided in the space where the scraped toner is stored. However, it cannot be applied to a housing in which such a space does not exist or a housing in which the volume of the space is small and a rib cannot be provided. In particular, when the cleaning device is downsized with the downsizing of the image forming apparatus, the space for storing the scraped toner is a very narrow space between the collection spiral for collecting the scraped toner and the inner surface of the housing. It becomes only. Therefore, in such a case, there is a problem that a rib that is a means for pressing the surface to which the support member of the cleaning blade is attached cannot be provided on the housing.

  Further, in the method using the temperature correction member described above, a wide plane for attaching the temperature correction member to the housing is required. For this reason, there exists a problem that it cannot apply, when the plane for attaching a temperature correction member to a housing cannot be taken widely continuously with size reduction of a cleaning apparatus. Furthermore, since the temperature correction member is formed in a thin plate shape and has a small amount of thermal expansion, there is a problem that a sufficient pressure contact force of the cleaning blade against the photosensitive drum may not be ensured in a high temperature environment. Furthermore, since it is necessary to attach the temperature adjusting member to the entire surface of the housing where the cleaning blade is attached, there is also a problem that the cost increases.

  Therefore, in consideration of the above circumstances, the present invention can be applied to a cleaning device having a housing without ribs or a small housing with a small empty space, thereby reducing the pressure contact force of the cleaning blade to the photosensitive drum in a high temperature environment. It is an object of the present invention to provide a cleaning device that can prevent the above.

  In order to achieve the above-described object, a cleaning device of the present invention includes a cleaning blade that presses against a photosensitive drum and removes toner remaining on the photosensitive drum, a support member that supports the cleaning blade, and the support member A cleaning device including a fixing member interposed between the support member and the housing, the fixing member being made of a material having a higher thermal expansion coefficient than the housing. The housing includes a recess into which the fixing member is fitted so that the supporting member can be pressed in a direction in which the cleaning blade is pressed against the photosensitive drum.

  By adopting such a configuration, it is possible to increase the volume of the fixing member and increase the amount of thermal expansion of the fixing member while narrowing the distance between the support member and the housing, thereby reducing the size of the housing. Even in a high-temperature environment, the support member can be pressed to keep the pressing force of the cleaning blade against the photosensitive drum at a predetermined value.

  In the cleaning device of the present invention, the fixing member extends in the pressing direction of the support member, and has one end fixed to the support member, and the other end side outer periphery of the shaft portion presses the support member. A flange extending in a direction perpendicular to the direction, and the recess is formed by a fitting portion formed so that the fixing member can be fitted from a surface of the housing on the photosensitive drum side, A back side slide part formed to be slidable from the fitting part and having the same width as the fitting part; and a narrower width than the back side slide part and from the fitting part to the shaft A front side slide part formed so that the part is slidable, and may be formed in a groove shape.

  By adopting such a configuration, the area required for attaching the fixing member to the housing can be reduced, so that even if the plane for attaching the fixing member cannot be continuously wide, it can be applied. Become.

  In the cleaning device of the present invention, the cleaning blade is provided so as to abut in a counter direction with respect to the rotation of the photosensitive drum, and the back-side slide portion and the near-side slide portion are provided from the fitting portion, The cleaning blade may be formed so as to extend in a direction along the rotation direction of the photosensitive drum at the contact point of the cleaning blade.

  By adopting such a configuration, the force acting on the fixing member via the cleaning blade along with the rotation of the photosensitive drum acts in the direction in which the fixing member is pushed into the recess, so that the fixing member may fall out of the recess. The fixing member can be firmly fixed to the housing without using screws or the like.

  The cleaning device of the present invention includes a claw portion formed in the collar portion of the fixing member, and a groove portion formed in the near side slide portion of the recess, and the fixing member is slid from the fitting portion. In this case, the claw portion may be formed so as to be engaged with the groove portion.

  By adopting such a configuration, the fixing member can be firmly fixed to the housing without using screws or the like.

  An image forming apparatus according to the present invention includes any one of the cleaning devices described above.

  According to the present invention, it is possible to ensure a large amount of thermal expansion of the fixing member by increasing the volume of the fixing member while reducing the size of the housing. Therefore, even in a high temperature environment, it is possible to increase the pressure contact force of the cleaning blade against the photosensitive drum, and to obtain various excellent effects such as prevention of poor cleaning.

