JP5768602B2 - Cleaning device, charging device, assembly, and image forming apparatus - Google Patents

Description

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

  A cleaning member that cleans the outer peripheral surface of the charging roll by winding an elastic body spirally around the shaft, extending in the axial direction of the charging roll, and rotating in contact with the outer peripheral surface of the charging roll Is conventionally known (see, for example, Patent Document 1).

JP 2010-286713 A

  The present invention relates to a cleaning device, a charging device, an assembly, and an image that can suppress a phenomenon in which a winding end end or a winding start end of an elastic layer spirally wound around a shaft portion is peeled off when contacting an object to be cleaned. The object is to obtain a forming device.

  In order to achieve the above object, a cleaning device according to claim 1 of the present invention includes a rotating body to be cleaned, a shaft portion whose outer shape is circular and rotatably supported, and the shaft. It is wound and fixed spirally from one end side to the other end side of the part, and rotates while cleaning the object to be cleaned including the winding start end and the winding end end. An elastic layer, and is formed integrally with the elastic layer and overlaps with the winding end end or the winding start end of the elastic layer extending in the rotation direction of the shaft portion, or the winding end end or And a pressing body that holds the winding start end.

  The cleaning device according to claim 2 is the cleaning device according to claim 1, wherein the pressing portion that presses the end portion of the winding end extends from the main body portion of the elastic layer. It is characterized by being extended in the direction that intersects.

  The cleaning device according to claim 3 is the cleaning device according to claim 1, wherein the winding start end portion extends in a direction intersecting with the extending direction of the main body portion of the elastic layer. And the said holding | suppressing part which hold | suppresses the said winding start end part is made into a part of main-body part of the said elastic layer, It is characterized by the above-mentioned.

  According to a fourth aspect of the present invention, there is provided a charging device comprising: the cleaning device according to any one of the first to third aspects; and the charged body as the rotating body to be cleaned. It is characterized by.

  Moreover, the assembly of Claim 5 which concerns on this invention rotates the cleaning apparatus of any one of Claims 1-3, the to-be-charged body, and the to-be-charged body, and rotates. The charged body as the body to be cleaned is assembled so as to be detachable integrally with the apparatus main body.

  An image forming apparatus according to a sixth aspect of the present invention is the cleaning apparatus according to any one of the first to third aspects, an image holding body capable of holding an image, and the image holding body. A charged body as the cleaning target that rotates and charges, the exposure device that exposes the image carrier charged by the charged body to form an electrostatic latent image, and the image carrier by the exposure device. And a developing device for developing the formed electrostatic latent image.

  According to the first aspect of the present invention, the end of winding or the end of winding is overlapped with the end of winding or the end of winding of the elastic layer extending in the rotation direction of the shaft. Compared to a configuration in which the pressing portion to be pressed is not formed on the elastic layer, it is possible to suppress a phenomenon in which the winding end end portion or the winding start end portion of the elastic layer peels off due to contact with the object to be cleaned.

  According to the second aspect of the present invention, it is possible to suppress or prevent a phenomenon in which the winding end end portion of the elastic layer is peeled off by contacting the object to be cleaned.

  According to the third aspect of the present invention, it is possible to suppress or prevent a phenomenon in which the winding start end portion of the elastic layer is peeled off by contacting the object to be cleaned.

  According to invention of Claim 4, compared with the structure which is not equipped with the cleaning apparatus of any one of Claims 1-3, the cleaning performance with respect to a charging body can be improved.

  According to the invention described in claim 5, the cleaning performance for the charged body can be improved as compared with the configuration in which the cleaning device according to any one of claims 1 to 3 is not provided.

  According to the invention described in claim 6, it is possible to suppress image defects due to poor cleaning as compared with the configuration that does not include the cleaning device according to any one of claims 1 to 3. .

Schematic showing the configuration of the image forming apparatus Schematic showing the configuration of the cleaning device as seen from the axial direction The top view which shows the structure of a cleaning apparatus seeing from the direction orthogonal to an axial direction The top view which shows the helical cleaning member of 1st Embodiment Exploded view of the elastic layer of the first embodiment The top view which shows the helical cleaning member of 2nd Embodiment. Exploded view of the elastic layer of the second embodiment The top view which shows the helical cleaning member of 3rd Embodiment. Exploded view of the elastic layer of the third embodiment Sectional drawing which shows the shape of the elastic layer of the state wound around the shaft Explanatory drawing which shows the cleaning operation | movement of the helical cleaning member with respect to a charging roll. (A) The top view which shows the helical cleaning member of a comparative example, (B) The expanded view of the elastic layer of a comparative example

  Embodiments according to the present invention will be described below in detail with reference to the drawings. An image forming apparatus 10 according to the present embodiment is a tandem-type full-color image forming apparatus, for example, as shown in FIG. In FIG. 1, the arrow UP is the upward direction of the image forming apparatus 10. First, a schematic configuration of the image forming apparatus 10 will be described.

  Inside the image forming apparatus 10, a photosensitive member 12 as an example of an image holding member (a member to be charged), a charging roll 14 as an example of a charged member, a developing device 24, and the like include yellow (Y), magenta (M ), Cyan (C), and black (K) as process cartridges 18Y, 18M, 18C, and 18K as an example of an assembly for each color.

  The process cartridges 18Y, 18M, 18C, and 18K are configured to be detachable from the image forming apparatus 10. Further, as the photoconductor 12, for example, a conductive cylinder having an outer peripheral surface (front surface) coated with a photoconductor layer made of an organic photosensitive material or the like is used, and is rotated by a motor (not shown). Yes.

  The outer peripheral surface of the photoconductor 12 is charged by a charging roll 14 disposed so as to be in contact with the outer peripheral surface, and then is exposed from an exposure device 16 disposed downstream of the charging roll 14 in the rotation direction of the photoconductor 12. Exposure is performed by the emitted laser beam LB, and an electrostatic latent image corresponding to image information is formed on the outer peripheral surface thereof.

  The electrostatic latent image formed on the outer peripheral surface of the photoreceptor 12 is developed by the developing devices 24Y, 24M, 24C, and 24K for each color of yellow (Y), magenta (M), cyan (C), and black (K). The toner image is developed to be a toner image of each color.

  For example, when a full-color image is formed, charging, exposure, and development processes are performed on the outer peripheral surface of each color photoconductor 12 in black (K), cyan (C), magenta (M), and yellow (Y). A toner image corresponding to each color of black (K), cyan (C), magenta (M), and yellow (Y) is formed on the outer peripheral surface of the photoconductor 12 of each color. It is a configuration.

  The toner images of the respective colors of black (K), cyan (C), magenta (M), and yellow (Y) formed on the outer peripheral surfaces of the respective photoreceptors 12 are applied with tension by the support rolls 40 and 42, while being applied with tension. It is conveyed on the sheet conveying belt 20 from the outer circumferential surface of each photoconductor 12 at a location where a transfer device 22 and a photoconductor 12 described later come into contact with each other via the sheet conveying belt 20 supported from the peripheral surface side. The recording paper P is sequentially transferred to the incoming recording paper P.

  Then, the recording paper P on which the toner image is transferred from the outer peripheral surface of each photoconductor 12 is conveyed to the fixing device 64 and heated and pressed by the fixing device 64, so that the toner is placed on the recording paper P. The image is fixed. The recording paper P is taken out from the paper storage container 28 by the take-out roll 30 and is conveyed to the paper transport belt 20 by the transport rolls 32 and 34.

  Here, in the case of single-sided printing, the recording paper P on which the toner image is fixed is discharged as it is onto a discharge unit 68 provided at the top of the image forming apparatus 10 by a discharge roll 66. On the other hand, in the case of double-sided printing, the discharge roll 66 rotates in the reverse direction while the rear end portion of the recording paper P on which the toner image is fixed on the surface by the fixing device 64 is sandwiched by the discharge roll 66 and the recording is performed. The conveyance path of the paper P is switched to the double-sided paper conveyance path 70.

