JP2003233271A - Electrophotographic sensitive body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic sensitive body with a flange which facilitates the press-fitting of the flange to which an earth plate is attached into an opening end part of photosensitive drum, has a high operability, hardly damages the flange and hardly causes a deformation of the earth plate and flange. <P>SOLUTION: This electrophotographic sensitive body is provided with a photosensitive drum which is made by forming a photosensitive layer including photoconductive material on the outer peripheral surface of conductive cylindrical base body, a resin flange having a fitting part which is fitted into the opening end part of the photosensitive drum and a conductive earth plate which is attached to the inside of the fitting part of the resin flange and is brought into contact with the cylindrical base body and the rotation shaft respectively in order to electrically earth the cylindrical base body. Therein, the conductive earth plate is projected outward from the fitting part almost on the middle position of the axial length of the outer peripheral part of the fitting part and is brought into contact with the inside surface of the base body. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a photosensitive layer containing an organic material as a main component formed on the outer peripheral surface of a cylindrical substrate, and a geared resin flange provided with a grounding mechanism by a ground plate at the open end thereof. And an electrophotographic photoreceptor.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member is a photosensitive drum provided with a photosensitive layer having photoconductivity on a cylindrical conductive substrate, and a flange without a gear, a flange with a spur tooth or a helical gear at each end of the drum. It is made up of tightly bound materials.

This electrophotographic photosensitive member is mounted on an electrophotographic apparatus such as a copying machine, a printer or a facsimile, or a process cartridge mounted on these apparatuses. When performing image formation, the rotational driving force on the device side must be stably and repeatedly transmitted to the photosensitive drum via a gear (gear) integrally formed with the flange. In order to prevent looseness, the resin flanges must be connected to both ends of the photosensitive drum with extremely high reliability.

FIG. 3 is a perspective view of a resin flange of a conventional electrophotographic photosensitive member (a) and a sectional view of a photosensitive drum (b).
FIG. 4 shows a plan view of the fitting portion side viewed from the axial direction of the resin flange.

As shown in FIG. 3B, the photosensitive layer 13 is formed on the outer surface.
An adhesive (not shown) is applied to the inner surface of the opening end 11 of the photosensitive drum 1 in which is formed, and the resin flange shown in FIG. 3A is press-fitted into the opening end 11 to obtain an electrophotographic photosensitive member. . FIG. 4 is a plan view of the fitting portion side viewed from the axial direction of the resin flange shown in FIG. 3, and the ground plate includes a contact portion 8 that contacts a rotating shaft (not shown) and a protrusion 4 that contacts the inner surface of the photosensitive drum 11. The fixing portion 6 is fixed to the end surface of the inner flange of the fitting portion 2. For example, a resin protrusion provided on the end surface of the flange is inserted into a hole for a fixing portion formed in advance on the ground plate, and thermocompression-bonded to fix or screw it.

In the following description, a photosensitive drum having flanges connected to both ends is referred to as an electrophotographic photosensitive member. In the electrophotographic apparatus, this electrophotographic photosensitive member is mounted so as to support a rotating shaft (not shown) through a central hole 7 provided in the resin flange so as to allow smooth rotation and to penetrate therethrough. . Also, by using one of the flanges connected to both ends of the photosensitive drum 1 as a bevel gear, a moment of a force acting in one axial direction is generated together with the rotational driving force, and the photosensitive member is rotated in the axial direction during rotation. It is configured to prevent blurring.

On the other hand, the image forming function in the electrophotographic apparatus is the function of the electrophotographic process member provided near the outer peripheral surface of the electrophotographic photosensitive member while rotating the electrophotographic photosensitive member, that is,
It is executed by sequentially performing each process such as charging, exposure, development, transfer, (fixing), cleaning, and charge removal on the surface of the photoconductor as one cycle. Furthermore, in order to perform these electrophotographic process functions without hindrance, some of the charges photogenerated in the exposure process are grounded and removed in the photosensitive layer coated on the conductive substrate made of aluminum alloy or the like. There is a need to. For that purpose, it is necessary to electrically connect the base body to the rotary shaft, and it is necessary to hold the conductive function on the flange made of an insulating resin. Although the conductive resin may be used as the flange, it is expensive and, if the supporting base of the photosensitive drum is made of an aluminum alloy, if the aluminum surface is covered with an anodic oxide film, it is not covered. Even if a natural oxide film is attached, stable conduction may not be obtained unless the oxide film is strongly contacted so as to destroy these oxide films.Therefore, a metal plate is usually added to the flange made of insulating resin. The inner surface of the substrate is press-fitted in a scratched manner to establish electrical continuity. This metal plate is referred to as a ground plate here.