1 is a schematic diagram illustrating an outline of a configuration of a color printer according to an embodiment of the present invention. It is sectional drawing which shows the cleaning apparatus of the color printer which concerns on one Embodiment of this invention. FIG. 3A is a perspective view showing a fixing member of a color printer cleaning device according to an embodiment of the present invention, and FIG. 3B is a perspective view showing a recess of the housing. FIG. 6 is a cross-sectional view illustrating a state in which the support member is attached to the housing using a fixing member in the color printer cleaning apparatus according to the embodiment of the present invention. FIG. 5A is a perspective view of a fixing member, FIG. 5B is a side sectional view of a concave portion of a housing, and FIG. 5B is a diagram illustrating another example of a color printer cleaning device according to an embodiment of the present invention. FIG. 5C is a side sectional view showing a state in which the fixing member is fixed to the recess.

  Hereinafter, a cleaning device and an image forming apparatus according to an embodiment of the present disclosure will be described with reference to the drawings.

  First, the overall configuration of a color printer 1 as an image forming apparatus will be described with reference to FIG. Here, FIG. 1 is a schematic diagram showing an outline of a configuration of a color printer 1 according to an embodiment of the present invention.

  The color printer 1 includes a box-shaped printer main body 2. A paper feed cassette 3 that stores paper (not shown) is provided at a lower portion of the printer main body 2. A tray 4 is provided.

  An intermediate transfer belt 5 is installed between a plurality of rollers on the upper part of the printer body 2, and an exposure unit 6 including a laser scanning unit (LSU) is disposed below the intermediate transfer belt 5. . A plurality of image forming units 7 are provided below the intermediate transfer belt 5. Each image forming unit 7 is provided corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K), for example. In each image forming unit 7, a photosensitive drum 10 is rotatably supported by a support shaft 10a. Around the photosensitive drum 10, a charger 11, a developing device 12, a primary transfer unit 13, a static eliminator 14, and a cleaning device 15 are arranged in the rotational direction of the photosensitive drum 10 (see the arrow in FIG. 1). Are arranged along. A developer container 16 is provided above each developing device 12.

  A paper transport path 20 is provided on one side of the printer main body 2 (on the right side in the drawing). A paper feed unit 21 is provided at the upstream end of the conveyance path 20, and a secondary transfer unit 22 is provided at the other end (right end in the drawing) of the intermediate transfer belt 5 at a middle portion of the conveyance path 20. A fixing unit 23 is provided on the downstream side, and a paper discharge port 24 is provided on the downstream end of the transport path 20.

  Next, an image forming operation of the color printer 1 having such a configuration will be described.

  When the color printer 1 is turned on, various parameters are initialized, and initial settings such as temperature setting of the fixing unit 23 are executed. When image data is input from a computer or the like connected to the color printer 1 and an instruction to start printing is given, an image forming operation is executed as follows.

  First, after the surface of the photoconductor drum 10 is charged by the charger 11, the photoconductor drum 10 is exposed according to the image data by the laser light (see arrow P) from the exposure device 6, and the photoconductor. An electrostatic latent image is formed on the surface of the drum 10. The electrostatic latent image is developed into a toner image of a corresponding color by the developing device 12. This toner image is primarily transferred to the surface of the intermediate transfer belt 5 at the primary transfer portion 13. Each image forming section 7 sequentially repeats the above operation, whereby a full-color toner image is formed on the intermediate transfer belt 5. The residual charge on the photosensitive drum 10 is neutralized by the static eliminator 14, and the toner remaining on the photosensitive drum 10 is removed by the cleaning device 15.

  On the other hand, the paper taken out from the paper feed cassette 3 or the hand tray (not shown) by the paper feed unit 21 is conveyed to the secondary transfer unit 22 in synchronism with the above-described image forming operation, and is subjected to secondary transfer. In the portion 22, the full color toner image on the intermediate transfer belt 5 is secondarily transferred to the paper. The sheet on which the toner image is secondarily transferred is conveyed downstream in the conveyance path 20 and enters the fixing unit 23 where the toner image is fixed on the sheet. The sheet on which the toner image is fixed is discharged from the sheet discharge outlet 24 to the sheet discharge tray 4.

  Next, the cleaning device 15 will be described with reference to FIG. Here, FIG. 2 is a cross-sectional view showing a configuration of the cleaning device 15.

  The cleaning device 15 includes a housing 31 provided along the longitudinal direction of the photosensitive drum 10, a cleaning blade 32 attached to the housing 31, a support member 33, and a collection spiral 34.

