Abstract:
An electrophotographic photosensitive drum unit includes a cylinder having a photosensitive layer at an outer periphery thereof. A drum flange provided at one end of the cylinder. A coupling member is engaged with the drum flange so that an axis of the coupling member is inclinable with respect to an axis of the drum flange. A regulation portion is provided in the drum flange so as to prevent the coupling member from disengaging from the drum flange. At least a portion of the coupling member and the regulating portion is configured to be deformed to permit the coupling member to disengage from the drum flange or to engage with the drum flange.

Description:
FIELD OF THE INVENTION AND RELATED ART 
       [0001]    The present invention relates to a dismounting method for a coupling member, a mounting method for a coupling member, and an electrophotographic photosensitive drum unit used for a process cartridge dismountably mounted to a main assembly of an electrophotographic image forming apparatus. Here, in the present invention, the process cartridge contains as a unit at least one of an electrophotographic photosensitive member drum, developing means as process means actable on the drum, cleaning means, and charging means. And, it is detachably mountable to the electrophotographic image forming apparatus main assembly. 
         [0002]    In addition, the electrophotographic image forming apparatus forms an image on a recording material through an electrophotographic type process. As examples of the electrophotographic image forming apparatus, there are an electrophotographic copying machine, an electrophotographic printer (LED printer, a laser beam printer), a facsimile device, a word processor, and so on. 
         [0003]    In addition, the main assembly of the electrophotographic image forming apparatus is a portion of the electrophotographic image forming apparatus except the process cartridge. 
         [0004]    In a known electrophotographic image forming apparatus in which the electrophotographic image forming process is used the electrophotographic photosensitive member drum, and the process means actable on the electrophotographic photosensitive member drum are integrated into a cartridge as a unit. And, this cartridge is detachably mountable to the main assembly of the electrophotographic image forming apparatus process cartridge type. 
         [0005]    According to this process cartridge type the maintenance of the image forming apparatus can be carried out by the user himself or herself without relying on the service person, and therefore, the operativity of the maintenance is remarkably improved. 
         [0006]    In addition, in the electrophotographic image forming apparatus, an image is formed on a recording material using a developer. The developer contained in the developer accommodating portion is consumed as the process cartridge having the developing means repeats the image formation. 
         [0007]    Simple disassembling, and remanufacturing methods for making usable again the process cartridge from which the developer has been consumed to such an extent that the image of the quality which can satisfy the user cannot be formed, are desired. And, an example of such a method is disclosed in U.S. Pat. No. 6,643,482. 
         [0008]    The easy assembling method of the process cartridge has been desired. 
         [0009]    The present invention further develops the above described prior art. 
       SUMMARY OF THE INVENTION 
       [0010]    Accordingly, it is a principal object of the present invention to provide an easy dismounting method for a coupling member. 
         [0011]    It is another object of the present invention to provide an easy mounting method for a coupling member. 
         [0012]    It is a further object of the present invention to provide an electrophotographic photosensitive drum unit, wherein dismounting of the coupling is easy. 
         [0013]    It is a further object of the present invention to provide an electrophotographic photosensitive drum unit, wherein mounting of the coupling is easy. 
         [0014]    According to an aspect of the present invention, there is provided a coupling member dismounting method for dismounting, from a drum flange mounted to an electrophotographic photosensitive drum usable with a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus, a coupling member for receiving a rotating force for rotating the electrophotographic photosensitive drum from the main assembly of the apparatus in a state in which the process cartridge is mounted to the main assembly of the apparatus, said method comprising (i) an inclining step of inclining the coupling member relative to a rotational axis of the drum flange, wherein the coupling member includes a rotating force receiving member having, at a free end portion, a rotating force receiving portion for receiving the rotating force, a spherical portion mounted to a rear end portion of the rotating force receiving member by a pin penetration; (ii) a pin urging step of pushing the pin from one end to the other end thereof, wherein said one and the other ends of the pin are projected out of the spherical portion in a state in which the coupling member is inclined by said inclining step; wherein a regulating portion provided along an inside of the drum flange with a gap between the spherical portion and the regulating portion and has a configuration nearer to a spherical surface of the free end portion than a flat plane which is perpendicular to a longitudinal direction of the electrophotographic photosensitive drum and which passes through a center of the spherical portion, and wherein said regulating portion includes a first surface extending from the regulating portion in a direction away from the coupling member toward the free end portion with respect to the longitudinal direction, and a second surface bent from the first surface extending from the regulating portion in a direction away from the coupling member toward the free end portion with respect to the longitudinal direction, (iii) a pin riding step of making a part of the pin which is further projected at the end by said pin urging step ride on the second surface; and (iv) a coupling member dismounting step of dismounting the coupling member from the drum flange by applying a force to a free end portion of the coupling member toward a fulcrum which is the portion of the pin riding on the second surface. 
         [0015]    According to another aspect of the present invention, there is provided a coupling member dismounting method for dismounting, from a drum flange mounted to an electrophotographic photosensitive drum usable with a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus, a coupling member for receiving a rotating force for rotating the electrophotographic photosensitive drum from the main assembly of the apparatus in a state in which the process cartridge is mounted to the main assembly of the apparatus, wherein the coupling member includes a rotating force receiving member having, at a free end portion, a rotating force receiving portion for receiving the rotating force, a resin spherical portion mounted to a rear end portion of the rotating force receiving member by a pin penetration, wherein said; the coupling member is mounted to a drum flange, mounted to one end of the electrophotographic photosensitive drum, by a resin regulating portion which is provided inside the drum flange and which is projected inwardly with respect to a radial direction of the drum flange with a gap between the spherical portion and the regulating portion, said method comprising (i) a gripping step of gripping the rotating force receiving member of the coupling member; (ii) a coupling member dismounting step of dismounting the coupling member, from the resin regulating portion, the resin spherical portion while deforming at least one of the resin regulating portion and the resin spherical portion by applying a force toward the free end portion in a state in which the rotating force receiving member is gripped by said gripping step. 
         [0016]    According to a further aspect of the present invention, there is provided a coupling member mounting method for mounting, to a drum flange mounted to an electrophotographic photosensitive drum usable with a process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus, a coupling member for receiving a rotating force for rotating the electrophotographic photosensitive drum from the main assembly of the apparatus in a state in which the process cartridge is mounted to the main assembly of the apparatus, wherein the coupling member includes a rotating force receiving member having, at a free end portion, a rotating force receiving portion for receiving the rotating force, a resin spherical portion mounted to a rear end portion of the rotating force receiving member by a pin penetration, wherein said; the coupling member is mounted to a drum flange, mounted to one end of the electrophotographic photosensitive drum, by a resin regulating portion which is provided inside the drum flange and which is projected inwardly with respect to a radial direction of the drum flange with a gap between the spherical portion and the regulating portion, said method comprising a coupling member mounting step of mounting the coupling member, into the resin regulating portion, the resin spherical portion while deforming at least one of the resin regulating portion and the resin spherical portion by pushing it longitudinally inwardly of the electrophotographic photosensitive drum. 
         [0017]    According to a further aspect of the present invention, there is provided an electrophotographic photosensitive drum unit to which a coupling member is mountable, wherein said coupling member includes, at a free end portion, a rotating force receiving member for receiving, from an electrophotographic image forming apparatus, a rotating force for rotating an electrophotographic photosensitive drum, a spherical portion mounted to a rear end portion of the rotating force receiving member by a pin penetration, said electrophotographic photosensitive drum unit comprising a cylinder having a photosensitive layer at an outer periphery thereof; and a drum flange provided at one end of said cylinder, said drum flange including, a plurality of resin regulating portions provided inside said drum flange and projected radially inwardly of the drum flange, wherein said regulating portions are effective to regulate movement of said spherical portion in a longitudinal direction of said drum unit when said coupling member is mounted thereto; a recess provided in said regulating portion at a position radially outside of said drum flange, for facilitating deformation of said regulating portion radially outwardly of said drum flange; and a plurality of rotating force receiving portion including a pin for receiving the rotating force, wherein said pin is provided between adjacent ones of said regulating portions. 
         [0018]    These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a sectional view of a main assembly, and a process cartridge of an image forming apparatus in an embodiment. 
           [0020]      FIG. 2  is an enlarged cross-sectional view of the process cartridge. 
           [0021]      FIG. 3  is a perspective view illustrating a frame structure of the process cartridge. 
           [0022]      FIG. 4  is a perspective view of the main assembly in the state that an openable and closable is door is opened. 
           [0023]      FIG. 5  is a perspective view of a drive shaft of the main assembly. 
           [0024]      FIG. 6  is a perspective view of a free end portion of a coupling member. 
           [0025]      FIG. 7  is an illustration showing the state that the coupling member and the drive shaft are connected with each other. 
           [0026]      FIG. 8  is a sectional view illustrating the state that the coupling member and the drive shaft are connected with each other. 
           [0027]      FIG. 9  is a perspective view of a rotational force receiving member which is a component part of the coupling member. 
           [0028]      FIG. 10  is a perspective view of a spherical portion which is a component part of the coupling member. 
           [0029]      FIG. 11  is a sectional view of the coupling member. 
           [0030]      FIG. 12  is a perspective view of the coupling member. 
           [0031]      FIG. 13  is an illustration of a drum flange. 
           [0032]      FIG. 14  is a sectional view taken along a line S 2 -S 2  in  FIG. 13 . 
           [0033]      FIG. 15  is a sectional view which illustrates the process in which the rotational force receiving member is assembled into the drum flange, in the section along a line S 1 -S 1  in  FIG. 13 . 
           [0034]      FIG. 16  is a sectional view which illustrates the process in which the coupling member is fixed to the drum flange, in the section taken along a line S 1 -S 1  in  FIG. 13 . 