  Then, the recording paper P whose front and back are reversed is transported again onto the paper transport belt 20 by the transport roll 72 disposed in the paper transport path 70 for double-sided printing, and each photoconductor is placed on the back surface of the recording paper P. A toner image is transferred from the outer peripheral surface of the toner. The recording paper P with the toner image transferred to the back surface of the recording paper P is fixed with the toner image by the fixing device 64, and the recording paper P with the toner image fixed on the back surface is discharged onto the discharge unit 68.

  The illustrated image forming apparatus 10 can perform double-sided printing, but may be an image forming apparatus capable of only single-sided printing. Further, residual toner, paper dust, and the like remaining on the outer peripheral surface of the photoconductor 12 after the toner image transfer process is completed are more photoconductive than the portion where the transfer device 22 contacts each time the photoconductor 12 rotates. The outer peripheral surface of each photoconductor 12 is prepared for the next image forming process.

<First Embodiment>
As shown in FIGS. 2 and 3, the charging roll 14 has a roll shape in which, for example, a conductive elastic layer 14B is formed around a conductive shaft 14A, and the shaft 14A is rotatable. It is supported by.

  The charging roll 14 is pressed against the photoconductor 12 by applying a load to both ends of the shaft 14A, and is elastically deformed along the peripheral surface of the elastic layer 14B to form a nip portion. 12 is driven to rotate. The configuration of the charging roll 14 will be described in detail later.

  Further, the outer peripheral surface (surface) of the charging roll 14 opposite to the photoreceptor 12 is rotated while being in contact with the outer peripheral surface, thereby transferring dirt such as toner and external additives on the outer peripheral surface. A cleaning device 100 that removes (cleans the outer peripheral surface) is disposed. The charging device 50 includes the charging roll 14 and the cleaning device 100, and the charging roll 14 is also an example of an object to be cleaned.

  As shown in FIG. 3, the cleaning device 100 supports a spiral cleaning member 102 as an example of a cleaning body and both ends of a shaft 104 (to be described later) of the spiral cleaning member 102 to be rotatable (rotatable). And a bearing member 110 as an example of a supporting member.

  As shown in FIG. 4, the spiral cleaning member 102 includes a shaft 104 as an example of a shaft portion (core body) disposed along the axial direction of the charging roll 14, and the periphery (outer peripheral surface) of the shaft 104. ) And a belt-shaped (strip-shaped) elastic sheet 106 that is wound spirally and fixed by adhesion.

  The shaft 104 of the spiral cleaning member 102 is formed in a cylindrical shape, and is disposed so as to extend along the axial direction of the charging roll 14. Then, as shown in FIG. 2, the load is applied to both ends of the shaft 104 by the bearing member 110, whereby the spiral cleaning member 102 is pressed against the charging roll 14, and the elastic sheet 106 is moved to the peripheral surface of the charging roll 14. A nip portion is formed by elastically deforming along the line.

  Thereby, the bending of the charging roll 14 is suppressed, and the uniformity of the nip portion in the axial direction between the charging roll 14 and the photoreceptor 12 is maintained. The spiral cleaning member 102 is pressed against the charging roll 14 including both end portions 107B and 107C of an elastic layer 107 described later. In the following, a direction (indicated by an arrow W in FIG. 10) orthogonal to the longitudinal direction of the elastic sheet 106 is defined as a width direction of the elastic sheet 106 (an elastic layer 107 described later).

  Further, a metal material such as aluminum, stainless steel, or brass is mainly used for the shaft 104, and a material and a surface treatment method are appropriately selected according to applications such as slidability. When a non-conductive material is used for the shaft 104, the shaft 104 may be processed by a general process such as a plating process to perform a conductive process, or may be used as it is.

  Further, since the grinding process is not performed at the time of manufacture and the rigidity of the shaft necessary for the process is low, a resin shaft may be used. The outer diameter of the shaft 104 is preferably about φ3 mm to φ6 mm because of the relationship between the miniaturization of the copying machine or the printer, the deflection of the shaft 104, and the manufacturing cost.

  As shown in FIG. 5, the elastic sheet 106 of the spiral cleaning member 102 is formed in an elongated band shape and is elastically deformable, and the elastic layer 107 is bonded to the entire surface and the back surface is formed. An adhesive layer 105 (see FIG. 10) that can be adhered to the outer peripheral surface of the shaft 104 is provided.

  The adhesive layer 105 is made of an adhesive material such as an adhesive or a double-sided tape, and the elastic sheet 106 is formed on the outer peripheral surface of the shaft 104 by the adhesive layer 105 from one axial end to the other end. It is designed to be pasted (fixed).

  Note that the adhesive layer 105 may be a single adhesive layer or a plurality of adhesive layers. Further, when the adhesive layer 105 is composed of a plurality of adhesive layers, a non-adhesive layer such as a conductive layer, a non-conductive layer, a semiconductive layer, a heat insulating layer, or a heat transfer layer is interposed between the adhesive layers. May be.

  A foam is used for the elastic layer 107. That is, the elastic layer 107 is made of a foam having a porous three-dimensional structure, sliced into a desired thickness, cut into a desired width and length by a punching die, etc., and then at a constant speed. The rotated shaft 104 is bonded while being spirally wound at a desired winding angle θ (see FIG. 4).

  Here, the cross-sectional shape in the width direction of the unloaded elastic layer 107 that is not wound around the shaft 104 is a rectangular shape that is long in the width direction. As shown in FIG. 10, the elastic layer 107 in a loaded state wound around the shaft 104 while being pulled with a constant tension is at least a cross section in the width direction (a cross section along a direction perpendicular to the winding direction). ), Both ends in the width direction are elastically deformed so as to protrude in a convex shape.

  That is, the elastic layer 107 spirally wound around the shaft 104 is configured to have a substantially rectangular shape surrounded by four sides (including a curve along the shaft 104) in the cross section in the width direction indicated by the arrow W. And although illustration is abbreviate | omitted, also in the cross section orthogonal to the axial direction of the shaft 104, it is the structure which becomes a substantially square shape enclosed by four sides (including the curve in alignment with the shaft 104) similarly.

  Then, as shown in FIG. 10, the thickness of both ends in the width direction of the elastic sheet 106 (the adhesive layer 105 is negligibly thin and may be referred to as the elastic layer 107 in the following) is Ta. When the thickness of the central portion is Tb, the following conditional expression (1) is satisfied, preferably the following conditional expression (2), and more preferably the following conditional expression (3): It has become. At this time, the outer diameter of the shaft 104 is φ4 mm.

(1) 1.00 <Ta / Tb <1.75
0.5mm <Ta <4.0mm and 0.5mm <Tb <4.0mm
(2) 1.02 <Ta / Tb <1.50
1.0mm <Ta <3.0mm and 1.0mm <Tb <3.0mm
(3) 1.03 <Ta / Tb <1.35
1.5mm <Ta <2.5mm and 1.5mm <Tb <2.5mm

  Therefore, as shown in FIG. 11, in this spiral cleaning member 102, the outer periphery including both ends in the width direction of the elastic layer 107 of the elastic sheet 106 (hereinafter sometimes referred to as “projection portion 107D”) and the center portion in the width direction. The surface is in contact with the outer peripheral surface (surface) of the charging roll 14 with sufficient pressure, and the helical cleaning member 102 is stably driven and rotated with respect to the charging roll 14.

  And with the driven rotation, the outer peripheral surface including the width direction both ends (projection portion 107D) and the width direction central portion of the elastic layer 107 wipes the outer peripheral surface of the charging roll 14 and adheres to the outer peripheral surface. It is the structure which scrapes off the foreign material. That is, the foreign matter is thereby removed from the outer peripheral surface of the charging roll 14.

  It should be noted that the tension when the elastic sheet 106 is wound around the shaft 104 is such that there is no gap between the shaft 104 and the adhesive layer 105, and it is desirable that tension is not applied as much as possible. If the tension is applied too much, the permanent elongation becomes large, and the elastic force necessary for cleaning decreases. Specifically, it is desirable that the elongation of the original elastic sheet 106 is 0% to 5%.