  The housing 31 has a housing portion 31a having a U-shaped cross section, and is disposed so that the opening of the housing portion 31a faces the photosensitive drum 10 side. A flat surface 31 b is formed in the housing 31 continuously to the lower end of the accommodating portion 31 a, and the flat surface 31 b extends in the longitudinal direction of the photosensitive drum 10. A static eliminator 14 is attached to the upper outer surface of the housing portion 31 a of the housing 31. As a material of the housing 31, polycarbonate + ABS resin that is not easily thermally deformed can be used.

  The cleaning blade 32 is a plate-like member that is long in the longitudinal direction of the photosensitive drum 10, and is attached so as to come into contact with the rotation of the photosensitive drum 10 in the counter direction. An elastic body such as urethane rubber can be used as the material of the cleaning blade 32.

  The support member 33 is an L-shaped cross-section, has a long piece 33 a and a short piece 33 b, and is a member that is long in the longitudinal direction of the photosensitive drum 10. The base of the cleaning blade 32 is attached to the long piece 33a of the support member 33 on the surface on the photosensitive drum side by adhesion. The long piece 33 a of the support member 33 is attached to the recess 40 formed in the flat surface 31 b of the housing 31 via the fixing member 50. The fixing member 50 and the recess 40 will be described later.

  The collection spiral 34 is disposed substantially at the center of the housing portion 31 a of the housing 31. The collection spiral 34 extends in the longitudinal direction of the photosensitive drum 10, and one end thereof is connected to a toner collection box (not shown) provided outside the cleaning device 15.

  Next, the fixing member 50 and the recess 40 will be described with reference to FIGS. Here, FIG. 3A is a perspective view of the fixing member 50. FIG. 3B is a perspective view showing a recess.

  As shown well in FIG. 3A, the fixing member 50 includes a rectangular parallelepiped shaft portion 51 and a rectangular shape extending in the direction orthogonal to and opposite from both sides of the proximal end side outer peripheral portion of the shaft portion 51. It is formed in a T shape by the plate-like collar portion 53. A screw hole 52 is formed in the distal end surface 51a of the shaft portion 51 (the upper surface in FIG. 3A), and a screw 54 inserted through the long piece 33a of the support member 33 is screwed into the screw hole 52. The fixing member 50 is fixed to the support member 33.

  The fixing member 50 is made of a material having a thermal expansion coefficient larger than that of the material of the housing 31, and ABS resin or the like can be used.

  The fixing member 50 having the above-described configuration is fitted into the recess 40 formed in the housing 31.

  As well shown in FIG. 3B, the recess 40 is formed in a groove shape having a T shape in a plan view as viewed from the photosensitive drum 10 side. The concave portion 40 includes a rectangular parallelepiped head portion 42a extending in the longitudinal direction of the photosensitive drum 10, and a body portion 42b extending downward from the center of the head portion 42a. The bottom surfaces of the head portion 42a and the body portion 42b are The same surface is formed.

  The head portion 42a is a fitting portion formed so that the fixing member 50 can be fitted from the flat surface 31b on the photosensitive drum 10 side of the housing 31, and the width W of the flange portion 53 of the fixing member 50 (FIG. 3A). )) And the depth equal to or less than the height H of the fixing member 50 (see FIG. 3A).

  The body part 42b is formed in two steps in the depth direction, and a back side slide part 42c formed with the same width as the head part 42a and a near side slide part formed narrower than the back side slide part 42c. 42d. The depth of the rear slide portion 42c (D2 in FIG. 3B) is substantially equal to the height of the flange portion 53 of the fixing member 50 (H1 in FIG. 3A), and the width of the front slide portion 42d (H1 in FIG. 3A). 3B is substantially equal to the width of the shaft portion 51 of the fixing member 50 (W1 in FIG. 3A). Thereby, the fixing member 50 fitted to the head portion 42a can slide from the head portion 42a to the body portion 42b side.

  Next, with reference to FIG. 3 (A), FIG. 3 (B), and FIG. Here, FIG. 4 is a cross-sectional view showing a state in which the support member 33 is attached to the housing 31 using the fixing member 50.

  With the shaft portion 51 of the fixing member 50 orthogonal to the flat surface 31 b of the housing 31, the flange portion 53 of the fixing member 50 is fitted to the head portion 42 a of the recess 40 from the photosensitive drum 10 side. Next, the fixing member 50 is slid downward along the recess 40 while the bottom surface of the collar portion 53 is in contact with the bottom surface of the head portion 42a (see the arrow in FIG. 3B). At this time, as for the fixing member 50, the collar part 53 passes the back side slide part 42c of the trunk | drum 42b, and the axial part 51 passes the front side slide part 42d of the trunk | drum 42b.