           [0035]      FIG. 17  is a perspective view of the drum unit, as seen from a driving side. 
           [0036]      FIG. 18  is a perspective view of the drum unit, as seen from a non-driving side. 
           [0037]      FIG. 19  is a perspective view illustrating a disassembling process of the photosensitive member unit. 
           [0038]      FIG. 20  is a perspective view illustrating a disassembling process of the photosensitive member unit. 
           [0039]      FIG. 21  is a perspective view illustrating a disassembling process of the photosensitive member unit. 
           [0040]      FIG. 22  is a perspective view illustrating a disassembling process of the photosensitive member unit. 
           [0041]      FIG. 23  is a sectional view illustrating a method of dismounting the coupling member directly from the drum unit. 
           [0042]      FIG. 24  is a partial enlarged view of the opening portion in  FIG. 23 . 
           [0043]      FIG. 25  is a sectional view illustrating a method of dismounting the coupling member directly from the drum unit. 
           [0044]      FIG. 26  is a sectional view illustrating a method of dismounting the coupling member directly from the drum unit. 
           [0045]      FIG. 27  is a sectional view illustrating a method of dismounting the coupling member directly from the drum unit. 
           [0046]      FIG. 28  is a perspective view which illustrates the state of  FIG. 27  three-dimensionally. 
           [0047]      FIG. 29  is a sectional view illustrating a method of dismounting the coupling member directly from the drum unit. 
           [0048]      FIG. 30  is a sectional view illustrating a method of dismounting the coupling member directly from the drum unit. 
           [0049]      FIG. 31  is a sectional view illustrating a method of reassembling the drum unit. 
           [0050]      FIG. 32  is a sectional view illustrating a method of reassembling of the drum unit. 
           [0051]      FIG. 33  is a perspective view illustrating a disassembling method for the development unit. 
           [0052]      FIG. 34  is a sectional view illustrating a method for reassembling the drum unit. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0053]    Referring to the accompanying drawings, the is preferred embodiments of the present invention will be described. The function, material, configuration, positional relations and the like of the elements described hereinbelow is not limiting to the present invention unless otherwise stated. As for the material, configuration and the like of the elements described once apply to the subsequent descriptions unless otherwise stated. 
       Embodiment 
     General Arrangement 
       [0054]      FIG. 1  is a sectional view of an image formation main assembly  1  (main assembly), and a process cartridge  2  (cartridge) of an image forming apparatus in an embodiment of the present invention.  FIG. 2  is an enlarged cross-sectional view of the cartridge  2 . Referring to  FIGS. 1-2 , a general arrangement, and an image formation process of the image forming apparatus in the present embodiment will be described. 
         [0055]    This image forming apparatus is a laser beam printer which utilizes electrophotography, wherein a cartridge  2  is detachably mountable to the main assembly  1 . When the cartridge  2  is set to the main assembly  1 , an exposure device (laser scanner unit)  3  is disposed on the upper portion of the cartridge  2 . The lower portion of the cartridge  2  is provided with is a sheet tray  4  which contains recording material (sheet material) P which is the object on which an image is formed. The main assembly  1  is provided with a pick-up roller  5   a , a feeding roller  5   b , a feeding roller pair  5   c , a transfer guide  6 , a transfer charging roller  7 , a feeding guide  8 , a fixing device  9 , a discharging roller pair  10 , a discharging tray  11 , and so on along a feeding direction of the sheet material P. 
       (Image Formation Process) 
       [0056]    The outline of the image formation process will be described. In response to a print start signal, an electrophotographic photosensitive member drum (drum)  20  is rotated at a predetermined peripheral speed (process speed) in a direction of the arrow R 1 . The a charging roller (charging means, process means)  12  which is supplied with a bias voltage contacts to an outer surface of the drum  20 , and the outer surface of by drum  20  is uniformly charged by the charging roller  12 . 
         [0057]    A laser beam L modulated correspondingly to a serial electrical digital pixel signal of the image information is outputted from the exposure device  3 . The laser beam L enters the cartridge  2  through an exposure window  53  of an upper surface of the cartridge  2  to scanningly expose the outer surface of the drum  20  by this, an electrostatic latent image corresponding to the image information is formed on the outer surface of the drum  20 . The electrostatic latent image is visualized by a developer T (toner) of a developing device unit  40  into a Toner image. 
         [0058]    The charging roller  12  is contacted to the drum  20 , and charges the drum  20  electrically. The charging roller  12  is rotated by the drum  20 . The developing device unit  40  supplies the toner into the developing zone of the drum  20  to develop the latent image formed on the drum  20 . 
         [0059]    The developing device unit  40  feeds the toner T in a toner chamber  45  to a toner feeding chamber  44  by the rotation of a stirring member  43 . The developing roller (developing means, process means)  41  which is a developer carrying member containing a magnet roller (stationary magnet)  41   a  is rotated, and the toner layer triboelectrically charged by the developing blade  42  is formed on the surface of the developing roller  41 . The toner is transferred onto the drum  20  in accordance with the latent image, so that the electrostatic latent image is visualized into a toner image. The developing blade  42  applies the triboelectrical charge while regulating the toner amount on the peripheral surface of the developing roller  41 . 
         [0060]    On the other h, and in accordance with the output timing of the laser beam L, the paper is fed to the sheet material P accommodated in the lower portion of the main assembly  1  from the sheet tray  4  by the pick-up roller  5   a , the feeding roller  5   b , and feeding roller pair  5   c . The sheet material P is timed and fed to a transfer position between the drum  20 , and a transfer charging roller  7  via the transfer guide  6 . In the transfer position, the toner image is transferred onto the sheet material P sequentially from the drum  20 . 
         [0061]    The sheet P onto which the toner image has been transferred is separated from the drum  20 , and fed to the fixing device  9  along the feeding guide  8 . The sheet material P is passed through a nip formed between a fixing roller  9   a , and a pressing roller  9   h  which constitute the fixing device  9 . The pressing and the heat-fixing process are carried out in the nip so that toner image is fixed on the sheet material P. The sheet material P having been subjected to the image fixing process for the toner image is fed to discharging roller pair  10 , and is discharged to the discharging tray  11 . 
         [0062]    On the other h, and the residual toner remaining on the outer surface of the drum  20  is removed by a cleaning blade (cleaning means, process means)  52  after the transferring  20 , and the drum is used for the next image formation which starts with the electrical charging operation. The waste toner removed from the drum  20  is stored in the waste toner chamber  52   a  in the photosensitive member unit  50 . 
         [0063]    The charging roller  12 , the developing roller  41 , the cleaning blade  52 , and so on are the process means actable on the drum  20 , respectively. 
       (Frame Structure of Process Cartridge) 
       [0064]      FIG. 3  is a perspective view illustrating structures of a frame of the cartridge  2 . 
         [0065]    Referring to  FIG. 2  and  FIG. 3 , the frame structure of the cartridge  2  will be described. 
         [0066]    As shown in  FIG. 2 , the drum  20 , the charging roller  12 , and the cleaning blade  52  is mounted to the drum frame  51 , and constitutes an integral photosensitive member unit  50 . 
         [0067]    On the other hand, the developing device unit  40  is constituted by the toner chamber  45  which contains the toner, the toner accommodating chamber  40   a  which forms the toner feeding chamber  44 , and the cover  40   b.    
         [0068]    The toner accommodating chamber  40   a  and the cover  40   b  is connected relative to each other by the means such as the welding. 
         [0069]    As shown in  FIG. 3 , the cartridge  2  is constituted by connecting the photosensitive member unit  50  and the developing device unit  40  rotatably relative to each other by a connection member  54  of a round pin. 
         [0070]    As shown in  FIG. 3 , the free end of an arm portion  55   a  formed on a side cover  55  provided at each end with respect to the longitudinal direction of the developing device unit  40  (axial direction of the developing roller  41 ) is provided with a round rotation hole extending in parallel with the developing roller  41   55   b.    
         [0071]    The drum frame  51  has an engaging hole  51   a  for receiving the connection member  54  co-axially with the rotation hole  55   b  when the arm portion  55   a  is inserted in the predetermined position of the drum frame  51 . 
         [0072]    The photosensitive member unit  50  and the developing device unit  40  are connected with each other rotatably about the connection member  54  by inserting the connection member  54  through both the rotation hole  55   b  and the engaging hole  51   a.    
         [0073]    At this time, a compression coil spring  46  mounted to the base portion of the arm portion  55   a  abuts to the drum frame  51  to urge the developing device unit  40  downwardly. 
         [0074]    By this, the developing roller  41  ( FIG. 2 ) is assuredly pressed toward the drum  20 . 
         [0075]    The spacing members (unshown) are mounted at the opposite ends of the developing roller  41 , so that the developing roller  41  is held with predetermined intervals from the drum  20 . 
       (Rotational Force Transmission Method to Process Cartridge) 
       [0076]      FIG. 4  is a perspective view of an inside of the main assembly with the door  140  open. 
         [0077]    The cartridge  2  is not mounted. 
         [0078]    Referring to  FIG. 4 , the rotational force transmission method to the cartridge  2  will be described. 
         [0079]    As shown in  FIG. 4 , a guiding rail  130  for the cartridge mounting and demounting is provided in the main assembly  1 , and the cartridge  2  is mounted into the inside of the main assembly  1  along a guiding rail  130 . 
         [0080]    In this case, a drive shaft  100  of the main assembly side and a coupling member  156  ( FIG. 3 ) which is a rotational force transmitting portion of the cartridge  2  connect with each other in interrelation with the mounting operation of the cartridge  2 . 
         [0081]    By this, the drum  20  receives the rotational force from the main assembly  1  to rotate. 
