JP2007264146A - Photoreceptor, method for manufacturing photoreceptor, developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoreceptor in which a layered film including a photosensitive layer does not peel even when intense mechanical pressure is applied to the surface, and to provide a method for manufacturing the photoreceptor. <P>SOLUTION: The uppermost layer film is applied so as to cover a cross section of a lower layer film which is exposed by removing an end portion, so that the cross section of the lower layer film is covered. Thereby, the uppermost layer film protects the cross section of the lower layer film. Even when intense mechanical pressure is applied to the surface, the uppermost layer film protects the end cross section of the lower layer film and prevents the layered film of the photoreceptor from peeling. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photosensitive member having a laminated film including a photosensitive layer, and relates to a developing device including the photosensitive member and an image forming apparatus including the developing device.

  When manufacturing a photosensitive drum, it is common to immerse the support of the photosensitive drum in a coating solution to form a coating layer. In this case, since the support of the photosensitive drum is immersed in the coating solution up to the end, a coating layer is formed on the entire support surface. When the photosensitive drum is pulled up from the coating solution, the film at the lower end of the coating layer is formed thick, so it is necessary to remove the lower end of the coating layer with a wiping tape.

  However, if the lower end of the coating layer is simply removed, burrs are generated on the removed cross section. This burr was rubbed and peeled off by a cleaning blade or the like, causing image defects. In order to prevent the occurrence of burrs, the end surface of the photosensitive drum is in contact with the surface perpendicular to the longitudinal direction of the photosensitive drum so that the running direction of the wiping tape impregnated with the solvent has an inclination angle greater than 0 degrees. The coating layer was wiped off (see, for example, Patent Document 1).

JP 2003-98696 A

  However, in the above-mentioned method, since the edge part of this coating-film layer is removed with a wiping tape, the edge part cross section of the coating-film layer which has a laminated structure will be exposed.

  Since a large mechanical pressure is generated in the end section of the coating layer due to frictional contact between the surface of the photosensitive drum and the cleaning blade, the photosensitive layer is peeled off by exposing the end of the coating layer. It has become a big problem to occur. Furthermore, in recent years, the mechanical pressure applied to the edge of the photosensitive layer has been further increased due to the increase in the speed and life of the image forming apparatus, and there is an urgent need to prevent peeling of the photosensitive layer.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a photoconductor and a method for producing the photoconductor, in which the photosensitive layer does not peel even when a large mechanical pressure is applied to the surface.

  The photoreceptor of the present invention comprises a cross-section of a conductive support, a lower layer film having an end portion removed after coating on the conductive support, and a cross section of the lower layer film exposed by removing the end portion. And an uppermost layer film formed so as to be covered.

  According to the photoreceptor of the present invention, the uppermost layer film is applied so as to cover the section of the lower layer film exposed by removing the end portion, thereby covering the section of the lower layer film. Thereby, the uppermost layer film can protect the cross section of the lower layer film. Therefore, even if a large mechanical pressure is applied to the surface, the photosensitive member does not peel off.

  The method for producing a photoconductor of the present invention is a method for producing a photoconductor comprising a conductive support, a lower layer film formed on the conductive support, and an uppermost layer film formed on the lower layer film. A step of applying the lower layer film on the conductive support, a step of drying the applied lower layer film, a step of wiping off an end portion of the dried lower layer film, and removing the end portion; The method includes a step of applying the uppermost layer film so as to cover a cross section of the lower layer film exposed by removing the end portion, and a step of drying the applied uppermost layer film.

  According to the method for producing a photoreceptor of the present invention, a lower layer film is applied and formed, and an end portion of the lower layer film is removed to expose a cross section of the lower layer film, and then the uppermost layer film is applied. Thereby, the cross section of the lower layer film is covered with the uppermost layer film. Thereby, the uppermost layer film can protect the cross section of the lower layer film. Therefore, by this method, it is possible to produce a photoreceptor that does not peel off the photosensitive layer even when a large mechanical pressure is applied to the surface.

  The developing device of the present invention includes the above-described photosensitive member, a charging unit that charges the photosensitive member to a predetermined potential, and a developing unit that supplies a developer to the photosensitive member. Therefore, even if a large mechanical pressure is applied to the surface of the photoreceptor provided in the developing device, the photosensitive layer does not peel off. Therefore, it is possible to provide a developing device that can obtain a high-quality image over a long period of time.

  Furthermore, the image forming apparatus of the present invention includes the above-described developing device, an exposure unit that exposes the surface of the photoconductor to form an electrostatic image based on image information, and the electrostatic latent image generated by the developing unit. The image forming apparatus includes a transfer unit that transfers a developer image formed by development onto a medium, and a fixing unit that fixes the transferred developer image on the medium. The photosensitive layer of the developing device described above does not peel off the photosensitive layer even when a large mechanical pressure is applied to the surface. Therefore, it is possible to provide an image forming apparatus that can obtain a high-quality image over a long period of time.

