JP2005338586A - Process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and a process cartridge in which "gathering" and scattering of a developer in a noncontact developing means are suppressed and high-quality developer images are obtained over a prolonged period of time because of no memory, with respect to an image forming apparatus and a process cartridge in which an electrostatic latent image formed on an image carrier is elicited by applying an alternating voltage to a developer carrier. <P>SOLUTION: In the image forming apparatus having a holding means to maintain an image carrier and a developer carrier in a noncontact state, wherein a plate-like member is interposed between the image carrier and the developer carrier so that one end of the plate-like member is disposed in a substantial developing region in such a way that the front edge of the plate-like member is kept in contact with the image carrier but the plate-like member does not come in contact with a developer sticking to a developer carrier surface in the developing region, the image carrier and the plate-like member are configured such that a coefficient of friction between these becomes ≤0.5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that uses an electrostatic recording system or an electrophotographic recording system, such as a laser printer, a copying machine, and a facsimile machine, and a process cartridge used in the image forming apparatus.

  FIG. 14 shows a basic configuration of a general image forming apparatus that has been conventionally used. FIG. 14 shows a monochromatic image forming apparatus that includes an image carrier, a developing device for non-contact development of an electrostatic latent image on the image carrier, a cleaning device, and the like, and forms an image on a recording material. It is a schematic diagram which shows an example.

  Here, as the image carrier, a photosensitive drum 101 formed in a cylindrical shape is used, and includes a charging roller 102 as a contact charging member that uniformly charges the image carrier 101 and a one-component developer T, A non-contact developing device (developing device) 103 which is a developing device for non-contact developing the electrostatic latent image formed on the photosensitive drum 101 is provided.

  The photosensitive drum 101 is a so-called organic photoreceptor in which a charge generation layer is formed on a core metal (not shown) made of aluminum or the like, and a charge transport layer is formed thereon.

  An oscillation voltage (alternating voltage) in which an AC voltage and a DC voltage are superimposed is applied to a core metal of the charging roller 102 via a sliding electrode (not illustrated) brought into contact with the core metal from a power source (not illustrated) provided in the image forming apparatus main body. Voltage) is applied.

  Further, the developing device 103 is in contact with the photosensitive drum 101, and a developing roller 103a which is a developer carrying member that performs development while rotating in the direction of arrow A in FIG. The rotation of the roller 103a and the direction of the arrow B in FIG. 14, which is the counter direction, supply roller 103b as developer supplying means for supplying the developer T to the developing roller 103a, and application of the developer T on the developing roller 103a A developing blade 103c as a regulating member as a developer regulating means for regulating the amount (layer thickness) and the charge amount, a stirring member 103d for supplying the developer T to the supply roller 103b and stirring the developer T, etc. It has. The space in the frame constituting the developing device 103 is used as a developer accommodating portion 103e for containing the developer T. The gap d formed by the photosensitive drum 101 and the developing roller 103a is kept constant by the regulation roller 103f. That is, the developing operation performed in the image forming apparatus employs a non-contact developing method.

  In the image forming process, the photosensitive drum 101 rotates in the direction of the arrow C in FIG. 14 which is the rotation direction and the forward direction of the developing roller 103a. obtain.

  Next, in the latent image forming step, the charged surface of the photosensitive drum 101 is subjected to scanning exposure by a laser scanner 105 which is an exposure unit (exposure light source) to form an electrostatic latent image of target image information. The

  In the developing process, when the electrostatic latent image carried on the photosensitive drum 101 reaches a portion facing the developing roller 103a carrying the developer T, an AC voltage is applied to the developing roller 103a from a power source (not shown). By applying an oscillating voltage superimposed with a DC voltage and forming an alternating electric field between the photosensitive drum 101 and the developing roller 103a, the developer T flies over the electrostatic latent image formed on the surface of the photosensitive drum 101.・ Transition and development are performed, and the electrostatic latent image becomes a developer image.

  The developer image formed on the photosensitive drum 101 is transferred to the recording material P by the transfer unit 106 provided in the image forming apparatus main body by the rotation of the photosensitive drum 101 (transfer process), and the recording material P is transferred to the fixing unit 107. Then, the developer image is fixed (fixing step), and the fixed image is completed on the recording material P.

  On the other hand, the developer T remaining on the photosensitive drum 101 at the time of transfer is scraped off by the cleaning blade 108 before passing through the charging roller 102 again, and is accumulated in the waste developer container 109 (cleaning step).

  Further, as shown in FIG. 15, each image for performing an image forming process (process) in the image forming apparatus shown in FIG. 14 for the purpose of facilitating maintenance such as developer replenishment and photosensitive drum replacement. A process cartridge 110 in which a forming unit (photosensitive drum 101, charging roller 102, developing roller 103a, developer accommodating portion 103e, etc.) is integrated as a component has been put into practical use.

  In the conventional image forming apparatus as described above, when the developing process is performed, a lot of developer gathers at the rear end of the developer image, and the density of the part is developed deeper than other parts. There was a “rush” that appeared in the formed image as it was. As a conventional technique for solving this problem, there has been proposed a conductive plate-like electrode member provided between a photosensitive drum 101 as an image carrier and a developing roller 103a as a developer carrier. (For example, refer to Patent Document 1).

  On the other hand, there has also been proposed a means for improving the above-mentioned “collapse” by setting the developing voltage applied to the developer carrying member to a predetermined condition (see, for example, Patent Document 2).

  Further, a means for inserting a plate-like member between the image carrier and the developer carrier and maintaining a gap between the two members has been proposed (for example, see Patent Document 3).

  However, in the image forming apparatus that visualizes the electrostatic latent image formed on the photosensitive drum 101 by non-contact development as described in the prior art, an AC voltage and a DC voltage are superimposed on the developing roller 103a. Since the oscillating voltage is applied, so-called developer scattering, in which the developer T acting on the development flies outside the development region, is likely to occur.

  In particular, the developer T that has jumped out of the development area in the gap between the developing roller 103 a and the photosensitive drum 101 is rotated by the air flow generated by the rotation of the developing roller 103 a and the photosensitive drum 101. It is carried downstream in the direction (in this case, since they are mutually rotating in the forward direction, the same direction in the facing portion). Accordingly, in the developer accommodating portion 103e, the structure of the image forming apparatus main body located near or below the developing device jaw 103g provided below the developing roller 103a is likely to be contaminated. The developer T that has not been used for development and did not fly out of the development area is collected by the developer carrier 103a and used for the next development.

  When the developer scattering described above deteriorates, the scanning exposure of the laser scanner 105 is hindered and the output image is adversely affected.

  Further, in the image forming apparatus that non-contact develops the electrostatic latent image formed on the photosensitive drum 101 by applying the vibration voltage in which the AC voltage and the DC voltage are superimposed on the developing roller 103a as described above, An image defect called “pumping” occurs.

  It is thought that “pagination” occurs by the mechanism described below.

  FIG. 16 is a schematic diagram showing lines of electric force H formed in a gap between the developing roller 103 a to which an oscillating voltage in which an AC voltage and a DC voltage are superimposed is applied and the photosensitive drum 101. The region where the electric lines of force H act substantially corresponds to the region acting on the development of the electrostatic latent image on the photosensitive drum 101, that is, the development region α.

  As shown in FIG. 16, at the central portion (a) of the gap between the developing roller 103a and the photosensitive drum 101, that is, at the portion where both members of the developing roller 103a and the photosensitive drum 101 are closest, the electric force line H is substantially linear. It is formed in a shape.

  On the other hand, at both sides of (a), that is, at portions (b) and (c) where the distance between the developing roller 103a and the photosensitive drum 101 is large, the electric lines of force H are formed in a curved shape.

  When the electrostatic latent image Rb exists on the surface of the photosensitive drum 101 facing the developing roller 103a to which such an electric action is applied, as shown in FIG. 17, in the gap between the developing roller 103a and the photosensitive drum 101. The developer T moves by the acting force of the electric field formed at the upstream end (b) in the rotation direction of the developing roller 103a and the photosensitive drum 101.

  The state of the moved developer T will be described with reference to FIG. The developer T has a vector velocity V1 in the tangential direction at a point a1 on the curved electric force line H1 formed at the upstream end (b) in the rotation direction of the developing roller 103a and the photosensitive drum 101, and further Move to point a2 on the outer curve H2.

  Subsequently, when the developer T reaches the point a2, the vector speed V2 is given to the developer T in the tangential direction of the electric force line H2 at the point a2. Then, the developer T temporarily flies from the point a2 in the direction of these combined vectors (V1 + V2).

  That is, at the upstream end (b) in the rotation direction of the developing roller 103a and the photosensitive drum 101, the developer T carried on the developing roller 103a is between the photosensitive drum 101 and the developing roller 103a as shown in FIG. The reciprocating motion along the electric force line H is repeated like the flight trajectory Q1 gradually going outward.

  Then, as shown in FIG. 19, the non-image portion Ra (surface potential is set to −600 V) where the electrostatic latent image on the photosensitive drum 101 is not formed, and the electrostatic latent image Rb (surface surface) continuously formed on the upstream side. When the boundary portion Rc with respect to the potential of −100 V reaches the upstream end (b) in the rotation direction of the developing roller 103a and the photosensitive drum 101 formed in a curved line of electric lines of force, the electrostatic latent image Rb Further, the developer T on the developing roller 103a on the downstream side flies as indicated by a flying locus Q2, and moves to the side facing the electrostatic latent image Rb. Therefore, the developer T concentrates on the boundary portion Rc, and these developers T return to the upstream side of the developing roller 103a again, so that a large pool S of the developer T is formed at the corresponding portion of the developing roller 103a.

  Also, as shown in FIG. 20, when the electrostatic latent image Rb is positioned at the upstream end (b) in the rotation direction of the developing roller 103a and the photosensitive drum 101, the developer T on the developing roller 103a is in a flight locus. As in Q3, the reciprocating motion toward the outside gradually with the photosensitive drum 101 is repeated. Therefore, despite the rotation of the developing roller 103a, a large pool S of developer T continues to be formed at a fixed position on the upstream side of the developing roller 103a.

  Further, as shown in FIG. 21, due to the rotation of the photosensitive drum 101, the boundary portion Re between the electrostatic latent image Rb and the non-image portion Rd connected to the upstream side thereof is upstream in the rotation direction of the developing roller 103 a and the photosensitive drum 101. When the end portion (b) is reached, the electric field concentrates on the boundary portion Re, and the developer T in the large reservoir S of developer T formed on the developing roller 103a is attracted to the boundary portion Re. Accordingly, the developer T in the developer reservoir S moves back and forth between the developing roller 103a and the photosensitive drum 101 like a flight locus Q4, and moves downstream as the boundary portion Re moves, so that the developing roller 103a. And passes through the gap between the photosensitive drums 101.

  Thereafter, as shown in FIG. 22, at the downstream end (c) in the rotation direction of the developing roller 103a and the photosensitive drum 101, the developer T in the large reservoir S of developer T is electrostatically charged as shown by the flight trajectory Q5. By adhering to the rear end of the latent image Rb, a “creeping” image is formed.

  As a result of the study, the inventors have inserted a plate-like member into the development region between the image carrier and the developer carrier, and arranged the tip portion of the plate-like member in contact with the image carrier. Thus, it has been found that the above-mentioned developer scattering and rushing can be suppressed.

  However, since the image carrier and the plate-like member are always in contact with each other, the image carrier and the plate-like member are brought into contact with each other by frictional charging due to vibration or the like during contact between the image carrier and the plate-like member. The generation of a charging memory due to reverse charging becomes a problem. In particular, when the plate member is insulative, the phenomenon becomes more prominent.

Further, in the image forming process, the occurrence of image defects such as image density unevenness and density reduction due to disturbance of the electrostatic latent image due to frictional charging between the image carrier and the plate-like member becomes a problem.
Japanese Patent No. 3366968 (see pages 2-7, Fig. 1) Japanese Patent No. 2971713 (pages 4-5) Japanese Examined Patent Publication No. 6-48404 (see pages 2-6, Fig. 1)

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and a process cartridge for visualizing an electrostatic latent image formed on an image carrier by applying an alternating voltage to the developer carrier, in a non-contact developing unit. An object of the present invention is to provide an image forming apparatus and a process cartridge capable of suppressing “sticking” and scattering of a developer and obtaining a high-quality developer image over a long period without a memory.

  Another object of the present invention is to provide an image forming apparatus and a process cartridge in which image defects such as density unevenness and density reduction in an image are prevented.

  In accordance with the present invention, the image bearing member and the developer bearing member are held in contact with each other, and a plate-like member is inserted between the image bearing member and the developer bearing member. One end of the member is disposed within the substantial development area, the tip of the plate-shaped member is disposed in contact with the image carrier, and the plate-shaped member is disposed on the surface of the developer carrier within the development area. In an image forming apparatus installed so as not to come into contact with an attached developer, an image forming apparatus having a friction coefficient of 0.5 or less between the image carrier and the plate-like member is provided. Is done.

  Further, according to the present invention, it has a holding means for maintaining at least the image carrier and the developer carrier in a non-contact manner, and a plate-like member is inserted between the image carrier and the developer carrier, One end of the plate-like member is disposed in the substantial developing area, the tip portion of the plate-shaped member is disposed in contact with the image carrier, and the plate-like member carries the developer in the developing area. In a process cartridge integrally including a developing device and an image carrier that are installed so as not to come into contact with the developer attached to the surface of the body, the coefficient of friction between the image carrier and the plate member is 0.5. A process cartridge is provided that is characterized as follows.

  The image forming apparatus and the process cartridge according to the present invention suppress the scattering and gathering of the developer, and also generate an image due to frictional charging between the image carrier and the plate-like member, and an electrostatic latent image disturbance. It has been found that defects can be prevented.

  Hereinafter, an image forming apparatus and a process cartridge according to the present invention will be described in more detail with reference to the drawings.

  FIG. 1 is a schematic diagram of a developing device in the image forming apparatus according to the present embodiment, and FIG. 2 is an enlarged view of the vicinity of a developer carrier in the developing device.

  The image forming apparatus according to the present embodiment includes an electrophotographic non-contact developing device 1, and an electrostatic latent image formed on an image carrier such as a photosensitive drum is disposed at a predetermined interval from the image carrier. Development is performed by applying an alternating electric field acting between the developer carrier and the image carrier to the developer carrier that rotates in one direction.

  For example, as the most basic configuration, the apparatus configuration shown in FIG. 3 is used as the image forming apparatus of this embodiment. As the image carrier 9, for example, a charge generation layer is formed on an aluminum substrate 9a having an outer diameter of 30 mm. An organic photosensitive drum in which 9b is formed and a charge transport layer 9c is formed thereon is used.

  As described above, around the image carrier 9, the roller charging device 12 that charges the surface of the image carrier 9 to a uniform potential, and the exposure that blinks at regular intervals as the image carrier 9 rotates. A light source 13 is provided.

  A non-contact developing device (developing device) 1 is arranged on the downstream side in the rotation direction of the image carrier 9 with respect to the position where the exposure light source 13 is installed.

  Here, the configuration of the non-contact developing device 1 will be described with reference to FIG.

  A space in the frame constituting the non-contact developing device 1 is used as a developer accommodating portion 2 for containing the developer T.

  The developer T filled in the developer container 2 is conveyed toward the supply roller 4 by the stirring member 3 that rotates in the direction of arrow D in FIG. At this time, since the developer container 2 and the supply roller 4 are separated by the partition plate 5, the developer T that has passed over the partition plate 5 by the pressing of the stirring member 3 is supplied to the supply roller 4 by a substantially constant amount. It is conveyed.

  The supply roller 4 supplies the developer T to the developing roller 6 by rotating in the direction of arrow E in FIG. 1 which is a counter direction while contacting the developing roller 6 which is a developer carrying member.

  The developer T carried on the developing roller 6 rotating in the direction of arrow F is formed in a predetermined layer thickness by the developing blade 7 which is a regulating member, and subsequently the image carrier 9 shown by a broken line in FIG. In the illustrated image forming apparatus, the image forming apparatus is conveyed to a developing region α facing a photosensitive drum 101 as an image bearing member and positioned in a gap d between the image bearing member 9 and the developing roller 6. Here, the developing roller 6 and the image carrier 9 are rotated in the forward direction that moves in the same direction at the opposing portion.

  The developer T transported to the gap d is reciprocated between the image carrier 9 and the developing roller 6 by an oscillation voltage obtained by superimposing an AC voltage and a DC voltage applied to the developing roller 6 from the developing power source 12. Development is performed by attaching to the electrostatic latent image formed on the surface of the image carrier 9. In the non-contact developing device 1 of this embodiment, a voltage obtained by superimposing a DC voltage of −300 V on an AC voltage having a peak-to-peak voltage of 2.0 kVpp and a frequency of 2.5 kHz was used as the developing voltage. The value can be appropriately adjusted according to various conditions such as the contrast of the electrostatic latent image formed on the image carrier 9 and the environment where the developing device 1 is placed.

  The developer T that has not transferred to the surface of the image carrier 9 is collected again by the developing roller 6 and used for the next development.

  As can be understood with reference to FIG. 2, the developing roller 6 surface is brought into contact with the developing roller 6 at both ends of the developing roller 6 at the inner diameter portion and the outer diameter portion is brought into contact with the image carrier 9. A ring-shaped regulating roller 8 is provided which serves to keep the surface of the image carrier 9 at a predetermined interval. The distance between the surface of the developing roller 6 and the surface of the image carrier 9 was adjusted so as to be maintained at 300 μm by the restriction roller 8.

  In the non-contact developing device 1 of this example, the resistance was adjusted by blending carbon or the like in the resin solution, and then the developer was applied on an aluminum base tube having an outer diameter of 15 mm as the developing roller 6. .

  The developer T is preferably a non-magnetic one-component toner that is negatively charged. However, any developer that is suitable for non-contact development can be used regardless of whether it is magnetic or non-magnetic.

  Here, as a feature of the present invention, in this embodiment, in the gap d constituted by the image carrier 9 and the developing roller 6, and in the developing area α which is an area acting on the development existing in the gap d. A sheet-like member 11 made of an insulating material was placed so as to hang down from the upstream side in the rotation direction of the developing roller 6 so as to penetrate.

  That is, in the non-contact developing device 1 of this embodiment, as shown in FIG. 2, a base 10 as a support member is fixed to the developing blade 7 and a PET sheet 11 having a thickness of about 60 μm is attached to the base 10. It was. This affixed portion 11 a becomes a fixed end of the sheet 11.

  The other free end G with respect to the fixed end 11 a of the PET sheet 11 that is not fixed to the pedestal 10 enters the developing area α in the gap d between the developing roller 6 and the image carrier 9 and hangs down from the pedestal 10. It is arranged depending on.

  In this embodiment, since the PET sheet 11 is attached so as to hang down from the upper direction with respect to the acting direction of gravity, this state is expressed as “hanging”.

  Here, in order to suspend the sheet member 11, it is necessary that the fixed end 11 a is disposed above the gravitational direction and the free end G is disposed below. Then, since it hangs down from the upstream in the rotation direction of the developing roller 6 in the gap d between the developing roller 6 and the image carrier 9, the rotational direction of the image carrier 9 of the developing roller 6 in the gap d (here, both members) Since they are rotating in the forward direction, the same direction) is made the gravity direction.

  However, the gap between the surface of the developing roller 6 and the surface of the image carrier 9 is as very narrow as 300 μm, and the PET sheet 11 having one free end G is likely to come into contact with the surface of the developing roller 6. When the PET sheet 11 comes into contact with the surface of the developing roller 6, the developer coat layer on the developing roller 6 is disturbed, and defects in the output image such as uneven density tend to occur.

  Therefore, when the non-contact developing device 1 faces the image carrier 9, the height h of the base 10 is set so that the free end G of the PET sheet 11 contacts the image carrier 9 and does not contact the surface of the developing roller 6. The positioning was performed sufficiently high. As described above, by positively pressing the PET sheet 11 against the image carrier 9 with a predetermined pressing force, the sheet member 11 is prevented from falling toward the developer roller 6, and the PET sheet contacts the surface of the developing roller 3. To prevent.

  Here, the development region α is a region where the lines of electric force H are generated by the development bias as described with reference to FIG. 16 in the conventional example, that is, a region actually acting on the development. The developing area α in this embodiment is the closest portion e between the image carrier 9 and the developing roller 6 when the outer diameter of the image carrier 9 is 30 mm under the above-described development bias conditions. From the above, it was found that the upstream and downstream sides in the rotation direction of the developing roller 6 each have a width of 1.5 mm to 1.8 mm, that is, a width of about 3.0 to 3.6 mm.

  Here, with respect to the amount that the PET sheet 11 blocks the development area α, that is, for the setting of δ shown in FIG. 2, the area blocked by the plate member in the gap formed by the image carrier and the developer carrier, By setting the developing area to half or less from the upstream end side in the rotation direction of the developer carrying member, it is possible to suppress “collapse” and developer scattering without causing a decrease in density of the developed image.

  In the present invention, in order to reduce the friction coefficient between the image carrier and the plate-like member to 0.5 or less, a method of reducing the friction coefficient of the surface layer of the image carrier itself, or the surface of the image carrier is roughened. For example, a method of reducing the friction coefficient by reducing the contact area between the image carrier and the plate-like member can be used.

  As the former method, the surface layer of the image carrier may be any one of a silicone-based comb-type graft polymer, a fluorine-type comb-type graft polymer, a fluorine-based resin particle, a resin containing a siloxane unit in the main chain or side chain, and inorganic particles. It is possible to make it contain. Preferably, the surface layer of the image carrier is grafted with a polycarbonate copolymer obtained by block polymerization of a siloxane unit in the main chain, a polycarbonate copolymer obtained by graft polymerization of a siloxane unit on a side chain, or a macromonomer having a silicone side chain. It is to contain at least one kind of polymerized resin.

  The latter method is not particularly specified, but for example, a method of adding fine particles to the surface layer, a polishing agent, a mechanical polishing method such as a sand blast method, etc., as well as drying conditions during coating, etc. Any method such as a method of making the surface distorted or exposing to a solvent may be used.

  In the present invention, the surface roughness of the image carrier is preferably such that the 10-point average surface roughness Rzjis (c) is 0.1 μm ≦ Rzjis ≦ 2.0 μm. When Rzjis> 2.0 μm, toner cleaning is poor, latent image dot reproducibility is lowered, scratches during durability, and scraping are likely to increase. Further, when Rzjis <0.1 μm, the effect of reducing the friction coefficient cannot be sufficiently obtained.

  The surface roughness is measured, for example, by measuring the 10-point average surface roughness Rzjis using a surface roughness measuring instrument SE-3400 manufactured by Kosaka Laboratory. More specifically, Rzjis at arbitrary six points of the image carrier is measured by this measuring device, and the average value of the six points is taken as the 10-point average surface roughness.

  In the present invention, when the coefficient of friction between the image carrier and the plate-like member is larger than 0.5, the frictional charge amount between the image carrier and the plate-like member becomes large, and the image due to the disturbance of the charge memory or the electrostatic latent image Density unevenness and image defects such as streaks occur.

  In the present invention, the coefficient of friction between the image carrier and the plate member was measured using HEIDON-14 (manufactured by Shinto Kagaku). The measurement is performed between the image carrier and the plate-like member when the plate-like member is placed on the image carrier with a load applied and the electrophotographic photosensitive member is moved at a scanning speed of 100 mm / min. The frictional force was measured as a strain amount of a strain gauge attached to the plate-like member side and converted to a tensile load. Further, the load applied to the plate-like member was changed and the same measurement was performed, and the friction coefficient between the image carrier and the plate-like member was calculated from the slope of the tensile load graph with respect to the load applied to the plate-like member.

  The image carrier has a structure in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order on a conductive support. Moreover, you may provide a surface protective layer on a charge transport layer as needed.

  The conductive support to be used may be any conductive support, such as a metal such as aluminum or stainless steel, or a metal provided with a conductive layer, paper, plastic, etc. The shape may be a sheet shape, a cylindrical shape, or the like. Can be mentioned. In particular, when the image input of LBP or the like is laser light, a conductive layer for the purpose of preventing interference fringes due to scattering or covering scratches on the support can be provided as necessary. This can be formed by dispersing conductive powder such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, more preferably 10 to 30 μm.

  An intermediate layer having an adhesive function and a barrier function can be provided thereon as necessary. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are dissolved in an appropriate solvent and applied. The thickness of the intermediate layer is preferably 0.05 to 5 μm, more preferably 0.3 to 1 μm.

  A charge generation layer is formed on the conductive support or the intermediate layer. Examples of the charge generating material include pyrylium, thiopyrylium dyes, phthalocyanine pigments, anthanthrone pigments, dibenzpyrenequinone pigments, pyratron pigments, azo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanines and quinocyanines.

  The charge generation layer is coated by dispersing the charge generation material together with 0.5 to 4 times the amount of binder resin and solvent by a method such as homogenizer, ultrasonic wave, ball mill, vibration ball mill, sand mill, attritor or roll mill. , Dried and formed. The thickness is preferably 5 μm or less, and particularly preferably in the range of 0.01 to 1 μm.

  The charge transport layer is formed by applying and drying a paint in which a charge transport material and a binder resin are mainly dissolved in a solvent. Examples of the charge transport material used include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylmethane compounds, and thiazole compounds.

  These are combined with 0.5 to 2 times the amount of binder resin based on the mass of the charge transport material, applied and dried to form a charge transport layer.

  Examples of the binder resin for the charge transport layer include polyarylate resin, polycarbonate resin, polyester resin, polymethacrylate ester, polystyrene resin, acrylic resin, polyamide resin, and other organic photoconductive materials such as poly-N-vinylcarbazole and polyvinylanthracene. May be used alone or in combination.

  The film thickness of the charge transport layer is preferably 5 μm or more and 40 μm or less, more preferably 10 μm or more and 25 μm or less.

  Hereinafter, the present invention will be described in more detail in Examples. In addition, "part" in an Example shows a mass part.

(Photoreceptor Preparation Example 1)
First, a photoconductor was prepared by the following procedure.

  An aluminum cylinder (JISA 3003 aluminum alloy) having a length of 260.5 mm, a diameter of 30 mm, a cylinder portion thickness of 0.7 mm, a maximum surface roughness of 5.0 μm, and an average surface roughness of 1.0 μm was prepared as a conductive support. .

  Next, 60 parts of powder composed of barium sulfate particles having a tin oxide coating layer (trade name: Pastoran PC1, manufactured by Mitsui Mining & Smelting Co., Ltd.), titanium oxide (trade name: TITANIX JR, manufactured by Teika Co., Ltd.) 60 parts, resol type phenol resin (trade name: Phenolite J-325, manufactured by Dainippon Ink & Chemicals, Inc., solid content 70%), silicone oil (trade name: SH28PA, manufactured by Toray Silicone Co., Ltd.) 10 parts of a silicone resin (trade name: Tospearl 120, manufactured by Toshiba Silicone Co., Ltd.), 60 parts of 2-methoxy-1-propanol and 60 parts of methanol are dispersed in a ball mill for about 20 hours to form a conductive layer. A dispersion was prepared. The conductive layer dispersion prepared in this manner was applied on the above-mentioned cylinder by a dipping method, and heat-cured at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 14.5 μm.

  Next, a solution obtained by dissolving 10 parts of a copolymer nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries Inc.) in a mixed solution of 60 parts of methanol / 40 parts of butanol is dip-coated on the conductive layer at 90 ° C. Heat drying for 10 minutes to form an intermediate layer having a thickness of 0.5 μm.

  Next, Bragg angles (2θ ± 0.2 °) of 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° in the characteristic X-ray diffraction of CuKα. 10 parts of a crystalline form of hydroxygallium phthalocyanine having a strong peak and 5 parts of polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) were added to 250 parts of cyclohexanone, and glass beads having a diameter of 1 mm were used. Disperse in a sand mill for 1 hour, add 250 parts of ethyl acetate and dilute it, apply this onto the intermediate layer, and dry at 100 ° C. for 10 minutes to form a charge generation layer with a thickness of 0.16 μm did.

  Next, 45 parts of a compound represented by the following formula (1) as a charge transport material,

下記式（２）で示される化合物５部と、

5 parts of a compound represented by the following formula (2),

下記式（３）で示される構成単位を有するポリアリレート樹脂（Ｍｗ＝１１００００）５０部

50 parts of polyarylate resin (Mw = 110000) having a structural unit represented by the following formula (3)

をモノクロルベンゼン４００部に溶解した溶液を、前記電荷発生層の上に浸漬塗布し、１２０℃で１時間加熱乾燥し、膜厚が１８μｍの電荷輸送層を形成し、感光体１とした。作製した感光体について、１０点平均粗さ（Ｒｚｊｉｓ）を前述した方法により測定したところ０．１５μｍであった。

A solution in which 400 parts of monochlorobenzene was dissolved was dip-coated on the charge generation layer and dried by heating at 120 ° C. for 1 hour to form a charge transport layer having a thickness of 18 μm. With respect to the produced photoreceptor, the 10-point average roughness (Rzjis) was measured by the method described above, and it was 0.15 μm.

(Photoreceptor preparation example 2)
In Photoconductor Preparation Example 1, the same procedure as in Photoconductor Preparation Example 1, except that 1 part of a silicone-based comb-type graft polymer (trade name: GS-101CP: manufactured by Toagosei Co., Ltd.) was added as a binder resin for the charge transport layer. Thus, a photoreceptor 2 was produced.

(Photoreceptor Preparation Example 3)
In Photoconductor Preparation Example 1, 2 parts of polytetrafluoroethylene powder (trade name: Lubron L-2: manufactured by Daikin) and 0.4 part of diorganopolysiloxane represented by the following formula (4) were added to the charge transport layer. Except for the above, a photoreceptor 3 was produced in the same manner as in photoreceptor preparation example 1.

(Photosensitive member production example 4)
In Photoconductor Preparation Example 1, the binder resin of the charge transport layer is 45 parts of a polyarylate resin represented by the above formula (3) and 5 parts of a siloxane-modified polycarbonate resin (Mw = 75000) represented by the following formula (5). A photoconductor 4 was produced in the same manner as in Photoconductor Production Example 1 except that.

(Photoreceptor Preparation Example 5)
A photoconductor similar to that of Photoconductor Preparation Example 1 was prepared, and then mechanical polishing was performed so that the ten-point surface average roughness (Rzjis) was 0.5 μm. Thus, a photoconductor 5 was manufactured.

(Photosensitive member preparation example 6)
A photoconductor similar to that of Photoconductor Preparation Example 1 was prepared, and then mechanical polishing was performed so that the ten-point surface average roughness (Rzjis) was 1.5 μm. Thus, a photoconductor 6 was manufactured.

(Photoreceptor Preparation Example 7)
Photoconductor 7 was prepared in the same manner as Photoconductor Preparation Example 1 except that 10 parts of colloidal silica (catalytic chemistry (produced by OSCAL1232)) was added in Photoconductor Preparation Example 1.

  The friction coefficient between the thus prepared photoreceptor of the present invention and a polyethylene terephthalate (PET) sheet having a thickness of 60 μm used as a plate member was measured using HEIDON-14 (manufactured by Shinto Kagaku). The results are shown in Table 1.

(Examples 1 to 5 and Comparative Examples 1 and 2)
For the produced photoreceptors 1 to 7, in the image forming apparatus of the present invention shown in FIG. 9, in order to confirm the effect of suppressing “sticking” and developer scattering, a) a state in which the PET sheet 11 is attached; b) With the PET sheet 11 removed, 2000 images were continuously formed.

  As an image to be output, a solid portion of 25 mm × 25 mm square (after the exposure by the laser scanner 105, the solid portion latent image potential on the photosensitive drum 9 is −100 V), the solid portion rear end is used. We will focus on whether or not “crushing” occurs.

  As a result, a) “Peak-up” did not occur in the solid portion when the PET sheet 11 was attached, whereas b) “Peak-up” was apparent when the PET sheet 11 was removed. It was.

  On the other hand, only when the PET sheet 11 was removed, a large amount of developer was found around the developing device jaw 1g, the developing blade 7, and the transfer portion 106.

  Next, the produced photoreceptors 1 to 7 are incorporated in a process cartridge in which the developing device and the photoreceptor as shown in FIG. 1 are integrated in a state where the photoreceptor and the PET sheet are in contact with each other. Were put in a packaging box and subjected to vibration and drop tests, respectively.

The vibration test is based on JIS-0232, with a frequency of 10 Hz to 100 Hz, a sweep time of 5 minutes (1 reciprocation), and an acceleration of 9.8 m / s ² for 1 hour each (12 reciprocations) in the x, y, and z directions. Gave. In the drop test, the product was dropped from the position of 1 m in height on the six sides and four corners (bottom corners) of the packaging box. About 24 hours after the vibration / drop test, the process cartridge was mounted on the above-described image forming apparatus and an image was output to check for the presence of a defective image. The image was evaluated as follows. The presence or absence of a halftone test chart charged memory image in which one dot was printed with a Keima pattern on the entire print surface was evaluated. The evaluation results are shown in Table 1.

  In the image forming apparatus according to the present embodiment, the PET sheet 11 is used as the sheet member 11 to be attached to the pedestal 10. However, the sheet has an insulating property such as urethane, and scratches or the like occur when contacting the photosensitive drum 9. If not, the same effect can be obtained.

