JP4704122B2 - Bearing member for image forming apparatus and bearing unit for image forming apparatus - Google Patents

Description

  The present invention supports, for example, a roll-shaped rotating body provided in an image forming apparatus such as a copying machine (digital PPC, color PPC, etc.), a printer (color LBP, color LED, etc.), and has an inner circumference serving as a bearing surface. The present invention relates to a bearing member having a surface formed of an electroformed part.

  In the image forming apparatus, a member involved in an image (electrophotography) formation process, for example, a photosensitive drum that forms an electrostatic latent image on its outer peripheral surface by exposure, or a developer is attached to the photosensitive drum by electric action. A number of rolls such as a roller (developing roller) of a developing device that develops such an electrostatic latent image, a transfer roller for transferring the developed image onto the output paper, and a fixing roller for fixing the transferred image onto the output paper A rotating body is equipped.

These roll-shaped rotating bodies are rotatably supported by a bearing member mounted on a fixed member. As this type of bearing member, for example, a rolling bearing such as a ball bearing is known (see, for example, Patent Document 1 and Patent Document 2).
JP-A-8-123194 JP 2001-254733 A

  By the way, in recent years, a quadruple tandem system in which four photosensitive drums are arranged side by side is frequently used in an image forming unit such as a color printer or a color copying machine. The quadruple tandem method is different from the conventional single light source method (a method in which each color is developed with four developing devices on one photosensitive drum), and each color is developed on each of the four photosensitive drums. Since the paper flow line is also short, there is an advantage that high-speed output is possible.

  On the other hand, the quadruple tandem system tends to increase in size and complexity mechanically due to an increase in the number of drums. Therefore, when the quadruple tandem system is adopted while maintaining the size of the conventional image forming apparatus, a bearing is used. Further miniaturization of each component including the member is required.

  In recent years, demands for cost reduction along with downsizing have increased, and in response to this demand, the bearing member is also required to reduce costs, but a rolling bearing is usually composed of a plurality of parts, In addition, since high processing accuracy is required for each, further cost reduction is difficult. In addition, if the rolling bearing is made smaller than the current size, the cost may be increased, which is not appropriate.

  For example, instead of the rolling bearing, a sliding bearing made of resin or sintered metal can be considered as a material aimed at reducing the material cost. However, these bearings inevitably have a relatively large gap (so-called radial bearing gap) between the outer peripheral surface of the rotating body to be supported due to problems in processing accuracy. In this case, the shaft runout increases, and in the worst case, play occurs between the rotating body and the rotating body satisfies the required performance that the rotating body should have, such as high-precision development on a photosensitive drum. You may not be able to. In addition, resin bearings have problems with wear characteristics (compatibility and wear resistance) with rotating bodies, and sintered metal bearings are impregnated with lubricating oil and the like. There is a risk of oil splashing outside, and a seal structure is essential.

  SUMMARY OF THE INVENTION An object of the present invention is to improve the image quality of an image by reducing shaft runout while reducing the size and cost of a bearing member for this type of image forming apparatus.

In order to solve the above-mentioned problems, the present invention provides an electrophotographic method in which a developer is attached to a photosensitive member on which an electrostatic latent image is formed, and the developed image is transferred to the surface of the output member and fixed. The roll-shaped rotating body involved in the forming process is supported by the electroformed part formed by electroforming as an insert part and is molded with a conductive resin , and the inner peripheral surface of the electroformed part Provides a bearing member for an image forming apparatus , which is formed by a deposition start surface on a master surface during electroforming, and a bearing surface for supporting a roll-shaped rotating body is formed by this deposition start surface. .