  The elongation of the elastic sheet 106 (elastic layer 107) when wound around the shaft 104 differs in the thickness direction. That is, the elongation of the elastic layer 107 is larger on the outer surface side than on the inner surface side. Therefore, it is desirable that the elongation on the outer surface side after winding is about 5%.

  Further, the elongation of the elastic layer 107 includes the tension when the elastic sheet 106 is wound around the shaft 104, the radius of curvature (or curvature) of the elastic sheet 106 wound around the shaft 104, and the thickness ( The radius of curvature of the elastic sheet 106 is controlled by the outer diameter of the shaft 104 and the winding angle of the elastic sheet 106 (hereinafter sometimes referred to as “spiral angle”) θ.

  The radius of curvature of the elastic sheet 106 is preferably (outer diameter of the shaft 104) /2+0.2 mm to (outer diameter of the shaft 104) /2+8.5 mm, more preferably (outer diameter of the shaft 104) / 2 + 0.5 mm to (outer diameter of the shaft 104) /2+7.0 mm. The winding angle (spiral angle) θ of the elastic sheet 106 at this time is preferably θ = 10 ° to 65 °, and more preferably θ = 20 ° to 50 °.

  The length of the elastic sheet 106 (elastic layer 107) is uniquely determined by the length and outer diameter of the shaft 104, the winding angle (spiral angle) θ, and the tension at the time of winding. Then, the spiral width R1 (see FIG. 4) of the elastic sheet 106 (elastic layer 107) is equal to the coverage of the elastic layer 107 (the helical pitch R2 of the elastic layer 107 (when the elastic sheet 106 is wound around the shaft 104)). (Refer to FIG. 4), R1 / (R1 + R2)) is preferably 20% to 70%, and more preferably 25% to 55%. .

  When the coverage is greater than 70%, the time of contact with the charging roll 14 becomes longer, so the toner or toner additive adhering to the elastic sheet 106 (elastic layer 107) reattaches to the charging roll 14 side. As a result, the charging roll 14 is contaminated. If the coverage is less than 20%, the width of the elastic sheet 106 (elastic layer 107) is smaller than the thickness, so that the thickness within the spiral width R1 of the elastic layer 107 becomes difficult to stabilize, and the cleaning capability is improved. descend.

  The spiral width R1 is desirably 3 mm to 25 mm, and more desirably 3 mm to 10 mm. Further, the helical pitch R2 is desirably 3 mm to 25 mm, and more desirably 15 mm to 22 mm. In particular, when the elastic layer 106 is formed by winding the elastic body sheet 106 around the shaft 104, the conditional expressions (1), (2), and (2) are controlled by controlling the spiral angle θ and the spiral width R1. Or it becomes easy to satisfy (3). That is, this range is suitable for improving the cleaning ability.

  Further, the thickness of the elastic sheet 106 (elastic layer 107) when wound around the shaft 104 is different at both ends in the width direction (projection portion 107D) and other than both ends in the width direction (central portion in the width direction). It is desirable to be within the range of 0.5 mm to 4.0 mm, and it is more desirable to be within the range of 1.5 mm to 3.0 mm. Here, the thickness of the elastic sheet 106 wound around the shaft 104 is measured by the following method, for example.

  In a state in which the circumferential position of the elastic sheet 106 wound around the shaft 104 is fixed, the spiral cleaning member 102 is moved at a speed of 1 mm / s with a laser measuring machine (laser scan micrometer manufactured by Mitutoyo Corporation, model: LSM6200). , And the profile of the thickness of the elastic sheet 106 is measured. Thereafter, the same measurement is performed by shifting the circumferential position of the elastic sheet 106 wound around the shaft 104 (for example, by shifting three positions at intervals of 120 °).

  Based on each profile thus measured, the thickness Ta of the elastic body sheet 106 (elastic layer 107) in the width direction both ends (projection 107D) and the thinnest part (width direction center) other than the width direction both ends. The wall thickness Tb is calculated. Note that the position of the elastic sheet 106 wound around the shaft 104 in the longitudinal direction of the spiral cleaning member 102 varies depending on the spiral winding angle (spiral angle) θ and the outer diameter of the shaft 104, but for each helical pitch R2. Are all measured.

  Here, as a method of forming the shape of the elastic layer 107 so as to satisfy the conditional expression (1), (2), or (3), an elastic sheet 106 (elastic layer 107) formed in a strip shape is used. Other than controlling the thickness of the elastic sheet 106 (elastic layer 107), the curvature of winding the elastic sheet 106 (elastic layer 107), the tension when winding the elastic sheet 106 (elastic layer 107), etc. In addition, the following method may be used.

  That is, for example, the elastic sheet 106 (elastic layer 107) is wound around the shaft 104 and fixed without applying tension, and then another small elastic layer (not shown) is formed on the elastic sheet 106 (not shown) on both ends in the width direction. The elastic layer 107) may be wound and fixed, and the protruding portion 107D of the elastic layer 107 may be formed by the small elastic layer. In other words, the protruding portion 107D of the elastic layer 107 may be configured by one member, or the elastic layer 107 serving as a base and the small elastic layers provided at both ends in the width direction of the elastic layer 107. The form comprised by two members may be sufficient.

  In the present embodiment, the spiral winding angle (helical angle) θ means an angle (acute angle) at which the longitudinal direction (spiral direction) of the elastic layer 107 and the axial direction of the shaft 104 intersect. Further, the spiral width R <b> 1 means the length of the elastic layer 107 along the axial direction of the shaft 104. Further, the helical pitch R <b> 2 means the length between the adjacent elastic layers 107 along the axial direction of the shaft 104. The elastic layer 107 is a layer made of a material that can be restored to its original shape even when deformed by applying an external force of 100 Pa (Pascal).

  As shown in FIGS. 4 and 5, when the elastic sheet 106 (elastic layer 107) is wound around the shaft 104, an end portion (hereinafter referred to as “end of winding”) of the elastic layer 107 on the main body portion 107A of the body portion 107A. In the vicinity of 107C (referred to as “end portion”), a pressing portion 108 extending in a direction intersecting with the extending direction of the main body portion 107A is integrally formed (extended).

  The pressing portion 108 extends in a branch shape from the middle portion of the main body portion 107A so that the winding end side of the elastic body sheet 106 (elastic layer 107) has a bifurcated shape. Then, the width D1, length L1 and angle (obtuse angle) α of the pressing portion 108 with respect to the main body portion 107A is such that the tip end portion 108A of the pressing portion 108 is placed on the winding end portion 107C of the elastic layer 107 wound around the shaft 104. The width, length, and angle are such that the winding end end portion 107C can be pressed from the top (from the outer peripheral side).

  That is, the front end portion 108A of the pressing portion 108 is overlapped from above on the winding end portion 107C of the elastic layer 107 extending in the rotation direction indicated by the arrow F of the shaft 104 as shown in FIG. It is supposed to be fixed. In the spiral cleaning member 102, an end portion (hereinafter referred to as a “winding start end portion”) 107B on the winding start side of the main body portion 107A of the elastic sheet 106 (elastic layer 107) 107B, and a tip end portion 108A of the pressing portion 108. Are directed in the same direction (upstream in the rotational direction).

  In more detail, the tip end portion 108A of the pressing portion 108 is adhered to the winding end end portion 107C so as to crush the winding end end portion 107C of the elastic layer 107 (tension is applied). , Beyond the winding end portion 107C, it is bonded and fixed to the outer peripheral surface of the shaft 104. Therefore, the conditional expression (1), (2), or (3) is also satisfied at the distal end portion 108A of the pressing portion 108.

  As the foam constituting the elastic layer 107, a foamable resin such as polyurethane, polyethylene, polyamide or polypropylene, or NBR, EPDM, SBR, CR, silicone rubber, fluorine rubber, urethane rubber, chlorinated polyisoprene, Isoprene, acrylonitrile-butadiene rubber, styrene-butadiene rubber, hydrogenated polybutadiene, butyl rubber, and other rubber materials are selected from one or a blend of two or more. Auxiliaries such as foaming agents, catalysts, curing agents, plasticizers, vulcanization accelerators are added.