  The width of the PET sheet 11 covers the entire developing area α where the developing roller 6 carries the developer T and extends to the inner side of the regulation roller 8 provided at both ends so that the entire developing width can be obtained. In this way, it is possible to suppress “crushing” and developer scattering.

1 is a schematic configuration diagram illustrating an embodiment of a developing device according to the present invention. It is an enlarged view showing an example of a sheet member attaching portion of the developing device according to the present invention. 1 is a schematic configuration diagram illustrating an example of an apparatus for operating a developing device according to the present invention. It is explanatory drawing which shows arrangement | positioning with respect to the image carrier of the developing device which concerns on this invention. It is explanatory drawing which shows arrangement | positioning with respect to the image carrier of the developing device which concerns on this invention. FIG. 3 is a schematic configuration diagram illustrating an example of an arrangement of a developing device according to the present invention with respect to an image carrier. It is a schematic block diagram which shows the other example of the developing device which concerns on this invention. It is an enlarged view which shows the other example of the sheet | seat member attaching part of the developing device which concerns on this invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. It is a schematic block diagram which shows the other example of the image forming apparatus which concerns on this invention. It is a schematic block diagram which shows the other example of the image forming apparatus which concerns on this invention. It is a schematic block diagram which shows the other example of the image forming apparatus which concerns on this invention. It is a perspective view showing an example of a sheet member concerning the present invention. It is a schematic block diagram which shows an example of the conventional image forming apparatus. It is a schematic block diagram which shows the other example of the conventional image forming apparatus. FIG. 4 is an explanatory diagram showing a state of lines of electric force between an image carrier and a developer carrier. FIG. 6 is an explanatory diagram showing a state of sweeping between an image carrier and a developer carrier. FIG. 6 is an explanatory diagram showing a state of sweeping between an image carrier and a developer carrier. FIG. 6 is an explanatory diagram showing a state of sweeping between an image carrier and a developer carrier. FIG. 6 is an explanatory diagram showing a state of sweeping between an image carrier and a developer carrier. FIG. 6 is an explanatory diagram showing a state of sweeping between an image carrier and a developer carrier. FIG. 6 is an explanatory diagram showing a state of sweeping between an image carrier and a developer carrier.

Explanation of symbols

1, 1a, 1b, 1c Non-contact developing device (developing device)
6 Development roller (developer carrier)
7 Development blade (regulating member)
8 Regulation roller 9 Image carrier (photosensitive drum)
10 Base (support member)
11, 14, 20, 29 PET sheet (sheet member)
27 Housing (frame)
110 Process cartridge d Gap α Development area T Developer

Claims (10)

  Holding means for maintaining the image carrier and the developer carrier in a non-contact state, a plate-like member is inserted between the image carrier and the developer carrier, and one end of the plate-like member Is disposed in the substantial development area, the tip portion of the plate-like member is placed in contact with the image carrier, and the plate-like member adheres to the surface of the developer carrier in the development area. An image forming apparatus installed so as not to come into contact with a developer, wherein the coefficient of friction between the image carrier and the plate-like member is 0.5 or less.   The image forming apparatus according to claim 1, wherein the plate-like member is insulative.   The image forming apparatus according to claim 1, wherein the surface roughness Rzjis of the surface layer of the image carrier is 0.1 μm or more and 2.0 μm or less.   Polycarbonate copolymer in which the surface layer of the image carrier is block-polymerized with a siloxane unit as a main chain, a polycarbonate copolymer in which a siloxane unit is graft-polymerized into a side chain, or a resin in which a macromonomer having a silicone side chain is graft-polymerized The image forming apparatus according to claim 1, comprising at least one of the above.   The image forming apparatus according to claim 1, wherein the developer is a nonmagnetic one-component developer.   Holding means for maintaining at least the image carrier and the developer carrier in a non-contact manner, a plate-like member is inserted between the image carrier and the developer carrier, and the plate-like member One end is disposed within the substantial development area, the tip of the plate-like member is disposed in contact with the image carrier, and the plate-like member adheres to the surface of the developer carrier within the development area. In a process cartridge having a developing device and an image carrier that are installed so as not to come into contact with the developer, a coefficient of friction between the image carrier and the plate member is 0.5 or less. Process cartridge.   The process cartridge according to claim 6, wherein the plate-like member is insulative.   8. The process cartridge according to claim 6, wherein the surface roughness Rzjis of the surface layer of the image carrier is 0.1 μm or more and 2.0 μm or less.   Polycarbonate copolymer in which the surface layer of the image carrier is block-polymerized with a siloxane unit as a main chain, a polycarbonate copolymer in which a siloxane unit is graft-polymerized into a side chain, or a resin in which a macromonomer having a silicone side chain is graft-polymerized The process cartridge according to claim 6 or 7 containing at least one of   The process cartridge according to claim 6, wherein the developer is a non-magnetic one-component developer.

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