  As described above, the first feature of the present invention is that the bearing surface of the bearing member for supporting the roll-shaped rotating body is configured by the inner peripheral surface of the electroformed part. Electroforming is a technique for forming a metal layer by electrodeposition (electrolytic deposition) of metal ions on the master surface. Due to the characteristics of electroforming, the surface shape of the master is on the order of microns on the inner surface of the electroformed part. Is transferred with high accuracy. Therefore, if the surface accuracy of the master is increased and the inner peripheral surface of the electroformed part is used as a bearing surface, a bearing surface having high surface accuracy can be obtained at a low cost without any special post-processing. Therefore, the inner diameter dimension of the bearing member (bearing surface) can be set in advance so that the clearance (bearing clearance) between the outer periphery of the roll-shaped rotating body is reduced, thereby reducing shaft runout. Electrophotography can be formed with high accuracy.

  The second feature of the present invention is that the bearing member for an image forming apparatus is formed by molding using an electroformed part as an insert part. According to such a configuration, the thickness of the electroformed part serving as the insert part can be made as thin as possible as long as the inner peripheral surface can function as a bearing surface. Therefore, other mold parts excluding the electroformed part (molding) The overall size of the bearing device can be reduced as compared with the conventional product by adjusting the size of the part. At the same time, the remaining part of the bearing member excluding the electroformed part is formed by molding, so that the degree of freedom of shape can be easily increased. In addition, by integrally molding the electroformed part as an insert part, a conventional bearing member made up of two or more members can be substantially composed of one member, improving assembly accuracy or simplifying the assembly process. Can be realized.

  In addition, electronic devices such as copiers and printers are usually provided with standards for the generation of electromagnetic noise in consideration of the effects on peripheral devices and the human body. For example, electrical conductivity is required. In response to this type of request, if the bearing surface is configured by the inner peripheral surface of the electroformed part as in the present invention, leakage of the noise to the periphery can be suppressed as much as possible by the electroformed part. Accordingly, it is possible to cope with the required characteristics for this type of image forming apparatus.

  The bearing member is preferably a resin molded product, and the resin is conductive. According to such a configuration, since all the portions (most part) of the bearing member excluding the electroformed part can be formed of resin, the material cost of the bearing member can be significantly reduced. Further, by using a resin having conductivity, leakage of the electromagnetic noise can be surely prevented, which can contribute to further improvement of the reliability of the image forming apparatus. The “resin having conductivity” as used herein is not limited to the resin itself having conductivity, for example, conductive fillers such as metal particles and carbon particles (or fibers), surfactants, electrolytes, and the like. The compound (conductive resin composition) which mix | blended this compound with resin which does not have electroconductivity is also included.

  It is preferable that the diameter gap between the bearing surface constituted by the inner peripheral surface of the electroformed part and the outer peripheral surface of the roll-shaped rotating body facing this is 10 μm or less. If it is the electroforming processing which concerns on this invention, the inner peripheral surface of the electroformed part used as a bearing surface can be finished with high precision so that the said diameter clearance may be 10 micrometers or less, and a diameter clearance is set to the said range. By doing so, it is possible to make it difficult for a developer such as toner to be used for development to enter the gap in the diameter. Therefore, it is possible to minimize the wear of the bearing surface due to the toner and the like entering the gap, and to stably exhibit the bearing performance over a long period of time. Further, by reducing the diameter gap as described above, the seal member that is required in the conventional product becomes unnecessary. Therefore, it is possible to save parts and reduce costs by the amount of the sealing member.

  The bearing member having the above configuration can be suitably used as a bearing member for a photosensitive drum, for example, when the roll-shaped rotating body is a photosensitive drum that forms an electrostatic latent image on the outer peripheral surface as it rotates.

  Further, the bearing member having the above-described configuration can be suitably used as a bearing member for the developing roller, for example, when the roll-shaped rotating body is a developing roller that attaches the developer to the photosensitive member as it rotates.

  Further, the bearing member having the above configuration is, for example, for the fixing roller or the pressure roller when the roll-shaped rotating body is a fixing roller or a pressure roller for fixing the developed image on the surface of the output body with the rotation. It can be suitably used as a bearing member.