  However, driven frictional friction with the charging roll 14 efficiently removes foreign substances such as external additives, and at the same time, the outer peripheral surface of the charging roll 14 is not scratched by rubbing. It is particularly desirable to select a polyurethane that is resistant to tearing, pulling, etc., so as not to break or break.

  Polyurethanes such as polyester polyols, polyether polyesters and acrylic polyols, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, and tolidine diisocyanate are not particularly limited as polyurethane. 1,6-hexamethylene diisocyanate and other isocyanate reactions may be involved, and it is desirable that a chain extender such as 1,4-butanediol and trimethylolpropane is mixed.

  In general, polyurethane is foamed using a foaming agent such as water, azodicarbonamide, azo compounds such as azobisisobutyronitrile. Moreover, you may add adjuvants, such as a foaming aid, a foam stabilizer, and a catalyst, to foamed polyurethane as needed. Of the foamed polyurethanes, ether-based foamed polyurethane is preferable. This is because the ester-based foamed polyurethane tends to be subject to wet heat degradation.

  Ether-based polyurethanes mainly use silicone oil foam stabilizers, but the image quality of silicone oil transferred to the object to be cleaned (eg, charging roll) during storage (especially long-term storage under high temperature and high humidity). Defects may occur. Therefore, image quality defects of the elastic layer 107 are suppressed by using a foam stabilizer other than silicone oil.

  Here, specific examples of the foam stabilizer other than silicone oil include organic surfactants that do not contain Si (for example, anionic surfactants such as dodecylbenzenesulfonic acid and sodium lauryl sulfate). It is done. Further, the elastic layer 107 may have a single-layer structure or a stacked structure. Specifically, the configuration of the elastic layer 107 may be, for example, a configuration composed of one layer of foam or a two-layer configuration of a solid layer and a foam layer.

  The coefficient of dynamic friction of the elastic sheet 106 in the spiral cleaning member 102 is preferably 0.1 to 1.0. When the dynamic friction coefficient of the elastic sheet 106 is less than 0.1, sufficient cleaning performance cannot be obtained, and as a result, vertical stripes may be generated on the image quality. If the dynamic friction coefficient of the elastic sheet 106 exceeds 1.0, the charging roll 14 is scratched, charging failure is caused at the scratched portion, and color points and minute color lines are generated on the image quality. There is.

  Such image defects include surface contamination (mainly toner external additives) of the charging roll 14 and the spiral cleaning member 102 (elastic body sheet 106), contamination of foreign matters (mainly paper dust), and discharge products. Since adhesion or the like occurs as a trigger, the risk of occurrence increases with longer use.

  In addition, as shown in FIG. 3, the cleaning device 100 includes a pair of bearing members 110 that rotatably support both ends of the shaft 104. Specifically, each of the bearing members 110 has a shape in which the inner side in the axial direction of the shaft 104 is opened and the outer side in the axial direction is closed by the side wall 110A. Both end portions of the shaft 104 rotate along the circumferential direction of the inner wall while sliding on the inner wall of the bearing member 110.

  The pair of bearing members 110 are fixed to fixing portions 114 formed on the side plates 112 on both sides. Note that the charging roller 14 according to the present embodiment is rotatably supported at both ends in the axial direction by a support member (not shown), and the photosensitive member 12 is rotatably supported at the both ends in the axial direction by the side plate 112. .

  Next, the configuration of the charging roll 14 will be described in detail. The charging roll 14 is formed by sequentially forming a conductive elastic layer as a charging layer and a surface layer on a conductive shaft 14A. The diameter of the charging roll 14 is φ8 mm to φ15 mm, more preferably φ9 mm to φ14 mm, and the thickness of the charging layer is preferably 1.5 mm to 4 mm.

  When the diameter of the charging roll 14 exceeds 15 mm, the number of times of contact with the photosensitive member 12 per one outer peripheral surface is reduced, and the number of discharges is reduced. It is disadvantageous from the viewpoint.

  If the diameter of the charging roll 14 is less than 8 mm, the image forming apparatus 10 can be downsized, which is advantageous. However, the number of times of contact with the photoreceptor 12 per outer peripheral surface increases and the number of discharges increases. Disadvantageous for long-term stability. The charging roll 14 is not limited to the following configuration as long as it has a desired charging performance.

  As the material of the shaft 14A, free-cutting steel, stainless steel, or the like is used, and the material and the surface treatment method are appropriately selected according to applications such as slidability. In the case of a material that does not have conductivity, the material may be processed by a general process such as a plating process to be conducted.

  The conductive elastic layer constituting the charging layer of the charging roll 14 is, for example, an elastic material such as elastic rubber, a conductive material such as carbon black or ionic conductive material that adjusts the resistance of the conductive elastic layer, and as necessary. Materials that can be added to ordinary rubber, such as softeners, plasticizers, curing agents, vulcanizing agents, vulcanization accelerators, anti-aging agents, and fillers such as silica and calcium carbonate, may be added.

  A conductive elastic layer is formed by covering the outer peripheral surface of the conductive shaft 14A with a mixture in which a material added to normal rubber is added. In addition, as the conductive agent for the purpose of adjusting the resistance value, a material in which a material that conducts electricity using electrons and / or ions as charge carriers, such as carbon black and ionic conductive agent blended in the matrix material, is used. It is possible. The elastic material may be a foam.

  The elastic material constituting the conductive elastic layer is formed, for example, by dispersing a conductive agent in a rubber material. Rubber materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, urethane rubber, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide. -Allyl glycidyl ether copolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber, natural rubber and the like, and blended rubbers thereof.

  Among these, silicone rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, acrylonitrile-butadiene copolymer rubber, and blended rubbers thereof are desirably used. These rubber materials may be foamed or non-foamed.

  As the conductive agent, an electronic conductive agent or an ionic conductive agent is used. Examples of the electronic conductive agent include carbon black such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, stainless steel; tin oxide, indium oxide, titanium oxide And fine powders such as various conductive metal oxides such as tin oxide-antimony oxide solid solution, tin oxide-indium oxide solid solution, and the like.

  Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium; perchlorates and chlorates of alkaline earth metals ;

  These conductive agents may be used alone or in combination of two or more. The amount of addition is not particularly limited, but in the case of the electronic conductive agent, it is preferably in the range of 1 to 60 parts by mass with respect to 100 parts by mass of the rubber material. Is preferably in the range of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the rubber material.

  The surface layer constituting the charging layer is formed for the purpose of preventing contamination by foreign matters such as toner, and the surface layer material may be any of resin, rubber, etc. It is not limited.

  For example, polyester, polyimide, copolymer nylon, silicone resin, acrylic resin, polyvinyl butyral, ethylenetetrafluoroethylene copolymer, melamine resin, fluororubber, epoxy resin, polycarbonate, polyvinyl alcohol, cellulose, polyvinylidene chloride, polyvinyl chloride , Polyethylene, ethylene vinyl acetate copolymer and the like.

  Of these, polyvinylidene fluoride, tetrafluoroethylene copolymer, polyester, polyimide, and copolymer nylon are preferably used from the viewpoint of external additive contamination. Copolymer nylon includes one or more of 610 nylon, 11 nylon, and 12 nylon as polymerized units, and other polymer units contained in the copolymer include 6 nylon, 66 nylon and the like.

  Here, it is desirable that the ratio of polymer units composed of 610 nylon, 11 nylon, and 12 nylon to be contained in the copolymer is 10% or more in total by weight ratio. When the polymerized unit is 10% or more, the composition is excellent in liquid preparation and film-forming properties during coating of the surface layer, and in particular, there is little abrasion of the resin layer and adhesion of foreign matter to the resin layer during repeated use, and the charging roll 14 Durability is excellent, and changes in properties due to the environment are reduced.

