WO2013187737A1

WO2013187737A1 - Photosensitive drum for electrophotographic image formation and process cartridge comprising photosensitive drum

Info

Publication number: WO2013187737A1
Application number: PCT/KR2013/005292
Authority: WO
Inventors: 최정환; 권진환; 도상일
Original assignee: 주식회사 파캔오피씨
Priority date: 2012-06-14
Filing date: 2013-06-14
Publication date: 2013-12-19
Also published as: KR20130040760A; KR101454461B1

Abstract

The present invention relates to a photosensitive drum for electrophotographic image formation and a process cartridge comprising the photosensitive drum and, more specifically, to a photosensitive drum for electrophotographic image formation, comprising: a cylindrical member having a photosensitive layer formed around the circumference thereof; and at least two protrusions having a cylindrical shape or a polygonal pillar shape provided on one end portion of the cylindrical member to receive a driving force from the rotatable driving member, wherein the protrusions are inserted into a distorted opening to transfer driving force by holding and fixing side surfaces of the protrusions at the entrance of the distorted opening when the rotatable driving member rotates, and are formed from a synthetic resin having the physical properties of 0.8-0.99 times of tensile strength, 0.8-0.99 times of yield elongation, 1.01-1.2 times of flexural modulus and 0.7-0.99 times of impact strength when compared with a material forming the distorted opening. The photosensitive drum for electrophotographic image formation and the process cartridge comprising the photosensitive drum, according to the present invention, can be coupled to a main body of an electrophotographic image formation device comprising a distorted opening having a non-circular cross section with a plurality of corners and can minimize damage to components, and can reduce manufacturing costs of molds and extend the replacement period of the molds through the simple structure thereof, and thus the present invention can be differentiated from the existing prior art, and economical efficiency can be obtained.

Description

Photosensitive drum for electrophotographic image forming and process cartridge including the photosensitive drum

The present invention relates to an electrophotographic photosensitive drum and a process cartridge including the photosensitive drum. More specifically, the present invention relates to a motor, a drive rotatable member that receives a driving force from the motor, and a center portion of the drive rotatable member. An electrophotographic photosensitive drum for electrophotographic image forming apparatus having a distortion hole having a non-circular cross section having a plurality of corner portions and for forming an image on a recording material, the photosensitive drum for electrophotographic image forming And a cylindrical member having a photosensitive layer on its circumferential surface, and a protrusion provided at one end of the cylindrical member to receive a driving force from the drive rotatable member and having at least two cylindrical or polygonal pillar-like protrusions, The protrusion is inserted into the distortion hole so that the recess The side surface of the protrusion is fixed to the hole inlet and the driving force is transmitted. The protrusion has a tensile strength of 0.8 to 0.99, an yield elongation of 0.8 to 0.99, and a flexural modulus of 1.01 to 1.2 in comparison with the material constituting the distortion hole. The present invention relates to an electrophotographic photosensitive drum and a process cartridge including the photosensitive drum, wherein the photosensitive drum is formed of a synthetic resin having physical properties in the range of 0.7 to 0.99 times.

BACKGROUND ART Electrophotographic image forming apparatuses, such as copiers and laser beam printers (LBPs), are one of the most popular electronic devices at present, along with computers. In the present specification, the electrophotographic image forming apparatus means an apparatus for forming an image on a recording medium using an electrophotographic image forming method, for example, an electrophotographic copying machine, an electrophotographic printer, a facsimile apparatus or the like. Further, the process cartridge may be detachably mounted to the main body of the electrophotographic image forming apparatus, and includes at least one of charging means as processing means, developing means as processing means, and cleaning means as processing means. Means a cartridge that is integrally disposed so that the electrophotographic photosensitive drum can be detachably mounted to the main body of the image forming apparatus. It can also be detachably mounted to the main body of the electrophotographic image forming apparatus, and the process cartridge disposed integrally so that the developing means as the processing means and the electrophotographic photosensitive drum can be detachably mounted to the main body of the image forming apparatus. Include.

In an electrophotographic image forming apparatus using an electrophotographic image formation type, a latent image is formed by selectively exposing an electrophotographic photosensitive member uniformly charged by a charging means to image forming light. The latent image is developed into a toner image by the developing means with the toner. The formed toner image is transferred to the recording medium by the transfer means to form an image on the recording material. Various methods have been proposed for rotating an electrophotographic photosensitive drum.

Representatively, Korean Patent No. 270672 to Canon Corp., which discloses a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, wherein the main assembly includes a motor, a main assembly side gear for receiving a driving force from the motor, and the like. And a main assembly recess formed by a twisted surface and substantially coaxial with the gear, and a main assembly protrusion provided in the main assembly and substantially coaxial with the gear, wherein the process cartridge includes: A drum, process means operable on the electrophotographic photosensitive drum, a twist cartridge protrusion engageable with the twisted surface and provided at a longitudinal end of the electrophotographic photosensitive drum, and a free end of the cartridge protrusion provided at the free end of the cartridge protrusion And virtually A coaxial cartridge recess, wherein the main assembly protrusion enters the cartridge recess when the process cartridge is mounted to the main assembly, and when the main assembly side gear rotates with the mutually coupled main assembly recess and cartridge protrusion A rotational driving force is transmitted from the gear to the photosensitive drum through engagement of the main assembly recess and the cartridge protrusion, and detachably to the main assembly of the image forming apparatus for forming an image on a recording material. A photosensitive drum embedded in a mountable process cartridge, wherein the main assembly includes a motor, a main assembly side gear for receiving driving force from the motor, a twist groove having a polygonal cross section formed substantially in the center of the gear, and the groove. Prepared main assembly protrusion Wherein the photosensitive drum includes a cylinder having a photosensitive layer thereon, and a drive transmission member mounted to an end of the cylinder, wherein the transfer member provides a drive force when the process cartridge is mounted to the main assembly. A gear for transferring from the assembly to the developing roller, a shaft provided substantially at the center of the gear, and a twisted protrusion provided at an end of the shaft, the protrusion exerted a driving force from the main assembly through engagement of the groove and the protrusion. And the cartridge recess is provided to the twist protrusion, the driving force is transmitted to the photosensitive drum through the shaft, and is transferred to the developing roller through the gear by the main assembly protrusion, and recording. Note of electrophotographic image forming apparatus for forming an image on a material A driving force transmitting member for transmitting driving force to an electrophotographic photosensitive drum embedded in a process cartridge detachably mountable to an assembly and a developing roller for developing a latent image formed on the photosensitive drum, the main assembly comprising a motor and the motor; A main assembly side gear for receiving a driving force from the main assembly, a twist groove having a polygonal cross section formed substantially in the center of the gear, and a main assembly protrusion provided in the groove, wherein the drive transmission member includes: A gear for transmitting a driving force from the main assembly to the developing roller when mounted, a shaft provided substantially at the center of the gear, and a twisted protrusion provided at an end of the shaft, the protrusion being provided with the groove from the main assembly. Driven through the engagement of the protrusions, A cartridge recess is provided in the twist protrusion, and the driving force is transmitted to the photosensitive drum through the shaft and is transferred to the developing roller through the gear while the main assembly protrusion is in the cartridge recess. Is disclosed. In addition, the patent publication of Korean Patent No. 258609 discloses a processing cartridge that can be detachably mounted to a main assembly of an electrophotographic image forming apparatus for forming an image on a recording material, wherein the apparatus includes a motor and a driving force from the motor. And a distorting hole having a drive rotatable member for transmitting, and a non-circular cross section formed in a central portion of the drive rotatable member, the non-circular cross section having a plurality of corner portions, wherein the processing cartridge includes an electrophotographic photosensitive drum and the electrophotographic photosensitive The processing cartridge is provided with processing means operable on a drum, and having a non-circular cross section provided at an end of the electrophotographic photosensitive drum, the non-circular cross section having a plurality of corner portions, and which can be combined with the distortion hole. A distortion mounted to a main assembly such that the drive rotatable member is engaged with the distortion hole When rotating with the protrusions, a rotational driving force is transmitted from the drive rotatable member to the electrophotographic photosensitive drum by the coupling between the distortion holes and the distortion protrusions, and the distortion protrusions are pressed toward the distortion holes. A driving force transmitting member for transmitting a driving force to a cartridge and a developing roller for developing a latent image formed on the photosensitive drum and the electrophotographic photosensitive drum, wherein the photosensitive drum and the developing roller transmit a driving force from the motor and the motor. Is housed in a processing cartridge that is removably mounted to the main assembly of the electrophotographic image forming apparatus, the main assembly gear comprising a main assembly gear and a distortion hole having a substantially triangular cross section and formed in a central portion of the main assembly gear, The driving force transmitting member is the processing cartridge A drum gear which transmits the driving force received from the main assembly to the developing roller when the main assembly is mounted to the main assembly, an axis provided at the center of the drum gear, and a substantially triangular prism shape at the end of the axis, and forming the image forming apparatus. An electrophotograph for forming an image on a driving force transmission member and a recording material, characterized in that it is coupled to a distortion hole of a main assembly of the main assembly, the distortion protrusion having a driving force from the main assembly when the processing cartridge is mounted to the main assembly. In an electrophotographic photosensitive drum for an image forming apparatus, the apparatus includes a motor, a drive rotatable member that receives a driving force from the motor, and a non-circular cross section having a plurality of corner portions formed in a central portion of the drive rotatable member. And a twisting hole having an electrophotographic photosensitive drum, A cylindrical member having a photosensitive layer, and a distortion protrusion having a non-circular cross section provided at one end of the cylindrical member and coupled with the distortion hole so as to receive a driving force from the main assembly, and having a plurality of corner portions. Thus, when the photosensitive drum is mounted to the main assembly, an electrophotographic photosensitive drum or the like is disclosed, wherein the distortion protrusion is coupled to the distortion hole to receive a driving force to rotate the electrophotographic photosensitive drum.

Canon's patents, as mentioned above, have now become the de facto industry standard for more than 90% of electrophotographic image forming devices, including laser beam printers worldwide. By the way, the photosensitive drum according to the above scheme can be combined with the distortion hole which is driven by being coupled to the distortion hole having a non-circular cross section with a plurality of corner portions of the main body, and has a non-circular cross section with a plurality of corner portions. It must have a distortion protrusion. Due to the existence of such patents, the price of photosensitive drums and process cartridges, which are consumables, is very high in the market, resulting in monopoly damage, and in addition to compromising free competition, there are problems such as rising mold costs due to complex shapes. .

Thus, efforts have been made to avoid the patent. Republic of Korea Utility Model Registration No. 2010-8538, the toner is provided with a first shaft formed in the center of rotation of the triangular torsion hole of the shape of the triangular torsional shape is rotated by a drive motor, the triangle cross section is rotated as the depth is deepened, the toner In the state where the process cartridge storing the pressure is mounted on the main body of the image forming apparatus, at least a portion of the insertion column of the drive assembly coupled to one end of the photosensitive drum in the process cartridge is inserted into the triangular torsion hole, In the rotation driving force transmission structure of the image forming apparatus in which the photosensitive drum is rotated while the insertion column is rotated in response to the rotational drive, three end portions protruding radially at the rotation angle positions corresponding to the vertices of the triangle at the leading end of the insertion column. A first locking projection is formed, the insertion spaced apart from the first locking projection At the base of the pillar, a second locking projection is radially protruded so as to have a rotational deviation by the twist angle of the triangular torsional section of the triangular torsion hole. When the first axis starts to rotate, the first locking projection is rotated while contacting the triangular torsion hole. The driving force is transmitted, and as the rotation of the first shaft progresses, the first locking projection reaches a deep position of the torsion coupling hole, and the second locking projection contacts the torsion surface of the inlet side of the triangular torsion hole, and the rotation driving force is transmitted. Disclosed is a rotation driving force transmission structure of an image forming apparatus. However, the driving force transmission structure disclosed in the above document has a high possibility of forming an infringement of the Canon patent, and has a side effect such that the locking projections are broken during use due to insufficient strength of the locking projections. The present applicant has developed a photosensitive drum having a protruding portion in the form of a simple triangular prism in order to circumvent the patent, but experienced the deformation or breakage of the shape of the protrusion or the distortion hole of the main body. This is because when the drum is coupled to the printer body, the shape of the distortion hole of the body to which the protrusion of the drum is coupled has a three-dimensional twisted shape. Therefore, the opening of the hole has a sharp edge. This is because the transmission appears in the form of point contact.

Accordingly, a technical object of the present invention is to be able to be bonded to an electrophotographic image forming apparatus main body having a distortion hole having a non-circular cross section having a plurality of corner portions, while minimizing damage to a part, and the structure is simple. In addition to reducing the manufacturing cost of the mold and can extend the replacement time of the mold to provide an electrophotographic drum that can avoid the existing patent and economical.

In order to achieve the above technical problem, the present invention includes a motor, a drive rotatable member that receives a driving force from the motor, and a distortion hole having a non-circular cross section formed at a central portion of the drive rotatable member and having a plurality of corner portions. And a photosensitive drum for electrophotographic image forming for forming an image on a recording material, the photosensitive drum for electrophotographic image forming comprising: a cylindrical member having a photosensitive layer on its peripheral surface; And a protrusion provided at one end of the cylindrical member and formed of at least two cylinders or polygonal cylinders to receive a driving force from the drive rotatable member, wherein the protrusion is inserted into the distortion hole to rotate the drive rotatable member. The side of the cylinder is fixed to the inlet of the distortion hole when the driving force The protrusions have physical properties ranging from 0.8 to 0.99 in tensile strength, 0.8 to 0.99 times in tensile strength, 1.01 to 1.2 times in flexural modulus, and 0.7 to 0.99 times in impact strength, compared to the materials constituting the distortion hole. An electrophotographic photosensitive drum for forming an electrophotographic image is provided.

In another aspect, the present invention provides a photosensitive drum for electrophotographic image formation, characterized in that the protrusion is composed of a main cylinder of the center portion and a plurality of secondary cylinders formed on the periphery of the main cylinder.

Further, the present invention provides a photosensitive drum for electrophotographic image formation, wherein the number of the secondary cylinders is equal to or less than the number of corner portions of the distortion hole.

In addition, the present invention is a photosensitive drum for electrophotographic image formation, characterized in that the synthetic resin is at least one selected from the group consisting of polyoxymethylene (polyoxymethylene, POM), polyfluoroethylene and polycarbonate (polycarbonate) to provide.

In addition, the present invention provides a photosensitive drum for electrophotographic image formation, characterized in that the secondary cylinder is formed symmetrically about the main cylinder.

In addition, the present invention is a through-hole having a locking jaw inside the distal end of the main cylinder, an elastic member located inside the through hole, a sleeve positioned at one end of the elastic member to prevent the advancement by the locking jaw and It provides an electrophotographic photosensitive drum, characterized in that it further comprises a metal grounding portion electrically connected to the photosensitive drum body and inserted into the sleeve.

In addition, the present invention provides a photosensitive drum for electrophotographic image formation, characterized in that the material of the metal ground portion is brass.

The present invention also provides a process cartridge comprising the photosensitive drum for electrophotographic image formation.

The photosensitive drum for electrophotographic image forming and the process cartridge including the photosensitive drum of the present invention can be coupled to an electrophotographic image forming apparatus main body having a distortion hole having a non-circular cross section having a plurality of corners, while minimizing damage to components. In addition, since the structure is simple, the manufacturing cost of the mold can be reduced, and the replacement time of the mold can be extended, thereby avoiding the existing patent and achieving economic feasibility.

1 is a structural diagram showing a coupling relationship between a protrusion 17 and a main body distortion hole 18 of a conventional electrophotographic photosensitive drum.

2 is a perspective view showing an example of a protrusion of an electrophotographic photosensitive drum according to the present invention;

3 is a cross-sectional view for explaining a process in which the rotational force is transmitted by coupling the protrusion of the photosensitive drum for electrophotographic imaging according to the present invention to a distortion hole 18 having a non-circular cross section having a plurality of corner portions of the main body portion.

Figure 4 is a partial perspective view of the electrophotographic image-forming photosensitive drum of the present invention further includes an elastic member for grounding, a sleeve and a metal grounding portion;

FIG. 5 is a partial cross-sectional view of further including an elastic member, a sleeve, and a metal grounding portion for the grounding of FIG. 4; FIG.

10: protrusion body 11: main cylinder

11a: cylinder column 16a: gear

18: distortion hole 20: drum flange

21: locking jaw 30: elastic member

40: metal ground part 50: sleeve

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a structural diagram showing a coupling relationship between the protrusion 17 and the main body distortion hole 18 of the conventional electrophotographic photosensitive drum. As can be seen in Figure 1, the conventional electrophotographic photosensitive drum has the effect that the rotational central axis is matched due to the presence of the twisted projections 17 coincident with the twisted shape of the distortion hole 18 of the body portion. . Most of the distortion holes 18 and the distortion protrusions have triangular cross sections. Therefore, an embodiment of the present invention also develops assuming the triangle distortion hole.

As described above, the inventors of the present invention manufactured a photosensitive drum having a protrusion of a simple triangular pillar form and coupled to the main body to test the result, the corner of the triangular prism is formed at the entrance of the sharp distortion hole 18 of the main body portion, It has been found that the inlet of the distortion hole 18 causes a problem of deformation or breakage. This is because the shape of the distortion hole 18 of the body portion has a three-dimensional twisted shape, the inlet of the hole 18 has a sharp edge (edge), which makes it difficult to apply a protrusion that does not have a twisted shape and cannon It will limit the type of photosensitive drum or process cartridge applicable to a printer or the like according to the patent.

The electrophotographic photosensitive drum of the present invention is a distortion hole 18 having a motor, a drive rotatable member that receives a driving force from the motor, and a non-circular cross section formed at the center of the drive rotatable member and having a plurality of corner portions. And an electrophotographic image forming apparatus for forming an image on a recording material. Description of the main body, the photosensitive drum and the process cartridge of the electrophotographic image forming apparatus has been described in the detailed description of the inventions of the above-mentioned Korean Patent No. 258609 and Korean Patent No. 270672, so that the detailed description thereof will not be given herein. do.

An electrophotographic photosensitive drum of the present invention is provided with a cylindrical member having a photosensitive layer on its peripheral surface, and provided at one end of the cylindrical member so as to receive a driving force from the drive rotatable member, and having at least two cylinders or And a

protrusion

10, 11, 11a having a polygonal pillar shape, wherein the

protrusions

11, 11a are fitted into the distortion holes 18 so that the protrusions are inserted into the distortion holes 18 when the drive rotatable member is rotated. The driving force is transmitted by being fixed to the side surface, and the protrusion has a tensile strength of 0.8 to 0.99, an yield elongation of 0.8 to 0.99 times, a flexural modulus of 1.01 to 1.2 times, and an impact, in comparison with the material constituting the distortion hole 18. It is characterized in that the strength is made of a synthetic resin having physical properties in the range of 0.7 to 0.99 times.

3 illustrates a process in which the

projections

11 and 11a of the electrophotographic photosensitive drum according to the present invention are coupled to a distortion hole 18 having a non-circular cross section having a plurality of corner portions of the main body portion so that rotational force is transmitted. It is sectional drawing for doing. As shown in Fig. 3, the

protrusions

11 and 11a of the photosensitive drum for electrophotographic image formation of the present invention are inserted into the distortion holes 18 (Fig. 3 (a)), thereby distorting during rotation of the rotatable member of the main body portion. The hole 18 is caught and fixed to the inlet (FIG. 3 (b)) to transmit the driving force to the parts requiring the driving force of the drum and the process cartridge. In addition, as shown in FIG. 3, the

protrusions

10, 11 and 11a may be subdivided into

portions

11 and 11a which are directly coupled to the protrusion body 10 and the distortion hole. In the present specification, the expression 'projection' may refer to both the protrusion body 10 and the

portions

11 and 11a directly coupling to the distortion hole 18 or directly to the distortion hole 18. Although it may mean a cylinder or the like which is the

portions

11 and 11a, the expression of 'protrusions' means

portions

11 and 11a which are directly coupled to the distortion holes 18 unless otherwise specified in the present specification. 3, the

protrusions

11 and 11a and the distortion hole 18 are in point contact when the driving force is transmitted. Therefore, when the driving force is transmitted, the

protrusions

11 and 11a or the inlet of the distortion hole 18 in contact with the

protrusions

11 and 11a may be damaged. The inventors of the present invention can apply to the electrophotographic image forming apparatus according to the above-described Canon patent, but also the sharpness of the inlet of the distortion hole 18 of the main body portion of the electrophotographic image forming apparatus, the inlet or the projection 11 of the distortion hole 18, As a result of researches for developing an electrophotographic photosensitive drum for effectively transmitting the rotational driving force generated in the main body portion to the photosensitive drum without damaging 11a), the

protrusions

11 and 11a have a plurality of shapes. It takes the form of a straight cylinder or a polygonal column, and its material has a tensile strength of 0.8 to 0.99, yield elongation of 0.8 to 0.99 times, flexural modulus of 1.01 to 1.2 times, and impact strength of 0.7 than the material of the distortion hole 18. In the case of the synthetic resin in the range of 0.99 times, it can be seen that it is possible to prevent the damage of the

photosensitive drum protrusions

11 and 11a, which are consumables, while preventing wear and damage of the distortion hole 18. The. That is, the material of the

protrusions

11 and 11a is softer and higher in elasticity than the material constituting the distortion hole 18, thereby preventing damage to the inlet of the distortion hole 18 and changing the life of the photosensitive drum until it is replaced. Damage to the

protrusions

11 and 11a can also be minimized. If the physical properties of the synthetic resin constituting the

protrusions

10, 11, and 11a are outside the numerical range, the distortion holes 18 may be deformed or damaged, or the protrusions may be severely damaged to fill the predetermined life of the photosensitive drum or cartridge. You will not. In addition, since the size, height, and the like of the

protrusions

11 and 11a are inserted into the distortion holes 18 and fixed, the shape and the depth of the

protrusions

11 and 11a are determined by the shape and depth of the distortion holes 18. Since those skilled in the art will be well aware of the detailed description will not be described herein.

In the photosensitive drum for electrophotographic image formation of the present invention, the synthetic resin is not particularly limited, and any synthetic resin is acceptable as long as it satisfies the above-described physical properties. However, the material constituting the main body distortion hole 18 of the image forming apparatus is POM, and a known synthetic resin satisfying the physical properties of the

protrusions

11 and 11a as described above is polyoxymethylene (POM). , Polyfluoroethylene, polycarbonate, and the like, and the kind of synthetic resin constituting the

protrusions

10, 11, and 11a may be polyoxymethylene (POM) or polyfluoroethylene. It is preferably one or more selected from the group consisting of (polyfluoroethylene) and polycarbonate.

2 is a perspective view showing an example of the drum flange 20 and the

protrusions

10, 11, 11a of the photosensitive drum for electrophotographic image formation according to the present invention. As shown in Fig. 2, in the electrophotographic photo-sensing drum of the present invention, the

protrusions

11 and 11a are formed on the main cylinder 11 at the center and the plurality of portions formed on the periphery of the main cylinder 11; It is preferable that it consists of the cylinder 11a, and it is preferable that the number of the plurality of secondary cylinders 11a is the same as or less than the number of the corner part of the said distortion hole 18. In addition, the plurality of secondary cylinders (11a) is preferably formed symmetrically around the main cylinder (11). In the present specification, the expression of the cylinders (11, 11a) refers to a circular pipe of the pipe shape of the cylinder itself or the center of the upper diameter and the lower diameter is the same, the secondary cylinder formed on the periphery of the main cylinder is The main cylinder and the circumference may be in contact or partially overlapping.

In addition, the

protrusions

11 and 11a manufactured as described above have a simple shape, and thus, a mold manufacturing cost and a mold use period are also reduced by about 5% compared to a conventional protrusion, and a mold use durability is about 20%. It can be extended to reduce the cost.

In the electrophotographic photosensitive drum of the present invention, the main cylinder has a through hole having a locking jaw 21 inside the distal end portion, an elastic member 30 positioned inside the through hole, and the elastic member 30. Located at one end of the sleeve 50 is further inhibited by the engaging jaw 21 and electrically connected to the photosensitive drum body and further includes a metal ground portion 40 inserted into the sleeve 50 Can be. 4 is a partial perspective view of the electrophotographic photoforming drum according to the present invention further comprising an elastic member 30, a sleeve 50 and a metal grounding portion 40 for grounding, and FIG. 5 is the elasticity of FIG. It is a partial sectional view which shows the structure of the member 30, the sleeve 50, and the metal ground part 40. FIG. In the case of the photosensitive drum, the formation of static electricity may be problematic when electrically insulated, so it is desirable to have a grounding structure for removing the photosensitive drum. In the case of the present invention, the metal grounding portion is preferably a metal having excellent electrical conductivity, for example, gold, silver, iron, copper, or an alloy thereof. Brass is a copper alloy in consideration of economical efficiency and durability. In the embodiment of the present invention, the sleeve 50 and the metal grounding part 40 are manufactured separately to fit both, but it is also possible to manufacture in one piece.

One embodiment of the present invention described above should not be construed as limiting the technical spirit of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

Claims

An electron for forming an image on a recording material having a motor, a drive rotatable member that receives a driving force from the motor, and a distortion hole having a non-circular cross section having a plurality of corner portions formed in a central portion of the drive rotatable member; In the photosensitive drum for electrophotographic image forming for a photographic image forming apparatus,

The electrophotographic photosensitive drum is provided with a cylindrical member having a photosensitive layer on a circumferential surface thereof and at least two cylinders or polygonal cylinders provided at one end of the cylindrical member to receive a driving force from the drive rotatable member. Including protrusions in the form,

The protrusion is inserted into the distortion hole so that the side surface of the protrusion is fixed to the inlet of the distortion hole when the driving rotatable member is rotated, and a driving force is transmitted. The protrusion has a tensile strength in comparison with the material constituting the distortion hole. An electrophotographic photosensitive drum, comprising a synthetic resin having physical properties ranging from 0.8 to 0.99, yield elongation of 0.8 to 0.99 times, flexural modulus of 1.01 to 1.2 times, and impact strength of 0.7 to 0.99 times.
The method of claim 1,

And the protruding portion includes a main cylinder of a central portion and a plurality of secondary cylinders formed on the periphery of the main cylinder.
The method of claim 2,

And the number of the plurality of secondary cylinders is equal to or less than the number of corner portions of the distortion holes.
The method of claim 1,

The synthetic resin is an electrophotographic photosensitive drum, characterized in that at least one selected from the group consisting of polyoxymethylene (polyoxymethylene, POM), polyfluoroethylene and polycarbonate (polycarbonate).
The method of claim 3,

And said plurality of secondary cylinders are formed symmetrically about said main cylinder.
The method of claim 2,

The main cylinder has a through hole having a locking jaw inside the distal end portion, an elastic member positioned inside the through hole, a sleeve positioned at one end of the elastic member to prevent advancement by the locking jaw, and the photosensitive drum body. An electrophotographic photosensitive drum comprising a metal ground portion electrically connected and inserted into the sleeve.
The method of claim 6,

The photosensitive drum for electrophotographic image formation, characterized in that the material of the metal ground portion is brass.
A process cartridge comprising the photosensitive drum for electrophotographic image forming according to any one of claims 1 to 5.