  The image forming apparatus bearing member described above can be suitably used as an image forming apparatus bearing unit including the bearing member.

  As described above, according to the present invention, it is possible to improve the image quality of the image by reducing the axial shake while reducing the size and cost of the bearing member for the image forming apparatus.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 conceptually shows a laser exposure type quadruple tandem image forming unit 20. The image forming unit 20 is used by being incorporated in an image forming apparatus such as a color printer, for example, and a plurality (four) of photosensitive drums 21, a plurality of developing devices 24 arranged around each photosensitive drum 21, A first transfer electrode 29, a second transfer electrode 31, and a fixing unit 32 that are disposed on the downstream side of the developing device 24 are mainly provided.

  Hereafter, the arrangement | positioning aspect of each component shown in FIG. 1 is explained in full detail. The four photosensitive drums 21 are arranged in parallel along the longitudinal direction of the endless belt-shaped intermediate transfer body 30. Around each photosensitive drum 21, a charging electrode 22 for charging the outer peripheral surface of the photosensitive drum 21 is provided, and on the downstream side in the rotation direction of the charging electrode 22, a plurality of single color signals obtained by color separation of input image information. An exposure device 23 for forming an electrostatic latent image by exposing each photosensitive drum 21 with a laser beam for each color is provided. Further, on the downstream side in the rotation direction of the exposure device 23, a developing device 24 that performs development with the developer (toner) of each color is arranged, and on the downstream side, a first transfer electrode 29 is arranged.

  When an electronic image is input by an image input means (not shown), the outer peripheral surface of the photosensitive drum 21 rotating in the direction of the arrow is charged to a constant voltage by the charging electrode 22. Next, each photosensitive drum 21 is irradiated with laser light of each color {yellow (Y), magenta (M), cyan (C), black (BK)} obtained by color separation of the input image from the exposure device 23, and electrostatic for each color. A latent image is formed on the surface of the photosensitive drum 21. A visible image (developed image) is formed by attaching each color toner having a charge of opposite polarity to the electrostatic latent image by the developing roller 25 of the developing device 24. Each visible image is sequentially transferred to the intermediate transfer member 30 by charging of the first transfer electrode 29, and further transferred from the intermediate transfer member 30 to output paper (a portion indicated by a broken line in FIG. 1) by charging of the second transfer electrode 31. Is done. Thereafter, the output paper released from the electrostatic adsorption state with the intermediate transfer member 30 by a separation electrode (not shown) is sent to the fixing unit 32, and the toner image is fixed on the paper surface by heating and pressurization by the fixing roller 33 and the pressure roller 34. To do. An electrophotographic image is formed through the above process.

  Hereinafter, the case where the bearing member (for the image forming apparatus) according to the present invention is used for rotating and supporting the photosensitive drum 21 and the developing roller 25 of the developing device 24 will be described. FIG. 2 is a cross-sectional view of the developing device 24. An elastic roller 26 and a developing roller 25 adjacent to the elastic roller 26 are disposed on the opening side of a storage portion 27 that stores toner as a developer. The Although not shown, the developing roller 25 is disposed close to the photosensitive drum 21 with a predetermined gap between the developing roller 25 and the photosensitive drum 21.

  In the developing device 24 configured as described above, the toner is supplied to the outer peripheral surface of the adjacent developing roller 25 by rotating the elastic roller 26 having the toner adhered to the outer peripheral surface while rotating the rotor blade 28 in the housing portion 27. To do. The developing roller 25 supplied with toner by the elastic roller 26 is rotated, and an electric action is generated between the developing roller 25 and the photosensitive drum 21 facing each other at a predetermined interval, whereby a toner layer having a constant thickness adheres to the photosensitive drum 21. It is formed.