  When the fixing member 50 slides to the lower end of the body portion 42b, the depth of the back side slide portion 42c (D2 in FIG. 3B) is equal to the height of the flange portion 53 (H1 in FIG. 3A), and the front side. Since the width of the side slide portion 42d (W2 in FIG. 3B) is equal to the width of the shaft portion 51 (W1 in FIG. 3A), as shown in FIG. Each inner surface forming 42 b is locked by being brought into contact with it and fixed to the recess 40.

  The support member 33 can be fixed to the housing 31 via the fixing member 50 at a central location or at a plurality of locations with a predetermined interval. And when fixing at one place of the center using the fixing member 50, it is good to support or fix about other parts other than the center using another means other than the fixing member 50.

  As described above, according to the cleaning device 15 according to the embodiment of the present invention, the fixing member 50 is formed of a material that is more easily thermally expanded than the housing 31 when the environmental temperature becomes high. However, it thermally expands in the direction toward the photosensitive drum 10 with respect to the housing 31 and in the longitudinal direction of the photosensitive drum 10. Among these, the cleaning blade 32 is pressed in the direction of the photosensitive drum 10 through the support member 33 by a force F (see arrows in FIGS. 2 and 4) that thermally expands in the direction toward the photosensitive drum 10. As a result, the pressure contact force of the cleaning blade 32 can be maintained at a predetermined value, and the deterioration of the cleaning ability at high temperatures can be prevented.

  Further, since the fixing member 50 is fitted into the recess 40 provided on the flat surface 31 b of the housing 31, the entire volume of the fixing member 50 is increased by the amount fitted into the recess 40. A large amount can be secured, and the pressing force of the cleaning blade 32 can be maintained at a predetermined value.

  Further, since it is mainly the thermal expansion force of the shaft portion 51 that contributes to the pressing of the support member 33, the volume of the shaft portion 51 is preferably as large as possible. However, if the height of the shaft portion 51 is increased, the distance between the support member 33 and the flat surface 31b of the housing 31 is increased, and there are cases where the device cannot be reduced in size. Therefore, in this case, if the depth of the back side slide part 42c of the recess 40 is made shallow and the depth of the near side slide part 42d is made deep, even if the height of the shaft part 51 is made high, The height at which the shaft portion 51 protrudes from the flat surface 31 b of the housing 31 can be suppressed.

  Furthermore, the support member 33 can be easily attached to the housing 31 only by fixing the support member 33 to the fixing member 50 with the screw 54 and by fitting the fixing member 50 into the recess 40 and sliding it. Further, since the cleaning blade 32 is in contact with the photosensitive drum 10 from the counter direction, a force in the rotation direction of the photosensitive drum 10 acts on the cleaning blade 32. The direction in which this force acts is along the direction in which the fixing member 50 is pressed against the lower end surface of the recess 40, so that the support member 33 does not fall out of the recess 40.

  Further, by using the fixing member 50, the area of the mounting surface of the support member 33 in the housing 31 can be minimized. Therefore, even if the area of the flat surface 31b of the housing 31 is reduced with the miniaturization of the cleaning device 15 or the flat surface 31b cannot be continuously formed, the fixing member 50 is interposed. The support member 33 can be securely attached to the flat surface 31 b of the housing 31.

  Next, a fixing member 50 ′ and a recess 40 ′ according to another example of the present embodiment will be described with reference to FIG. 5. 5A is a perspective view of the fixing member, FIG. 5B is a side sectional view of the concave portion, and FIG. 5C is a side sectional view showing a state in which the fixing member is slid into the concave portion. In FIG. 5, the same reference numerals as those in FIG. 3 are assigned to the same components as those of the fixing member and the recess according to the above-described embodiment, and detailed description thereof is omitted.

  As shown in FIG. 5A, the fixing member 50 'includes a shaft portion 51 and a flange portion 53, as in the above example. In this example, a claw portion 55 is formed on the surface of the flange portion 53 that faces the bottom surface of the recess 40 '. The cross-sectional shape of the claw portion 55 forms a wedge shape that tapers in the sliding direction.

