JP2011191548A - Cleaning device, assembly, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress cleaning unevenness arises in the axial direction of a charging roll 23 in cleaning the surface of the charging roll 23. <P>SOLUTION: In an arrangement where an amount of adhesion is larger in both ends in the axial direction of the charging roll 23 than in the center portion, a winding angle of a cleaning material 66 is made smaller at both the ends of a shaft 64 than at the center portion of the shaft 64. Since cleaning capability is higher in smaller winding angle than in larger winding angle, an extraneous material adhered to the surface of both the ends of the charging roll 23 where the amount of adhesion is large can be removed in a larger amount than the center portion in the axial direction where the amount of adhesion is small. Thereby, cleaning unevenness arises in the axial direction of the charging roll 23 is suppressed in cleaning the surface of the charging roll 23. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Patent Document 1 discloses a charging roller cleaning device in which the cleaning means is formed of a spiral elastic member that extends in the axial direction of the charging roller and abuts against the roller surface.

  In Patent Document 2, in the cleaning roll 100 for cleaning the charging roll 14, a sponge layer 100B to be brought into contact with the charging roll 14 is formed of the first sponge material 102 and the second sponge material 104 having different foam hardness, and each sponge is used. A configuration in which materials are alternately arranged in the circumferential direction of the cleaning roll 100 is disclosed.

JP-A-8-137208 JP 2007-241106 A (FIG. 5)

  This invention makes it a subject to suppress the cleaning nonuniformity which arises in the axial direction of a to-be-cleaned body when cleaning the surface of a to-be-cleaned body.

  According to the first aspect of the present invention, there is provided a shaft portion disposed along the surface of the object to be cleaned having a distribution along the axial direction on the amount of adhesion of foreign matter, and spirally wound along the axial direction of the shaft portion. The cleaning ability is higher so that the cleaning ability for cleaning the object to be cleaned is higher in the part where the amount of foreign matter adheres on the surface of the object to be cleaned than in the part where the amount of foreign matter attached is small. And a cleaning material having a distribution along the axial direction of the shaft portion.

  According to a second aspect of the present invention, the cleaning material has a winding angle on the side formed with an acute angle between the axial direction of the shaft portion and the winding direction of the cleaning material, and the foreign matter adheres to the surface of the object to be cleaned. The cleaning device according to claim 1, wherein the cleaning device is set to be smaller than a portion where the amount of foreign matter is small in a portion where the amount is large.

  According to a third aspect of the present invention, the cleaning material is a portion where a width of the cleaning material is perpendicular to a winding direction of the cleaning material, and a portion of the surface of the object to be cleaned where the amount of the foreign material is increased is small. It is a cleaning apparatus of Claim 1 set narrower than.

  According to a fourth aspect of the present invention, at least one end portion of a cross section perpendicular to the winding direction of the cleaning material protrudes in the radial direction of the shaft portion from the central portion. This is a cleaning device.

  According to a fifth aspect of the present invention, there is provided a cleaning device according to any one of the first to fourth aspects, an image holding body capable of holding an image, and a charging body as the object to be cleaned that charges the image holding body. Is an assembly that is detachably assembled to the apparatus main body.

  According to a sixth aspect of the present invention, there is provided a cleaning device according to any one of the first to fourth aspects, an image holding body capable of holding an image, and a charged body as the object to be cleaned that charges the image holding body. And an image forming apparatus.

  The invention according to claim 7 is the attachment of the cleaning device according to any one of claims 1 to 4 and the transfer body as the cleaning object, which transfers the image to the transfer object, integrally with the apparatus main body. The assembly is possible.

  The invention according to claim 8 is an image forming apparatus comprising: the cleaning device according to any one of claims 1 to 4; and a transfer body as the cleaning target that transfers an image to the transfer target. .

  According to the structure of Claim 1 of this invention, compared with the structure where the cleaning capability of the cleaning material is constant along the axial direction of a to-be-cleaned body, when cleaning the surface of a to-be-cleaned body, the axial direction of a to-be-cleaned body Cleaning unevenness that occurs in

  According to the structure of Claim 2 of this invention, compared with the structure where the winding angle of a cleaning material is constant along the axial direction of a to-be-cleaned body, when cleaning the surface of a to-be-cleaned body, the axial direction of a to-be-cleaned body Cleaning unevenness that occurs in

  According to the structure of Claim 3 of this invention, compared with the structure where the width | variety of the cleaning material is constant along the axial direction of a to-be-cleaned body, when cleaning the surface of a to-be-cleaned body, it is to the axial direction of a to-be-cleaned body. Uneven cleaning can be suppressed.

  According to the configuration of the fourth aspect of the present invention, cleaning unevenness that occurs in the axial direction of the object to be cleaned when cleaning the surface of the object to be cleaned is compared with a configuration in which the end portion does not protrude in the radial direction from the central portion. It can be suppressed more.

  According to the structure of Claim 5 of this invention, the cleaning nonuniformity which arises in the axial direction of a to-be-cleaned body can be suppressed when the surface of a to-be-cleaned body is cleaned compared with the structure which is not equipped with the said cleaning apparatus.

  According to the structure of Claim 6 of this invention, compared with the structure which is not provided with the said cleaning apparatus, the image degradation resulting from the cleaning nonuniformity in the axial direction of a to-be-cleaned body can be suppressed.

  According to the structure of Claim 7 of this invention, compared with the structure which is not equipped with the said cleaning apparatus, when cleaning the surface of a to-be-cleaned body, the cleaning nonuniformity which arises in the axial direction of a to-be-cleaned body can be suppressed.

  According to the configuration of the eighth aspect of the present invention, it is possible to suppress the image deterioration caused by the cleaning unevenness in the axial direction of the object to be cleaned, as compared with the configuration not including the cleaning device.

FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present embodiment. FIG. 2 is a schematic diagram illustrating a configuration of the cleaning device according to the present embodiment. FIG. 3 is a schematic diagram illustrating the configuration of the cleaning body according to the present embodiment. FIG. 4 is a view showing a cross section along the axial direction of the shaft portion of the cleaning material according to the present embodiment. FIG. 5 is an explanatory diagram for explaining the winding angle, width, and biting amount of the cleaning material according to the present embodiment. FIG. 6 is an explanatory diagram for explaining the cleaning operation of the cleaning body according to the present embodiment. FIG. 7 is a schematic view illustrating a configuration in which the winding angle of the cleaning material according to the present embodiment is smaller than both axial end portions in the axial center portion of the shaft portion. FIG. 8 is a schematic diagram illustrating a configuration in which the winding angle of the cleaning material according to the present embodiment is gradually or gradually reduced from one axial end portion to the other end portion of the shaft portion. FIG. 9 is a schematic diagram showing a configuration in which the width of the cleaning material according to the present embodiment is made smaller than the axial central portion at both axial end portions of the axial portion. FIG. 10 is a schematic diagram illustrating a configuration in which the width of the cleaning material according to the present embodiment is smaller than both axial end portions in the axial central portion of the axial portion. FIG. 11 is a schematic diagram illustrating a configuration in which the width of the cleaning material according to the present embodiment is gradually or stepwise narrowed from one axial end portion to the other end portion of the shaft portion. FIG. 12 is a schematic diagram illustrating a configuration in which the cleaning material according to the present embodiment is doubled at both axial end portions of the shaft portion and single at the axial center portion. FIG. 13 is a schematic diagram illustrating a configuration in which the cleaning material according to the present embodiment is formed of a material having a higher cleaning ability than the central portion in the axial direction at both axial ends of the axial portion. FIG. 14 is a table showing the evaluation results of Example 1. FIG. 15 is a table showing the evaluation results of Example 2. FIG. 16 is a table showing the evaluation results of Example 3. FIG. 17 is a graph showing the electrical resistance value in the axial direction of the charging roll after an image is formed on a considerable number (for example, 50,000) of recording media by the image forming apparatus according to the present embodiment. FIG. 18 is a graph showing the electrical resistance value in the axial direction of the charging roll after an image is formed on a considerable number (for example, 50,000) of recording media by the image forming apparatus according to the present embodiment.

  Below, an example of an embodiment concerning the present invention is described based on a drawing.

(Configuration of image forming apparatus according to the present embodiment)
First, the configuration of the image forming apparatus according to the present embodiment will be described. FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present embodiment. In addition, arrow UP shown in a figure shows the vertical direction upper direction.

  As shown in FIG. 1, the image forming apparatus 10 includes an image forming apparatus main body 11 in which each component is housed. Inside the image forming apparatus main body 11, a recording medium accommodating unit 12 that accommodates a recording medium P such as paper, an image forming unit 14 that forms an image on the recording medium P, and the recording medium accommodating unit 12 to the image forming unit. 14, a transport unit 16 that transports the recording medium P to 14, and a control unit 20 that controls the operation of each unit of the image forming apparatus 10. In addition, a recording medium discharge unit 18 for discharging the recording medium P on which an image is formed by the image forming unit 14 is provided on the upper portion of the image forming apparatus main body 11.

  The image forming unit 14 includes image forming units 22Y, 22M, 22C, and 22K (hereinafter referred to as 22Y to 22K) that form toner images of colors of yellow (Y), magenta (M), cyan (C), and black (K). And an intermediate transfer belt 24 as an example of a transfer medium onto which the toner images formed by the image forming units 22Y to 22K are transferred, and the toner images formed by the image forming units 22Y to 22K to the intermediate transfer belt 24. A first transfer roll 26 as an example of a transfer body to be transferred to the medium, and a transfer member that transfers the toner image transferred to the intermediate transfer belt 24 by the first transfer roll 26 from the intermediate transfer belt 24 to the recording medium P. The toner image transferred from the intermediate transfer belt 24 to the recording medium P by the second transfer roll 28 and the second transfer roll 28 is recorded on the recording medium P. Includes a fixing device 30 for wearing, the.

  The image forming units 22 </ b> Y to 22 </ b> K are arranged side by side at the center in the vertical direction of the image forming apparatus 10 while being inclined with respect to the horizontal direction. Each of the image forming units 22Y to 22K includes a photoreceptor 32 that rotates in one direction (clockwise direction in FIG. 1) as an image holder that holds an image. Since the image forming units 22Y to 22K are configured in the same manner, the reference numerals of the respective parts of the image forming units 22M, 22C, and 22K are omitted in FIG.

  Around each photoconductor 32, the charging device 34 for charging the photoconductor 32 and the photoconductor 32 charged by the charging device 34 are exposed in order from the upstream side in the rotation direction of the photoconductor 32, and the photoconductor 32 is electrostatically charged. An exposure device 36 that forms a latent image, a developing device 38 that develops an electrostatic latent image formed on the photoconductor 32 by the exposure device 36 to form a toner image, and a photoconductor 32 that contacts the photoconductor 32. And a removing member 40 for removing the remaining toner.

  The exposure device 36 is configured to form an electrostatic latent image based on the image signal sent from the control unit 20. Examples of the image signal sent from the control unit 20 include an image signal acquired by the control unit 20 from an external device.

  The developing device 38 includes a developer supply body 38A that supplies the developer to the photoconductor 32, and a plurality of transport members 38B that transport the developer applied to the developer supply body 38A while stirring.

  The charging device 34 includes a charging roll 23 as an example of a charging body that charges the photoconductor 32, and a cleaning device 60 that cleans the charging roll 23. The charging roll 23 rotates in contact with the outer peripheral surface of the photoconductor 32 and charges the outer peripheral surface of the photoconductor 32. The charging roll 23 is an example of an object to be cleaned that is cleaned by the cleaning device 60. The specific configuration of the cleaning device 60 will be described later.

  Each of the image forming units 22 </ b> Y to 22 </ b> K is configured to be detachable from the image forming apparatus main body 11, and functions as an assembly (process cartridge) assembled to the image forming apparatus main body 11 so as to be detachable integrally. Note that the assembly of this embodiment may include at least the photoreceptor 32, the charging roll 23, and the cleaning device 60.

  The image forming units 22Y to 22K may be configured to be supported by a common support frame and not attached to or detached from the image forming apparatus main body 11 without being unitized.

  As shown in FIG. 1, the intermediate transfer belt 24 is formed in an annular shape and is disposed above the image forming units 22 </ b> Y to 22 </ b> K. Winding rolls 42 and 44 around which the intermediate transfer belt 24 is wound are provided on the inner peripheral side of the intermediate transfer belt 24. The intermediate transfer belt 24 circulates (rotates) in one direction (counterclockwise direction in FIG. 1) while being in contact with the photosensitive member 32 when any of the winding rolls 42 and 44 is rotationally driven. ing. The winding roll 42 is an opposing roll that faces the second transfer roll 28.

  The first transfer roll 26 faces the photoconductor 32 with the intermediate transfer belt 24 interposed therebetween. A space between the first transfer roll 26 and the photoconductor 32 is a first transfer position where the toner image formed on the photoconductor 32 is transferred to the intermediate transfer belt 24. The first transfer roll 26 is in contact with the intermediate transfer belt 24 and is configured to rotate following the intermediate transfer belt 24 that circulates and moves.

  The second transfer roll 28 faces the winding roll 42 with the intermediate transfer belt 24 interposed therebetween. A space between the second transfer roll 28 and the winding roll 42 is a second transfer position where the toner image transferred to the intermediate transfer belt 24 is transferred to the recording medium P.

  The transport unit 16 is disposed along the transport path 48, a feed roll 46 that feeds the recording medium P accommodated in the recording medium container 12, a transport path 48 that transports the recording medium P sent to the transport roll 46, and the transport path 48. A plurality of transport rolls 50 are provided for transporting the recording medium P delivered by the delivery roll 46 to the second transfer position.

  The fixing device 30 is disposed downstream in the transport direction from the second transfer position, and fixes the toner image transferred at the second transfer position to the recording medium P. A discharge roll 52 that discharges the recording medium P on which the toner image is fixed to the recording medium discharge unit 18 is provided downstream of the fixing device 30 in the transport direction.

  Next, an image forming operation for forming an image on the recording medium P in the image forming apparatus 10 according to the present embodiment will be described.

  In the image forming apparatus 10 according to the present embodiment, the recording medium P sent out from the recording medium container 12 by the sending roll 46 is sent to the second transfer position by the plurality of transport rolls 50.

  On the other hand, in the image forming units 22 </ b> Y to 22 </ b> K, the photosensitive member 32 charged by the charging device 34 is exposed by the exposure device 36 to form an electrostatic latent image on the photosensitive member 32. The electrostatic latent image is developed by the developing device 38 to form a toner image on the photoreceptor 32. The color toner images formed by the image forming units 22Y to 22K are superimposed on the intermediate transfer belt 24 at the first transfer position to form a color image. Then, the color image formed on the intermediate transfer belt 24 is transferred to the recording medium P at the second transfer position.

  The recording medium P to which the toner image has been transferred is conveyed to the fixing device 30, and the transferred toner image is fixed by the fixing device 30. The recording medium P on which the toner image is fixed is discharged to the recording medium discharge unit 18 by the discharge roll 52. As described above, a series of image forming operations are performed.

  The image forming apparatus 10 may have a configuration in which a cleaning device 60 is provided for the first transfer roll 26 in addition to the charging roll 23 or instead of the charging roll 23. In this case, the 1st transfer roll 26 is comprised as a to-be-cleaned body.

  In the configuration in which the cleaning device 60 is provided for the first transfer roll 26, the intermediate transfer belt 24, the winding rolls 42 and 44, and the first transfer roll 26 are instructed by a support body (not shown), and the intermediate transfer is performed. The unit 45 may be configured. In this case, for example, the intermediate transfer unit 45 is detachably provided to the image forming apparatus main body 11, and an example of an assembly (process cartridge) assembled to the image forming apparatus main body 11 so as to be integrally removable. Eggplant.

(Configuration of the cleaning device 60 according to the present embodiment)
Next, the configuration of the cleaning device 60 according to the present embodiment will be described. FIG. 2 is a schematic diagram illustrating a configuration of the cleaning device 60 according to the present embodiment.

  As shown in FIG. 2, the cleaning device 60 according to the present embodiment includes a cleaning body 62 that cleans the charging roll 23 as an example of a body to be cleaned. The cleaning body 62 includes a shaft portion 64 that is disposed along the axial direction of the charging roll 23, and a cleaning material 66 that is spirally wound around the outer periphery of the shaft portion 64.

  The shaft portion 64 is formed in a cylindrical shape and has a length along the axial direction of the charging roll 23. Moreover, the axial part 64 is comprised with the metal material, for example.

  The cleaning material 66 is made of, for example, a porous material such as a foam material (sponge) formed of urethane resin or the like, and is formed in a belt shape and elastically deformable. The cleaning material 66 is fixed to the outer periphery of the shaft portion 64 from one end portion in the axial direction to the other end portion by an adhesive, a double-sided tape, or the like.

  As shown in FIG. 3, cylindrical holding members 68 that hold the longitudinal ends of the cleaning material 66 between the shaft portions 64 are provided at both ends in the axial direction of the shaft portions 64. The pressing member 68 is fixed to the shaft portion 64 and is rotated integrally with the shaft portion 64. A support member 76 that rotatably supports the presser member 68 is fixed to a fixing portion 74 formed on the side plate 72 as shown in FIG. In the present embodiment, the charging roll 23 is supported by the support member 76 so as to be rotatable with respect to the side plate 72, and the photoreceptor 32 is supported so as to be rotatable with respect to the side plate 72.