Such a ground plate is fixedly attached to the end face of the resin flange in the fitting portion 2 as described above.
In addition, the outer diameter of the fitting part of the resin flange is set to a value almost equal to (or more than) the inner diameter of the photosensitive drum in order to prevent the resin flange from coming off or loosening after the connection. Since the resistance due to the protruding portion of the ground plate is also added, a highly controlled press-fitting work is required to insert such a flange into the photosensitive drum so as not to be displaced or skewed. In order to fit the flange to which the ground plate is attached into the opening end 11 of the photosensitive drum 1, the photosensitive drum 1 is placed upright on a stand (not shown), and the opening 5 of the opening end 11 of the drum 1 is removed. Adhesive is applied to the inner surface of ~ 8mm, and the fitting part 2 of the flange
Down on the opening end 11, and using a jig or the like that presses the gear side flat part of the flange so as not to scratch or deform the flange, press the flange into the photosensitive drum 1, A method of connecting the flange and the drum is adopted.

Regarding the electrophotographic photosensitive member having such a resin flange, JP-A-8-262925, JP-A-8-262926 and JP-A-9-146411 are available.
Japanese Patent Laid-Open No. 10-319783, Japanese Patent Laid-Open No. 10-319783
No. 319784, No. 11-352831, No. 2000-56618, No. 2000-
No. 181286, JP 2001-5340 A,
JP 2001-75423 A, JP 2001-24
In Japanese Patent No. 2747, there is a description of a partially related invention.

In particular, the above-mentioned Japanese Patent Laid-Open No. 8-262925 discloses an invention of an electrophotographic photosensitive member provided with a ground plate attached to one end surface of a resin flange. The earth plate includes a pointed terminal that elastically contacts the inner peripheral surface of the cylindrical base body and scrapes off the oxide film on the inner peripheral surface. The pointed terminal has a distance from the edge of the base body of 7 mm or less. It is said to be attached so that it can be contacted in the area.

However, specifically, as described in the paragraph 0012 of the embodiment of the publication, the ground plate has sidewalls standing from two parallel sides of a flat plate portion whose planar shape is substantially octagonal. Since the shape is such that the pointed terminals are raised from the upper end of each side wall to the outside, the ground plate becomes a resistance when press-fitting, and the workability of press-fitting is not necessarily good.

[0012]

As described above, when the flange is joined to the photosensitive drum, a ground plate having a protrusion having a diameter larger than the inner diameter of the drum is fixedly attached to the end face of the fitting portion of the flange. Since it is difficult to press fit due to the influence of this protrusion, even if it can be pressed in, the workability is poor, and even if it is inserted at an angle, the flange is scratched, and it is not pressed evenly, so the ground plate or flange There are some problems such as deformation.

In such press-fitting work, even if an automatic press-fitting machine or the like is adopted to solve the above problem, there are many types of shapes of the flange or the ground plate, and the press-fitting condition must be delicately changed for each shape. However, it was difficult to respond.

In view of the problems described above, an object of the present invention is to easily press-fit a flange to which an earth plate is attached into the opening end of the photosensitive drum, to improve workability, and to damage the flange. It is an object of the present invention to provide an electrophotographic photosensitive member provided with a resin flange that is less likely to be attached to the ground plate or the flange and to be deformed.

[0015]

According to the present invention, the object is to provide a photosensitive drum having a photosensitive layer containing a photoconductive material formed on an outer peripheral surface of a conductive cylindrical substrate, and A resin flange having a fitting portion to be fitted into the opening end of the photosensitive drum, and a cylindrical base and a rotary shaft attached to the fitting portion of the resin flange for electrically grounding the cylindrical base. In an electrophotographic photosensitive member including a conductive ground plate that contacts each other, the conductive ground plate projects to the outside of the fitting portion at a position approximately in the middle of the axial length of the outer peripheral portion of the fitting portion, and contacts the inner surface of the base body. This can be achieved by using an electrophotographic photosensitive member.

According to the present invention as set forth in claim 2, the conductive earth plate has a central hole through which the rotary shaft penetrates, a contact portion with the rotary shaft, and a protrusion protruding outward from an outer peripheral portion of the fitting portion. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member comprises a portion, and the protruding portion comes into contact with the cylindrical substrate through a notch formed in the outer peripheral portion of the fitting portion.

According to the third aspect of the present invention, the electronic part according to the first or second aspect is characterized in that the projecting portion comes into contact with the cylindrical substrate through the bottom of the notch formed in the outer peripheral portion of the flange fitting portion. A photographic photoreceptor is more preferable.

According to the present invention of claim 4, the resin flange is made of a material whose main component is a polycarbonate resin or a polyoxymethylene resin, and the conductive ground plate is mainly made of phosphor bronze or a stainless steel plate. It is desirable to use the electrophotographic photosensitive member described in any one of 1 to 3.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The electrophotographic photosensitive member of the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the examples described below as long as the gist thereof is not exceeded.

FIG. 1 is a view of an electrophotographic photosensitive member according to the present invention, showing a state before a resin flange is fitted into an opening end portion of a photosensitive drum, (a) is a perspective view of the resin flange, and (b) is a perspective view of the resin flange. 2) is a sectional view of the photosensitive drum, and FIG. 2 is a plan view of the fitting portion of the resin flange shown in FIG.

The electrophotographic photosensitive member according to the present invention (see FIG. 1,
2) is an end face 1 in the fitting portion to which the ground plate 9 is attached, as compared with the conventional electrophotographic photoreceptor shown in FIGS.
2 (FIG. 2) is not the tip of the fitting portion, but is depressed to the middle of the fitting portion 2 as shown in FIG.
As shown in FIG. 3, the protrusion 5 of the ground plate 9 that contacts the inner surface of the photosensitive drum 1 is formed from the notch 14 formed on the outer peripheral portion of the fitting portion 2 so as to correspond to the protrusion outside the fitting portion 2. The place where it jumps out is different.

Thus, the resin flange 1 according to the present invention
At 0 , the protrusion 5 of the ground plate 9 is fixed in a state of protruding outward from the bottom 15 of the notch 14 near the middle of the fitting portion 2. Therefore, the resin flange 10 is fixed to the outer surface of the photosensitive layer. Opening end portion 1 of the photosensitive drum 1 in which 13 is formed
When press-fitting into 1, the projection 5 of the earth plate 9 extends to the middle part of the fitting part that serves as a guide for press-fitting, and there is no resistance due to the projection, and relatively smooth press-fitting is possible. The fitting portion 2 does not tilt and the workability is good, and the flange fitting portion 2 is not damaged, and the ground plate 9 is less likely to be deformed.

In the electrophotographic photosensitive member according to the present invention, it goes without saying that the resin flange, which is press-fitted into the opening end portion of the photosensitive drum as described above, is disconnected during operation in the electrophotographic apparatus. Since it is not even possible to loosen it, not only an adhesive is used for the fitting portion, but also the outer diameter of the fitting portion and the inner diameter of the photosensitive drum are so-called tight fit. It is preferable that they are dimensionally related.

However, the mounting position of the ground plate in the fitting portion is preferably the same depth as the position of the bottom portion 15 of the cutout portion 14 protruding outward from the outer peripheral portion because the shape of the ground plate is simplified. However, the depth can be changed as long as it does not affect the contact strength of the protrusion 5. Further, it is also preferable to bend the protrusion 5 in advance as shown in FIG. 1 in order to facilitate the press-fitting operation. Further, even if the position of the flange end face 12 in the fitting portion is deeper than the depth of the mounting position of the ground plate 9, a support base is provided so that the ground plate 9 is at the same depth as the projecting portion. The position of the end face 12 in the outer peripheral portion is not so important to the present invention, since it can be provided at the same depth position as described above if it is provided on the outer peripheral surface 12.

However, it is important to adjust the degree of protrusion of the protrusion outside the fitting part so that the deformation of the inner surface of the conductive substrate due to the press-fitting of the protrusion does not affect the outer surface of the substrate. For that purpose, it is advisable to form a dent or the like on the flange fitting portion side, which is adjusted according to the shape and thickness of the protruding portion, if necessary.

On the other hand, regarding the shape of the contact portion 8 and the protruding portion 5 with the rotating shaft of the ground plate 9, the shape shown in FIG. 2 is an example, and other shapes may be used. Since it does not impair the effect of, it belongs to the present invention.

[0027]

(Example) (Production of photosensitive drum) Made of aluminum alloy of JIS6063 and having an outer diameter of 24 mm.
An undercoat layer, a charge generation layer, as described below, on the outer peripheral surface of a cylindrical substrate having φ, an inner diameter of 22.5 mmφ, and a length of 257 mm.
A photosensitive layer 13 composed of a charge transport layer was formed.

As the subbing layer, 100 parts of a dip coating film was prepared from a coating solution prepared by dispersing aminosilane-treated titanium oxide fine particles in an alcohol-soluble polyamide resin (CM-8000 Toray Co., Ltd.) with a methanol / dichloromethane mixed solvent. It was dried at 30 ° C. for 30 minutes to form a film having a thickness of 1 μm.

The charge generation layer laminated on the undercoat layer is formed by dip coating from a coating solution in which titanyl phthalocyanine is dispersed in polyvinyl butyral resin (BX-1 manufactured by Sekisui Chemical Co., Ltd.) and a dichloromethane solvent. 1 at ℃
It was dried for 5 minutes to have a thickness of 0.2 μm.

The charge transport layer is a polycarbonate resin (Panlite L1225, manufactured by Teijin Chemicals Ltd.) having 1 part by weight of a styrylamine compound represented by the following chemical formula (1) and a repeating unit represented by the following chemical formula (2).
Part by weight was dissolved in 10 parts by weight of dichloromethane, and this solution was applied onto the charge generation layer and dried to form a charge transport layer. The film thickness after drying was 20 μm.

The electrophotographic photosensitive member according to the present invention is not limited to the above-mentioned cylindrical substrate material and photosensitive layer material, and other well-known materials can be adopted.

[0032]

[Chemical 1]

[0033]

[Chemical 2]

(Production of Resin Flange) A resin flange having a shape shown in FIG. 1 was produced by injection molding a polyoxymethylene (POM) resin material. This resin flange includes a fitting portion 2 having an outer diameter of 22.5 mmφ, a helical gear portion 3 having an outer diameter of 25.0 mmφ, and a central hole 7 through which a rotating shaft having an outer diameter of 5 mmφ passes. The axial length from the tip of the fitting part 2 to just before the helical gear part was 8 mm. The fitting portion (outer peripheral portion) 2 has a notch portion 14 formed at a position of the outer peripheral portion 2 corresponding to the protruding portion 5 of the ground plate 9 up to 4 mm from the tip. In FIG. 1, four notch portions 14 are formed in the fitting portion (outer peripheral portion) 2, but this number corresponds to the protrusion portion 5 of the ground plate.
The number can be increased or decreased as necessary. The flange end surface 12 in the fitting portion 2 has a distance 4 of the cutout portion 14.
The shape was lowered to the same depth as mm. A resin protrusion is provided on the end face 12 in the fitting portion 2 at a position corresponding to reference numeral 6 in FIG. 2, and the resin protrusion is inserted into a fixing hole formed in a separately prepared ground plate 9 to heat the end plate 12. The ground plate 9 and the resin flange 10 were fixed by pressure bonding. The position and the number of the fixing portions 6 can be changed as needed.

In the above case, since the end face 12 in the fitting portion and the notch 14 in the outer peripheral portion both have the same depth from the tip of the fitting portion, the ground plate 9 is stable on the end surface and close to the protruding portion. It is possible to provide a fixing portion on the surface of the photosensitive drum, and there is an advantage in that it has a large strength for preventing falling or loosening when the photosensitive drum is fitted. The length of the protrusion 5 is 2 mm, but it is not particularly limited. Further, a dent 18 with an inclination is provided on the outer peripheral side of the fitting portion according to the length and thickness of the protrusion so that the outer surface of the photosensitive drum is not affected by the deformation of the protrusion.

In the present invention, the depth position of the end face in the fitting portion may be deeper than the depth of the bottom portion 15 of the cutout portion 14. In that case, the depth of the resin protrusion fixed by the fixing portion 6 for fixing the ground plate 9 is increased to the same height as the depth of the notch 14 and the bottom portion 15 to make the ground plate horizontal. It may be fixed so as to support it.

In the present invention, as described above, it is most preferable that the inner end surface of the fitting portion and the bottom portion 15 of the notch portion 14 of the fitting portion have the same depth, but the notch portion 14 may be deeper. Even if the end face is deepened, the effect of the present invention can be obtained.

It is also preferable that the tip of the outer peripheral portion of the fitting portion has an outer peripheral portion tip shape that is inclined in the direction of the concavity in order to facilitate press-fitting into the opening end of the photosensitive drum.

This earth plate 9 was made by punching out a phosphor bronze plate having a spring elasticity of 0.2 mm as a material. As a material for the ground plate, a stainless steel plate may be used in addition to the phosphor bronze plate.

As the material for the resin flange, the above-mentioned PO is used.
Besides M resin, polycarbonate resin can also be used.

(Assembly of Electrophotographic Photoreceptor) Using 1000 photosensitive drums and resin flanges produced as described above, a cyanoacrylate adhesive (Loctite 403, Nippon Loctite Co., Ltd.) is attached to the opening end of the photosensitive drum. Product) and press it into the flat end surface of the resin flange on the bevel gear side with a uniform force using a jig. There is little resistance during work, the flange may be scratched,
It is less likely that the ground plate will be deformed.
All 00 pieces could be fitted smoothly.
Even after the image was repeatedly printed on 10000 sheets, there was no image failure or image failure due to the looseness or looseness of the flange connection.

[0042]

According to the present invention, a photosensitive drum, in which a photosensitive layer containing a photoconductive material is formed on the outer peripheral surface of a conductive cylindrical substrate, and a fitting fit in the opening end of the photosensitive drum. An electrophotographic photosensitive member including a resin flange having a portion, and a conductive ground plate that is mounted in a fitting portion of the resin flange and that is in contact with the cylindrical base and the rotating shaft to electrically ground the cylindrical base. In the above, since the conductive ground plate is an electrophotographic photosensitive member that protrudes outward from the fitting portion at a position approximately in the middle of the axial length of the fitting portion outer peripheral portion and contacts the inner surface of the base body, the ground plate is It is easy to press the attached flange into the open end of the photosensitive drum,
It is possible to provide an electrophotographic photosensitive member having a flange that has high workability and that is less likely to be damaged by the flange and that the ground plate and the flange are not deformed.

[Brief description of drawings]

FIG. 1 is a view before assembly of an electrophotographic photosensitive member according to the present invention, (a) is a perspective view of a resin flange, and (b) is a sectional view of an opening end portion of a photosensitive drum.

FIG. 2 is a plan view of the fitting portion of the resin flange according to the present invention as viewed from the axial direction.

FIG. 3 is a view before assembly of a conventional electrophotographic photosensitive member,
3A is a perspective view of a resin flange, and FIG. 3B is a cross-sectional view of an opening end portion of a photosensitive drum.

FIG. 4 is a plan view of a fitting portion side viewed from the axial direction of a conventional resin flange.

[Explanation of symbols]

1 photosensitive drum 2 Fitting part (outer peripheral part) 3 Bevel gear section 4 Fitting part protrusion 5 Fitting part protrusion 6 fixed part 7 Center hole 8 Rotating shaft contact part 9 ground plate 10 Resin flange 11 Open end 12 end faces 13 Photosensitive layer 14 Notch 15 bottom

Claims (4)

[Claims] 1. A photosensitive drum, in which a photosensitive layer containing a photoconductive material is formed on an outer peripheral surface of a conductive cylindrical substrate, and a resin flange having a fitting portion fitted into an opening end portion of the photosensitive drum. , Mounted in the fitting part of this resin flange,
In an electrophotographic photosensitive member including a cylindrical base body and a conductive ground plate that is in contact with a rotating shaft for electrically grounding the cylindrical base body, the conductive ground plate has an axial direction of an outer peripheral portion of the fitting portion. An electrophotographic photosensitive member characterized in that it projects outward from a fitting portion at a position approximately in the middle of its length and contacts the inner surface of the base body. 2. The conductive ground plate includes a central hole through which the rotating shaft penetrates, a contact portion with the rotating shaft, and a protruding portion protruding outward from an outer peripheral portion of the flange fitting portion. 2. The electrophotographic photosensitive member according to claim 1, wherein is contacted with the cylindrical substrate through a notch formed in the outer peripheral portion of the fitting portion. 3. The electrophotographic photosensitive member according to claim 1, wherein the projecting portion comes into contact with the cylindrical substrate through the bottom of the notch formed in the outer peripheral portion of the flange fitting portion. 4. The resin flange is made of a material containing polycarbonate resin or polyoxymethylene resin as a main component, and the conductive ground plate is made of phosphor bronze or a stainless steel plate as a main component. The electrophotographic photosensitive member according to any one of items.