  On the other hand, as shown in FIG. 5 (B), a groove portion 45 with which the claw portion 55 engages is formed on the bottom surface of the concave portion 40 ′ on the lower end side in the sliding direction. Similar to the cross-sectional shape of the claw portion 55, the cross-sectional shape of the groove portion 45 forms a wedge shape that tapers in the sliding direction.

  In the fixing member 50 ′ and the recess 40 ′ having such a configuration, when the fixing member 50 ′ is fitted into the recess 40 ′ and is slid, as shown in FIG. The sliding movement of the fixing member 50 in the reverse direction is restricted. Therefore, the fixing member 50 'can be fixed to the housing 31 in a non-removable manner without using screws or the like. In this fixing member 50 ', since the thickness of the collar portion 53 is increased by the height of the claw portion 55, the claw portion 55 is compressed when the fixing member 50' slides in the recess 40 '. In addition to being elastically deformed, the wall portions on both sides of the front side slide portion 42d of the recess 40 'are also elastically deformed so as to slightly warp outward, but after the claw portion 55 is completely engaged with the groove portion 45, These deformations return to their original state.

  In the above-described embodiment of the present invention, the case where the shaft portion 51 of the fixing members 50 and 50 ′ is a rectangular parallelepiped shape has been described. However, in another different form, the shaft portion 51 is a columnar shape or a polygonal column. Also good. In addition, the flange portion 53 of the fixing members 50 and 50 ′ has a shape extending in the opposite direction from the proximal end side outer peripheral portion of the shaft portion 51. You may form in a shape.

  Further, in the embodiment of the present invention, the case where the recesses 40, 40 ′ are formed in a groove shape so as to cut out the flat surface 31b of the housing 31 is described, but the present invention is not limited to this case, For example, a hole that penetrates the housing 31 may be formed as a recess. This is effective when the thickness of the housing 31 is thin and a groove-shaped recess having two levels of depth cannot be formed. In this case, it is necessary to provide means for fixing the fixing members 50 and 50 'in the portion on the side opposite to the photosensitive drum of the through portion of the hole.

  Furthermore, in the embodiment of the present invention, the case where the configuration of the present invention is applied to the color printer 1 has been described. However, in other different embodiments, the image forming apparatus other than the printer 1 such as a copying machine, a facsimile machine, and a multifunction machine is used. The configuration of the present invention may be applied.

  Furthermore, since the above description of the embodiments of the present invention describes preferred embodiments of the cleaning device and the image forming apparatus according to the present invention, various technically preferable limitations may be imposed. However, the technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 Color printer 10 Photosensitive drum 15 Cleaning apparatus 31 Housing 32 Cleaning blade 33 Support member 40, 40 'Recess 45 Groove part 50, 50' Fixing member 51 Shaft part 53 Gutter part 55 Claw part

Claims (4)

A cleaning device comprising a cleaning blade that presses against a photosensitive drum and removes toner remaining on the photosensitive drum, a support member that supports the cleaning blade, and a housing to which the support member is attached,
A fixing member interposed between the support member and the housing, the fixing member being formed of a material having a higher thermal expansion coefficient than the housing; and the cleaning blade is disposed on the photosensitive drum in the housing. A recess into which the fixing member is fitted is formed so that the support member can be pressed in a direction in which the support member is pressed .
The fixing member extends in a pressing direction of the support member, and one end of the fixing member extends in a direction orthogonal to the pressing direction of the support member at a shaft portion fixed to the support member and an outer peripheral portion on the other end side of the shaft portion. And has a buttocks
The concave portion includes a fitting portion formed so that the fixing member can be fitted from a surface of the housing on the photosensitive drum side, and has the same width as the fitting portion and extends from the fitting portion to the flange portion. A rear side slide part formed so as to be slidable, and a front side slide part which is narrower than the rear side slide part and is formed so that the shaft part can slide from the fitting part. A cleaning device having a groove shape . The cleaning blade is provided in contact with the rotation of the photosensitive drum in a counter direction, and the back side slide portion and the near side slide portion are contacted with the cleaning blade from the fitting portion. The cleaning device according to claim 1 , wherein the cleaning device extends in a direction along a rotation direction of the photosensitive drum. A claw portion formed on the flange portion of the fixing member, and a groove portion formed on the near side slide portion of the concave portion, and when the fixing member is slid from the fitting portion, the claw portion is the cleaning device according to claim 1 or 2, characterized in that said formed so as to engage the groove. An image forming apparatus comprising: a cleaning device according to any one of claims 1-3.

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