  In addition, the said polymeric material may be used independently, and 2 or more types may be mixed and used for it. The number average molecular weight of the polymer material is preferably in the range of 1,000 to 100,000, and more preferably in the range of 10,000 to 50,000. The surface layer can contain a conductive material to adjust the resistance value. The conductive material preferably has a particle size of 3 μm or less.

  In addition, as a conductive agent for the purpose of adjusting the resistance value, carbon black or conductive metal oxide particles blended in a matrix material, or a material that conducts electrons and / or ions as charge carriers, such as an ionic conductive agent. It is possible to use a material in which is dispersed.

  Specifically, carbon black as a conductive agent includes “Special Black 350”, “Special Black 100”, “Special Black 250”, “Special Black 5”, “Special Black 4” manufactured by Degussa, "Special Black 4A", "Special Black 550", "Special Black 6", "Color Black FW200", "Color Black FW2", "Color Black FW2V", "MONARCH1000" manufactured by Cabot, Cabot “MONARCH1300” manufactured by the company, “MONARCH1400” manufactured by Cabot, “MOGUL-L”, “REGAL400R”, and the like.

  The carbon black has a pH of 4.0 or less, and has a good dispersibility in the resin composition due to the effect of oxygen-containing functional groups present on the surface, compared to general carbon black. By blending, it is possible to improve the charging uniformity as compared with those not blended, and to further reduce the variation of the resistance value.

  The conductive metal oxide particles, which are conductive particles for adjusting the resistance value, are conductive particles such as tin oxide, tin oxide doped with antimony, zinc oxide, anatase titanium oxide, and ITO. Any conductive agent that uses electrons as charge carriers can be used and is not particularly limited. These can be used alone or in combination of two or more.

  In addition, any particle size may be used as long as the present invention is not inhibited, but from the viewpoint of resistance value adjustment and strength, it is preferably tin oxide, antimony-doped tin oxide, anatase-type titanium oxide, Tin oxide and antimony-doped tin oxide are desirable. By performing resistance control with such a conductive material, the resistance value of the surface layer does not change depending on environmental conditions, and stable characteristics can be obtained.

  Further, a fluorine-based or silicone-based resin is used for the surface layer. In particular, the surface layer is preferably composed of a fluorine-modified acrylate polymer. Further, fine particles may be added to the surface layer. As a result, the surface layer becomes hydrophobic and acts to prevent adhesion of foreign matter to the charging roll 14.

  Further, insulating particles such as alumina and silica are added to give irregularities to the outer peripheral surface (surface) of the charging roll 14, thereby reducing the burden at the time of rubbing against the photoreceptor 12. It is also possible to improve the mutual wear resistance between the toner and the photoconductor 12.

  The micro hardness of the charging roll 14 is preferably 45 to 60 degrees. When the micro hardness is higher than 60 degrees, even when the cleaning device 100 is attached, the stability of the nip portion with respect to the photoconductor 12 is not ensured, and image quality density unevenness occurs. When it becomes softer than 45 degrees, the stability of the nip portion with respect to the photoreceptor 12 is ensured without the cleaning device 100, but in order to reduce the hardness, the amount of plasticizer added is increased, or the silicone rubber It is necessary to use such a low-hardness material. In the former case, the plasticizer oozes out and causes problems such as image quality degradation, and in the latter case, the cost is greatly increased.

  Further, the developer used in the image forming apparatus 10 preferably contains spherical silica as an external additive. The reason for this is that silica has a refractive index of around 1.5, and even when the particle size is increased, the transparency decreases due to light scattering, especially for the PE value (index of light transmission) at the time of image preparation on the OHP surface. It has no effect.

  On the other hand, general fumed silica has a specific gravity of 2.2, and the maximum particle size of 50 nm may be a limit in production. Further, although it is possible to increase the particle size as an aggregate, uniform dispersion may be difficult, and the sealing effect may not be exhibited stably.

  Silica suitable as an external additive material contained for improving the cleaning property, particularly spherical monodispersed silica having a specific gravity of 1.3 to 1.9 can be obtained by a sol-gel method which is a wet method. Since the sol-gel method is a wet method and is a method of manufacturing without firing, the specific gravity can be controlled to be lower than other methods such as a vapor phase oxidation method.

  Further, it is possible to further adjust the specific gravity by controlling the type of hydrophobic treatment agent or the treatment amount in the hydrophobization treatment step. The particle diameter of the silica can be freely controlled by the hydrolysis of the sol-gel method, the mass ratio of alkoxysilane, ammonia, alcohol, water in the condensation polymerization step, the reaction temperature, the stirring rate, and the supply rate. Monodispersed and spherical silica can be formed by the sol-gel method.

  A specific method for producing silica is as follows. First, a silane compound such as tetramethoxysilane is dropped into a mixed solution of water and alcohol with stirring using ammonia water as a catalyst while stirring. Next, the produced silica sol suspension is centrifuged to separate it into wet silica gel, alcohol and aqueous ammonia.

  Then, a solvent is added to the wet silica gel to form a silica sol again, and a hydrophobizing agent is added to hydrophobize the silica surface. As the hydrophobization treatment, a general silane compound can be used. Next, the target silica is obtained by removing the solvent from the hydrophobized silica sol, drying, and sieve. Further, the silica thus obtained may be treated again by the sol-gel method.

  Further, as the developer toner used in the image forming apparatus 10, it is desirable to use a polymerized toner produced by a polymerization method. Due to the irregular shape of the toner, the fluidity may not be sufficient even with the addition of a fluidity aid, and due to the movement of fine particles on the toner surface to the toner recesses due to mechanical shearing force during use, The developability, transferability, and cleaning properties are deteriorated due to the decrease in fluidity and the embedding of the fluidity aid in the toner.

  Further, when the toner collected by cleaning is returned to the developing device 24 and used again, the image quality is more likely to deteriorate. If the flow aid is further increased in order to prevent these, contamination, filming, scratches, etc. on the photoreceptor 12 will occur. For this reason, as a means for intentionally enabling control of the toner shape and the surface structure, a toner production method by an emulsion polymerization aggregation method has been proposed.

  In general, a dispersion of resin fine particles is prepared by a polymerization method such as emulsion polymerization, and on the other hand, a colorant particle dispersion in which a colorant is dispersed in a solvent is prepared, and after mixing these, heating and / or pH By controlling, adding a flocculant, and the like, the resin fine particles and the colorant are agglomerated until a desired particle size is obtained, and then the aggregated particles are stabilized at a desired particle size. A toner is produced by heating and fusing to a temperature.

  The developer used in the image forming apparatus 10 preferably contains polytetrafluoroethylene (PTFE) as an external additive, and the blending amount is 0.1 wt% to 1.0 wt%. Particularly desirable. PTFE can suppress the wear of the photoconductor 12 and is useful for extending the life of the image forming apparatus 10.

  The toner particles obtained by the emulsion polymerization agglomeration method have extremely superior characteristics (particularly the particle size distribution is smaller than those obtained by other polymerization methods typified by the conventional suspension polymerization method). If it is used as a toner, it is possible to obtain high quality image quality over a long period of time.

  In addition, the toner production method by the emulsion polymerization aggregation method is such that the aggregated particles are heated and fused to the glass transition point (Tg) or more of the resin fine particles, so that the shape can be changed from an irregular shape by controlling the heating method and pH. Since it is possible to produce toners having various shapes up to spherical particles, the electrophotographic system to be used can select the shape from a so-called potato shape to a spherical shape.

  Next, the operation of the cleaning device 100 configured as described above will be described. Foreign substances such as developer remaining on the outer peripheral surface of the photoconductor 12 without being transferred to the recording paper P are removed from the photoconductor 12 by the cleaning blade 26. However, foreign substances such as external additives having a relatively small particle diameter among the components of the developer pass through the cleaning blade 26.

  Here, the charging roll 14 is applied with a load on both ends of the shaft 14A and pressed against the photosensitive member 12 side, and is elastically deformed along the peripheral surface of the elastic layer 14B. A nip portion is formed between them. In addition, the helical cleaning member 102 suppresses the deflection of the charging roll 14 in the axial direction, and the uniformity of the nip portion in the axial direction is ensured. Accordingly, foreign substances such as external additives that have passed through the cleaning blade 26 adhere to the outer peripheral surface of the charging roll 14.