  The present invention covers the cross section of the lower layer film by applying the uppermost layer film so as to cover the cross section of the lower layer film exposed by removing the end portion. Thereby, the uppermost layer film can protect the cross section of the lower layer film. Therefore, even when a large mechanical pressure is applied to the surface, the uppermost layer film protects the end cross section of the lower layer film, and the photoreceptor is not peeled off.

  The present invention will be described below with reference to the drawings.

  The image forming apparatus of the present invention uses a developing device and a transfer device provided with a photosensitive member (hereinafter simply referred to as “photosensitive drum”) as an electrostatic latent image carrier, and transfers the transferred developer image. Is fixed on a sheet using a fixing device and discharged to a predetermined stacker. At this time, the photosensitive drum provided in the developing device has a structure to be described later, and is a photosensitive drum that prevents a decrease in durability due to thinning.

  First, the configuration of the image forming apparatus 1 and the operation during printing will be described in detail.

  As shown in FIG. 1, the image forming apparatus 1 includes a developing device 10 that develops a developer image based on image information, a paper feeding mechanism 11 that feeds paper P to the developing device 10, and a paper feeding mechanism 11 that has been fed out. A transfer device 12 that transports the paper P along a predetermined paper transport path, a transfer device 13 as a transfer unit that transfers the developer image onto the paper P, and a transfer device 13 that transfers the paper P onto the paper P. A fixing device 14 as a fixing unit for fixing the developed developer image on the paper P, a discharge mechanism 15 for discharging the paper P on which the developer image has been fixed in the fixing device 14 to the outside of the image forming apparatus 1, and development described later. The surface of the photosensitive drum 20 of the apparatus 10 is constituted by an exposure device 16 as an exposure unit that exposes a latent image based on image information.

  The paper feed mechanism 11 includes a paper feed stacker 11a on which the paper P is deposited, a paper feed stage 11c formed on the paper feed stacker 11a, which moves the paper P upward by biasing from the spring 11b, and a paper feed stage 11c. And a paper feed roller 11d that feeds the paper P moved upward one by one into the image forming apparatus 1 one by one.

  In such a paper feed mechanism 11, when a user deposits paper P on the paper feed stacker 11 a and image information is transmitted from the information processing apparatus to the image forming apparatus 1, a paper feed stage by a print control unit (not shown). 11c is moved upward. The sheet P comes into contact with the sheet feed roller 11d as the sheet feed stage 11c moves upward, and the sheet P is fed into the image forming apparatus 1 as the sheet feed roller 11d rotates. The paper P fed out into the image forming apparatus 1 is transported to the developing device 10 by the transport device 12 on a predetermined transport path.

  The developing device 10 is detachably formed from the image forming apparatus 1 and is a member that develops a latent image based on image information transmitted from a host device such as an information processing device. Further, the developing device 10 is integrally formed by a cartridge case 10a having a hollow inside, and inside the cartridge case 10a, a photosensitive drum 20 on the surface of which a latent image based on image information is exposed, and A charging roller 10b as a charging unit for applying a predetermined bias voltage to the photosensitive drum 20, a cleaning blade 10c for removing the developer remaining on the surface of the photosensitive drum 20, and a latent image on the surface of the photosensitive drum 20 A developing roller 10d for developing a developer image, a supply roller 10e as a supply unit for supplying the developer to the developing roller 10d, a developer cartridge 10f for storing the developer supplied to the cartridge case 10a, and a developing roller 10d The developing blade 10g for uniformizing the developer adhering to the surface and removed by the developing blade 10g The developer and conveying device 10h for conveying to the developer cartridge 10f that, a stirring member 10i for stirring the cartridge case 10a inside the developer is formed.

  In such a developing device 10, when image information is transmitted from the information processing device, the image information is converted into a signal of a predetermined format by a print control unit (not shown) and supplied to the exposure device 16. The exposure device 16 is configured by arranging a plurality of light emitting elements such as LEDs (Light Emitting Diodes), for example, and the light emitting element 1 emits light based on a signal supplied from a print control unit (not shown). The latent image for the line is exposed, and these operations are performed in synchronization with the rotation of the photosensitive drum 20. At this time, a bias voltage is applied to the surface of the photosensitive drum 20 by the charging roller 10b, and the bias voltage at a portion exposed by the exposure device 16 is neutralized as will be described in detail later. Thereafter, the exposed portion comes into contact with the developing roller 10d, so that the developer adheres to the exposed portion, and the developer image based on the image information is developed on the surface of the photosensitive drum 20. . Thereafter, the developing device 10 transfers the developer image developed on the surface of the photosensitive drum 20 onto the paper P by nipping and conveying the paper P together with the transfer device 13 to which the surface is applied by a voltage power source (not shown). The sheet P on which the developer image is transferred to the surface is further transported to the fixing device 14 by the transport device 12.