  FIG. 3 is a cross-sectional view including shafts of the bearing units 1 and 11 that rotatably support the photosensitive drum 21 and the developing roller 25. In the drawing, shafts 21 a and 25 a extending from one end of the photosensitive drum 21 and the developing roller 25 are inserted into the inner circumferences of the bearing members 2 and 12 attached to the fixed member 35. And the bearing units 1 and 11 are comprised by the bearing members 2 and 12 and the shafts 21a and 25a rotatably supported by these bearing members 2 and 12, respectively.

  The bearing member 2 includes an electroformed part 4 and a resin part 3 obtained by molding the electroformed part 4 as an insert part, and is manufactured through the following steps, for example. In addition, although the manufacturing process of the bearing member 2 is described below, the bearing member 12 is manufactured through the same process.

  The bearing member 2 includes a step of masking the outer surface of the master shaft 5 used in electroforming with an insulating material, a step of electroforming the masked master shaft 5 to form the electroformed portion 4, The cast member 4 and the master shaft 5 are used as insert parts, and the bearing member 2 is molded through a process of molding (insert molding) and a process of separating the electroformed part 4 and the master shaft 5 in this order.

  The master shaft 5 serving as a molding base of the electroformed part 4 is formed of, for example, stainless steel in a perfect circular cross-sectional shape and a uniform diameter in the axial direction. The material of the master shaft 5 can be arbitrarily selected from metals and non-metals as long as it has a masking property, conductivity, and chemical resistance, such as a chromium alloy or a nickel alloy, in addition to stainless steel. It is.

  The master shaft 5 may be a solid shaft in which a hollow shaft or a hollow portion is filled with resin in addition to the peeled shaft (solid shaft). Moreover, since the outer peripheral surface accuracy of the master shaft 5 directly affects the surface accuracy of the inner peripheral surface 4a of the electroformed part 4 serving as a bearing surface, it is desirable that the accuracy be finished as high as possible.

  As shown in FIG. 4, masking is performed on the outer surface of the master shaft 5 except for a region where the electroformed part 4 is to be formed. As the covering material for forming the masking portion 6, a material having insulating properties and corrosion resistance against the electrolyte solution is selectively used.

  In the electroforming process, the master shaft 5 is immersed in an electrolyte solution containing metal ions such as Ni and Cu, and the target metal is removed from the outer surface of the master shaft 5 except for the masking portion 6 by energizing the electrolyte solution. This is performed by electrolytic deposition on the exposed area of the outer peripheral surface 5a. The electrolyte solution can contain a sliding material such as PTFE or carbon, or a stress relaxation material such as saccharin, if necessary. In this embodiment, PTFE particles are used as a sliding material in an electrolyte solution. The kind of the deposited metal is appropriately selected according to required properties such as hardness required for the bearing surface of the bearing or resistance to lubricating oil (oil resistance).

  Through the above steps, as shown in FIG. 5, an electroformed shaft 7 in which a cylindrical electroformed portion 4 is formed in a region other than the masking portion 6 on the outer periphery of the master shaft 5 is manufactured. In this case, the above-mentioned PTFE particles are dispersed in the electroformed part 4 formed by precipitation, and a part thereof is present on the inner peripheral surface 4a serving as a bearing surface. If the thickness of the electroformed part 4 is too thin, it leads to a decrease in the durability of the bearing surface (inner peripheral surface 4a), and if it is too thick, the peelability from the master shaft 5 may be reduced. Is set to an optimum thickness, for example, in the range of 5 μm to 200 μm, according to the bearing performance and the bearing size to be used, and the application.

  The electroformed shaft 7 manufactured through the above steps is supplied and arranged as an insert part in a mold for insert-molding the bearing member 2.

  FIG. 6 conceptually shows an insert molding process of the bearing member 2, and a runner 10 a, a dotted gate 10 b, and a cavity 10 are provided in a mold including the fixed mold 8 and the movable mold 9. As shown in the figure, the dotted gates 10b are formed at positions corresponding to one end surface in the axial direction of the resin portion 3 of the molding die, and are formed at a plurality of positions at equal intervals in the circumferential direction. The gate area of each dotted gate 10b is set to an appropriate value according to the viscosity of the molten resin to be filled and the shape of the molded product. In addition to the dotted gate 10b shown in FIG. 6, the gate shape is provided in a state of being annularly connected to a position corresponding to the outer peripheral edge of the one end surface in the axial direction of the resin portion 3 in addition to the dotted gate 10b shown in FIG. It is also possible to adopt a so-called film gate.

  In the mold having the above configuration, the movable mold 9 is brought close to the fixed mold 8 and clamped while the electroformed shaft 7 is positioned. Next, in a state where the mold is clamped, the molten resin P is injected and filled into the cavity 10 through the spool (not shown), the runner 10a, and the dotted gate 10b, and the resin portion 3 is connected to the electroformed shaft 7. Molded in one piece.

  Examples of the resin material include crystalline resins such as liquid crystal polymer (LCP), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyacetal (POM), polyamide (PA), or polyphenylsulfone (PPSU). Amorphous resins such as polyethersulfone (PES), polyetherimide (PEI), and polyamideimide (PAI) can be used as the base resin. In addition, from the viewpoint of preventing leakage of electromagnetic noise as described above, it is possible to use a resin in which a conductive filler typified by carbon fiber, SUS powder or the like is blended. Of course, these are merely examples, and a resin material suitable for the application and use environment of the bearing can be arbitrarily selected. For example, it is also possible to use a conductive resin composition in which a conductive filler such as metal or carbon (regardless of shape) or a compound such as a surfactant or an electrolyte is mixed with the above resin for the purpose of improving conductivity. it can. Alternatively, it is also possible to use a material obtained by blending a reinforcing material (also in any shape) with the above resin for the purpose of improving the strength and dimensional stability of the resin portion 3.

  After the mold opening, the molded product in which the master shaft 5, the electroformed part 4, and the resin part 3 are integrated is removed from the molds 8 and 9. This molded product is separated into a bearing member 2 (see FIG. 3) composed of the electroformed portion 4 and the resin portion 3 and the master shaft 5 in a subsequent separation step.

  In the separation step, for example, an impact is applied to the master shaft 5 or the electroformed part 4, thereby peeling the inner peripheral surface 4 a of the electroformed part 4 from the outer peripheral surface 5 a of the master shaft 5. Thereby, the master shaft 5 is pulled out from the bearing member 2 (electroformed part 4), and the bearing member 2 as a finished product is obtained.

  As the separating means for the electroformed part 4, in addition to the above means, for example, a method in which the electroformed part 4 and the master shaft 5 are heated (or cooled), and a difference in thermal expansion is generated between them, or A means using both means (impact and heating) in combination can be used.

  The bearing member 2 formed as described above is fixed to the fixed-side member 35 shown in FIG. 3, and a shaft 21 a separate from the extracted master shaft 5 is inserted into the inner periphery of the fixed bearing member 2. Thus, the bearing unit 1 shown in FIG. 3 is completed. Further, the shaft 25a is inserted into the inner periphery of the bearing member 12 formed in the same manner, whereby the bearing unit 11 shown in FIG. 3 is completed.

  Thus, the electroformed part 4 constituting the bearing member 2 is formed by electrodeposition (electrolytic deposition) of metal ions in the electrolyte solution on the outer peripheral surface 5 a of the master shaft 5. The inner peripheral surface 4a is a surface to which the shape of the outer peripheral surface 5a of the master shaft 5 is transferred with high accuracy on the order of microns due to the characteristics of electroforming. For this reason, if the master shaft 5 having improved surface accuracy of the outer peripheral surface 5a to be a deposit surface of the electroformed metal is used, the inner peripheral surface 4a having high surface accuracy is obtained without performing post-processing particularly for increasing the surface accuracy. Can be obtained at low cost. For the same reason, the inner peripheral surface 14a of the electroformed part 14 in the bearing member 12 can be formed with high accuracy and low cost. Therefore, if such inner peripheral surfaces 4a and 14a are used as the bearing surfaces of the bearing members 2 and 12, respectively, the inner diameter surface (radial bearing clearance) between the outer peripheral surfaces of the shafts 21a and 25a is minimized. The diameter of the peripheral surfaces (bearing surfaces) 4a and 14a can be set. As a result, the shaft runout during use can be reduced and the distance between the photosensitive drum 21 and the developing roller 25 adjacent to the photosensitive drum 21 can be kept constant, and the development on the photosensitive drum 21 by the developing roller 25 can be performed with high accuracy. It can be carried out.

  Further, as described above, the high precision finishing of the inner peripheral surfaces 4a and 14a of the electroformed parts 4 and 14 which become the bearing surfaces is possible, so that a gap (radial bearing gap) between the shafts 21a and 25a is provided. It can be made as small as possible. Therefore, the toner (developer) attached to the developing roller 25 and the photosensitive drum 21 can be prevented from entering the radial bearing gap as much as possible, and wear inside the bearing can be minimized. Specifically, since the toner diameter is 3 to 10 μm, the inner diameter dimension of the electroformed part 4 is set so that the radial bearing gap is 10 μm or less in terms of the diameter gap, so that the toner can be more reliably invaded. Can be deterred.

  In this embodiment, since the electrolyte solution containing PTFE particles is used for the electroforming of the electroformed part 4, PTFE particles are formed on the inner peripheral surface 4 a of the electroformed part 4 as a finished product. It becomes a distributed state. Therefore, it is possible to improve the friction characteristics with respect to the shaft 21a and the wear resistance characteristics, and it is possible to suppress degradation of image quality associated with the aging of the image forming apparatus as much as possible.

  Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment and can be applied to other forms.

  In the bearing member 2 according to the present invention, most of the outer diameter side excluding the electroformed part 4 is formed of a resin or metal mold part. For example, the fixed-side member 35 shown in FIG. It is also possible to integrally mold with the same material as the mold part (resin part 3 in the figure). In this case, for example, although not illustrated, the resin members 3 and 13 and the fixed member 35 are integrally formed of resin with the electroformed portions 4 and 14 as insert parts, so that the bearing members 2 and 12 and the fixed side are formed. Since the formation of the member 35 and the assembly of the bearing members 2 and 12 and the fixed member 35 can be performed in a single process, the work process can be simplified. Further, the bearing members 2 and 12 and the fixed member 35 are integrally formed by the same method, so that the inner peripheral surfaces 4a and 14a of the electroformed portions 4 and 14 that become the bearing surfaces of the shafts 21a and 25a are formed. The relative position of can be set with higher accuracy. Accordingly, it is possible to more appropriately manage the facing distance between the photosensitive drum 21 and the developing roller 25 that are rotatably supported by the bearing members 2 and 12.

  Further, in the above embodiment, the bearing surface is formed by the perfectly circular inner peripheral surface 4a of the electroformed portion 4, and a radial bearing gap having a constant diameter is formed across the entire axial length between the shaft 21a. Although a so-called perfect circle bearing has been described, other forms are possible.

  For the purpose of improving moment proof stress and reducing loss torque, for example, although not shown, a plurality of axially spaced bearing surfaces are formed on the inner peripheral surface 4a of the electroformed portion 4, and the space between these bearing surfaces And an intermediate clearance portion having a larger inner diameter than the bearing surface.

  Further, as a bearing other than the perfect circle bearing, for example, although not shown, a fluid dynamic pressure action is generated in a bearing gap between the inner peripheral surface 4a of the electroformed portion 4 and the outer peripheral surface of the shaft 21a facing the same. Therefore, a so-called dynamic pressure bearing provided with a dynamic pressure generating portion can be configured. Of course, in such a case, the fluid inside the bearing (lubricating oil or the like) is prevented from leaking out of the bearing, for example, the fluid is held inside at the axial end of the electroformed part 4 constituting the radial bearing gap. It is preferable to form a sealing space.