  As shown in FIG. 4, the cleaning material 66 has a quadrilateral shape surrounded by four sides (including a curve) in the cross section along the axial direction S of the shaft portion 64, and the axial direction S of the shaft portion 64. 66A have protrusions 66A protruding outward in the radial direction R from the central portion 66B at both ends. For example, the protrusion 66A applies a tension to the cleaning material 66 to cause a difference in outer diameter between the central portion 66B of the outer peripheral surface (upper surface in FIG. 4) of the cleaning material 66 and the both end portions 66A. Is formed. Similarly, the cleaning material 66 includes four sides (curved lines) in a cross section along a direction (B direction in FIG. 5A) orthogonal to the winding direction (A direction in FIG. 5A). ) And projecting portions 66A that project outward in the radial direction R at both ends in the width direction.

  In the cleaning body 62, the protruding portion 66A and the outer peripheral surface (the upper surface in FIG. 4) of the cleaning material 66 are in contact with the charging roll 23, and the shaft portion 64 is driven to rotate. As a result, the outer peripheral surface of the cleaning material 66 wipes the outer peripheral surface of the charging roll 23, and the protrusion 66A of the cleaning material 66 scrapes off the foreign material so that the foreign material is removed.

  Here, in the present embodiment, the charging roll 23 has a distribution in the amount of adhesion to which foreign matter (for example, an external additive contained in the developer) adheres along the axial direction thereof. Specifically, the charging roll 23 has a larger amount of foreign matter at both axial end portions than at the axial central portion. The amount of foreign matter attached can be confirmed, for example, by measuring the electrical resistance value in the axial direction of the charging roll 23 after the image forming operation of the image forming apparatus 10.

  The electrical resistance value of the charging roll 23 changes mainly when a discharge product (for example, nitrogen oxide) generated by discharge adheres to the charging roll 23. The discharge product has the property of increasing the electrical resistance of the charging roll 23 and the property of increasing the adsorption force for adsorbing foreign substances such as external additives to the charging roll 23. Accordingly, when the electrical resistance value in the axial direction of the charging roll 23 after the image forming operation of the image forming apparatus 10 is higher at both axial ends of the charging roll 23 than at the central portion in the axial direction, the charging roll 23. It is confirmed that the adhering amount of foreign matter is larger at both axial end portions than at the axial central portion (see FIG. 17B).

  In addition, in the axial direction of the charging roll 23, a large amount of discharge products is generated in a portion where the discharge amount is larger than a portion where the discharge amount is small. For example, the discharge amount of the charging roll 23 increases in a portion where the wear amount is larger than a portion where the wear amount is small in the axial direction of the photoreceptor 32. In this way, the uneven wear in which the wear amount is biased in the axial direction of the photoconductor 32 occurs, for example, when the contact pressure of the removing member 40 is biased in the axial direction of the photoconductor 32.

  In the present embodiment, the cleaning material 66 is such that the cleaning ability for cleaning the charging roll 23 is higher on the surface of the charging roll 23 than on the portion where the foreign matter adhesion amount is large and the foreign matter adhesion amount is small. In addition, the cleaning ability is distributed along the axial direction of the shaft portion 64.

  Specifically, the winding angle θ is set so that the winding angle θ of the cleaning material 66 with respect to the shaft portion 64 is smaller at the portion where the amount of adhesion is large on the surface of the charging roll 23 than at the portion where the amount of foreign matter is small. The shaft portion 64 has a distribution along the axial direction.

  Specifically, as shown in FIG. 3, the winding angle θ of the cleaning material 66 with respect to the shaft portion 64 is set to be smaller at both axial end portions of the shaft portion 64 than the axial center portion of the shaft portion 64. The width W of the cleaning material 66 is constant, and the width W of the cleaning material 66 is the same at both axial end portions and the axial center portion of the shaft portion 64. As the winding angle θ decreases, the direction of the protrusion 66A of the cleaning material 66 approaches parallel to the axis of the charging roll 23. That is, the direction of the protrusion 66 </ b> A of the cleaning material 66 comes to be perpendicular to the relative rotation direction of the charging roll 23. For this reason, it becomes easy for foreign matter to be caught on the protrusion 66A of the cleaning material 66, and the performance for removing the foreign matter, that is, the cleaning ability is enhanced.

  As shown in FIG. 5A, the width W of the cleaning material 66 is a length along the orthogonal direction B orthogonal to the winding direction A of the cleaning material 66, and between the side ends 66C of the cleaning material 66. Is the shortest distance. As shown in FIG. 5A, the winding angle θ of the cleaning material 66 is formed at an acute angle between the winding direction A of the cleaning material 66 (side end of the cleaning material 66) and the axial direction S of the shaft portion 64. Side angle θ.

(Operation of this embodiment)
Next, the operation of this embodiment will be described.

  In the present embodiment, foreign substances such as developer remaining on the photoconductor 32 without being transferred to the intermediate transfer belt 24 are removed from the photoconductor 32 by the removing member 40.

  Foreign substances such as external additives having a relatively small particle diameter among the components of the developer pass through the removing member 40. Foreign substances such as external additives that have passed through the removing member 40 adhere to the surface of the charging roll 23.

  As for the foreign matter adhering to the surface of the charging roll 23, the protrusion 66 </ b> A and the outer peripheral surface (upper surface in FIG. 4) of the cleaning material 66 come into contact with the charging roll 23, and the outer peripheral surface of the cleaning material 66 is the outer peripheral surface of the charging roll 23. The protrusion 66A of the cleaning material 66 is removed by scraping off the foreign matter.

  Specifically, as shown in FIGS. 6A and 6B, foreign substances such as external additives attached to the outer peripheral surface of the charging roll 23 rotating in one direction (counterclockwise in FIG. 6) are driven and rotated. The protrusion 66A of the cleaning material 66 of the cleaning body 62 to be pressed is pushed by the outer peripheral surface of the charging roll 23, and the height direction of the cleaning material 66 (G direction shown in FIG. 6A) and the width direction (FIG. 6A). ) In the H direction), and is pushed and aggregated by the cleaning material 66. Then, as shown in FIG. 6C, the aggregated foreign substances such as external additives are more dense than the restoring force by the restoration of the charging roll 23 in the cleaning material 66 of the cleaning body 62 that is driven to rotate. They are loosened from the state or repelled from the outer peripheral surface of the charging roll 23.

  In the above embodiment, the protrusion 66A is provided at both ends in the axial direction S of the shaft 64. However, the protrusion 66A is provided only at one end of the shaft 64 in the axial direction S. It may be present (see FIG. 4). Even in a configuration in which the protruding portion 66A is provided only at one end, it is considered that the protruding portion 66A operates in the same manner as the configuration in which the protruding portion 66A is provided at both ends.

  Here, in this embodiment, the part where the winding angle θ of the cleaning material 66 is small comes into contact with both ends of the surface of the charging roll 23 where the adhesion amount is large and removes foreign matter. A portion where the winding angle θ of the cleaning material 66 is large comes into contact with an axially central portion where the amount of adhesion is small on the surface of the charging roll 23 to remove foreign matter.

  The smaller the winding angle θ, the higher the cleaning ability than the larger winding angle θ. Therefore, more foreign matter is removed at both ends of the charging roll 23 in the axial direction where the amount of adhesion is larger than in the axial central portion where the amount of adhesion is small. The

  The distribution of the adhesion amount of the foreign matter in the axial direction of the charging roll 23 differs depending on, for example, the image forming apparatus 10. For the charging roll 23 having a distribution in the adhesion amount along which the foreign matter adheres along the axial direction, In the central portion in the direction, there may be a case where the amount of foreign matter attached is greater than that at both axial end portions. In this case, as shown in FIG. 7, the winding angle θ of the cleaning material 66 with respect to the shaft portion 64 is set to be smaller at the axial center portion of the shaft portion 64 than at both axial ends of the shaft portion 64. . The width W of the cleaning material 66 is constant, and the width W of the cleaning material 66 is the same at both axial end portions and the axial center portion of the shaft portion 64.

  According to this configuration, the smaller the winding angle θ, the higher the cleaning ability than the larger winding angle θ. Therefore, the surface of the charging roll 23 has an axially central portion where the amount of adhesion is large and is smaller than both axial ends where the amount of adhesion is small. A lot of foreign matter is removed.

  Further, as the charging roll 23 having a distribution in the amount of adhesion of foreign matter along the axial direction, the amount of foreign matter attached may increase gradually or stepwise from one end to the other end in the axial direction. In this case, as shown in FIG. 8, the winding angle θ of the cleaning material 66 with respect to the shaft portion 64 is changed from one axial end portion (right end portion in FIG. 8) to the other end portion (in FIG. 8). It is gradually or gradually reduced toward the left end). The width W of the cleaning material 66 is constant, and the width W of the cleaning material 66 is the same from one axial end portion to the other end portion of the shaft portion 64.

  According to this configuration, the smaller the winding angle θ, the higher the cleaning ability than the larger winding angle θ. Therefore, the other axial end of the surface of the charging roll 23 with a larger amount of adhesion than the one end with a small amount of adhesion. A lot of foreign matter is removed at the portion.

(First modification)
As a configuration in which the cleaning ability is distributed along the axial direction of the shaft portion 64, the width W of the cleaning material 66 is narrower on the surface of the charging roll 23 where the amount of adhesion is larger than the portion where the amount of foreign matter is less. As such, the width W may be distributed along the axial direction of the shaft portion 64.

  Specifically, for a configuration in which both ends in the axial direction of the charging roll 23 have a larger amount of foreign matter than in the central portion in the axial direction, as shown in FIG. At both ends in the axial direction of 64, it is narrower than the central portion in the axial direction of the shaft 64. The winding angle θ of the cleaning material 66 is constant, and the winding angle θ of the cleaning material 66 is the same at both axial ends and the axial center of the shaft portion 64. The narrower the width W, the easier it is for the cleaning material 66 to be deformed in the width direction in a state in which the protrusion 66A of the cleaning material 66 is in contact with the surface of the charging roll 23, and to swing. For this reason, the frictional operation of the protrusion 66A of the cleaning material 66 with respect to the surface of the charging roll 23 is increased, and the performance of removing foreign substances, that is, the cleaning ability is improved.

  Thus, since the cleaning capability is higher when the width W is narrower than that when the width W is wider, foreign matter is present at both ends of the charging roll 23 in the axial direction where the amount of adhesion is larger than in the axial central portion where the amount of adhesion is small. Many are removed.

  Note that for a configuration in which the amount of foreign matter attached to the central portion of the charging roll 23 in the axial direction is larger than that of both ends in the axial direction, the width W of the cleaning material 66 is less than the shaft of the shaft portion 64 as shown in FIG. In the central portion in the direction, it is narrower than both axial ends of the shaft portion 64. The winding angle θ of the cleaning material 66 is constant, and the winding angle θ of the cleaning material 66 is the same at both axial end portions and the axial center portion of the shaft portion 64.

  According to this configuration, the narrower width W has a higher cleaning ability than the wider case, so that the surface of the charging roll 23 has a larger amount of adhesion in the axial central portion than the smaller amount of axial end portions. Many foreign substances are removed.

  Further, for a configuration in which the amount of foreign matter attached gradually or stepwise from one end portion to the other end portion of the charging roll 23 in the axial direction, as shown in FIG. The portion 64 is gradually or gradually reduced from one axial end to the other end. The winding angle θ of the cleaning material 66 is constant, and the winding angle θ of the cleaning material 66 is the same from one axial end portion to the other end portion of the shaft portion 64.

  Since the narrower width W has a higher cleaning ability than the wider case, a larger amount of foreign matter is removed from the surface of the charging roll 23 at the other end in the axial direction with a larger amount of adhesion than at one end in the axial direction with a smaller amount of adhesion. Is done.

(Second modification)
As a configuration in which the cleaning capability is distributed along the axial direction of the shaft portion 64, the number of the cleaning materials 66 is increased so that the number of the cleaning materials 66 is increased in a portion where the amount of adhesion is large on the surface of the charging roll 23. A configuration having a distribution along the axial direction of the shaft portion 64 may be used.