  The fixing device 14 is a member that fixes the developer image attached on the paper P onto the paper P using heat. The fixing device 14 includes a fixing roller 14a having a heat source (not shown) therein, and a pressure roller 14b that sandwiches and conveys the paper P together with the fixing roller 14a. When the paper P is transported to such a fixing device 14, the paper P is nipped and transported by a fixing roller 14a and a pressure roller 14b previously heated by a heat source (not shown), and the heat of the fixing roller 14a and the fixing roller 14a are heated. The developer on the paper P is dissolved and fixed by the pressure with the pressure roller 14b. Thereafter, the paper P having the developer fixed on the surface thereof is conveyed to the discharge mechanism 15 and discharged to the outside of the image forming apparatus 1 by the discharge mechanism 15 to be provided to the user.

  Next, the structure of the photosensitive drum 20 will be described in detail.

  The photosensitive drum 20 is detachable with respect to the developing device 10, and as shown in FIG. 2, the photosensitive drum 20 is a member that rotates about a shaft 202 whose both ends are rotatably supported by the cartridge case 10a. Specifically, the photosensitive drum 20 includes a drum body 201 in which a material described later is formed in a cylindrical shape, a metal shaft 202 made of a conductor, a flange 203 that closes one end of the drum body 201, and a drum body. A support member 204 that closes the other end of 201, a gear 205 that drives the shaft 202, a drive gear 206 that transmits a driving force to the gear 205, and a fixed that transmits a driving force from a driving source (not shown) to the driving gear 206. The shaft 207 includes a collar 208 disposed between the flange 203 and the cartridge case 10a. Further, such a photosensitive drum 20 is mounted on a frame 209 for mounting the developing device 10 when the developing device 10 is mounted inside the image forming apparatus 1. The frame 209 has long holes 210a and 210b. When the developing device 10 is mounted on the frame 209, both ends of the shaft 202 are locked to the long holes 210a and 210b.

  The shaft 202 is a member that serves as a rotating shaft of the photosensitive drum 20, and is formed so as to be detachable from the developing device 10 together with the photosensitive drum 20. Further, the shaft 202 is inserted through a hole formed at the center of the gear 205 and fixed. Further, the vicinity of one end of the shaft 202 is inserted into a bearing hole 211b formed in the cartridge case 10a, and further accommodated inside the elongated hole 210b. On the other hand, the vicinity of the other end of the shaft 202 is inserted into a bearing hole 211a formed in the cartridge case 10a, and further accommodated in the elongated hole 210a. Further, the other end of the shaft 202 is in contact with a spring member 212 fixed to the cartridge case 10a.

  The flange 203 is a member press-fitted in the vicinity of one end of the drum body 201, and is fixed to the inside of the drum body 201 using a non-conductive adhesive. A shaft 202 is inserted in the vicinity of the center of the flange 203, and the flange 203 is attached to the shaft 202 so as to be rotatable. As the material of the flange 203, for example, synthetic resin such as polyamide, polycarbonate, ABS (acrylonitrile butyrene styrene) resin, polyacetal, etc. is used, and conductive powder such as metal powder, carbon black, graphite or the like is blended in these materials. By doing so, the flange 203 is made conductive.

  The support member 204 is a member that is press-fitted in the vicinity of the other end of the drum body 201, and is rotatably attached to the shaft 202 and is fixed to the inside of the drum body 201 like the flange 203. A gear 205 is fixed to the surface of the support member 204 exposed to the outside of the drum body 201. Such a support member 204 is a member that rotates the entire photosensitive drum 20 by rotating in synchronization with the gear 205. Specifically, when the gear 205 rotates around the shaft 202, the support member 204 rotates in synchronization with the gear 205, and when the support member 204 further rotates, the drum body 201 rotates.

  As shown in FIG. 3, the gear 205 and the drive gear 206 are formed by so-called helical gears, and the torsion angles of the teeth are set in opposite directions. The gear 205 and the drive gear 206 rotate in the direction of arrow A in FIG. 3 with the fixed shaft 207 as the axis, and thus the gear 205 rotates in the direction of arrow B with the shaft 202 as the axis. As the gear 205 rotates in the direction of arrow B, the other end of the shaft 202 is urged in a direction to press against the spring member 212. Since the shaft 202 presses the spring member 212, the contact between the other end of the shaft 202 and the spring member 212 is improved.

  The collar 208 is a conductive member disposed between the flange 203 and the cartridge case 10a. The collar 208 is formed in a substantially cylindrical shape, and the shaft 202 is inserted into the collar 208 so that the collar 208 can rotate with respect to the shaft 202 and can slide in the axial direction of the shaft 202.

  The frame 209 is a member that supports the shaft 202, and a spring member 212 is fixed to the outside of the frame 209 by pins 213. The spring member 212 is connected to the ground and has a biasing force in the inner direction. When the cartridge case 10a is not mounted, the spring member 212 is positioned slightly inward from the position shown in FIG. 2, but the upper end of the spring member 212 is inclined outward to mount the cartridge case 10a from above. Is possible. In the mounted state, the spring member 212 is in pressure contact with the shaft 202.

  The drum body 201 is a member whose surface is exposed to an electrostatic image by the exposure device 16, and as shown in FIG. 4, a conductive support 50 serving as a base of other members, an undercoat layer 51, and a charge generation layer. 72 and the charge transport layer 73.

  As shown in FIG. 4A, the conductive support 50 is a cylindrical member having a length l of 30 cm to 100 cm and an outer diameter r of 1.5 cm to 20 cm, and various conventionally known ones can be used. . For example, metallic materials such as aluminum, brass, and stainless steel, polyethylene terephthalate, polybutylene terephthalate, polymer materials such as polypropylene, nylon, polystyrene, and phenol resin, and other materials such as hard paper are used in a cylindrical shape. can do.

  When an insulating material such as a polymer material is used for the conductive support 50, a conductive treatment is performed. Examples of the conductive treatment include methods such as impregnation with a conductive substance, lamination of metal foils, and metal deposition.

  On the conductive support 50, an undercoat layer 51 for preventing halation is formed as shown in FIG. 4B (enlarged cross-sectional view of the region A in FIG. 4A). The thickness of the undercoat layer 51 is preferably 0.5 μm to 1.0 μm. If the undercoat layer 51 becomes too thick, the charge generated in the charge generation layer 72 does not flow to the conductive support 50. When the thickness is 2 μm or more, the residual potential of the photoconductor after exposure becomes high, and the characteristics when the photoconductor is repeatedly used become unstable.

  An inorganic layer or an organic layer can be applied to the undercoat layer 51. Examples of the inorganic layer include an aluminum anodic oxide coating, aluminum oxide, and aluminum hydroxide. Examples of the organic layer include polyamide, copolymer nylon, polyvinyl alcohol, polyurethane, polyester, epoxy, phenol resin, casein, cellulose, gelatin and the like, and particularly alcohol-soluble copolymer nylon is often used. And when applying an organic layer, these are disperse | distributed to water and various organic solvents. Examples of the various organic solvents include, for example, a single solvent of alcohols such as methanol, ethanol and butanol, a mixed solvent of water and alcohols, a mixed solvent of two or more alcohols, acetone, dioxolane and the like and alcohols. Examples thereof include mixed solvents, mixed solvents of chlorinated solvents such as dichloroethane, chloroform and trichloroethane and alcohols.

  The charge generation layer 72 is formed on the undercoat layer 51. The charge generation layer 72 includes a charge generation material and a binder resin as main components. As the charge transport material used for the charge generation layer 72, various organic pigments and dyes can be used. Among them, metals such as metal-free phthalocyanine, copper indium chloride, gallium chloride, tin, oxytitanium, zinc, or vanadium, Alternatively, it is preferable to use an azo pigment such as an oxide or chloride coordinated phthalocyanine, monoazo, bisazo, trisazo, or polyazo. In addition, the charge generation layer 72 may be formed from fine particles of these substances such as polyester resin, polyvinyl acetate, polyacrylate ester, polymethacrylate ester, polyester, polycarbonate, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin, epoxy. You may use with the dispersion layer of the form bind | concluded with various binder resin, such as resin, urethane resin, a cellulose ester, or a cellulose ether. The use ratio in this case is used in the range of 30 to 500 parts by weight with respect to 100 parts by weight of the binder resin, and the film thickness is preferably 0.1 μm to 2 μm. This is due to the following reason. When the film thickness is smaller than 0.1 μm, it is difficult to form a stable film, and the chargeability tends to vary. On the other hand, when the film thickness is larger than 2 μm, the charge potential fluctuates due to the charge left in the charge generation layer 72, so-called residual charge, and the sensitivity to exposure is reduced. Specifically, for example, when considering the case where the photosensitive drum 20 is negatively charged, electrons generated in the charge generation layer 72 move toward the conductive support 50, but are generated in the charge generation layer 72. Electrons tend to remain in the charge generation layer 72 when the mobility is low. As a result, a decrease in sensitivity of the photosensitive drum 20 occurs. The charge generation layer 72 may contain various additives such as a leveling agent, an antioxidant, and a sensitizer for improving the coating property as necessary. The charge generation layer may be a vapor deposition film of the charge generation material.

  The charge transport layer 73 is formed on the charge generation layer 72. The charge transport layer 73 includes a charge transport material and a binder resin as main components. Examples of the charge transport material used for the charge transport layer 73 include heterocyclic compounds such as carbazole, indole, imidazole, oxazole, pyrazole, oxadiazole, pyrazoline, and thiadiazole, aniline derivatives, hydrazone compounds, and aromatic amines. It is preferable to use an electron donating substance such as a derivative, a stilbene derivative, or a polymer having a main chain or a side chain of a group composed of these compounds.

  Further, as the binder resin used for the charge transport layer 73, for example, a vinyl polymer such as polycarbonate, polymethyl methacrylate, polystyrene, or polyvinyl chloride, or polyester, polyester carbonate, polysulfone, polyimide, phenoxy, epoxy, silicone resin. Or a copolymer thereof is preferably used. Further, partially crosslinked cured products or the like may be used alone or as a mixture, and it is particularly preferable to use polycarbonate. This is because polycarbonate has good compatibility with the charge transporting material, so that good electrical characteristics as a photoreceptor can be obtained. Furthermore, because polycarbonate is resistant to mechanical stress, the wear resistance of the charge transport layer 73 can be improved. The charge transport layer 73 may contain various additives such as an antioxidant and a sensitizer as necessary. Furthermore, the film thickness of the charge transport layer 73 is, for example, 5 μm to 30 μm.

  In the present invention, an example in which a stacked photosensitive layer in which the charge transport layer 73 is stacked on the charge generation layer 72 is applied as the photosensitive layer on the conductive support 50 will be described. However, the present invention is not limited to this. For example, a reverse two-layer type photosensitive layer in which a charge generation layer is laminated on a charge transport layer, or a dispersion type photosensitive layer in which a charge generation material is dispersed in a layer containing a charge transport material and a binder resin. Good.

  Each layer is formed by sequentially applying a coating solution obtained by dispersing or dissolving a substance contained in each layer on a conductive support 50. The cylindrical conductive support 50 can be coated with the coating liquid 66 by the coating apparatus shown in FIG. The coating apparatus includes a coating tank 61, a coating liquid tank 62, and a coating circulation mechanism. The coating tank 61 is filled with a coating liquid 66. And the electroconductive support body 50 is immersed in the application tank 61 by the support body raising / lowering apparatus which is not shown in figure, and the electroconductive support body 50 is pulled up from the application tank 61. FIG. The coating liquid tank 62 temporarily stores the coating liquid 66 overflowing from the coating tank 61. The coating circulation mechanism includes an overflow piping system 67 that connects the coating tank 61 and the coating liquid tank 62 and sends the coating liquid 66 overflowing from the coating tank 61 to the coating liquid tank 62, and a circulation pump 63. And a supply piping system 68 for feeding the coating liquid 66 to the coating tank 61.

  First, the conductive support 50 is vertically lowered and immersed in the coating tank 61 in which the liquid level of the coating liquid 66 is kept constant by overflow. Next, the conductive support 50 is pulled up vertically. At that time, by controlling the lowering and rising speed of the conductive support 50 to be, for example, 20 mm / s or less, vibration of the coating liquid surface around the conductive support 50 is prevented, and a coating defect ( Flow unevenness) can be prevented.

  This coating apparatus is provided with a number corresponding to the type of layer formed on the conductive support 50 in order to manufacture the photosensitive drum 20. In order to form the laminated photosensitive layer described here on the conductive support 50, three kinds of coating apparatuses for forming the undercoat layer 51, for forming the charge generation layer 72, and for forming the charge transport layer 73 are provided. Each coating solution 66 is applied to the conductive support 50 by each coating apparatus.

  The conductive support 50 coated with the coating liquid is mounted on a pallet of a transport line and sent to the drying process. The drying in this drying step can be performed by a conventionally known method. For example, a temperature rising drying method or a natural drying method can be mentioned.

  The temperature rising drying method uses an air convection drying device (hot air drying device) to raise the temperature of the conductive support 50 coated with the coating liquid to a predetermined temperature and dry the coating liquid. It is. In this temperature rising drying method, the so-called bubble defect can be prevented from occurring by controlling the temperature rising rate to be, for example, 3 to 10 ° C./ms.

  The natural drying method is a method in which the conductive support 50 coated with the coating liquid is statically dried in a space sealed with a cover and then naturally dried. In this natural drying method, the concentration of solvent vapor in the sealed space is controlled to be, for example, 50 to 60% of the saturated concentration, thereby adjusting the drying speed and preventing the occurrence of uneven thickness. can do.

  Hereinafter, the production of the photosensitive drum 20 will be described in detail with reference to FIGS. First, as shown in FIG. 7A, the undercoat layer 51 is formed on the conductive support 50. In step 1, the coating liquid for forming the undercoat layer 51 is applied to the conductive support 50 using the above-described coating apparatus. The conductive support 50 coated with the coating solution is held by a chuck device (not shown), transferred to a pallet on a transport line, and sent to a drying process. In step 2, the outer peripheral surface of the conductive support 50 is dried. Thereby, the undercoat layer 51 is formed on the conductive support 50.

  After the undercoat layer 51 is formed on the conductive support 50, the charge generation layer 72 is formed on the conductive support 50 as shown in FIG. 7B. In step 3, as in the case of the undercoat layer 51, a coating solution for forming the charge generation layer 72 is applied to the conductive support 50. The conductive support 50 coated with the coating solution is held by a chuck device (not shown), transferred to a pallet on a transport line, and sent to a drying process. In step 4, the outer peripheral surface of the conductive support 50 is dried. As a result, the charge generation layer 72 is formed on the undercoat layer 51.

  After the charge generation layer 72 is formed on the conductive support 50, the wiping tape is brought into contact with the end portions of the undercoat layer 51 and the charge generation layer 72 by a known technique. By removing the film at the end of the layer 72 and removing the end as shown in FIG. 7C, the cross section is exposed to the undercoat layer 51 and the charge generation layer 72. As the material of the wiping tape, it is preferable to use a non-woven fabric made of synthetic resin fibers, in which at least the fibers of the surface portion are heat-welded. Examples of the fibers constituting the nonwoven fabric include polyamides such as nylon-6 and nylon-6, 6, polyesters, isotactic polypropylene, and polyethylene. Nylon is particularly preferable. Further, in order to weld non-woven fibers, a non-contact heating means such as a so-called oven equipped with a hot stove or a heater is used. In this heating means, it heats at the temperature which melt | dissolves only the surface, without melt | dissolving the whole each fiber which comprises a nonwoven fabric. The temperature at which only the surface of each fiber is melted differs depending on the thickness of the fiber and the processing time, but for example, a temperature that is about 10 ° C. higher than the melting temperature of the fiber. Further, when removing the film at the end by wiping, the width for removing the film may be in a range that does not cover the print area effective in the image forming apparatus using the photosensitive drum 20.

  After film removal of the end portions of the undercoat layer 51 and the charge generation layer 72 is performed, a charge transport layer 73 is formed on the conductive support 50 as shown in FIG. 7D. In step 6, as in the case of the undercoat layer 51, a coating solution for forming the charge transport layer 73 is applied to the conductive support 50. The conductive support 50 coated with the coating solution is held by a chuck device (not shown), transferred to a pallet on a transport line, and sent to a drying process. In step 7, the outer peripheral surface of the conductive support 50 is dried. As a result, a charge transport layer 73 covering the exposed cross section of the charge generation layer 72 and the undercoat layer 51 is formed on the conductive support 50.

  After the charge transport layer 73 is formed on the conductive support 50, the film removal at the end of the charge transport layer 73 is performed in Step 8 in the same manner as the film removal at the end of the undercoat layer 51 and the charge generation layer 72. Then, the charge transport layer 73 from which the end portion is removed as shown in FIG. 7E is formed. At this time, when removing the film of the end portion by wiping, the width for removing the film may be in a range where the end cross sections of the undercoat layer 51 and the charge generation layer 72 are not exposed. As shown in FIG. 7E, the charge transport layer 73 which is the uppermost layer film covers the end cross sections of the undercoat layer 51 and the charge generation layer 72 which are lower layer films. Therefore, since the cross sections of the undercoat layer 51 and the charge generation layer 72 are not exposed, peeling of the laminated film does not occur.

  As described above, the drum body 201 in which the undercoat layer 51, the charge generation layer 72, and the charge transport layer 73 are laminated on the conductive support 50 has the flange described above near one end of the cylindrical conductive support 50. 203 is press-fitted, and a gear 205 is fixed in the vicinity of the other end of the conductive support 50 to manufacture the photosensitive drum 20. The manufactured photosensitive drum 20 is provided in the developing device 10 as described above. The developing device 10 including the photosensitive drum 20 is included in the image forming apparatus 1.

  As described above, according to the present invention, when the photosensitive layer of the photosensitive drum 20 is formed, after forming the undercoat layer 51 and the charge generation layer 72 as lower layers, the edges of the undercoat layer 51 and the charge generation layer 72 are formed. The charge transport layer 73 to be the uppermost layer film is formed by removing the portion. Therefore, the cross section of the laminated film of the undercoat layer 51 and the charge generation layer 72 is not exposed and is covered with the uppermost charge transport layer 73. Therefore, even if a large mechanical pressure is applied to the surface of the photosensitive drum 20, the photosensitive layer does not peel off. Therefore, the developing device and the image forming apparatus can obtain a high-quality image over a long period of time.

  The present invention is not limited to the above. For example, an overcoat layer may be formed on the charge transport layer of the photosensitive drum described above. Hereinafter, an example in which this overcoat layer is the uppermost layer film will be described with reference to FIGS.

  On the charge transport layer 73, an overcoat layer 74 for protecting the photosensitive layer worn by the cleaning blade 10c is formed. The overcoat layer 74 has a thickness of, for example, 5 to 10 μm. This is due to the following reason. The surface of the charge transport layer 73 formed under the overcoat layer 74 is usually scraped by repeating the printing operation, and the film thickness gradually decreases. The amount of film reduction is about 5 to 10 μm when the photosensitive drum 20 is used for a lifetime (for example, about 20,000 sheets of A4 size printing with a photosensitive drum having a diameter of 30 mm). The charge transport layer 73 can be formed thick in advance in consideration of the amount of film reduction. However, when the charge transport layer 73 is thick, the sensitivity to exposure is reduced. Therefore, an overcoat layer 74 is formed on the charge transport layer 73 to prevent the charge transport layer 73 from being reduced while ensuring the sensitivity of the charge transport layer 73 to exposure. For this reason, the thickness of the overcoat layer 74 may be substantially the same as the film reduction amount of the charge transport layer 73 when the photoconductor drum 20 is used for the lifetime. Further, when the overcoat layer 74 is made of a material that is more excellent in wear resistance than the charge transport layer 73, the thickness of the overcoat layer 74 is smaller than the amount of film reduction of the charge transport layer 73. There may be.

  For this overcoat layer 74, conventionally known materials can be used, for example, fluorinated polymer, siloxane polymer, fluorosilicone polymer, silane, polyethylene, polypropylene, polyurethane, polycarbonate, polyester, acrylated polyurethane, acrylated epoxy resin. Or a combination thereof may be mentioned.

  Further, instead of the overcoat layer 74, a film in which the amount of the charge transport material of the charge transport layer 73 is reduced may be formed. At this time, the amount is not limited as long as the amount of the charge transport material is smaller than the amount of the charge transport material contained in the charge transport layer 73. By forming a film with a reduced amount of charge transport material as the uppermost layer, printing durability is improved. In the present invention, a film with a reduced amount of the charge transport material is also included in the overcoat layer.

  The photosensitive drum 20 on which the overcoat layer 74 is formed can be manufactured as follows. First, in the same manner as described above, in Step 1 and Step 2, the undercoat layer 51 is formed on the conductive support 50 as shown in FIG. 9A. Thereby, the undercoat layer 51 is formed on the conductive support 50.

  After the undercoat layer 51 is formed on the conductive support 50, the charge generation layer 72 is formed on the conductive support 50 in step 3 and step 4 as shown in FIG. As a result, the charge generation layer 72 is formed on the undercoat layer 51.

  After the charge generation layer 72 is formed on the conductive support 50, the charge transport layer 73 is formed on the conductive support 50 as shown in FIG. 9C. In step 5, as with the undercoat layer 51, a coating solution for forming the charge transport layer 73 is applied to the conductive support 50. The conductive support 50 coated with the coating solution is held by a chuck device (not shown), transferred to a pallet on a transport line, and sent to a drying process. In step 6, the outer peripheral surface of the conductive support 50 is dried. Thereby, the charge transport layer 73 is formed on the charge generation layer 72.

  After the charge transport layer 73 is formed on the conductive support 50, the wiping tape is brought into contact with the undercoat layer 51, the charge generation layer 72, and the end of the charge transport layer 73. The end portions of the generation layer 72 and the charge transport layer 73 are removed, and the end portions as shown in FIG. 9D are removed, so that the cross section is exposed to the undercoat layer 51, the charge generation layer 72, and the charge transport layer 73. . When removing the film at the end by wiping, the width for removing the film may be in a range that does not cover the print area effective in the image forming apparatus using the photosensitive drum 20.

  After the end portions of the undercoat layer 51, the charge generation layer 72, and the charge transport layer 73 are removed, an overcoat layer 74 is formed on the conductive support 50 as shown in FIG. 9E. In step 8, as with the undercoat layer 51, a coating solution for forming the overcoat layer 74 is applied to the conductive support 50. The conductive support 50 coated with the coating solution is held by a chuck device (not shown), transferred to a pallet on a transport line, and sent to a drying process. In step 9, the outer peripheral surface of the conductive support 50 is dried. As a result, an overcoat layer 74 that covers the exposed cross section of the charge transport layer 73, the charge generation layer 72, and the undercoat layer 51 is formed on the conductive support 50.

  After the overcoat layer 74 is formed on the conductive support 50, the end of the overcoat layer 74 is removed in Step 10 in the same manner as the film removal at the ends of the undercoat layer 51, the charge generation layer 72 and the charge transport layer 73. Part of the film is removed to form an overcoat layer 74 from which the end part is removed as shown in FIG. 9F. At this time, when removing the film at the end by wiping, the width for removing the film may be within a range in which the end cross sections of the undercoat layer 51, the charge generation layer 72, and the charge transport layer 73 are not exposed. As shown in FIG. 9F, the overcoat layer 74 that is the uppermost layer film covers the end cross sections of the undercoat layer 51 that is the lower layer film, the charge generation layer 72, and the charge transport layer 73. Therefore, since the cross section of the undercoat layer 51, the charge generation layer 72, and the charge transport layer 73 is not exposed, peeling of the laminated film does not occur.

  As described above, the drum body 201 in which the undercoat layer 51, the charge generation layer 72, the charge transport layer 73, and the overcoat layer 74 are laminated on the conductive support 50 has one end of the cylindrical conductive support 50. The flange 203 described above is press-fitted in the vicinity, and the gear 205 is fixed in the vicinity of the other end of the conductive support 50 to manufacture the photosensitive drum 20. The manufactured photosensitive drum 20 is provided in the developing device 10 as described above. The developing device 10 including the photosensitive drum 20 is included in the image forming apparatus 1.

  As described above, the present invention covers the cross section of the laminated film of the undercoat layer 51, the charge generation layer 72, and the charge transport layer 73 with the overcoat layer 74, which is the uppermost layer film. Even if pressure is applied, peeling of the photosensitive layer does not occur. Furthermore, since the overcoat layer 74 is used as the uppermost layer film, the photosensitive drum 20 is excellent in wear resistance. Such a photosensitive drum 20 having excellent wear resistance can be used for a long time even if it is downsized or thinned. Therefore, the developing device and the image forming apparatus can obtain a high-quality image over a long period of time.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus of the present invention. It is principal part sectional drawing of the image development apparatus of this invention. FIG. 3 is a perspective view of a gear fixed to an end portion of the photoconductor of the present invention. It is a figure which shows the shape of the photoreceptor of this invention. It is the A section expanded sectional view of Drawing 4A. It is sectional drawing which shows the structure of the coating device of the coating liquid used by manufacture of the photoreceptor of this invention. It is a flowchart of the manufacturing method of the photoreceptor of this invention. In the manufacturing method of this invention, it is sectional drawing of the photoreceptor in which the undercoat layer was formed. In the manufacturing method of this invention, it is sectional drawing of the photoreceptor in which the electric charge generation layer was formed. In the manufacturing method of this invention, it is sectional drawing of the photoreceptor which wiped off the edge part of the undercoat layer and the electric charge generation layer. In the manufacturing method of this invention, it is sectional drawing of the photoreceptor in which the charge transport layer was formed. In the manufacturing method of this invention, it is sectional drawing of the photoreceptor which wiped off the edge part of an electric charge transport layer. It is a flowchart of the manufacturing method of the photoreceptor of another example of this invention. In the manufacturing method of another example of this invention, it is sectional drawing of the photoreceptor in which the undercoat layer was formed. FIG. 6 is a cross-sectional view of a photoreceptor having a charge generation layer formed in another manufacturing method of the present invention. In the manufacturing method of another example of this invention, it is sectional drawing of the photoreceptor in which the charge transport layer was formed. In the manufacturing method of another example of this invention, it is sectional drawing of the photoreceptor which wiped off the edge part of the undercoat layer, the electric charge generation layer, and the electric charge transport layer. In the manufacturing method of another example of this invention, it is sectional drawing of the photoreceptor in which the overcoat layer was formed. In the manufacturing method of another example of this invention, it is sectional drawing of the photoreceptor which wiped off the edge part of the overcoat layer.

Explanation of symbols

50 conductive support 51 undercoat layer 72 charge generation layer 73 charge transport layer 74 overcoat layer

Claims (8)

On a conductive support;
An underlayer film from which an end portion is removed after being coated on the conductive support;
And a top layer film formed by coating so as to cover a cross section of the lower layer film exposed by removing the end portion. The lower layer film includes a charge generation layer,
The photoreceptor according to claim 1, wherein the uppermost layer film is a charge transport layer. The lower layer film includes a charge generation layer and a charge transport layer,
The photoreceptor according to claim 1, wherein the uppermost layer film is an overcoat layer protecting the lower layer film. A method for producing a photoreceptor comprising a conductive support, a lower layer film formed on the conductive support, and an uppermost layer film formed on the lower layer film,
Applying the lower layer film on the conductive support;
Drying the applied underlayer film,
Wiping off the edge of the dried underlayer film, removing the edge;
Applying the uppermost layer film so as to cover a cross section of the lower layer film exposed by removing the end part;
And a step of drying the coated uppermost layer film. The lower layer film includes a charge generation layer,
5. The method for producing a photoreceptor according to claim 4, wherein the uppermost layer film is a charge transport layer. The lower layer film includes a charge generation layer and a charge transport layer,
5. The method of manufacturing a photoreceptor according to claim 4, wherein the uppermost layer film is an overcoat layer that protects the lower layer film. A photoconductor according to any one of claims 1 to 3,
A charging unit for charging the photosensitive member to a predetermined potential;
A developing device comprising: a developing unit that supplies a developer to the photosensitive member. A developing device according to claim 7;
An exposure unit that exposes the surface of the photoreceptor based on image information to form an electrostatic image;
A transfer unit that transfers a developer image formed by developing the electrostatic latent image to the medium by the developing unit;
An image forming apparatus comprising: a fixing unit that fixes the transferred developer image on the medium.