  Foreign substances such as external additives attached to the outer peripheral surface of the charging roll 14 come into contact with the charging roll 14 and rotate on the outer peripheral surface (winding end portion) of the elastic sheet 106 (elastic layer 107) of the spiral cleaning member 102. 107B and the pressing portion 108 (including the winding end portion 107C) are in contact with the outer peripheral surface of the charging roll 14, and are removed by wiping the outer peripheral surface.

  That is, the cross-sectional shape in the width direction of the elastic layer 107 of the elastic sheet 106 is a shape in which both end portions in the width direction protrude upwardly (projecting portions 107D). When the thickness of both ends in the width direction of the elastic layer 107 when wound around the shaft 104 is Ta, and the thickness of the central portion in the width direction is Tb, the conditional expression shown in the following (1), preferably The conditional expression shown in the following (2), more preferably the conditional expression shown in the following (3) is satisfied. At this time, the outer diameter of the shaft 104 is φ4 mm.

(1) 1.00 <Ta / Tb <1.75
0.5mm <Ta <4.0mm and 0.5mm <Tb <4.0mm
(2) 1.02 <Ta / Tb <1.50
1.0mm <Ta <3.0mm and 1.0mm <Tb <3.0mm
(3) 1.03 <Ta / Tb <1.35
1.5mm <Ta <2.5mm and 1.5mm <Tb <2.5mm

  Therefore, insufficient contact pressure of the elastic layer 107 with respect to the outer peripheral surface of the charging roll 14 does not occur, and cleaning failure due to insufficient contact pressure is suppressed or prevented. That is, as a result, the spiral cleaning member 102 is stably driven to rotate in the direction of arrow F with respect to the charging roll 14 rotating in the direction of arrow J shown in FIG. Is scraped off by the outer peripheral surface including both end portions in the width direction of the elastic layer 107 (projecting portions 107D) and the center portion in the width direction.

  Therefore, the cleaning property of the charging roll 14 is improved as compared with a spiral cleaning member (not shown) provided with an elastic layer not configured as described above. As a result, the cleaning property of the charging roll 14 can be maintained over a long period of time, and the image forming apparatus 10 that is less prone to image quality defects can be obtained.

  By the way, in the spiral cleaning member 202 according to the comparative example shown in FIG. 12, the winding start end portion 207B which is one end portion of the elastic sheet 206 (elastic layer 207) and the winding end end portion 207C which is the other end portion. In the circumferential direction (rotation direction) of the shaft 204, the shafts 204 face in opposite directions (extend in opposite directions).

  Therefore, when the spiral cleaning member 202 is incorporated in the cleaning device 100 and rotated, the charging roll is placed on the winding end end portion 207C facing the rotation direction, for example, the same direction as the arrow F direction (downstream in the rotation direction). The force is applied in the direction of rolling up from the outer peripheral surface of the shaft 204 by the frictional force received by contact with the shaft 14. Therefore, the winding end portion 207 </ b> C may be peeled off from the outer peripheral surface of the shaft 204.

  However, in the spiral cleaning member 102 shown in FIG. 4, the tip end portion 108A of the holding portion 108 that overlaps the winding end end portion 107C of the elastic sheet 106 (elastic layer 107) from above and presses the winding end end portion 107C. And the winding start end portion 107B of the elastic sheet 106 (elastic layer 107) are both directed in the same direction (both extend in the same direction) in the circumferential direction (rotational direction) of the shaft 104. .

  Therefore, in the first embodiment, the spiral cleaning member 102 is assembled to the cleaning device 100 so that the spiral cleaning member 102 is rotated in the direction opposite to the direction (the direction of arrow F, which will be described later). The charging roll 14 is brought into contact with the charging roll 14.

  As a result, not only the winding start end portion 107B of the elastic sheet 106 (elastic layer 107) but also the winding end end portion 107C is suppressed from curling from the outer peripheral surface of the shaft 104 via the tip end portion 108A of the pressing portion 108. Force can be applied in the direction of attachment. Therefore, the both end portions 107B and 107C are suppressed or prevented from peeling (dripping) from the outer peripheral surface of the shaft 104.

Second Embodiment
The shape of the elastic sheet 106 (elastic layer 107) is not limited to the bifurcated shape of the first embodiment shown in FIGS. 4 and 5, but is the same as that of the second embodiment shown in FIGS. Further, the elastic layer 107 is integrally extended from the main body portion 107A so as to have a substantially “<” shape as a whole (bent at an angle (obtuse angle) β described later), and a part of the main body portion 107A ( Hereinafter, a shape having a winding start end portion 107 </ b> E pressed by the pressing portion 109 may be formed by overlapping the “pressing portion 109” from above (from the outer peripheral side).

  That is, when the elastic sheet 106 (elastic layer 107) is wound around the shaft 104, the winding direction of the body portion 107A around which the winding start end portion 107E is wound at the spiral angle θ is temporarily opposite to the axial direction. It is formed in a substantially “<” shape so that it can be wound around. Then, as the main body portion 107A wound after the corner portion 107F constituting the substantially “<” shape is wound at the spiral angle θ, the pressing portion 109 which is a part of the body portion 107A is wound around the winding start end portion 107E. It is designed to be fixed from above.

  That is, the winding start end portion 107E is wound around the shaft 104 at an angle that intersects (substantially orthogonally) with the main body portion 107A wound around the shaft 104 at a spiral angle θ, and its width D2, length L2, and The angle (obtuse angle) β with respect to the main body portion 107A is the width and length with which the pressing portion 109, which is a part of the main body portion 107A, is overlapped from above when the main body portion 107A starts to be wound around the shaft 104 at the helical angle θ. And the angle.

  The winding start end portion 107E is hidden from above by the pressing portion 109 which is a part of the main body portion 107A of the elastic sheet 106 (elastic layer 107), so that the object to be cleaned is removed in the spiral cleaning member 102. As the elastic layer 107 to be cleaned, the elastic layer 107 does not protrude from the outer peripheral surface of the shaft 104, and does not come into contact with the charging roll 14 which is an example of the cleaning target.

  That is, the winding start end portion 107E is in a state of being crushed by the pressing portion 109 that is a part of the main body portion 107A on the winding start side. Therefore, the winding start end portion 107E of the elastic sheet 106 (elastic layer 107) does not peel off from the outer peripheral surface of the shaft 104 regardless of the rotation direction of the spiral cleaning member 102.

  Therefore, in the case of this second embodiment, the direction opposite to the direction in which the winding end portion 107C of the elastic sheet 106 (elastic layer 107) faces (extends) (the direction of arrow F, the forward direction described later). The spiral cleaning member 102 may be assembled to the cleaning device 100 and brought into contact with the charging roll 14 so that the spiral cleaning member 102 is rotated.

  According to this, since the force can be applied to the winding end portion 107C of the elastic layer 107 in a direction to suppress the sag from the outer peripheral surface of the shaft 104, the winding end end portion 107C becomes the outer periphery of the shaft 104. Peeling (dripping) from the surface is suppressed or prevented. Of course, the conditional expression (1), (2), or (3) is also satisfied in the pressing portion 109 that is a part on the winding start side of the main body portion 107A.

<Third Embodiment>
As the shape of the elastic sheet 106 (elastic layer 107), the bifurcated shape of the first embodiment shown in FIGS. 4 and 5 and the substantially “<” shape of the second embodiment shown in FIGS. The shape is not limited to the shape, and the shape of the third embodiment shown in FIG. 8 and FIG.

  According to this, the winding start end portion 107E of the elastic sheet 106 (elastic layer 107) passes through the pressing portion 109, and the winding end end portion 107C passes through the tip end portion 108A of the pressing portion 108, respectively. A force can be applied in a direction to suppress dripping from the surface.