  Specifically, for a configuration in which both ends in the axial direction of the charging roll 23 have a larger amount of foreign matter than in the central portion in the axial direction, as shown in FIG. At both ends in the direction, it is configured in a double (double spiral), and in the central portion in the axial direction of the shaft portion 64, it is configured in a single (single spiral). The winding angle θ and the width W of the cleaning material 66 are constant, and the winding angle θ and the width W of the cleaning material 66 are the same at both axial ends and the axial center of the shaft portion 64. The larger the number of cleaning materials 66, the larger the contact area of the protrusion 66A of the cleaning material 66 with the surface of the charging roll 23, so that the performance of removing foreign substances, that is, the cleaning ability is improved.

  Thus, since the cleaning capability is higher when the number of cleaning materials 66 is larger than when the number of cleaning materials 66 is small, the both ends of the surface of the charging roll 23 in the axial direction where the amount of adhesion is large are larger than the axial central portion where the amount of adhesion is small. A lot of foreign matter is removed.

  Although not shown in the drawing, the number of cleaning materials 66 is the center of the axial portion 64 in the axial direction for a configuration in which the amount of foreign matter attached to the central portion in the axial direction of the charging roll 23 is larger than that of both ends in the axial direction. The part may be configured to be larger than both end parts in the axial direction of the shaft part 64.

  Although not shown in the drawings, the number of cleaning materials 66 is the number of shaft portions 64 for a configuration in which the amount of foreign matter increases gradually or stepwise from one end portion to the other end portion of the charging roll 23 in the axial direction. The structure which increases gradually or in steps from one axial direction end part to the other end part may be sufficient.

(Third Modification)
The configuration in which the cleaning capability is distributed along the axial direction of the shaft portion 64 may be a configuration in which a material having a high cleaning capability is used on the surface of the charging roll 23 where the adhesion amount increases.

  Specifically, for a configuration in which both ends in the axial direction of the charging roll 23 have a larger amount of foreign matter than in the central portion in the axial direction, as shown in FIG. 65A of low capacity parts comprised by the material which is arrange | positioned in the direction center part, and was comprised with the material whose cleaning ability is lower than the axial direction both ends of the axial part 64, and arrange | positioned at the axial direction both ends of the axial part 64, and the axial direction of the axial part 64 And a high-capacity part 65B made of a material having a higher cleaning ability than the center part. The winding angle θ and the width W of the cleaning material 66 are constant, and the winding angle θ and the width W of the cleaning material 66 are the same at both axial ends and the axial center of the shaft portion 64.

  The cleaning capability of the low-capacity portion 65A and the high-capacity portion 65B is, for example, the hardness, density, and a plurality of cavities (cells) formed inside the material in the low-capacity portion 65A and the high-capacity portion 65B. It depends on the size. A material having a higher cleaning ability than the low ability part 65A is used for the high ability part 65B by the combination of hardness, density, and cavity size, and a material having a lower cleaning ability than the high ability part 65B is used as the low ability part 65A. Used for.

  As described above, by using a material having a high cleaning ability, a larger amount of foreign matter is removed at both end portions in the axial direction where the amount of adhesion is large on the surface of the charging roll 23 than in the central portion in the axial direction where the amount of adhesion is small.

  Although illustration is omitted, for the configuration in which the amount of foreign matter attached to the central portion of the charging roll 23 in the axial direction is larger than that of both ends in the axial direction, the cleaning material 66 is disposed at the central portion in the axial direction of the shaft portion 64. Further, a configuration using a material having a higher cleaning ability than both end portions in the axial direction of the shaft portion 64 may be used.

  Although illustration is omitted, for a configuration in which the amount of foreign matter increases gradually or stepwise from one end to the other end in the axial direction of the charging roll 23, the cleaning material 66 is used as the shaft of the shaft 64. The structure may be changed to a material having a high cleaning ability gradually or stepwise from one end portion in the direction to the other end portion.

  In addition, as a structure which the cleaning capability has distribution along the axial direction of the axial part 64, the winding angle (theta) of the cleaning material 66 shown in the said embodiment, the width W of the cleaning material 66 shown in the 1st modification, the 1st You may comprise so that it may have a distribution by combining any 2 or more of the number of the cleaning materials 66 shown by 2 modification, and the material of the cleaning material 66 shown by 3rd modification.

Example 1
As shown in FIG. 14, the cleaning material 66 of each of the comparative examples 1, 1A, and 1B is applied to the charging roll 23 in which both end portions in the axial direction have a larger amount of foreign matter than the central portion in the axial direction. The cleaning property was evaluated by changing the winding angle θ, the width W, and the amount of biting. The amount of biting of the cleaning material 66 refers to the amount of deformation (the length in the radial direction) of the cleaning material 66 due to the cleaning body 62 being pressed against the charging roll 23 as shown in FIG. The winding angle θ and the width W of the cleaning material 66 are as described above.

  In Comparative Example 1, the winding angle θ of the cleaning material 66 is set to 26 ° and the width W of the cleaning material 66 is set to 6 mm at both axial end portions and the axial center portion of the shaft portion 64. In Comparative Example 1, the amount of biting of the cleaning material 66 was set to 0.75 mm and 0.4 mm.

  In Example 1A, the winding angle θ of the cleaning material 66 is 26 ° at both axial ends of the shaft portion 64, and the winding angle θ of the cleaning material 66 is 58 ° at the axial center portion of the shaft portion 64. In Example 1A, the width W of the cleaning material 66 was 6 mm and the amount of biting of the cleaning material 66 was 0.75 mm at both axial ends and the axial center of the shaft portion 64.

  In Example 1B, the winding angle θ of the cleaning material 66 is set to 26 ° at both axial end portions and the axial center portion of the shaft portion 64. In Example 1B, the width W of the cleaning material 66 is 3 mm at both axial ends of the shaft portion 64, and the width W of the cleaning material 66 is 6 mm at the axial center portion of the shaft portion 64. Moreover, in Example 1B, the amount of biting of the cleaning material 66 was 0.75 mm.

  The outer diameter of the charging roll 23 was set to 9 mm, the outer diameter of the shaft portion 64 was set to 6 mm, and the thickness of the cleaning material 66 was set to 2 mm.

  For example, as shown in FIG. 17B, the amount of foreign matter attached to both ends of the charging roll 23 in the axial direction is larger than that of the central part in the axial direction. It was confirmed that the electrical resistance value in the axial direction of the charging roll 23 after the image formation on the recording medium P in FIG. The electric resistance value of the charging roller 23 in a new state is constant in the axial direction as shown in FIG.

  The evaluation was performed by measuring the electrical resistance value in the axial direction of the charging roll 23 after cleaning with the cleaning body 62 and visually observing the image actually formed on the recording medium P. In measuring the electrical resistance value, it is checked whether there is a difference in the electrical resistance value in the axial direction. If there is a height difference, it is determined that there is a residue of foreign matter in the portion where the electrical resistance value is high in the axial direction. . In visual observation of the image, it is confirmed whether or not there is a portion where the image is deteriorated in the width direction of the recording medium P (corresponding to the axial direction of the charging roll 23).

  As a result of evaluating Comparative Example 1 / Example 1A / Example 1B, as shown in FIG. 14, in Comparative Example 1, when the biting amount was 0.75 mm, both ends in the axial direction of the charging roll 23 were good. However, it was found that image degradation occurred in the central portion of the charging roll 23 in the axial direction. This is considered to be because the surface of the charging roll 23 is scraped because the contact pressure of the cleaning material 66 against the charging roll 23 is too strong at the central portion in the axial direction of the charging roll 23.

  Further, in Comparative Example 1, when the amount of biting was set to 0.4 mm, the foreign matter remained at both axial end portions of the charging roll 23 although it was successfully cleaned at the axial central portion of the charging roll 23. I understood. This is presumably because the contact pressure of the cleaning material 66 on the charging roll 23 is insufficient at both axial ends of the charging roll 23.

  In Example 1A and Example 1B, it turned out that it was able to clean favorably in the axial direction center part and both ends of the charging roll 23.

(Example 2)
As shown in FIG. 15, the central portion of the axial direction has a larger amount of foreign matters than both ends of the axial direction. As shown in FIG. 15, the cleaning material 66 of each of Comparative Example 2, Example 2A, and Example 2B The cleaning property was evaluated by changing the winding angle θ, the width W, and the amount of biting. The amount of biting, the winding angle θ, and the width W of the cleaning material 66 are as described above.

  In Comparative Example 2, the winding angle θ of the cleaning material 66 was set to 26 ° and the width W of the cleaning material 66 was set to 6 mm at both axial end portions and the axial center portion of the shaft portion 64. In Comparative Example 1, the amount of biting of the cleaning material 66 was set to 0.75 mm and 0.4 mm.

  In Example 2A, the winding angle θ of the cleaning material 66 is set to 26 ° at the axial center portion of the shaft portion 64, and the winding angle θ of the cleaning material 66 is set to 58 ° at both axial ends of the shaft portion 64. In Example 2A, the width W of the cleaning material 66 is 6 mm and the amount of biting of the cleaning material 66 is 0.75 mm at both axial ends and the axial center of the shaft portion 64.

  In Example 2B, the winding angle θ of the cleaning material 66 was set to 26 ° at both axial end portions and the axial center portion of the shaft portion 64. In Example 1B, the width W of the cleaning material 66 is 3 mm at the axial center of the shaft portion 64, and the width W of the cleaning material 66 is 6 mm at both axial ends of the shaft portion 64. Moreover, in Example 2B, the amount of biting of the cleaning material 66 was 0.75 mm.

  The outer diameter of the charging roll 23 was set to 9 mm, the outer diameter of the shaft portion 64 was set to 6 mm, and the thickness of the cleaning material 66 was set to 2 mm.

  For example, as shown in FIG. 18A, the amount of foreign matter attached to the central portion of the charging roll 23 in the axial direction is larger than that of both ends in the axial direction. It was confirmed that the electrical resistance value in the axial direction of the charging roll 23 after the image formation on the recording medium P) was higher at the axial central portion of the charging roll 23 than at both axial ends.

  The evaluation was performed by measuring the electrical resistance value in the axial direction of the charging roll 23 after cleaning with the cleaning body 62 and visually observing the image actually formed on the recording medium P. In measuring the electrical resistance value, it is checked whether there is a difference in the electrical resistance value in the axial direction. If there is a height difference, it is determined that there is a residue of foreign matter in the portion where the electrical resistance value is high in the axial direction. . In visual observation of the image, it is confirmed whether or not there is a portion where the image is deteriorated in the width direction of the recording medium P (corresponding to the axial direction of the charging roll 23).

  As a result of evaluating Comparative Example 2 / Example 2A / Example 2B, as shown in FIG. 15, in Comparative Example 2, when the amount of biting was 0.75 mm, the central portion in the axial direction of the charging roll 23 was good. However, it was found that image degradation occurred at both ends of the charging roll 23 in the axial direction. This is considered to be because the surface of the charging roll 23 was scraped because the contact pressure of the cleaning material 66 against the charging roll 23 was too strong at both ends in the axial direction of the charging roll 23.

  In Comparative Example 2, when the biting amount is 0.4 mm, both ends in the axial direction of the charging roll 23 can be cleaned well, but foreign matter remains in the central portion in the axial direction of the charging roll 23. I understood. This is presumably because the contact pressure of the cleaning material 66 on the charging roll 23 is insufficient at the axial center of the charging roll 23.

  In Example 2A and Example 2B, it was found that the central portion and both end portions in the axial direction of the charging roll 23 could be cleaned well.

(Example 3)
For the charging roll 23 in which the amount of foreign matter increases gradually or stepwise from one end to the other in the axial direction, as shown in FIG. 16, for each of Comparative Example 3, Example 3A, and Example 3B, The cleaning property was evaluated by changing the winding angle θ, the width W, and the amount of biting of the cleaning material 66. The amount of biting, the winding angle θ, and the width W of the cleaning material 66 are as described above.

  In Comparative Example 3, the winding angle θ of the cleaning material 66 was set to 26 ° and the width W of the cleaning material 66 was set to 6 mm at both axial end portions and the axial center portion of the shaft portion 64. In Comparative Example 1, the amount of biting of the cleaning material 66 was set to 0.75 mm and 0.4 mm.

  In Example 3A, the winding angle θ of the cleaning material 66 is set to 58 ° at one axial end portion of the shaft portion 64, and the winding angle θ is gradually or gradually decreased from one axial end portion to the other end portion. The winding angle θ of the cleaning material 66 is set to 26 ° at the other axial end of the shaft portion 64. In Example 3A, the width W of the cleaning material 66 was 6 mm from the one axial end of the shaft 64 to the other axial end, and the amount of biting of the cleaning material 66 was 0.75 mm.

  In Example 3B, the winding angle θ of the cleaning material 66 was set to 26 ° from one axial end of the shaft 64 to the other axial end. In Example 3B, the width W of the cleaning material 66 is 6 mm at one end in the axial direction of the shaft portion 64, and the width W is gradually or gradually reduced from one end to the other end in the axial direction. At the other axial end of 64, the width W of the cleaning material 66 was 3 mm. Moreover, in Example 3B, the amount of biting of the cleaning material 66 was 0.75 mm.

  The outer diameter of the charging roll 23 was set to 9 mm, the outer diameter of the shaft portion 64 was set to 6 mm, and the thickness of the cleaning material 66 was set to 2 mm.

  For example, as shown in FIG. 18 (B), the amount of adhesion of foreign matter increases gradually or stepwise from one end portion to the other end portion of the charging roll 23 in the axial direction. It was confirmed that the electrical resistance value in the axial direction of the charging roll 23 after forming an image on the recording medium P of 50,000 sheets was higher from one axial end of the charging roll 23 to the other axial end. .

  The evaluation was performed by measuring the electrical resistance value in the axial direction of the charging roll 23 after cleaning with the cleaning body 62 and visually observing the image actually formed on the recording medium P. In measuring the electrical resistance value, it is checked whether there is a difference in the electrical resistance value in the axial direction. If there is a height difference, it is determined that there is a residue of foreign matter in the portion where the electrical resistance value is high in the axial direction. . In visual observation of the image, it is confirmed whether or not there is a portion where the image is deteriorated in the width direction of the recording medium P (corresponding to the axial direction of the charging roll 23).

  As a result of evaluating Comparative Example 3 / Example 3A / Example 3B, as shown in FIG. 16, in Comparative Example 3, when the biting amount was 0.75 mm, the other end in the axial direction of the charging roll 23 was Although it was successfully cleaned, it was found that image degradation occurred at one end of the charging roll 23 in the axial direction. This is considered due to the fact that the surface of the charging roll 23 has been scraped because the contact pressure of the cleaning material 66 against the charging roll 23 is too strong at one axial end of the charging roll 23.

  In Comparative Example 3, when the biting amount was 0.4 mm, the one end in the axial direction of the charging roll 23 could be cleaned well, but foreign matter remained at the other end in the axial direction of the charging roll 23. I understood it. This is probably because the contact pressure of the cleaning material 66 on the charging roll 23 is insufficient at the other axial end of the charging roll 23.

  In Example 3A and Example 3B, it was found that the one end and the other end in the axial direction of the charging roll 23 could be cleaned well.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made.

10 Image forming apparatuses 22Y to 22K Image forming unit (an example of an assembly)
23 Charging roll (an example of a member to be cleaned, an example of a charged member)
26 First transfer roll (an example of a transfer body)
32 photoconductor (an example of an image carrier)
45 Intermediate transfer unit (an example of an assembly)
60 Cleaning device 64 Shaft 66 Cleaning material

Claims (8)

A shaft portion arranged along the surface of the object to be cleaned, which has a distribution along the axial direction in the amount of adhesion to which foreign matter is attached
The cleaning ability for cleaning the object to be cleaned is spirally wound along the axial direction of the shaft portion, and the amount of the foreign matter is small at the portion where the amount of the foreign matter is attached on the surface of the object to be cleaned. A cleaning material in which the cleaning ability is distributed along the axial direction of the shaft portion so as to be higher than the portion;
A cleaning device comprising:   In the cleaning material, the winding angle on the side formed at an acute angle between the axial direction of the shaft portion and the winding direction of the cleaning material is a portion where the adhesion amount of the foreign matter is increased on the surface of the cleaning object. The cleaning device according to claim 1, wherein the cleaning device is set to be smaller than a portion where the amount of foreign matter attached is small.   The width of the cleaning material orthogonal to the winding direction of the cleaning material is set to be narrower than the portion of the surface of the object to be cleaned where the amount of foreign matter attached is large and the portion where the amount of foreign matter attached is small. The cleaning device according to claim 1.   The cleaning device according to claim 1, wherein at least one end portion of a cross section perpendicular to the winding direction of the cleaning material protrudes in a radial direction of the shaft portion from a central portion. The cleaning device according to any one of claims 1 to 4,
An image carrier capable of holding an image;
A charged body as the body to be cleaned for charging the image holding body;
Is an assembly that is assembled to the main body of the apparatus so as to be detachable. The cleaning device according to any one of claims 1 to 4,
An image carrier capable of holding an image;
A charged body as the body to be cleaned for charging the image holding body;
An image forming apparatus comprising: The cleaning device according to any one of claims 1 to 4,
A transfer body as the body to be cleaned, which transfers the image to the body to be transferred;
Is an assembly that is assembled to the main body of the apparatus so as to be detachable. The cleaning device according to any one of claims 1 to 4,
A transfer body as the body to be cleaned, which transfers the image to the body to be transferred;
An image forming apparatus comprising:

Images