  Specifically, a so-called step bearing in which a plurality of axial grooves are formed on either the inner peripheral surface 4a or the outer peripheral surface of the shaft 21a can be configured.

  Alternatively, a wedge-shaped diameter is provided between the radially outer surface and a plurality of circular arc surfaces arranged continuously in the circumferential direction on either the inner circumferential surface 4a or the outer circumferential surface of the shaft 21a. A so-called multi-arc bearing in which a directional gap (bearing gap) is formed can be configured.

  Alternatively, a dynamic pressure bearing in which a plurality of inclined grooves (so-called dynamic pressure grooves) are arranged in a herringbone shape on either the inner peripheral surface 4a or the outer peripheral surface of the shaft 21a can be configured.

  In the above description, the case where the present invention is applied to the photosensitive drum 21 and the bearing for the developing roller 25 is exemplified. However, the present invention is not limited to this, and other rolls involved in the electrophotographic forming process. It is also widely used in bearings that are mounted on a rotating member such as an elastic roller 26 that supplies toner to the developing roller 25, and a fixing roller 33 and a pressure roller 34 that fix the toner on the output paper. Can be applied.

  Although not shown in the figure, instead of the transfer electrodes 29 and 31, for example, a transfer roller provided with a voltage applying means can be used. In this case as well, as in the above embodiment, the transfer roller It is possible to apply the bearing member 2 having the electroformed part 4 as a bearing.

It is sectional drawing which shows notionally the image formation part which concerns on a 4-unit tandem system. It is an expanded sectional view of a developing device. It is sectional drawing of the bearing member provided with the electroformed part. It is a perspective view of the master axis | shaft which formed the nonelectroconductive masking part. It is a perspective view of the electroformed shaft in which the electroformed part was formed. It is a figure which shows notionally the injection molding process of the resin part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 Bearing unit 2, 12 Bearing member 3, 13 Resin part 4, 14 Electroformed part 4a, 14a Inner peripheral surface 5 Master shaft 6 Masking part 7 Electroformed shaft 10 Cavity 20 Image forming part 21 Photosensitive drum 21a Shaft 22 Charging Electrode 23 Exposure device 24 Developing device 25 Developing roller 25a Shaft 26 Elastic roller 29 First transfer electrode 30 Intermediate transfer member 31 Second transfer electrode 33 Fixing roller 34 Pressure roller 35 Fixed side member

Claims (6)

A roll-shaped rotating body involved in the electrophotographic forming process is obtained by attaching a developer to a photoreceptor on which an electrostatic latent image has been formed, transferring the developed image to the surface of the output body, and fixing it to obtain an electrophotographic image. A bearing member for an image forming apparatus to be supported,
An electroformed part formed by electroforming is used as an insert part and is molded with conductive resin , and the inner peripheral surface of the electroformed part is formed by a deposition start surface on the master surface during electroforming. A bearing member for an image forming apparatus, characterized in that a bearing surface for supporting a roll-shaped rotating body on a deposition start surface is formed.   The bearing member for an image forming apparatus according to claim 1, wherein a diameter gap between a bearing surface constituted by an inner peripheral surface of the electroformed part and an outer peripheral surface of the roll-shaped rotating body opposed to the bearing surface is 10 μm or less.   The bearing member for an image forming apparatus according to claim 1, wherein the roll-shaped rotator is a photosensitive drum that forms an electrostatic latent image on the outer peripheral surface with rotation.   The bearing member for an image forming apparatus according to claim 1, wherein the roll-shaped rotating body is a developing roller that adheres a developer to the photosensitive member with rotation.   The bearing member for an image forming apparatus according to claim 1, wherein the roll-shaped rotating body is a fixing roller or a pressure roller for fixing the developed image on the surface of the output body with rotation. The image forming apparatus bearing unit with an image forming apparatus bearing member according to any one of claims 1-5.

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