       1. Drive Shaft  100 : 
       [0082]      FIG. 5  is a perspective view of the drive shaft  100  of the main assembly side. 
         [0083]    The drive shaft  100  is coupled with the drive transmitting means, such as an unshown gear train and the unshown motor provided in the main assembly  1 . 
         [0084]    The free end portion  100   a  of the drive shaft  100  has a substantial semispherical shape, and is provided with rotational force transmitting pins as the rotational force applying portion  100   b.    
       2. Coupling: 
       [0085]    In the state where the cartridge  2  is dismountably mounted to the main assembly  1 , the coupling member  156  has the function of receiving a rotational force for rotating the drum  20  from the main assembly  1 . 
         [0086]    As shown in  FIG. 11  and  FIG. 12 , this coupling member  156  has a rotational force receiving member  150  which has a rotational force receiving portion  150   e  ( 150   e   1 - 150   e   4 ) for receiving the rotational force at the free end portion thereof. 
         [0087]    In addition, it has a spherical portion (spherical member)  160  mounted by penetrating the pin  155  through a rear end portion of the rotational force receiving member  150 . 
         [0088]      FIG. 6  is a perspective view of the rotational force receiving member  150 . 
         [0089]    The material of the rotational force receiving member  150  is resin material of the polyacetal, the polycarbonate, PPS, or the like. 
         [0090]    However, in order to enhance the rigidity of the rotational force receiving member  150 , glass fibers, carbon fibers, and/or the like may be mixed in the resin material in response to the required torque load. 
         [0091]    In the case of mixing such a material, the rigidity of the rotational force receiving member  150  can be enhanced. 
         [0092]    The rigidity may further be enhanced by inserting a metal member material in the resin material, and the whole rotational force receiving member  150  may be made of metal or the like. 
         [0093]    The free end of the rotational force receiving member  150  is provided with a plurality of drive receiving projections  150   d  ( 150   d   1 - 150   d   4 ). 
         [0094]    In addition, the drive receiving projection  150   d  ( 150   d   1 - 150   d   4 ) is provided with rotational force receiving portion  150   e  ( 150   e   1 - 150   e   4 ) inclined relative to the axis L 150  of the rotational force receiving member  150 . 
         [0095]    In addition, the inside of drive receiving projection  150   d   1 - 150   d   4  is provided with a funnel-like funnel  150   f.    
       3. Connection State Between Drive Shaft  100  and Coupling Member  156 : 
       [0096]      FIG. 7  is an illustration showing the state that the rotational force receiving member  150  of the coupling member  156  and the drive shaft  100  connects with each other. 
         [0097]      FIG. 8  is a sectional view illustrating the state that the rotational force receiving member  150  and the drive shaft  100  connect with each other. 
         [0098]    Referring to  FIG. 7  and  FIG. 8 , the connection state between the drive shaft,  100  and the coupling member  156  will be described. 
         [0099]    The rotational force transmitting pin  100   b  of the drive shaft  100  is in engagement with the rotational force receiving portion  150   e  ( 150   e   1 - 150   e   4 ). 
         [0100]    Although it is not visible in  FIG. 7 , the rotational force transmitting pin  100   b  on the back side is also in engagement with the rotational force receiving portion  150   e.    
         [0101]    In addition, the free end portion  100   a  of the drive shaft  100  is in contact with the recess  150   f  of the rotational force receiving member  150 . 
         [0102]    The rotational force is transmitted from the rotational force transmitting pin  100   b  to the rotational force receiving portion  150   e  by the drive shaft  100  rotating. 
         [0103]    In addition, by the rotational force receiving portion  150   e  inclining relative to the axis L 150  of the rotational force receiving member  150 , the rotational force receiving member  150  and the drive shaft  100  are attracted relative to each other and the free end portion  100   a  and the recess  150   f  contact them to each other assuredly, so that the stabilized rotational force transmission is accomplished. 
       4. Coupling Member  156  and Connection Part: 
       [0104]      FIG. 9  is a perspective view illustrating the rotational force receiving member  150 , and  FIG. 10  is a perspective view illustrating the spherical portion  160 . 
         [0105]      FIG. 11  is a sectional view of the coupling member  156 , and  FIG. 12  is a perspective view of the coupling member  156 . 
         [0106]    As shown in  FIG. 9 , the end on the side opposite from the rotational force receiving portion  150   e  of the rotational force receiving member  150   150   s  is provided with a through-hole  150   r.    
         [0107]    As shown in  FIG. 10 , the spherical portion  160  connected with the rotational force receiving member  150  has the substantial spherical shape and is provided with the rotational force receiving member  150  and the hole for receiving the pin  155  as will be described hereinafter. 
         [0108]    A one-end-closed hole  160   a  receives the end  150   s  of the rotational force receiving member  150 . 
         [0109]    The through-hole  160   b  receives the pin  155  which will be described hereinafter with the hole  160   a.    
         [0110]    As shown in  FIG. 11  and  FIG. 12 , the rotational force receiving member  150  is inserted into the spherical portion  160 , and the pin  155  is inserted in the state that the through-hole  150   r  and the through-hole  160   b  are aligned with each other. 
         [0111]    In this embodiment, the rotational force receiving member  150  and the one-end-closed-hole  160   a  are engaged with each other with the loose-fit. 
         [0112]    The pin  155  and the through-hole  150   r  are engaged with each other with the loose-fit. 
         [0113]    The pin  155  and the through-hole  160   b  are engaged with each other with the press-fit. 
         [0114]    Accordingly, the pin  155  and the spherical portion  160  are connected with each other integrally. 
         [0115]    A part provided by the connection between the rotational force receiving member  150  and the spherical portion  160  is the coupling member  156 . 
         [0116]    When the rotational force is received from the drive shaft  100 , the rotational force receiving member  150  rotates about the axis L 150 , and the through-hole  150   r  is engaged with the pin  155 . 
         [0117]    More particularly, the rotational force from the main assembly  1  is converted to the force for rotating the pin  155  about the rotation shaft L 150  through the rotational force receiving member  150 . 
         [0000]    5. The Rotational Force Transmission to the Drum  20  from the Coupling Member  156 : 
         [0118]      FIG. 13  is an illustration illustrating the drum flange  151 , and  FIG. 14  is a sectional view taken along line S 2 -S 2  in  FIG. 13 . 
         [0119]      FIG. 15  is a sectional view taken along a line S 1 -S 1  in  FIG. 13 , illustrating the process in which the rotational force receiving member  150  is assembled into the drum flange  151 . 
         [0120]      FIG. 16  shows a sectional view taken along a line S 1 -S 1  in  FIG. 13 , illustrating the process in which the rotational force receiving member  150  is fixed to the flange  151 . 
         [0121]      FIG. 17  is a perspective view of the electrophotographic photosensitive drum unit (drum unit)  21 , as seen from the driving side (rotational force receiving member  150 ). 
         [0122]      FIG. 18  is a perspective view of the drum unit  21 , as seen from the non-driving side (longitudinally opposite from the rotational force receiving member  150 ). 
         [0123]    Referring to  FIG. 13  and  FIG. 14 , an example of the drum flange  151  (flange) to which the rotational force receiving member  150  is mounted will be described. 
         [0124]      FIG. 13  illustrates the flange  151 , as seen from the drive shaft  100  side. 
         [0125]    An opening  151   g  ( 151   g   1 - 151   g   4 ) shown in  FIG. 13  is a groove which extends in the direction of a rotation shaft of the flange  151 . 
         [0126]    When the rotational force receiving member  150  is mounted to the flange  151 , the pin  155  is received in the either two of openings  51   g   1 - 151   g   4 . 
         [0127]    The clockwisely upstream side of openings  151   g   1 - 151   g   4  is provided with the rotational force transmitting surface (rotational force receiving portion)  151   h  ( 151   h   1 - 151   h   4 ). 
         [0128]    When the rotational force is transmitted to the flange  151  from the pin  155 , the pin  155  and the rotational force transmitting surface  151   h  contact to each other. 
         [0129]    In addition, adjacent to the center axis L 151  of the flange  151 , a recess (space)  151   f  is formed. 
         [0130]    The recess  151   f  provides a space surrounded by the cylindrical surface  151   j  ( 151   j   1 - 151   j   4 ), a retaining portion  151   i  ( 15111 - 151   i   4 ) which is a regulating portion, and the opening  151   k  ( 151   k   1 - 151   k   4 ). 
         [0131]    The cylindrical surface  151   j  ( 151   j   1 - 151   j   4 ) is a substantially cylindrical surface which is co-axial with the axis L 151  and which is adjacent to the opening  151   g , and has diameter D 151   a.    
         [0132]    The retaining portion  151   i  ( 151   i   1 - 151   i   4 ) is a substantially semispherical surface which continues smoothly with the cylindrical surface  151   j , and has the radius of SR 151 . 
         [0133]    The opening  151   k  ( 151   k   1 - 151   k   4 ) is positioned at the drive shaft side of the retaining portion  151   i , and has diameter of D 151   b.    
         [0134]    More particularly, the opening  151   k  is a first surface of the regulating portion which continues from the retaining portion  151   i  (regulating portion) and which is extended in the direction away from the coupling member  156  toward the free end of the rotational force receiving member  150  with respect to the longitudinal direction of the drum  20 . 
         [0135]    In addition, the relation of the spherical portion  160  relative to outside dimension D 160  is as follows ( FIG. 14 ,  FIG. 15 ): 
         [0000]        D 151 b&lt;D 160 &lt;D 151 a= 2 ×SR 151 
         [0136]    Although the spherical portion  160  can be inserted with the gap G ( FIG. 24 ) into the recess  151   f , the movement toward the opening  151   k  of the axis L 151  is prohibited. 
         [0137]    The spherical portion  160  (coupling member  156 ) does not separate from the flange  151  (process cartridge  2 ) under the normal service condition by this prohibition. 
         [0138]    More particularly, the flange  151  is mounted to the end of the drum  20 , and the coupling member  156  is mounted to this flange  151 . 
         [0139]    In order to mount the coupling member  156 , the flange  151  is provided with the regulating portion extended along the inside peripheral surface of the flange  151  (retaining portion  151   i ). 
         [0140]    This regulating portion (retaining portion  151   i ) has the gap G relative to the spherical portion  160 , and has a nearer configuration to the configuration of the surface of the spherical portion  160  of the rotational force receiving member  150  than a flat plane which is perpendicular to the longitudinal direction of the drum  20  and which passes through the center of the spherical portion  160 . 
         [0141]    Referring to  FIGS. 15 and 16 , the process of assembling the rotational force receiving member  150  to the flange  151  and fixing will be described. 
         [0142]    The end portion  150   s  is inserted in the direction of an arrow X 1  into the flange  151 . 
         [0143]    Then, the spherical portion  160  is put over the end portion  150   s  in a direction indicated by an arrow X 2 . 
         [0144]    In addition, the through-holes  160   b  of the spherical portion  160  and the through-hole  150   r  of the end portion  150   s  are aligned with each other, and, thereafter, the pin  155  is inserted thereinto in the direction of an arrow X 3 . 
         [0145]    The pin  155  penetrates the through-holes  160   b  and the through-hole  150   r.    
         [0146]    Since the inner diameter of the through-holes  160   b  is smaller than that of the pin  155 , there is a frictional force between the pin  155  and the through-holes  160   b.    
         [0147]    In this embodiment, the interference therebetween is about 50 micrometers. 
         [0148]    By this, the pin  155  is held without deviation during the ordinary use, and the coupling member  156  constituted by the connection between the rotational force receiving member  150  and the spherical portion  160  is provided. 
         [0149]    In addition, the coupling member  156  is moved in a direction X 4 , and the spherical portion  160  is contacted or approached to the retaining portion  151   i.    
         [0150]    Then, retaining portion material  157  is inserted in the direction indicated by an arrow X 4 , and is fixed to the flange  151 . 
         [0151]    Since a play (gap) remains relative to the spherical portion  160 , the coupling member  156  can change the orientation. 
         [0152]    Referring to  FIG. 17  and  FIG. 18 , the structures of the drum unit  21  will be described. 
         [0153]    The flange  151  which has the mounted coupling member  156  is fixed to the end side of the drum  20  so that the drive receiving projection  150   d  is exposed, 
         [0154]    In addition, the drum flange  152  of the non-driving side is fixed to the other end side of the drum  20 . 
         [0155]    The fixing method may be the crimping, the bonding, the welding, and so on. 
         [0156]    In the state that the driving side of the drum unit  21  is supported by the bearing member  158  ( FIG. 3 ,  FIG. 19 ), and the non-driving side thereof is supported by the drum unit supporting pin  159  ( FIG. 19 ), the drum unit  21  is supported rotatably by the drum frame  51  ( FIG. 3 ). 
         [0157]    As has been described hereinbefore, the rotational force from the motor (unshown) of the main assembly  1  rotates the drive shaft  100  through the drive transmitting means, such as the gear of the main assembly  1  (unshown). 
         [0158]    The rotational force is transmitted to the cartridge  2  through the rotational force receiving member  150  of the coupling member  156 . 
         [0159]    In addition, the rotational force is transmitted from the rotational force receiving member  150  to the flange  151  through the pin  155  to apply the rotational force to the drum  20  integrally fixed to the flange  151 . 
         [0160]    The outside periphery of the flange  151  is provided with a helical gear molded integrally with the flange  151   151   c.    
         [0161]    This gear  151   c  transmits the rotational force received from the drive shaft  100  by the rotational force receiving member  150  to the developing roller  41  ( FIG. 2 ). 
         [0162]    More particularly, the outside portion is opposed to the retaining portion which is the regulating portion of the flange  151   151   i  is provided with the helical gear  151   c , and the gear transmits the rotational force received from the main assembly  1  by the coupling member  156  to the developing roller  41 . 
       (Remanufacturing Method of Cartridge) 
       [0163]    In the cartridge  2  mounted and used in the main assembly  1  the toner T contained in the toner chamber  45  is consumed in accordance with the repetition of the image formation. 
         [0164]    When the toner T is consumed to the degree it becomes impossible to form the image of the quality which satisfies the user of the cartridge  2 , it loses the commodity value as the cartridge  2 . 
         [0165]    In view of this, for example, a means (unshown) for detecting the remainder amount of the toner of the cartridge  2  is provided, and a main assembly control circuit (unshown) compares the detected remaining amount with a predetermined threshold for the cartridge lifetime forenotice and/or the cartridge lifetime warning. 
         [0166]    When the detected remaining amount is smaller than the threshold, a display portion (unshown) displays the lifetime forenotice or the lifetime warning of the cartridge  2 . 
         [0167]    By this, the user is prompted for the preparation for the exchange cartridge  2 , and in this manner, the quality of the output images is maintained. 
         [0168]    The used-up process cartridge  2  is collected, and the cleaning, the parts replacement, and so on are carried out, and the fresh toner is filled thereinto. 
         [0169]    By this, it is remanufactured to reuse. 
         [0170]    Here, the remanufacturing method of the used-up cartridge will be described. 
         [0171]    Here, the cleaning is carried out by the air suction, the air-blowing, the wet type cleaning, wiping, and so on, for example. 
       (i) Unit Separating Step: 
       [0172]    When the connection member  54  which connects the photosensitive member unit  50  and the developing device unit  40  rotatably relative to each other is pulled out, the developing device unit  40  and the photosensitive member unit  50  are separable from each other ( FIG. 3 ). 
       (ii) the Disassembling, Cleaning, Parts Replacement, Reassembling of the Photosensitive Member Unit  50 : 
       [0173]      FIGS. 19-22  are perspective views illustrating processes of disassembling the photosensitive member unit  50 . 
         [0174]    After separating the photosensitive member unit  50  and the developing device unit  40  from each other, the disassembling, the cleaning, the parts replacement, re-assembly of the photosensitive member unit  50  is carried out. 
         [0175]    These operations will be described. 
         [0176]    First, referring to  FIG. 19 , the disassembling of a protecting member  101  and an urging spring  102  will be described. 
         [0177]    A shaft portion  101   a  of the protecting member  101  for light shielding and protection of the drum  20  is dismounted with the urging spring  102  from a U-like bearing portion  51   d  of the drum frame  51 . 
         [0178]    Referring to  FIG. 20 , the dismounting method of the drum unit  21  will be described. 
         [0179]    The drum unit  21  is supported by a bearing member  158  and a drum unit supporting pin  159  provided at the respective ends of the photosensitive member unit  50  (drum frame  51 ). 
         [0180]    When the pin  159  is pulled out, the non-driving side (pin side) of the drum unit  21  is disengaged. 
         [0181]    The non-driving side wall  51   b  of the drum frame  51  is opened longitudinally outwardly, and simultaneously the bearing member  158  integrally fixed on the driving side wall  51   c  of the drum frame  51  at the driving side is opened longitudinally outwardly. 
         [0182]    These directions are indicated by the arrows in  FIG. 19 . 
         [0183]    Then, the drum unit  21  is rotated in the direction indicated by an arrow X 201  about the driving side of the drum unit  21 . 
         [0184]    Until the non-driving side drum flange  152  ( FIG. 18 ) does not overlap with the non-driving side wall  51   b  with respect to the axial direction (the direction of an arrow X 202 ) of the drum unit  21 , it is rotated, and then, the drum unit  21  is easily pulled out in the direction indicated by the arrow X 202 . 
         [0185]    Referring to  FIG. 21 , the removal of the waste toner and the dismounting of the charging roller  12  will be described. 
         [0186]    When the drum unit  21  is dismounted, an elongated waste toner collection opening  57  is exposed between a cleaning blade  52  and a waste toner leak preventing sheet  56  mounted to the drum frame  51 . 
         [0187]    By this, the removal of the waste toner stored in the waste toner chamber  52   a  ( FIG. 2 ) of the drum frame  51  can be accomplished using the waste toner collection opening  57 . 
         [0188]    This removal is carried out by air suction, blowing, wet type cleaning, wiping, for example. 
         [0189]    For the dismounting of the charging roller  12 , a roller shaft is dismounted in the direction indicated by the arrow from charging roller bearings  13  on the drum frame side which supports the opposite ends of the roller shaft. 
         [0190]    In the state that the charging roller  12  is is dismounted, when the removal of the waste toner is carried out, the contamination of the charging roller  12  and the damage of the charging roller  12  at the time of the removal are avoided. 
         [0191]    The dismounting of the cleaning blade  52  is carried out by dismounting the two screws  58  which fix the cleaning blade  52  to the drum frame  51 . 
         [0000]    (iii) Dismounting and Disassembling of Coupling Member  156  (1): 
         [0192]    In this embodiment, the rotational force receiving member  150  and the pin  155  of the coupling member  156  are made of metal, in order to accomplish high image quality. 
         [0193]    Since they are of metals, the durability is excellent and the repetition usage can be performed, and therefore, it is desirable to dismount and reuse them. 
         [0194]    In the method for dismounting the coupling member  156 , the manufacturing method of the drum unit  21  described above is carried out inversely. 
         [0195]    In other words, the drum  20  is dismounted from the drum unit  21  and then retaining portion material  157  ( FIG. 16 ) is separated from the flange  151 . 
         [0196]    Subsequently, the pin  155  is pulled out of the coupling member  156 . 
         [0197]    By this, the rotational force receiving member  150  and the spherical portion  160  can be separated from each other. 
         [0198]    The pin  155  and the rotational force receiving member  150  at least are reused (Unshown). 
       (iv) Dismounting and Disassembling of Coupling Member  156  (2): 
       [0199]    As another method, the coupling member  156  is directly dismounted from the drum unit  21 . 
         [0200]    In this case, since the operation for separating the drum  20  and the retaining member  157  from each other is unnecessary, working efficiency is excellent. 
         [0201]    The method of dismounting the coupling member  156  directly from the drum unit  21  will be described. 
         [0202]      FIG. 23  is a sectional view illustrating the method of dismounting the coupling member  156  directly from the drum unit  21 . 
         [0203]    The sectional view is a S 2 -S 2  sectional view of  FIG. 13 . 
         [0204]      FIG. 24  is a detailed view of the opening  151   k  portion (surrounded portion) in  FIG. 23 . 
         [0205]    Since the flange  151  has the gear  151   c , usually, it is made of resin material of a high slidability, such as polyacetal. 
         [0206]    Since the spherical portion  160  swings in the recess  151   f  similarly, it is made of a resin members, is such as polyacetal, similarly. 
         [0207]    More particularly, the spherical portion  160  and the flange  151  (regulating portion  151  the retaining portion as S  151   i ) are made of resin material. 
         [0208]    As has been described hereinbefore, the outside dimension D 160  of the spherical portion  160  is larger than the diameter D 151   b  of the opening  151   k , and therefore, usually, at the time of the usage, it does not separate from the spherical portion  160  (coupling member  156 ) from the flange  151  (process cartridge  2 ). 
         [0209]    The opening  151   k  is continuing with the retaining portion  151   i , and inclines away from the coupling member  156  (spherical portion  160 ). 
         [0210]    In more detail, in this embodiment, the difference between the outside dimension of the spherical portion  160  D 160  and the diameter of the opening  151   k  D 151   b  is approx. 0.4 mm. 
         [0211]    However, since the flange  151  and the spherical portion  160  are made of resin material, they relatively easily deform in accordance with the external force. 
         [0212]    Therefore, they deform, so that they can pass the spherical portion  160 . 
         [0213]    Therefore, the coupling member  156  can be pulled out from the flange  151 . 
         [0214]    First, the member other than the rotational force receiving member  150  of the drum unit  21 , i.e. the drum  20  and the flange  151  are held assuredly. 
         [0215]    Then, while nipping the driven portion  150   a  and the connecting portion  150   c  which have the rotational force receiving portion  150   e  by a nipping tool  201  such as a pliers or a pincher (cross hatching portion which utilizes connecting portion  150   c  in  FIG. 23 ) (grip step), they are pulled in the direction (direction indicated by the arrow X 231 ) of the axis L 150 . 
         [0216]    By this, the spherical portion  160  contacts to the retaining portion  151   i.    
         [0217]    In addition, when drawing force is increased, the outside dimension D 160  of the spherical portion  160  reduces, and, the retaining portion  151   i , the opening  151   k , and taper surface  151   n  of the flange  151  deforms outwardly in the radial direction from the axis L 151  of the flange  151  (direction indicated by the arrow in  FIG. 24 ). 
         [0218]    The taper surface  151   n  of the flange  151  extends to the opening  151   k , and it inclines away from the coupling member  156  toward the free end side of the coupling member  156  which is in the driven portion side with respect to the axial direction L 151 . 
         [0219]    This taper surface  151   n  is the portion of the second surface of the regulating portion  151  S. 
         [0220]    More particularly, the taper surface  151   n  is inclined from the opening which is the first surface of the retaining portion  151   i  which is the regulating portion  151 S  151   k , and is extended away from the coupling member  156  toward the free end of the rotational force receiving member  150  with respect to the longitudinal direction of the drum. 
         [0221]    In other words, the spherical portion  160 , the retaining portion which is the regulating portion  151  S which projects radially inwardly of the flange  151  sets, the opening  151   k , and taper surface  151   n  bend, and at the time of the diameter of the opening  151   k  D 151   b  and the outside dimension of the spherical portion  160  D 160  becoming the same, the coupling member  156  can be taken out from the flange  151  (Dismounting step). 
         [0222]    The force required at this time is approx. 9-11 kgf (88-108 Ns). 
         [0223]    In order to utilize the pulling force efficiently, it is preferable to carry out the drawing operation in the state that the axis of the flange  151  L 151  and the axis of the rotational force receiving member  150  L 150  are aligned with each other (positional relation shown in  FIG. 23 ). 
         [0224]    The flexibility of the flange regulating portion (retaining portion  151   i , opening  151   k , taper surface  151   n ) of  151  depends on the recess  151   q   1 - 8  which is in the positions outside in the radial direction of the drum flange  151  as seen from the regulating portion part  151 S  FIG. 13 . 
         [0225]    In detail, when the recesses  151   q  are large, it separates easily, and it is hard to separate when it is small. 
         [0226]    In this embodiment, the dimensional relation in this embodiment is selected such that in the normal use, the retention function is effective, and at the time of dismounting, it can be dismounted by the above described force. 
         [0227]    With this method, as described above, the coupling member  156  can be directly dismounted from the drum unit  21 . 
         [0228]    Accordingly, the operation for separating the drum  20  and the retaining member  157  from each other is unnecessary, and therefore the operational efficiency improves. 
         [0229]    In addition, since the operation can be performed with an ordinary tool  201  such as a pliers and a pincher, without using a special tool, the operation is easy. 
         [0230]    In addition, manual dismounting is practical, even without using the ordinary tool, in the case where a small number of drum units are disassembled. 
         [0231]    Thereafter, the pin  155  is drawn out or pushed out of the spherical portion  160 . By this, the coupling member  156  is separable into the rotational force receiving member  150 , the pin  155  and the spherical portion  160 . 
         [0232]    Here, the recesses  151   q  ( 151   q   1 - 151   q   8 ) are provided in the symmetric positions with respect to the axis  151  L of the flange  151 . 
         [0233]    More particularly, the recess  151   q   1  and the recess  151   q   5 , the recess  151   g   2  and the recess  151   q   6 , the recess  151   q   3  and the recess  151   q   7 , and the recess  151   q   4  and the recess  151   q   8  are provided at the symmetric positions with respect to the axis  151 L, respectively. 
         [0234]    By such the disposition, when the coupling member  156  is dismounted from the flange  151 , the deformation of the regulating portion arises uniformly with respect to the circumferential direction of the flange  151 , and therefore, the deformation of the gear portion  151 C can be eased. 
         [0235]    This applies also in the case of mounting the coupling member  156  to the flange  151 . 
         [0236]    The axis  151 L is aligned with the axis  20 L of the drum  20 , and with the axis  20 AL of the drum cylinder  20 A ( FIG. 13 ,  FIG. 34 ). Designated by reference character S is the photosensitive layer. 
       (v) Dismounting, and Disassembling (3) of Coupling Member  156 : 
       [0237]    Furthermore, another method for dismounting the coupling member  156  directly from the drum unit  21  will be described.  FIGS. 25-27  And  FIGS. 29 and 30  are sectional views illustrating a method for dismounting the coupling member  156  directly from the drum unit  21 . Here, they are the sectional views along a plane including the axis L 151  of the flange  151 , and the axis of the pin  155 .  FIG. 28  is a perspective view for illustrating the state of  FIG. 27  in three dimensions. The detailed description will be made with these views. 
         [0238]    First, the coupling member  156  is rotated relative to the flange  151  in the direction of the arrow in  FIG. 25  about the center of the spherical portion  160  (coupling member inclination step). Then, the end surface  155   a  of the pin  155  is exposed. 
         [0239]    Then, the end surface  155   a  is pushed toward the end surface  155   b  in the direction of the arrow in  FIG. 26 . More particularly, in the state where the coupling member  156  is inclined through the above described inclination step, the pin  155  of which the one end, and the other end project from the spherical portion  160  is pushed toward the other end from the one end (pin urging step). As has been described hereinbefore, the frictional force is produced between the pin  155 , and the spherical portion  160 , and therefore, the pin  155  is held, but the pin  155  can be pushed in, without destroying the parts (coupling is member  156 ) by a pressing tool  202  such as a screw driver having a tip. When the end surface  155   a  is pushed in to the neighborhood the surface of the spherical portion  160 , the end surface  155   b  of the opposite side moves to the state that a clearance is maintained relative to the inner surface  151   m  of the flange  151 . 
         [0240]    Then, the coupling member  156  is lightly pulled in the direction of an arrow X 271  in  FIG. 27 . By this, the spherical portion  160  contacts to the retaining portion  151   i . Furthermore, the coupling member  156  is rotated in the direction of an arrow X 272 . By this, the end surface  155   b  side is exposed. 
         [0241]    Then, when the coupling member  156  inclines the axis L 150 , and L 151  cross with each other, the coupling member  156  is rotated about the axis L 151  of the flange  151  in  FIG. 27  in the direction of the arrow in  FIG. 28 . 
         [0242]    Before pushing the end  155   a  of the pin  155  in, the rotational force transmitting surface  151   h  ( FIG. 13 ), and the pin  155  are in contact to each other, but the pin end  155   a  is pushed in, and therefore, it can be rotated, without contacting to the rotational force transmitting surface  151   h . In addition, the rotation is not restricted in the end  155   b  by providing the clearance between the pin  155 , and the tapered surface  151   n.    
         [0243]    The coupling member  156  is rotated to the position that the pin end  155   b  as seen in the longitudinal direction overlaps with the tapered surface  151   n  of the flange  151  ( FIG. 29 ). 
         [0244]    As mentioned above, the a part of the pin which is further projected from the other end portion by being pushed through the above described pin urging step rides on the tapered surface  151   n  which is the second surface of the retaining portion  151   i  which is the regulating portion. 
         [0245]    Furthermore, while holding the driven portion  150   a  of the rotational force receiving member  150 , a force is applied to the direction of rotating the coupling member  156  in the direction of the arrow in  FIG. 29 . 
         [0246]    When the force is applied with such the positional relation, the driven portion  150   a  is a force application point, the contact points between the pin  155 , and the tapered surface  151   n  is a fulcrum P 1 , and the contact portion between the spherical portion  160 , and the retaining portion  151   i  is a point of application. 
         [0247]    As shown in  FIG. 29 , the connecting portion  150   c  of the rotational force receiving member  150  is long, and the distance between the fulcrum P 1 , and the point of application is shorter than the distance between the force application point, and the fulcrum P 1 , and therefore, the so-called “lever rule” works. By increasing the force, the outside dimension D 160  of the spherical portion  160  at the point of application reduces. And, the retaining portion  151   i , the opening  151   k , and the tapered surface  151   n  of the flange  151  outwardly deform with respect to the radial direction of the axis L 151  of the flange  151  (direction of arrow in  FIG. 24 ). By this, the spherical portion  160  (coupling member  156 ) is dismounted from the flange  151 . The force required at this time is approx. 8-10 kgf ( 78 - 98 N). 
         [0248]    As described above, the force toward the fulcrum is applied at the free end of the coupling member  156  with the fulcrum at the pin part which rides on the tapered surface  151   n , so that the coupling member  156  is dismounted from the flange  151  (coupling member dismounting step). 
         [0249]    With this method, it is possible to dismount the coupling member  156  directly from the drum unit  21 . Accordingly, the operation for separating the drum  20 , and the retaining member  157  from each other is unnecessary, and therefore, the operational efficiency is improved. In addition, the operation can be carried out using the ordinary tool  202  such as the screw driver, without using the special tool, and therefore it is excellent in the easiness of the operation. In addition, the force applied until the spherical is portion  160  (coupling member  156 ) separates from the flange  151  ( FIG. 30 ), is small by the “leverage”. 
       (vi) Re-Assembling Method of Drum Unit  21  (1): 
       [0250]    A first method is the same as the assembling method of the drum unit  21  described above substantially. In other words, the rotational force receiving member  150  is inserted into the flange  151 , and the spherical portion  160  is covered. Then, the rotational force receiving member  150 , the spherical member  160 , and the pin  155  are integrally connected by the pin  155 , and the coupling member  15  is assembled to the flange  151  ( FIG. 15 ). Furthermore, the retaining member  157  is inserted in the direction of the arrow X 4 , and it is fixed to the flange  151  ( FIG. 16 ). Then, the drum  20 , and the flange  151  are connected with each other. Finally, non-driving side drum flange  152  is fixed to the other end portion of the drum  20  ( FIG. 18 ). 
         [0251]    At this time, the rotational force receiving member  150  disassembled, and taken out is reused, but the spherical portion  160 , and the pin  155  may be reused after checking the degrees of the damage, and deformation. 
         [0000]    (vii) Re-Assembling Method of Drum Unit  21  (2): 
         [0252]      FIG. 31 , and  FIG. 32  are sectional views illustrating the re-assembling method of the drum unit  21  according to another embodiment. Here,  FIGS. 31 , and  32  are a sectional views taken along a line S 1 -S 1  in  FIG. 13 .  FIG. 34  is a sectional view illustrating a drum unit  21  of the other embodiment. 
         [0253]    First, referring to  FIG. 31 , the description will be made. In the assembling method described above, the coupling member  156  is assembled in the flange  151 , but in the present embodiment, the coupling member  156  is assembled independently. At this time, the rotational force receiving member  150  disassembled, and taken out is reused, but the spherical portion  160 , and the pin  155  may be reused after checking the degrees of the damage, and deformation. 
         [0254]    Apart from it, the retaining member  157  is fixed to the flange  151 , and then the drum  20  and the flange  151  are connected with each other. Furthermore, non-driving side drum flange  152  is fixed to the other end portion of the drum  20  ( FIG. 18 ,  FIG. 34 ). 
         [0255]    Finally, the coupling member  156  is pushed in in the direction of the arrow in  FIG. 31 , and the spherical portion  160  is contacted to the tapered surface  151   n , and when it is further pushed in, the spherical portion  160 , and the neighborhood of the tapered surface  151   n  of the flange  151  which is the regulating portion deforms (arrow in  FIG. 24 ) The spherical portion  160  (coupling member  156 ) can be accommodated in the recess  151   f  by this deformation ( FIG. 23 ). 
         [0256]    Here, the easiness of the deformations of the regulating portion  1515  (retaining portion  151   i , the opening  151   k , tapered surface  151   n ) of the flange  151  depend on the recess  151   q  ( FIG. 13 ,  FIG. 34 ) which is in the outside with respect to the radial direction of the drum flange  151 , and the easiness is increased with the size of the recess  151   q . In this embodiment, the dimensional relations are such that at the time of the usage, it has the retention function normally, and is easily pushed in. It is not inevitable that the regulating portion  151 S has the retaining portion  151   i , the opening  151   k , and the tapered surface  151   n . The regulating portion  151 S may have the retaining portion  151   i  at least. 
         [0257]    Therefore, in mounting the coupling member  156  to the flange  151  the spherical portion  160  contacts to the tapered surface  151   n , and the center position of the spherical portion  160  is regulated on the axis of the flange  151 . By this, the contacted state of the spherical portion  160  relative to the tapered surface  151   n  is uniform. Accordingly, the regulating portion  151 S deforms uniformly, and therefore, the spherical portion  160  can be smoothly mounted to the flange  151 . 
         [0258]    Therefore, even if the flange  151  and the spherical portion  160  are made of the resin material, as with the present embodiment, the damage can be prevented when they contact. 
         [0259]    In this embodiment, the coupling member  156  is made of the metal, and therefore, the strength is high. 
         [0260]    However, the center position of the spherical portion  160  is set on the axis  151 L. Accordingly, the coupling member  156  can be smoothly mounted to the flange  151 . 
         [0261]    In the spherical portion  160  at least the portion contacted to the regulating portion  151 S has the spherical configuration when mounting the coupling member  156  smoothly to the flange  151 . 
         [0262]    The pin  155  can be inserted into the spherical portion  160  and the rotating force receiving portion  150  without inserting the rotational force receiving member  150  into the flange  151 , and therefore, the insertion of the pin  155  is easy. In addition, it is not necessary to mount the parts from the retaining member  157  side, and therefore, it can manufacture as a single part by molding the flange  151 , and the retaining member  157  integrally (integral-type flange  153 ), as shown in  FIG. 32 . By this, the simplification of the remanufacturing step, and the cost reduction of the product are accomplished. 
         [0000]    (viii) Re-Assembling Method of Photosensitive Member Unit  50 : 
         [0263]    The reassembling of the photosensitive member unit  50  after this is carried out through the reverse process as with the case of the disassembling of the photosensitive member unit  50 . More particularly, the cleaning blade  52 , the charging roller  12 , and the drum unit  21  are mounted in the order named order. 
         [0264]    In the above-described reassembling, a new article is used at least as for the drum  20 . 
       (ix) Disassembling Method, and Re-Assembling Method of Developing Device Unit  40 : 
       [0265]      FIG. 33  is a perspective view illustrating a disassembling method of the development unit  40 . Referring to  FIG. 33 , the description will be made about the disassembling method of the development unit  40 . 
         [0266]    First, the side covers  55  at the opposite longitudinal ends of the developing device unit  40  are dismounted. The side cover  55  is fixed to the toner accommodating chamber  40   a  by fastening means such as unshown screws, and therefore, by unfastening them, it can be dismounted from the developing device unit  40 . 
         [0267]    Then, the developing roller unit  39  is dismounted. The developing roller unit  39  is rotatably supported by the bearing members  47  provided on the opposite ends of the developing roller  41 . Each of the upper portion, and the lower portion of the bearing member  47  is provided with two holes  47   a , and which are engaged with the shaft  55   c  of the side cover  55 . Accordingly, when the side covers  55  at both end portions are dismounted, the developing roller unit  39  can be easily dismounted from the development unit  40 . Furthermore, the developing roller unit  39  is provided at each end of the developing roller  41  with the spacer member  48  for holding a predetermined gap between the developing roller  41 , and the drum  20 . In addition, the end of the developing roller  41  is provided with the gear  49  for transmitting the rotational force to the developing roller  41  by engaging with the gear  151   c  of the flange  151 . 
         [0268]    Then, the developing blade  42  is dismounted. The developing blade  42  is fixed to the toner accommodating chamber  40   a  by the screws  59  at the opposite ends thereof together with the cleaning member  38  for effecting a cleaning operation, while contacting to the end surface of the developing roller  41 . Therefore, the developing blade  42  can be dismounted by removing the two screws  59 . 
         [0269]    A toner refilling step will be described. A toner supply opening  37  ( FIG. 2 ,  FIG. 33 ) communicated with the toner feeding chamber  44 , and the toner chamber  45  is exposed, through the above described disassembling step. The toner is filled into the toner chamber  45  through the toner supply opening  37 . The toner filling is carried out while holding the developing device unit  40  with the toner supply opening  37  at the upper position, and the toner chamber  45  at the lower position. And, the feeding means such as the funnel is used, and the toner is refilled into the toner supply opening  37 . 
         [0270]    As described above, after refilling the toner, the developing device unit  40  is assembled. In the case of the reassembling of the developing device unit  40 , the operations are carried out through the process opposite from the process of the disassembling step described above. More particularly, after the end of the refilling of the toner, the developing blade  42 , the developing roller unit  39 , and the side cover  55  are mounted. 
       (x) Re-Assembling Method of Cartridge  2 : 
       [0271]    The operations are carried out through the process opposite from the process of the disassembling in the reassembling of the cartridge  2 . More particularly, by the connection member  54  ( FIG. 3 ), the photosensitive member unit  50 , and the developing device unit  40  are connected rotatably with each other. Finally, in the state that the urging spring  102  is mounted to the protecting member  101  ( FIG. 19 ), the shaft portion  101   a  of the protecting member  101  is inserted into the U-shaped bearing portion  51   d  of the drum frame  51 . 
         [0272]    The remanufacturing of the process cartridge  2  is completed through the above-described steps. 
         [0273]    In the assembling method, the disassembling method, the remanufacturing method of the process cartridge, the steps may simultaneously be carried out by the different operators. In addition, the orders of the steps set forth in the foregoing or in the claims may be properly modified by one skilled in the art. 
         [0274]    In addition, the assembly, the disassembling, the remanufacturing of the process cartridge can be carried out by manual operations, automatic operation using automated machines, and combinations of the manual operations, and the automatic operations. In addition, the tools may be used properly. 
         [0275]    In addition, in this embodiment, the used process cartridges are collected, and disassembled. And, the parts taken out of the process cartridges by the disassembling are gathered for same parts, respectively. Thereafter, the parts may be re-used, and in some cases, a part of the parts (non-reusable part) may not be used, and a new part may instead be used. In addition, in another type of the present embodiment the used process cartridges are collected, and disassembled. And, a part of parts (non-reusable parts) may not be used, and instead, a reusable part collected from another used cartridge may be reused. Therefore, in the claims, the members, the parts, the portions, and devices with “said or the” covers other members, parts, portion, and devices which have the same function as the very members, parts, portions, and devices. 
         [0276]    As has been described hereinbefore, according to the embodiments described above, the process cartridge which is easy in assembling is provided. In addition, the process cartridge which is simple in disassembling is provided. In addition, the simple remanufacturing method of the process cartridge is accomplished. In addition, a remanufacturing method of making reusable a process cartridge from which the developer has been used to such an extent that the images of a quality satisfactory to the user are not formed, is accomplished. In addition, the developer can be refilled easily into the process cartridge from which the toner has been consumed. 
         [0277]    The structures of the process cartridge of the foregoing embodiments are summarized as follows. 
         [0278]    (1) The process cartridge  2  detachably mountable to the main assembly  1  of the electrophotographic image forming apparatus comprises the electrophotographic photosensitive member drum  20 , and the process means  12 ,  41 ,  52  actable on the electrophotographic photosensitive member drum. It includes the coupling member  156  for receiving the rotational force for rotating the electrophotographic photosensitive member drum from the main assembly in the state that the process cartridge is dismountably mounted to the main assembly. This coupling member includes the rotational force receiving member  150  which has the rotational force receiving portion  150   e  for receiving the rotational force at the free end portion, and the spherical portion  160  mounted by the pin  155  penetration to the rear end portion of the rotational force receiving member. In addition, it includes the retaining portion  151   i  which is the regulating portion extended along the inner peripheral surface of the flange  151  in order to mount the coupling member  156  to the drum flange  151  mounted to the end of the electrophotographic photosensitive member drum  20 . The configuration of the retaining portion  151   i  provides the gap G relative to the spherical portion  160 , and is nearer to the configuration extended along the surface of the spherical portion  160  of the free end portion than the flat plane which is perpendicular to the longitudinal direction of the drum  20 , and which passes through the center of the spherical portion  160 . 
         [0279]    With this structure, the process cartridge which can be easily assembled is accomplished. In addition, the process cartridge which can be easily disassembling is accomplished. 
         [0280]    More particularly, the coupling member can be directly dismounted from the electrophotographic photosensitive drum unit  21 , and therefore, the operation for separating the electrophotographic photosensitive member drum, and the retaining member from each other is unnecessary, by which the operational efficiency is excellent. In addition, the disassembling is possible by the ordinary tools such as the pliers, and the pincher, without using special tools. 
         [0281]    (2) regulating portions  151 S include the first surface (opening)  151   k  extended away from the coupling member  156  toward the free end portion with respect to the longitudinal direction from the regulating portion  151 S. 
         [0282]    (3) regulating portions  1515  include the second surface (tapered surface)  151   n  bent from the first surface (opening)  151   k , and the second surface (tapered surface)  151   n  is extended away from the coupling member  156  toward the free end portion with respect to the longitudinal direction. 
         [0283]    (4) The outside which faces the retaining portion  151   i  of the flange  151  are provided with the helical gear  151   c , and the helical gear transmits the rotational force received by the coupling member  156  from the main assembly  1  to the developing roller  41 . 
         [0284]    The (5) the spherical portion  160 , and the regulating portion  151 S are made of resin material. 
         [0285]    In addition, the dismounting methods of the coupling member  156  of the embodiments described above are summarized as follows. 
         [0286]    The coupling member  156  is dismounted from the (6) the drum flange  151  mounted to the electrophotographic photosensitive member drum  20  usable with the process cartridge  2  detachably mountable to the main assembly  1  of the electrophotographic image forming apparatus. In the state in which the process cartridge  2  is dismountably mounted to the main assembly  1  the coupling member  156  receives the rotational force for rotating the electrophotographic photosensitive member drum  20  from the main assembly  1 . 
         [0287]    The coupling member  156  has the rotational force receiving member  150  which has the rotational force receiving portion  151   e  for receiving the rotational force, ad the free end portion, and the resin spherical portion  160  mounted by the pin  155  penetration to the rear end portion of the rotational force receiving member. And, the coupling member  156  is mounted to the drum flange  151  by the regulating portion (retaining portion)  151   i , and the configuration of the regulating portion (retaining portion)  151   i  provides the gap G relative to the spherical portion  160 , and nearer, than the flat plane which is perpendicular to the longitudinal direction of the electrophotographic photosensitive member drum  20  of flat surface, and is, and which passed through the center of the spherical portion  160 , to the configuration extended along the surface of the spherical portion of free end portion. 
         [0288]    (i) It has the gripping step of gripping the rotational force receiving member  150  of the coupling member  156  by the tool  201 . 
         [0289]    (ii) It has the coupling member dismounting step of applying the force to the tool  201  toward the free end portion with respect to the longitudinal direction in the state where the rotational force receiving member  150  is gripped through the gripping step. By this, while elastically deforming the opening  151   k  of the retaining portion  151   i  which is the resin regulating portion, the tapered surface  151   n , and the resin spherical portion  160 , the resin spherical portion  160  is dismounted from the resin material regulating portion (retaining portion  151   i ), by which the coupling member  156  is dismounted. 
         [0290]    There is provided a method in which the coupling member  156  is mounted to the drum flange which has the resin material regulating portion provided inside of the flange  151  mounted to the end of the photosensitive drum  20   151 S (retaining portion  151   i , opening  151   k , tapered surface  151   n ). Here, the regulating portion  151 S inwardly projects with respect to the radial direction of the flange  151 . 
         [0291]    The method includes the gripping step of gripping the rotational force receiving member  150  of the coupling member  156 . It includes the coupling member mounting step. In the coupling member mounting step, while elastically deforming the at least one side of the resin regulating portion  151 S, and the resin spherical portion  160 , the spherical portion  160  is pushed into the inside of the regulating portion  151 S with respect to the direction of the axis  20 L of the photosensitive drum  20 , by which the coupling member  156  is mounted to the flange  151 . 
         [0292]    In addition, the dismounting step of dismounting the coupling member  156  from the flange  151  has the following steps. It has the gripping step of gripping the rotational force receiving member  150  of the coupling member  156 . It has the coupling member dismounting step, wherein in the state where the rotational force receiving member  150  is gripped by the gripping step, the spherical portion  160  is dismounted from the regulating portion  151 S, while deforming the at least one side of the regulating portion  151 S, and the spherical portion  160  by applying the force toward the free end portion, by which, the coupling member  156  is dismounted from the flange  151 . 
         [0293]    The regulating portions  151 S are provided inside of the flange  151  together with the interval along the circumferential direction of the flange  151 . Furthermore, the recess  151   f  is provided inside of the flange  151 , and it is provided at the outside of the regulating portion  151 S with respect to the radial direction of the flange  151 . The outside surface of the flange  151  opposed to the recess  151   f  is provided with the gear portion  151 C. The gear portion  151 C is provided along the outer surface of the flange  151 . The gear portion  151 C transmits the rotational force received by the coupling member  156  from the main assembly  1  to the developing roller  41 . 
         [0294]    According to the dismounting method for this coupling member, it is possible to dismount the coupling member directly from the electrophotographic photosensitive drum unit, the operation for separating the electrophotographic photosensitive member drum, and the retaining member is unnecessary. In addition, the operation is possible by an ordinary tool such as the pliers, and the pincher, without using special tools. 
         [0295]    (7) There is provided a method, wherein the coupling member  156  is dismounted from the drum flange  151  mounted to the electrophotographic photosensitive member drum  20  usable with the process cartridge  2  detachably mountable to the main assembly  1  of the electrophotographic image forming apparatus. The coupling member  156  receives the rotational force for rotating the electrophotographic photosensitive member drum  20  from the main assembly  1  in the state in which the process cartridge  2  is dismountably mounted to the main assembly  1 . The coupling member  156  has the rotational force receiving member which has the rotational force receiving portion for receiving the rotational force at the free end portion, and the spherical portion mounted at the rear end portion of the rotational force receiving member by the penetration of the pin  155 . 
         [0296]    (i) It has the inclination step of inclining the coupling member  156  with respect to the rotation axis of the drum flange  151 . 
         [0297]    (ii) It has the pin urging step of pushing the pin  155  of which the one end, and the other end thereof project from the spherical portion  160  toward the other end from the one end in the state of the coupling member  156  being inclined through the inclination step. 
         [0298]    (iii) It has the pin riding step of making a part of the pin which is further projected from the other end portion by being pushed by the pin urging step ride on the second surface (tapered surface)  151   n  of the regulating portion provided along the inner peripheral surface of the drum flange  151 . Here, the retaining portion  151   i  as the regulating portion provides the gap G relative to the spherical portion  160 , and the configuration thereof is nearer, than the flat plane which is perpendicular to the longitudinal direction of the photosensitive drum  20 , and, and which passes through the center of the spherical portion  160 , to the configuration extended along the surface of the spherical portion of the free end portion. And, the regulating portion  151 S is extended from the retaining portion  151   i , and it has the first surface (opening)  151   k  extended away from the coupling member  156  toward the free end portion with respect to the longitudinal direction. The second surface (tapered surface)  151   n  is bent from the first surface (opening)  151   k , and is extended away from the coupling member  156  toward the free end portion with respect to the longitudinal direction. 
         [0299]    (iv) It has the coupling member dismounting step of applying the force toward a part of the pin which rides, at the free end of the coupling member  156 , on the second surface, and dismounting the coupling member  156  from the drum flange  151 . 
         [0300]    According to the dismounting method for the coupling member of the embodiments described above, the coupling member can be dismounted directly from the electrophotographic photosensitive drum unit. Therefore, the operation for separating the electrophotographic photosensitive member drum and the retaining member is unnecessary, and therefore, the disassembling operational efficiency is excellent. In addition, without using special tools, the operation is possible using an ordinary tool such as pliers, pincher, and so on, and therefore, the operation is easy. By utilizing the leverage, the force required to dismount the coupling member directly is small. 
         [0301]    In addition, when the structures of the electrophotographic photosensitive drum unit  21  of the embodiments described above are summarized as follows. 
         [0302]    (8) electrophotographic photosensitive member drum  20  is used in the electrophotographic photosensitive drum unit  21  usable with the process cartridge  2  detachably mountable to the main assembly  1  of the electrophotographic image forming apparatus. It has the coupling member  156  for receiving the rotational force for rotating the photosensitive drum  20  from the main assembly  1 , in the state that the process cartridge  2  is dismountably mounted to the main assembly  1 . The coupling member  156  has the rotational force receiving member  150  which has the rotational force receiving portion  151   e  for receiving the rotational force at the free end portion, and the spherical portion  160  mounted by the penetration of the pin  155  at the rear end portion of the rotational force receiving member  150 . And, the coupling member  156  is mounted to the flange  151  mounted to the end of the photosensitive drum  20  by the regulating portion  151 S (retaining portion  151   i ). The regulating portion  151 S (retaining portion  151   i ) is provided along the inner peripheral surface of the flange  151  in order to mount the coupling member  156  to the flange  151  mounted to the end of the photosensitive drum  20 . In addition, the regulating portion  1515  (retaining portion  151   i ) provides the gap relative to the spherical portion, and the configuration thereof is nearer, than the flat plane which is perpendicular to the longitudinal direction of the photosensitive drum  20 , and, and which passes through the center of the spherical portion  160 , to the configuration extended along the surface of the spherical portion  160  of the free end portion  160 . 
         [0303]    As has been described hereinbefore, the structure of the drum unit  21  is as follows. 
         [0304]    First, the coupling member  156  is mountable to the drum unit  21 . And, the coupling member  156  has the rotational force receiving member  150  which has the rotational force receiving portion  151   e  for receiving the rotational force at the free end portion, and the spherical portion  160  mounted by the penetration of the pin  155  at the rear end portion of the rotational force receiving member  150  in order to rotate the drum  20  from the main assembly  1  of the electrophotographic image forming apparatus. 
         [0305]    And, the drum unit  21  has the cylinder  20 A which is provided with the photosensitive layer S at the peripheral surface, and the drum flange  151  provided at the end of the cylinder  20 A. The drum flange  151  has the resin material regulating portion  151 S which inwardly projects with respect to the radial direction of the drum flange  151  in the inside of the drum flange  151 . The regulating portion  151 S prevents the spherical portion  160  from moving in the longitudinal direction of the drum unit  21 , when the coupling member  156  is mounted. And, the regulating portions  151 S are provided with the intervals along the circumferential direction in the inside of the flange  151 . In addition, the drum flange  151  has the recess  151   q  ( 151   q   1  to  151   q   8 ) provided in the regulating portion  151 S at the outside with respect to the radial direction of the flange  151 , wherein the recess  151   q  facilitate or permits the regulating portion  1515  to outwardly deform with respect to the radial direction of the flange  151 . In addition, the flange  151  has a plurality of rotational force transmitting surface (rotational force transmitted portion)  151   h  ( 151   h   1 - 151   h   4 ) which are provided between the regulating portions  151 S in order to receive the rotational force from the pin  155 . 
         [0306]    In addition, the resin material regulating portions  151 S are provided at the same positions as the gear portion  151 C with respect to the longitudinal direction of the cylinder  20 A in the resin flange  151 , and they are disposed with the intervals along the circumferential direction of the cylinder  20 A. And, in the regulating portion  151 S, the free end portion with respect to the longitudinal direction of the cylinder  20 A inwardly projects with respect to the radial direction of the flange  151 . In addition, the recess  151   q  ( 151   q   1  to  151   q   8 ) is provided between the regulating portion  151 S, and the inner surface  151   t  ( FIG. 13 ,  FIG. 34 ) of the flange  151  with respect to the radial direction. And, the recess  151   q  facilitates or permits the regulating portion  151 S to outwardly deform with respect to the radial direction. 
         [0307]    Here, the regulating portion  151 S outwardly deforms easily with respect to the radial direction by the provision of the recess  151   q . In addition, thereafter, the regulating portion  151 S which deformed is restored. 
         [0308]    In addition, designated by  151   r  ( FIG. 13 ) is the connecting portion for connecting the regulating portion  151 S, and the inner surface  151   t  ( FIG. 13 ,  FIG. 34 ) of the flange  151  with each other. The recess  151   q  is provided between the connecting portions  151   r . In other words, the connecting portion  151   r , and the recess  151   q  are provided by turns along the circumferential direction of the flange  151 . Therefore, the regulating portion  1515  deforms easily. 
         [0309]    In addition, the coupling member  156  is mounted to the flange  151 . The coupling member  156  receives the rotational force to be transmitted from the main assembly  1  to the flange  1 . The coupling member  156  has the rotational force receiving member  150  which has the rotational force receiving portion  150   e  ( 150   e   1  to  150   e   4 ) for receiving the rotational force at the free end portion, and the spherical portion  160  mounted by the penetration of the pin  155  at the rear end portion of the rotational force receiving member  150 . In the state that the coupling member  156  is mounted to the flange  151 , the pin  155  is movable in the circumferential direction, and the longitudinal direction of the cylinder between the regulating portion  151 S, and the regulating portion  151 S provided along the circumferential direction of the flange  155 . In addition, the coupling member  156  is revolvable relative to the flange  151  in the state in which the spherical portion  160  is movable in the circumferential direction, and is regulated in the movement in the longitudinal direction by the regulating portion  151 S. More particularly, the coupling member  156  is mounted revolvably to the flange  151  in the state that the spherical portion  160  is movable within the limits that the pin  155  is regulated in the movement by the regulating portion  151 S in the circumferential direction, and it is regulated in the movement by the regulating portion  151 S in the longitudinal direction. 
         [0310]    According to the drum unit  21  described above, the dismounting of the coupling member  156  is easy. 
         [0311]    According to the drum unit  21  described above, the mounting of the coupling member  156  is easy. 
         [0312]    According to the structure of the drum unit  21 , it is possible to dismount the coupling member  160  directly from the drum unit  21 , and the operation for separating the drum  20 , and the retaining member from each other is unnecessary, and therefore, the operational efficiency is excellent. In addition, since the operation is possible by an ordinary tool such as pliers, a pincher, and so on, without using special tools, it is advantageous in the easiness of the operation. 
         [0313]    (9) regulating portions  1515  (retaining portion  151   i ) have the first surface (opening)  151   k  extended away from the coupling member  156  toward the free end portion with respect to the longitudinal direction from the retaining portion  151   i  as the regulating portion  151 S. 
         [0314]    (10) regulating portions have the second surface (tapered surface)  151   n  bent from the first surface (opening)  151   k , and it is extended away from the coupling member  156  toward the free end portion with respect to the longitudinal direction. 
         [0315]    (11) the outside which faces the retaining portion  151   i  of the drum flange  151  is provided with the helical gear  151   c , and the helical gear transmits the rotational force received by the coupling member  156  from the main assembly  1  to the developing roller  41 . 
         [0316]    According to the embodiments described above, an easy dismounting method for the coupling member can be provided. 
         [0317]    According to the embodiment described above, an easy mounting method for the coupling member can be provided. 
         [0318]    According to the embodiments described above, the electrophotographic photosensitive drum unit from which the coupling member can be easily dismounted, can be provided. 
         [0319]    According to the embodiments described above, the electrophotographic photosensitive drum unit to which the coupling member can be easily mounted can be provided. 
         [0320]    While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purpose of the improvements or the scope of the following claims. 
         [0321]    This application claims priority from Japanese Patent Application No. 207291/2008 filed Aug. 11, 2008 which is hereby incorporated by reference.