  Therefore, the both end portions 107E and 107C are suppressed or prevented from peeling (dripping) from the outer peripheral surface of the shaft 104. Of course, the conditional expression (1), (2), or (3) is also satisfied in the pressing portion 109 which is a part of the winding start side of the main body portion 107A and the distal end portion 108A of the pressing portion 108. It is like that.

  The helical cleaning member 102 of the first embodiment shown in FIG. 4, the second embodiment shown in FIG. 6, and the third embodiment shown in FIG. 8 has a strip-like elastic shape on the outer peripheral surface of the shaft 104. Since the body sheet 106 (elastic layer 107) is manufactured by being wound in a spiral shape, it is configured to prevent the elastic layer from being twisted (peeled off) by molding or cutting out from a cylindrical roll. Compared to the cleaning member, there are advantages that the manufacturing is easy and the manufacturing cost can be reduced.

  Hereinafter, specific examples and comparative examples of the spiral cleaning member 102 and specific examples of the charging roll 14 will be described. The spiral cleaning member 102 according to the present embodiment is not limited to these examples. Moreover, the same thing was used for the charging roll 14 in each Example and the comparative example. Therefore, a specific example of the charging roll 14 is shown only in the first embodiment.

<Example 1>
[Charging roll]
(Formation of elastic layer)
The following mixture is kneaded with an open roll, coated on the surface of a conductive shaft 14A made of SUS416 with a diameter of 6 mm in a cylindrical shape with a thickness of 3 mm, and placed in a cylindrical mold with an inner diameter of 18.0 mm. After vulcanizing at 170 ° C. for 30 minutes, taking out from the mold, polishing was performed to obtain a cylindrical conductive elastic layer 14B.

・ Rubber material (Epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber; GECHRON 3106: manufactured by Nippon Zeon Co., Ltd.) ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 100 parts by mass ・ Conducting agent (carbon black Asahi Thermal: manufactured by Asahi Carbon Co., Ltd.) ) ... 25 parts by mass Conductive agent (Ketjen Black EC: Lion Corporation) ... 8 parts by mass ion conductive agent (lithium perchlorate) ... ········· 1 part by mass · Vulcanizing agent (sulfur) 200 mesh: manufactured by Tsurumi Chemical Co., Ltd. · ······· 1 part by mass · Vulcanization accelerator (Noxeller DM: manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) ... 2.0 parts by massVulcanization accelerator (Noxeller TT: manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) ... .... 0.5 parts by mass

(Formation of surface layer)
The following mixture was dispersed with a bead mill, and the resulting dispersion was diluted with methanol, dip-coated on the surface of the conductive elastic layer 14B, and then heated and dried at 140 ° C. for 15 minutes to obtain a thickness of 4 mm. A surface layer was formed to obtain a charging roll 14.

-Polymer material (copolymer nylon) (Alamine CM8000: manufactured by Toray Industries, Inc.)-100 parts by mass-Conductive agent (antimony-doped tin oxide) (SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)-30 parts by mass-Solvent (methanol)・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 500 parts by mass ・ Solvent・ ・ ・ ・ 240 parts by mass

[Spiral cleaning member]
A foamed urethane (EP-70; manufactured by Inoac Corporation) sheet with a thickness of 3.5 mm is affixed with a double-sided tape with a thickness of 0.2 mm, the main body portion 107A is 6 mm wide and 243 mm long, and the holding portion A bifurcated elastic sheet 106 (see FIG. 5) having a width of 6 mm and a length of 12 mm was cut out by punching with a punching die.

  Next, the elastic sheet 106 is placed with the surface with the double-sided tape facing upward, and in this state, the release paper of the double-sided tape on the winding start side (the side not made into the forked shape) is peeled off, and the release paper is peeled off. One end of the metal shaft 104 (outer diameter φ4 mm, total length 230 mm, effective length of the elastic layer 107 is 220 mm) was placed on the double-sided tape so that the spiral angle θ was 25 °.

  Then, the shaft 104 is rotated while peeling the release paper of the double-sided tape, and the elastic sheet 106 (the body portion 107A of the elastic layer 107) is tensioned on the outer peripheral surface of the shaft 104 so that the total length is extended by about 0 to 5%. And finally, the tip end portion 108A of the pressing portion 108 is bonded to the winding end portion 107C of the elastic layer 107 from above, and is also bonded to the outer peripheral surface of the shaft 104. did.

  In this way, the spiral cleaning member 102 in which the front end portion 108A of the pressing portion 108 was oriented in the same direction as the winding start end portion 107B of the elastic layer 107 was produced. The rotational direction of the spiral cleaning member 102 is the forward direction (the direction in which the elastic cleaning layer 107 does not wind up with respect to the winding start end portion 107B of the elastic layer 107 and the tip end portion 108A, and the winding start end portion 107B and the pressing portion 108. The spiral cleaning member 102 was set in the cleaning device 100 so that the tip end portion 108 </ b> A was opposite to the direction in which the tip end portion 108 </ b> A was directed.

<Example 2>
[Spiral cleaning member]
A urethane foam (EP-70; manufactured by Inoac Corporation) sheet with a thickness of 3.5 mm is attached to one side of a double-sided tape with a thickness of 0.2 mm. The main body 107A has a width of 6 mm and a length of 243 mm. An elastic sheet 106 (see FIG. 7) having a substantially “<” shape with an end 107E having a width of 6 mm and a length of 12 mm was cut out by punching with a punching die.

  Next, the elastic sheet 106 is placed with the surface with the double-sided tape facing upward, and in this state, the release paper of the double-sided tape at the winding start end 107E is peeled off, and the metal is placed on the double-sided tape from which the release paper is peeled off. One end portion of the shaft 104 (outer diameter φ4 mm, total length 230 mm, effective length of the elastic layer 107 is 220 mm) was placed so that the spiral angle θ in the main body portion 107A excluding the winding start end portion 107E was 25 °.

  Then, the shaft 104 was rotated while peeling the release paper of the double-sided tape, and the winding start end portion 107E was first wound around the outer peripheral surface of the shaft 104. After completion of winding of the winding start end portion 107E, the elastic sheet 106 (the main body portion 107A of the elastic layer 107) is spirally applied to the outer peripheral surface of the shaft 104 so that the entire length of the elastic sheet extends about 0 to 5%. In addition, the pressing portion 109 as a part of the main body portion 107A was bonded onto the winding start end portion 107E so as to press the winding start end portion 107E from above.

  Thus, the spiral cleaning member 102 in which the winding start end portion 107E is prevented from protruding (not contacting the charging roll 14) by concealing the winding start end portion 107E with the pressing portion 109 of the main body portion 107A was produced. The rotational direction of the spiral cleaning member 102 is forward with respect to the winding end end portion 107C of the elastic layer 107 (a direction in which the spiral cleaning member 102 does not twist and is opposite to the direction in which the winding end end portion 107C faces). The spiral cleaning member 102 was set on the cleaning device 100.

<Example 3>
[Spiral cleaning member]
A urethane foam (EP-70; manufactured by Inoac Corporation) sheet with a thickness of 3.5 mm is attached to one side of a double-sided tape with a thickness of 0.2 mm. The main body 107A has a width of 6 mm and a length of 243 mm. A bifurcated elastic sheet 106 (see FIG. 9) having an end portion 107E having a width of 6 mm and a length of 12 mm and a pressing portion 108 having a width of 6 mm and a length of 12 mm is punched. Cut out by punching.

  Next, the elastic sheet 106 is placed with the surface with the double-sided tape facing upward, and in this state, the release paper of the double-sided tape at the winding start end 107E is peeled off, and the metal is placed on the double-sided tape from which the release paper is peeled off. One end portion of the shaft 104 (outer diameter φ4 mm, total length 230 mm, effective length of the elastic layer 107 is 220 mm) was placed so that the spiral angle θ in the main body portion 107A excluding the winding start end portion 107E was 25 °.

  Then, the shaft 104 was rotated while peeling the release paper of the double-sided tape, and the winding start end portion 107E was first wound around the outer peripheral surface of the shaft 104. After completion of winding of the winding start end portion 107E, the elastic sheet 106 (the main body portion 107A of the elastic layer 107) is spirally applied to the outer peripheral surface of the shaft 104 so that the entire length of the elastic sheet extends about 0 to 5%. In addition, the pressing portion 109 as a part of the main body portion 107A was bonded onto the winding start end portion 107E so as to press the winding start end portion 107E from above. Finally, the front end portion 108A of the pressing portion 108 is bonded to the outer peripheral surface of the shaft 104 while being bonded to the winding end portion 107C of the elastic layer 107 from above.

  Thus, by concealing the winding start end portion 107E with the pressing portion 109 of the main body portion 107A, the winding start end portion 107E is prevented from protruding (not contacting the charging roll 14), and the tip end portion 108A of the pressing portion 108 is A spiral cleaning member 102 facing the same direction as the winding start end portion 107B of the elastic layer 107 was produced. The rotational direction of the spiral cleaning member 102 is the forward direction with respect to the distal end portion 108A of the pressing portion 108 of the elastic layer 107 (the direction in which the spiral cleaning member 102 does not twist and the opposite direction to the direction in which the distal end portion 108A of the pressing portion 108 faces). The spiral cleaning member 102 was set on the cleaning device 100 so as to become.

<Comparative Example 1>
A foamed urethane (EP-70; manufactured by Inoac Corporation) sheet with a thickness of 3.5 mm is affixed with a double-sided tape, cut into a strip sheet with a width of 6 mm and a length of 243 mm, and an elastic sheet 206 ( FIG. 12B was manufactured. The elastic sheet 206 is wound around the metal shaft 204 (outer diameter φ4 mm, total length 230 mm) so that the spiral angle θ is 25 °, and the spiral cleaning member 202 (see FIG. 12A) according to the comparative example is manufactured. did.

  The rotational direction of the spiral cleaning member 202 is the forward direction (the direction in which the elastic layer 207 is wound) 207B, and the reverse direction (the direction is twisted) with respect to the winding end 207C. The spiral cleaning member 202 is set on the cleaning device 100 so that the direction of the cleaning device 100 becomes.

<Comparative Example 2>
In the spiral cleaning member 102 manufactured in Example 1, the rotation direction of the spiral cleaning member 102 is opposite to the winding start end portion 107B of the elastic layer 107 and the distal end portion 108A of the pressing portion 108 (the direction in which the spiral cleaning member 102 rolls). ) To be set in the cleaning device 100.

<Comparative Example 3>
The cleaning device for the spiral cleaning member 102 manufactured in Example 2 is set so that the rotation direction of the spiral cleaning member 102 is opposite to the winding end portion 107 </ b> C of the elastic layer 107. Set to 100.

<Evaluation>
DOCUPRINT C2110 which is a full-color copying machine: The charging roll 14 and the helical cleaning member 102 produced in Examples 1 to 3 or the helical cleaning member 202 produced in Comparative Example 1 were mounted on Fuji Xerox Co., Ltd. Then, a printing test for 100,000 sheets of A4 paper was performed. After completion, the presence or absence of peeling of the elastic sheets 106 and 206 of the spiral cleaning members 102 and 202 was visually determined.

<Evaluation results>
Table 1 shows the results of using the helical cleaning member 102 produced in Examples 1 to 3 and the helical cleaning member 202 produced in Comparative Example 1. From Table 1, it was found that the spiral cleaning member 102 in Examples 1 to 3 did not peel off, and had better peeling resistance than the spiral cleaning members 102 and 202 in Comparative Examples 1 to 3.

  In Table 1, the direction of rotation opposite to the direction in which the winding start ends 107B and 207B or the winding end ends 107C and 207C of the elastic layers 107 and 207 face (extend) is the “forward direction”. The direction of rotation in the same direction as the direction in which the start ends 107B and 207B or the winding end ends 107C and 207C face (extend) is the “reverse direction”.

  Further, the winding start end portion 107E in Examples 2 and 3 and Comparative Example 3 does not peel regardless of the rotation direction. Therefore, in Examples 2 and 3 and Comparative Example 3, the presence / absence of peeling is evaluated based on the difference in the rotation direction with respect to the winding end end portion 107C (tip portion 108A of the pressing portion 108).

  As described above, the spiral cleaning member 102 according to the present embodiment has been described based on the drawings and the examples. However, the spiral cleaning member 102 according to the present embodiment is limited to the illustrated ones and the examples. Various modifications, changes, and improvements are possible.

  For example, in the present embodiment, the mode in which the spiral cleaning member 102 is always in contact with the charging roll 14 and driven to rotate is described. However, the spiral cleaning member 102 is charged only when the charging roll 14 is cleaned. You may make it the aspect rotated by making it contact with the roll 14 and being driven. Further, the spiral cleaning member 102 may be rotationally driven to give a peripheral speed difference to the charging roll 14.

  In the image forming apparatus 10 according to the present embodiment, the process cartridge 18 including the photosensitive member 12, the charging device 50 (unit of the charging roll 14 and the cleaning device 100), the developing device 24, and the cleaning blade 26 is described. However, the process cartridge 18 includes a charging device 50, and other components selected from the photosensitive member 12, the exposure device 16, the transfer device 22, the developing device 24, and the cleaning blade 26 as necessary. Also good. Note that these devices and members may be arranged directly on the image forming apparatus 10 without being formed into a cartridge.

  Further, in the image forming apparatus 10 according to the present embodiment, the aspect in which the charging roll 14 is employed as the member to be cleaned has been described. It is done. Then, the unit of the object to be cleaned and the cleaning device 100 arranged in contact therewith may be directly arranged in the image forming apparatus 10 or may be formed into a cartridge like the process cartridge 18 to form the image forming apparatus 10. You may arrange in. Further, the image forming apparatus 10 according to the present embodiment is not limited to the above configuration, and may be, for example, an intermediate transfer type image forming apparatus.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Photoconductor (an example of an image holding body / charged body)
14 Charging roll (an example of charged / cleaned object)
16 Exposure device 18 Process cartridge (an example of an assembly)
24 Developing Device 50 Charging Device 100 Cleaning Device 102 Spiral Cleaning Member (Example of Cleaning Body)
104 Shaft (Example of shaft)
DESCRIPTION OF SYMBOLS 106 Elastic sheet 107 Elastic layer 107A Main body part 107B Winding start edge part 107C Winding end edge part 107D Protrusion part 107E Winding start edge part 108 Holding part 109 Holding part

Claims (6)

A rotating object to be cleaned;
A shaft portion whose outer shape is circular and rotatably supported, and is wound and fixed spirally from one end portion side to the other end portion side of the shaft portion, and a winding start end portion on the object to be cleaned, and An elastic layer that rotates while contacting and including the winding end end to clean the object to be cleaned, and the elastic layer that is formed integrally with the elastic layer and extends in the rotation direction of the shaft portion. A cleaning body comprising: a winding end end or a pressing portion that is superimposed on the winding start end and presses the winding end end or the winding start end; and
A cleaning device comprising:   The cleaning device according to claim 1, wherein the pressing portion that presses the winding end end portion extends from a main body portion of the elastic layer in a direction intersecting with an extending direction of the main body portion.   The winding start end is extended in a direction intersecting with the extending direction of the main body portion of the elastic layer, and the pressing portion that presses the winding start end is part of the main body portion of the elastic layer. The cleaning device according to claim 1, wherein the cleaning device is provided. The cleaning device according to any one of claims 1 to 3,
A charged body as the object to be cleaned that rotates;
A charging device comprising: The cleaning device according to any one of claims 1 to 3,
A charged body,
A charged body as the body to be cleaned that charges and rotates the body to be charged; and
Is assembled to the apparatus main body so as to be detachable integrally. The cleaning device according to any one of claims 1 to 3,
An image carrier capable of holding an image;
A charged body as the cleaning object that charges and rotates the image carrier;
An exposure device that exposes the image carrier charged by the charged body to form an electrostatic latent image;
A developing device for developing the electrostatic latent image formed on the image carrier by the exposure device;
An image forming apparatus comprising: