Abstract:
A mounting method for mounting an electroconductive sheet on a developer seal member for sealing a developer discharging opening provided in a developer accommodating container for accommodating a developer. The electroconductive sheet is provided with an adhesive material on one surface thereof. A separation sheet is adhered to the one surface, wherein the separation sheet is larger than the electroconductive sheet. The method includes a suction step of contacting a suction tool to the other surface of the electroconductive sheet. The suction tool is effective to suck air to attract the electroconductive sheet thereon. An exposure step separates the separation sheet from the electroconductive sheet, while the electroconductive sheet is being sucked by the attraction tool, so that the one surface of the electroconductive sheet is exposed. A bonding step, after performing the exposure step, binds the one surface of the electroconductive sheet to the developer seal member, while the electroconductive sheet is being sucked by the suction tool.

Description:
FIELD OF THE INVENTION AND RELATED ART 
     The present invention relates to a method for attaching an electrically conductive sheet to a developer sealing member used to seal an opening with which a developer container is provided to release developer. An electrically conductive sheet is used, for example, to detect whether the developer sealing member is open. A developer container is placed in, for example, a developer cartridge or a process cartridge, which is removably mountable in the main assembly of an image forming apparatus. 
     Here, an image forming apparatus includes an apparatus which forms an image on recording medium with the use of, for example, an electrophotographic image forming system. As examples of an electrophotographic image forming apparatus, there are an electrophotographic copying machine, an electrophotographic printer (for example, laser beam printer, LED printer, and the like), a facsimile apparatus, a word processor, and the like. 
     A process cartridge means a cartridge in which at least one among a charging means, a developing means, and a cleaning means, and a photosensitive member, are integrally placed, and which is removably mountable in the main assembly of an image forming apparatus. 
     Conventionally, an image forming apparatus which employs an electrophotographic image formation process also employs a process cartridge system. According to a process cartridge system, an electrophotographic photosensitive member, and a single or plural processing means, which act on an electrophotographic photosensitive member, are integrally placed in a cartridge which is removably mountable in the main assembly of an image forming apparatus. Also according to the process cartridge system, an image forming apparatus can be maintained by users themselves without relying on service personnel, and therefore, operational efficiency can be drastically improved. As a result, a process cartridge system is widely used in the field of the image forming apparatus. 
     The developer releasing opening of the developer (toner) containing portion of the above described process cartridge is sealed with a toner sealing member. A toner sealing member is removed to release the developer into a developing means containing portion. As for a method for removing a toner sealing member, there are a method in which a toner sealing member is pulled off by a user, and a method in which one end of a toner sealing member is fixed to a winding shaft, and the toner sealing member is automatically wound away by the driving force transmitted from the image forming apparatus main assembly. 
     The above-described methods for removing a toner sealing member also apply to a developer cartridge. 
     Thus, a method has been sought for detecting whether the developer releasing opening of a developer containing portion is entirely exposed when a toner sealing member is automatically removed. For this purpose, it has been a common practice that an electrically conductive portion which is severed as the toner sealing member is removed is formed on a toner sealing member, and whether the developer releasing opening is entirely exposed is detected by reading the condition of the electrically conductive portion, on the image forming apparatus main assembly side. However, the electrically conductive portion is an extremely thin sheet of electrically conductive material, such as aluminum foil, coated with adhesive, and therefore, tends to plastically deform when it is separated from a separation sheet, or in the like situations. Therefore, a conventional method for pasting an electrically conductive portion onto a toner sealing member, without deforming the electrically conductive portion, and with a high degree of positional accuracy, requires a substantial number of steps, which in turn results in a high cost. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a method for pasting an electrically conductive sheet on a developer sealing member and a developer holding portion, with a high degree of positional accuracy, without plastically deforming the electrically conductive sheet. 
     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 
     FIG. 1 is a schematic sectional view of the process cartridge in the first embodiment of the present invention, at a plane perpendicular to the longitudinal direction of the process cartridge. 
     FIG. 2 is a schematic sectional view of the main assembly of the image forming apparatus in the first embodiment of the present invention, at a plane perpendicular to the longitudinal direction of the process cartridge in the apparatus. 
     FIG. 3 is a schematic perspective view of the toner holding portion of the process cartridge, in a brand-new condition, in the first embodiment of the present invention. 
     FIG. 4 is a schematic perspective view of the toner holding portion of the process cartridge in the first embodiment of the present invention, after the toner sealing member was wound away. 
     FIG. 5 is a schematic perspective view of the toner holding portion of the process cartridge in the first embodiment of the present invention, while the stirring member is rotated. 
     FIG. 6 is a schematic perspective view of the toner holding portion of the process cartridge in the first embodiment of the present invention, while the toner sealing member is wound away. 
     FIG. 7 is a schematic perspective view of the toner holding portion of the process cartridge in the first embodiment of the present invention, while the photosensitive drum and stirring member are rotated. 
     FIG. 8 is a sectional view of the toner sealing member in the first embodiment of the present invention. 
     FIG. 9 is a plan view of the toner sealing member in the first embodiment of the present invention. 
     FIG. 10 is a schematic perspective view of the toner holding portion of the process cartridge in the first embodiment of the present invention, during the process in which an electrically conductive member formed of metallic foil is pasted to the toner holding portion. 
     FIG. 11 is a schematic perspective view of the separation sheet backed electrically conductive member formed of metallic foil, which is being held to the suction based holding jig by suction, in the first embodiment of the present invention 
     FIG. 12 is a schematic perspective view of the separation sheet backed electrically conductive member formed of metallic foil, a portion of which has been bent inward of the recess of the suction based holding jig, in the first embodiment of the present invention. 
     FIG. 13 is a schematic perspective view of the separation sheet backed electrically conductive member formed of metallic foil, a portion of the separation sheet portion of which has been separated from the electrically conductive member, and has become a separation tab for peeling the separation sheet from the electrically conductive member, in the first embodiment of the present invention. 
     FIG. 14 is a schematic perspective view of the electrically conductive member formed of metallic foil, which is being held to the suction based holding jig, in the first embodiment of the present invention. 
     FIG. 15 is a schematic perspective view of the first coupling of the process cartridge, and the first coupling of the image forming apparatus main assembly, in the first embodiment of the present invention. 
     FIG. 16 is a plan view of the second coupling of the process cartridge, and the second coupling of the image forming apparatus main assembly, in the first embodiment of the present invention, while they are rotating in the direction to remove the toner seal. 
     FIG. 17 is a plan view of the second coupling of the process cartridge, and the second coupling of the image forming apparatus main assembly, in the first embodiment of the present invention, while they are rotating in the direction to drive the stirring member. 
     FIG. 18 is a flowchart of the toner seal removing operation in the first embodiment. 
     FIG. 19 is a simplified version of the toner seal removal detection circuit in the first embodiment. 
     FIG. 20 is a schematic perspective view of the toner container, and the electrically conductive member formed of metallic foil, in the second embodiment of the present invention, during the process for pasting the electrically conductive member to the toner container. 
     FIG. 21 is a schematic perspective view of the separation sheet backed electrically conductive member formed of metallic foil, which is being held to the suction based holding jig by suction, in the second embodiment of the present invention. 
     FIG. 22 is a schematic perspective view of the separation sheet backed electrically conductive member formed of metallic foil, a portion of which has been bent inward of the recess of the suction based holding jig, in the second embodiment of the present invention. 
     FIG. 23 is a schematic perspective view of the separation sheet backed electrically conductive member formed of metallic foil, a portion of the separation sheet portion of which has been separated from the electrically conductive member, and has become a separation tab for peeling the separation sheet from the electrically conductive member, in the second embodiment of the present invention. 
     FIG. 24 is a schematic perspective view of the electrically conductive member formed of metallic foil, which is being held to the suction based holding jig by suction, in the second embodiment of the present invention. 
     FIG. 25 is a plan view of the toner seal, electrically conductive member formed of metallic foil, and suction based holding jig, during the process in which the electrically conductive member formed of metallic foil is pasted to the toner seal with the use of the suction based holding jig, in the second embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the preferred embodiments of the present invention will be described with reference to the appended drawings. 
     Embodiment 1 
     (Description of Process Cartridge and Image Forming Apparatus Main Assembly) 
     Referring to FIGS. 1 and 2, the first embodiment of the present invention will be described. FIG. 1 is a sectional view of the process cartridge in this embodiment, at a plane perpendicular to the longitudinal direction of the process cartridge, and FIG. 2 is a sectional view of the main assembly of the image forming apparatus in this embodiment, at a plane perpendicular to the longitudinal direction of the process cartridge. This process cartridge is provided with an image bearing member, and a single or plurality of processing means which act on the image bearing member. As for the processing means, there are, for example, a charging means for charging the peripheral surface of the image bearing member, a developing means for forming a toner image on the image bearing member, and a cleaning means for removing the toner remaining on the peripheral surface of the image bearing member. A requirement for a cartridge to be a process cartridge, is to be provided with an image bearing member, and a minimum of one processing means. 
     This embodiment relates to a process cartridge which comprises at least a developing means. Referring to FIG. 1, the process cartridge  15  in this embodiment comprises: an electrophotographic photosensitive drum  11  (hereinafter, “photosensitive drum”); a charge roller  12  as a charging means; a development roller  18  as a developing means; a development blade  19 ; a toner holding frame portion  16  as a developer container in which toner as developer is held; a stirring member  20 , that is, a rotational member, for stirring the toner within the toner holding frame portion  16 ; a cleaning blade  14  as a cleaning means; and a cleaning means holding portion  37 ; and a housing in which the preceding components are integrally placed, and which is removably mountable in the main assembly of an image forming apparatus main assembly  13 . The charge roller  12 , development roller  18 , development blade  19 , and cleaning blade  14  are positioned in a manner to surround the peripheral surface of the photosensitive drum  11 . 
     This process cartridge  15  is mounted in the image forming apparatus main assembly  13  illustrated in FIG. 2, to be used for image formation. An image forming operation is carried out in the following manner. First, a sheet S of recording medium is fed out of a sheet cassette  6  mounted in the bottom portion of the image forming apparatus main assembly  13 , into the image forming apparatus main assembly  13 , by a sheet feeding roller  7   a,  and then is conveyed to a transfer station by a conveying roller pair  7   b  having a retarding function, and a registration roller pair  7   c.  In the transfer station, the toner image on the photosensitive drum  11  is transferred onto the recording medium sheet S. As for the photosensitive drum  11 , after being charged by the charge roller  12 , the peripheral surface of the photosensitive drum  11  is selectively exposed by an exposing apparatus  8 , in accordance with image formation information. As a result, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum  11 . The exposing process by the exposing apparatus  8  is carried out in synchronism with the sheet conveyance by the registration roller pair  7   c.  Meanwhile, the toner within the toner holding frame portion  16  is sent into the developing means holding frame portion  17 , in which the toner is coated in a thin layer onto the peripheral surface of the development roller  18  by the development blade  19 , and then, the toner on the development roller  18  is supplied to the peripheral surface of the photosensitive drum  11 , in accordance with the latent image on the photosensitive drum  11 , by applying development bias to the development roller  18 . As a result, a toner image is formed on the peripheral surface of the photosensitive drum  11 . Then, this toner image is transferred onto the recording medium sheet S by the bias voltage applied to a transfer roller  9 , in the transfer station. Then, the recording medium sheet S is conveyed to a fixing apparatus  10 , in which the toner image on the recording medium sheet S is fixed to the recording medium sheet S. Finally, the recording medium sheet S is discharged into a delivery portion  2  on top of the apparatus main assembly, by discharge roller pairs  1 . 
     (Description of Opening of Toner Seal and Stirring Drive) 
     FIGS. 3 through 5 show the toner holding frame portion  16  of the process cartridge in this embodiment. FIGS. 6 and 7 show the gear trains in the process cartridge  15  and image forming apparatus main assembly  13 . FIG. 3 shows the process cartridge  15  in the brand-new state. In this state, the opening  31  of the toner holding frame portion  16  of the process cartridge  15  is covered with a toner sealing member  21 , which is welded or pasted to the seal attachment surface  16   c , that is, the surrounding edge portion of the opening  31 , of the toner holding frame portion  16 . More specifically, the toner sealing member  21  is placed across the opening  31  from one longitudinal end of the opening to the other, and then is folded upon the portion attached to the surrounding edge portion of the opening  31 , all the way back to the starting point being fixed to a winding member  23  rotationally attached to the toner holding frame portion  16 . For the sake of convenience in describing this embodiment, FIG. 3 shows the states of the developing means holding frame portion  17 , toner holding frame portion  1 , and their adjacencies, before they are joined. In reality, however, the developing means holding frame portion  17  and toner holding frame portion  16  are attached to each other, with the interposition of another frame portion, and with the dowel-like positioning projections  16   a  and  16   b  of the toner holding frame portion  16  fitted in the unillustrated positioning holes of the developing means holding frame portion  17 . 
     The toner sealing member  21  is provided with an electrically conductive portion  22   a  (hereinafter, “conductive portion  22   a ”) for detecting whether the opening  31  is fully exposed, and an electrically conductive portion  22   b  (hereinafter, “conductive portion  22   b ”) for detecting whether the process cartridge  15  is properly positioned in the image forming apparatus main assembly  13 . In this embodiment, the dimensions of the conductive portions  22   a  and  22   b  corresponding to the width direction of the opening  31 , that is, the direction perpendicular to the removing direction of the toner sealing member  21 , are made greater than the width W of the portion of the toner sealing member  21 , which is to be torn away. The conductive portions  22   a  and  22   b  are placed on the toner sealing member  21  to be opened, perpendicular to the longitudinal direction of the opening  31 , across the opening  31 . They are formed of aluminum foil ( 30  μm thick) and are coated with adhesive (50 μm thick). To these conductive portions  22   a  and  22   b , voltage is applied by detecting portions  35  and  36  of the image forming apparatus main assembly  13 , through a metallic plate with contacts  34   a ,  34   b , and  34   c , of the process cartridge  15 . 
     As the process cartridge  15  in the brand-new state is mounted into the image forming apparatus main assembly  13 , the detecting portion  35  becomes electrically connected to the contacts  34   b  and  34   c  which are electrically connected to each other by the conductive portion  22   b,  whereas the detecting portion  36  becomes electrically connected to the contacts  34   a  and  34   c  which are connected to each other by the conductive portion  22   a.  Prior to the winding away of the toner sealing member  21 , the conductive portions  22   a  and  22   b  are intact in terms of electrical conductivity. These states of the conductive portions  22   a  and  22   b  are detected by the detecting portions  35  and  36  of the image forming apparatus main assembly  13 . After the mounting of the process cartridge  15  into the image forming apparatus main assembly  13 , a motor  26  as a driving force source provided on the image forming apparatus main assembly  13  side begins to rotate in the direction of an arrow mark A (FIGS.  3  and  6 ). 
     Referring to FIG. 6, as the motor  26  rotates in the direction of the arrow mark A, a first coupling  43  on the image forming apparatus main assembly  13  side moves in the direction of an arrow mark D while being rotated in the direction of an arrow mark C by the motor  26  through an idler gear  42 , so that the first coupling  43  rotates without engaging with a first coupling  44  attached to one of the longitudinal ends of the photosensitive drum  11  in the process cartridge  15 . A pinion gear  26   a  fitted around the shaft of the motor  26  is meshed with the idler gear  42 , which is meshed with a gear  43   g  which is the peripheral portion of the first coupling  43 . A second coupling gear  24  on the process cartridge  15  side is engaged with a second coupling  25 , and is rotated in the direction indicated by an arrow mark E as the driving force from the motor  26  on the image forming apparatus main assembly  13  side is transmitted through the pinion gear  26   a,  an idler gear  33 , and the gear  25   g  of the second coupling  25  on the image forming apparatus main assembly  13  side, as shown in FIG.  3 . 
     The second coupling gear  24  transmits the driving force to a pivotal gear  29 , by meshing with the pivotal gear  29  with which the process cartridge  15  is provided. The pivotal gear  29  is rotationally supported by the end portion of an unillustrated arm attached to the process cartridge  15  in such a manner that the pivotal axis of the pivotal gear  29  coincides with the rotational axial of the second coupling gear  24 . Thus, the pivotal gear  29  pivots in the clockwise direction, remaining engaged with the second coupling gear  24 , due to the presence of the load applied to the teeth of the pivotal gear  29  by the teeth of the second coupling gear  24  as the second coupling gear  24  rotates in the direction of an arrow mark E. As the pivotal gear  29  is pivoted in the clockwise direction, it meshes with an idler gear  30 , transmitting the driving force to the idler gear  30 . As a result, a bevel gear  23   g,  which is an integral part of a winding member  23 , and is meshed with a bevel gear portion  30   g  of the idler gear  30 , rotates, causing the toner sealing member  21  to be wound away in the direction of an arrow mark B by the winding member  23 . During this period, the pivotal gear  29  remains separated from an idler gear  27 , it remains disengaged from the idler gear  27 . 
     Referring to FIG. 4, toward the end of the process in which the opening  31  is entirely exposed, the conductive portion  22   a  is severed, and therefore, the electrical conduction between the contacts  34   a  and  34   c  is interrupted. As this interruption of the electrical conduction caused by the severing of the conductive portion  22   a  is detected by the detecting portion  36  of the image forming apparatus main assembly  13 , the motor  26 , the driving force of which has been transmitted to the winding member  23 , begins to rotate in reverse, that is, in the direction indicated by an arrow mark F, as shown in FIGS. 5 and 7. As the motor  26  rotates in reverse in the direction of the arrow mark F as shown in FIGS. 5 and  7 , the driving force is transmitted to the first coupling  43  on the image forming apparatus main assembly  13  side through the pinion gear  26   a,  idler gear  42 , and gear  43   g,  and moves the first coupling  43  in the direction of an arrow mark H, while rotating it in the direction of an arrow mark G. As a result, the first coupling gear  43  engages with the first coupling  44  attached to one of the longitudinal ends of the photosensitive drum  11  in the process cartridge  15 , and rotates with the first coupling  44 , transmitting the driving force to the photosensitive drum  11 . In this embodiment, the gears  42  and  43   g  are given helical teeth to move the first coupling  43  on the image forming apparatus main assembly  13  side in the direction indicated by either the arrow mark D or H. However, another mechanical arrangement may be employed to move the first coupling  43  on the main assembly side. Meanwhile, the second coupling gear  24  on the process cartridge  15  side rotates in reverse, that is, in the direction of an arrow mark I. As a result, the pivotal gear  29  is disengaged from the idler gear  30  by the load received by the teeth of the pivotal gear  29  from the second coupling gear  24 , and meshes with the idler gear  27 , rotating the idler gear  27 . Consequently, the driving force is transmitted to a pair of stirring gears  32  which rotate the stirring members  20  within the toner holding frame portion  16  illustrated in FIG. 1, through an idler gear  28  meshed with the idler gear  27 . The idler gears  27  and  28  are step gears. 
     (Description of Toner Sealing Member) 
     The toner sealing member  21  used in this embodiment is shown in FIGS. 8 and 9. This toner sealing member  21  has a laminar structure. That is, listing from the top side, the toner sealing member  21  comprises: a surface layer, or a 12 μm thick polyester layer (strength providing layer; designated by a reference character  21   i  in FIG.  8 ); a 7 μm thick aluminum foil layer (laser light shielding layer; designated by a reference character  21   j  in FIG.  8 ); a 50 μm thick polyester layer (tear line providing layer; designated by a reference character  21   k  in FIG.  8 ); and a 50 μm thick sealant layer (adherent layer; designated by a reference character  211  in FIG.  8 ). 
     Tear lines  21   e  (FIG.  9 ), along which the toner sealing member  21  is torn away to expose the opening  31 , are formed by a laser. More specifically, a laser beam is projected upon the toner sealing member  21  from the sealant layer  211  side to melt predetermined portions of polyester layer, as the tear line providing layer  21   k,  and the sealant layer  211 , so that numerous perforations  21   h  (FIG. 8) are created. FIG. 8 is a sectional view of the toner sealing member  21 , and shows one of the perforations  21   h  created by a laser. The aluminum foil layer  21   j  shields the top layer, or the polyester layer  21   i,  from the laser beam, and therefore, the polyester layer  21   i  is not damaged by the laser beam, remaining fully capable of keeping the toner sealed in the toner holding frame portion  16 . When exposing the opening  31 , as the toner sealing member  21  is pulled, the stress caused by the pulling concentrates to the perforations  21   h  created by the laser, assuring that the toner sealing member  21  is torn along the tear lines  21   e  to expose the opening  31 . 
     The conductive member  22  in this embodiment is a patterned piece of aluminum foil pasted on the toner sealing member  21 . One aspect of the conductive member  22  is electrical resistance. The value of the electrical resistance of the conductive member  22  to which voltage is applied to test the conductivity of the conductive member  22  may be as large as it can be, as long as the amplitude of the voltage applied to test the conductivity of the conductive member  22  can be increased accordingly. In reality, however, applying high voltage for testing the conductivity is difficult from the standpoints of safety as well as cost. Thus, the electrical resistance value of the conductive member  22  is desired to be as small as possible so that the conductivity can be tested even if the low voltage is applied. More specifically, it is desired to be no more than 100 Ω, possibly, no more than 10 Ω. The electrical resistance value of the conductive member  22  in this embodiment is approximately 1 Ω; in other words, the conductivity of the conductive member  22  is excellent prior to its severance. After the severance, the electrical resistance of the conductive member  22  is infinite, preventing electrical current from flowing through the once conductive member  22 . 
     In other words, as for the material for the conductive member, any material will suffice as long as it satisfies the requirement that the electrical resistance value of the conductive member must be low enough to afford the conductive member a sufficient degree of electrical conductivity, prior to its severance. For example, foil of copper, nickel, or the like metals, can be used as the material for the conductive member. Further, the conductive member  22  must be severed along the tear lines  21   e  of the developer sealing member. Thus, if it is not assured that the conductive member  22  can be severed with the application of a small amount of force, it is possible that the force which must be applied to open the conductive member  22  will be excessively large, or the entirety of the conductive member  22  formed of metallic foil, will be peeled away, adhering to, or falling onto, the other parts of the apparatus. As for a method for reducing the tear resistance of the conductive member  22 , it is effective to reduce the thickness of the metallic foil. However, the reduction in the metallic foil thickness tends to cause the conductive member  22  formed of metallic foil to deform, when the conductive member  22  is separated from a separation sheet  53 , or when the conductive member  22  is pasted to the toner sealing member  21 . 
     (Method for Pasting Adhesive Coated Conductive Member) 
     Referring to FIGS. 10 through 14, a method for pasting an adhesive coated metallic foil will be described. Here, it is assumed that the opening  31  of the toner holding frame portion  16  has been already sealed with the toner sealing member  21 . First, the conductive member  22 , the separation paper  53 , and a suction based holding jig  50 , are prepared. One surface of the conductive member  22  has been coated with adhesive, and this adhesive coated surface of the conductive paper  53  placed in contact with the adhesive layer. The separation paper  53  is greater in size than the conductive member  22 , extending beyond the edge of the conductive member  22 , and is square. Referring to FIG. 10, the toner releasing opening  31  of the toner holding frame portion  16  is entirely sealed with the toner sealing member  21  which has been heat-welded to the surrounding edge of the opening  31 . Further, the toner holding frame portion  16  is provided with the dowel-like projections  16   a  and  16   b  for positioning the toner holding portion  16  relative to the developing means holding frame portion  17 . 
     A method for forming the conductive member  22  on the toner sealing member  21  will be described. Referring to FIG. 11, the suction based holding jig  50  is provided with a plurality of suction holes  51 . The conductive member  22  formed of metallic foil, coated with a layer of adhesive and backed by the separation paper as a separation sheet, is held by suction to the positioning portion  52  of the suction based holding jig  50 , with the separation paper  53  being on the outward side, so that the separation paper can be peeled away while leaving the conductive member  22  held to the suction based holding jig  50 . The suction holes  51  are connected to a hose  50   d  (FIGS. 11-14) connected to a suction generating apparatus (unillustrated). The area of the suction based holding jig  50 , to which the aforementioned extending portion of the separation paper  53  is held, is provided with a recess  50   a,  which is located so that it partially overlaps with the conductive member  22  formed of metallic foil when the metallic foil is being held to the suction based holding jig  50 . With the conductive member  22  formed of metallic foil, coated with adhesive and backed by the separation paper  53 , being held to the suction based holding jig  50 ; if the separation paper backed corner portion  53   a  of the metallic foil, which extends over the recess  50   a  as shown in FIG. 11, is bent inward of the recess  50   a  as shown in FIG. 12, the corner portion  53   a  of the conductive member  22  formed of metallic foil remains bent inward of the recess  50   a,  whereas the portion of the separation paper  53  corresponding to the portion  53   a  straightens back, separating itself from the corner portion  53   a,  becoming a separation tab  53   b  (FIG.  13 ), because the separation paper  53  is harder to deform compared to the conductive member  22  formed of metallic foil. With the employment of this method, the separation paper  53  can be safely separated from the adhesive coated surface of the conductive member  22  formed of metallic foil, without deforming the conductive member  22  formed of metallic foil, except for the portion corresponding to the above-described separation tab  53   b.  Next, the separation paper  53  is separated (FIG.  14 ). Then, the suction based holding jig  50  is placed on the toner holding frame portion  16 , with the metallic foil holding surface facing the toner holding frame portion  16 , and also with the dowel-like positioning projections  16   a  and  16   b,  which are provided on the toner holding frame portion  16  in order to paste the conductive member  22  formed of metallic foil, held to the surface of the suction based holding jig  50 , to the toner sealing member  21 , being aligned with the corresponding positioning holes  50   b  and  50   c  of the suction based holding jig  50 . Then, the suction to the suction based holding jig  50  is stopped. As a result, the conductive member  22  formed of metallic foil is accurately positioned to be pasted to the toner sealing member  21 , across the predetermined area (FIG.  10 ). Thereafter, the conductive member  22  formed of metallic foil is pressed again onto the toner sealing member  21 . With the employment of the above described method, the conductive member  22  can be perfectly pasted to the toner sealing member  21 , from one longitudinal edge of the toner releasing opening  31  to the other, from one longitudinal edge of the toner sealing member  21  to the other, or even from one longitudinal edge of the toner holding frame portion  16  to the other, across the opening  31  in terms of its width direction. 
     (Description of Driving Force Transmitting Method and Coupling Members) 
     Next, referring to FIGS. 15 through 17, the shapes of the couplings will be described. Referring to FIG. 15, the first coupling  44  on the process cartridge side has a projection  44   a , which has a sectional profile of an approximately equilateral triangle; more precisely, the projection  44   a  is in the form of a triangular pillar twisted about its rotational axis in its rotational direction. The first coupling  43  on the apparatus main assembly side, which engages with the first coupling  44 , has a hole  43   a , which is in the form of a triangular pillar twisted about its rotational axis in its rotational direction, and into which the projection  44   a  engages. With the provision of this structural arrangement between the two couplings  44  and  43 , as the first coupling  43  on the main assembly side is rotated, with the first coupling  44  on the process cartridge side engaged in the hole  43   a , the lateral edges of the projection  44   a  come into contact with the corresponding lateral walls of the hole  34   a , and cause the first coupling  44  on the process cartridge side to rotate in a manner to equalize the three interfaces between the corresponding lateral edges of the projection  44   a  and the lateral walls of the hole  43   a  in terms of the contact pressure. As a result, driving force is transmitted from the first coupling  43  on the apparatus main assembly side to the first coupling on the process cartridge side while the rotational axis of the two couplings  44  and  43  are maintained in alignment with each other. 
     Referring to FIGS. 16 and 17, the second coupling  25  on the apparatus main assembly side has a projection in the form of a flatted round pillar, whereas the second coupling within the process cartridge  15  has a hole  24   b,  the side wall of which constitutes the second coupling gear  24 , which is a combination of the cylindrical, lateral wall of the hole  24   b,  and a pair of ribs  24   a  in the form of a pillar having a sectional profile of a right-angled triangle, attached to the cylindrical, lateral wall of the hole  24   b  in symmetrical manner with respect to the center axis of the hole  24   b.  Looking squarely at FIGS. 16 and 17, each rib  24   a  has a sectional profile in the form of a triangle, one of the apexes of which points to the axial line of the gear  24 ; in other words, the ribs  24   a  are symmetrically positioned with respect to the axial line of the gear  24 , and the surfaces of one of the ribs  24   a,  and the surfaces of the other rib  24   a,  which are symmetrically positioned with respect to the axial line of the gear  24 , are parallel to each other. 
     Referring to FIG. 16, as the second coupling  25  on the apparatus main assembly side rotates in the direction to remove the toner sealing member  21 , that is, in the direction of the arrow mark E, the surface  24   a - 1  of each of the ribs  24   a , which is comparable to one of the two sides of a right-angle triangle, or the shape of the profile of the rib  24   a , comes into contact with the corresponding contact portion  25   a  of the coupling  25 , and transmits driving force. The cylindrical portion of the hole  24   b , the lateral wall portions of which constitute portions of the second coupling gear  24 , is not perfectly circular in cross sectional profile; the distance from the portions of the lateral wall of the hole  24   b  immediately adjacent to the ribs  24   a  to the rotational axis of the coupling gear  24  is rendered smaller than the distance between the rest of the lateral wall of the hole  24   b  to the rotational axis of the coupling gear  24 , in order to reduce the gap  40  between the coupling  25  on the apparatus main assembly side and the coupling gear  24  in terms of the diameter direction of the two couplings. 
     In this embodiment, the gap  40  between the second coupling gear  24 , and the second coupling  25  on the main assembly side, in terms of their diameter direction, is approximately 0.5 mm. 
     As the drive for removing the toner sealing member  21  ends, the second coupling  25  on the apparatus main assembly side is rotated in reverse, that is, in the direction of the arrow mark I. As a result, the contact portions  25   b  of the second coupling  25  on the apparatus main assembly side come into contact with the corresponding surfaces  24   a - 2  of the ribs  24   a,  which are comparable to the other sides of the right-angle triangle, or the shape of the profile of the rib  24   a,  and drive the second coupling gear  24 , transmitting driving force to the stirring members. The second coupling  25  on the main assembly side and the second coupling gear  24  on the process cartridge side are structured so that during this reversal rotation of the second coupling  25  on the main assembly side, the second coupling  25  on the main assembly side and the second coupling gear  24  on the process cartridge side, hold a gap  41  in terms of their radius direction. Therefore, rotational driving force can be transmitted from the second coupling  25  on the apparatus main assembly side to the second coupling gear  24  on the process cartridge side while allowing their rotational axes to remain unaligned with each other. 
     In this embodiment, the gap  41  is approximately 2 mm. 
     With the employment of this structural arrangement, when the toner sealing member  21  is removed, the rotational axes of the second coupling  25  on the apparatus main assembly side and the second coupling gear  24  on the process cartridge side are aligned with each other, and the photosensitive drum  11  is not driven. Then, after the completion of the removal of the toner sealing member  21 , in other words, during an actual image forming process, the rotational axis of the first coupling  44  of the photosensitive drum  11  and the rotational axis of the first coupling  43  on the apparatus main assembly side are aligned with each other, whereas the second coupling gear  24  on the process cartridge side, and the second coupling  25  on the apparatus main assembly side, for transmitting driving force to the stirring members  20 , simply transmit driving force so that they do not interfere with the alignment between the rotational axes of the first coupling  43  and its counterpart. 
     To summarize the above-described operations, a flowchart which sums up the above-described operations is given in FIG. 18, and a simplified version of the control circuit for the above-described operations is given in FIG.  19 . Referring to FIG. 18, after the mounting (S 1 ) of the process cartridge  15  in this embodiment into the image forming apparatus main assembly  13 , it is tested whether electrical current flows through the conductive portion  22   b  (S 2 ). If the flow of electrical current through the conductive portion  22   b  is confirmed, it is tested whether or not electrical current flows through the conductive portion  22   a  (S 3 ). If the flow of electrical current through the conductive portion  22   a  is confirmed, the winding of the toner sealing member  21  is started (S 4 ). As soon as the severance of the conductive portions  22   a  is detected (S 5 ), it is determined that the removal of the toner sealing member  21  has been completed (S 6 ). At this point, the mounting of the process cartridge  15  into the brand-new state is ended (S 7 ). Thereafter, the motor on the image forming apparatus main assembly side is rotated in reverse to start rotating the toner stirring members. On the contrary, if it is confirmed in (S 2 ) that electrical current does not flow through the conductive portion  22   b , (S 9 ) is taken, in which it is displayed that there is no process cartridge in the apparatus main assembly  13 . When it is determined in (S 3 ) that electrical current does not flow through the conductive portion  22   a , (S 8 ) is taken, in which it is tested whether electrical current flows through the conductive portion  22   b . If the flow of electrical current through the conductive portion  22   b  is confirmed, (S 6 ) is taken, whereas if the flow of electrical current through the conductive portion  22   b  cannot be confirmed, (S 9 ) is taken. 
     Referring to FIG. 9, the detecting portions  35  and  36  are provided with a DC current detector and an electrical current which flows through the conductive portions  22   a  and  22   b  while applying electrical voltage to them from a power source. Whether the toner sealing member  21  has been removed, and whether a process cartridge has been mounted in the correct position in the image forming apparatus main assembly, are determined by a CPU  38  based on the measurements provided by the detecting portions  35  and  36 . 
     Embodiment 2 
     Referring to FIGS. 20 through 25, another method for pasting an adhesive coated conductive member will be described. It is assumed that the opening  31  of the toner holding frame portion  16  has been already sealed with the toner sealing member  21 . First, the conductive member  62 , the separation paper  61 , and a suction based holding jig  60 , are prepared. One of the two surfaces of the conductive member  62  has been coated with adhesive, and this adhesive coated surface of the conductive member  62  is entirely covered with the separation paper  61  placed in contact with the adhesive layer. The separation paper  61  is greater in size than the conductive member  62 , extending beyond the edge of the conductive member  62 , and is square. Referring to FIG. 20, the toner releasing opening  31  of the toner holding frame portion  16  is entirely sealed with the toner sealing member  21  which has been heat-welded to the surrounding edge of the opening  31 . Further, the toner holding frame portion  16  is provided with the dowel-like projections  16   d  and  16   e  for positioning the toner holding frame portion  16  relative to the developing means holding frame portion  17 . 
     A method for forming the conductive member  62  on the toner sealing member  21  will be described. Referring to FIG. 21, the suction based holding jig  60  is provided with a plurality of suction holes  60   a . Further, the suction based holding jig  60  is provided with a pair of retractable positioning bosses  60   b , which are located on the surface to which the separation paper  61  is held. The separation paper  61  is provided with a pair of positioning holes  61   a , the positions of which perfectly match the positions of the retractable positioning bosses  60   b , one for one. Also, the suction based holding jig  60  is provided with a pair of holes, into or from which the retractable positioning bosses  60   b  can be retracted or projected. In order to paste the conductive member  62  to the toner sealing member  21 , first, the bosses  60   b  are put through the positioning holes  61   a  of the separation paper  61  to which the conductive member  62  is adhering. As a result, the separation paper  61  to which the conductive member  62  is adhering is accurately positioned relative to the suction based holding jig  60 . Then, the separation paper  62 , to which the conductive member  62  formed of metallic foil coated with adhesive is adhering, is secured to the surface of the suction based holding jig  60  by suction, with the conductive member  62  formed of metallic foil placed in contact with the surface of the suction based holding jig  60 . Consequently, the combination of the conductive member  62  and separation paper  61  are held to the suction based holding jig  60  in a manner to allow the separation paper  61  to be peeled away from the layer of the adhesive coated on the conductive member  62 . The suction holes  60   a  are connected to a hose  60   e  (FIGS. 21 through 24) connected to a suction generating apparatus (unillustrated). Next, the portion  61   b  of the combination of the conductive member  62  formed of metallic foil, and the separation paper  61 , where the conductive member  62  and separation paper  61  overlap with each other, is bent into the recess  60   c  (FIG.  22 ). As a result, the corner portion of the conductive member  62  formed of metallic foil corresponding to the portion  61   b  remains bent inward of the recess  60   c , whereas the portion of the separation paper  61  corresponding to the portion  61   b  straightens back, separating itself from the portion of the conductive member  62  corresponding to the portion  61   b , becoming a separation tab, because the separation paper  61  is harder to deform compared to the conductive member  62  formed of metallic foil. In this state, the bosses  60   b  of the suction based holding jig  60  are retracted into the suction based holding jig  60 , away from the separation paper  61  (FIG.  23 ). With the employment of this method, the separation paper  62  can be safely separated from the adhesive coated surface of the conductive member  62  formed of metallic foil, without deforming the conductive member  62  formed of metallic foil, except for the portion corresponding to the above-described separation tab. Next, the separation paper  61  is separated using the separation tab. In this state, the conductive member  62  is still held to the suction based holding jig  60  by the suction which is acting on the conductive member  62  through the suction holes  60   a  (FIG.  24 ). Then, in order to paste the conductive member  62  formed of metallic foil, being held to the suction based holding jig  60  by suction, to the toner sealing member  21 , the dowel-like positioning projection  16   d  provided on the toner holding frame portion  16  side is inserted into the positioning groove  60   d  of the suction based holding jig  60 , and the rotation controlling boss  60   f  of the suction based holding jig  60  is held against the bottom wall of the toner holding frame portion  16 . In this state, the suction is stopped (FIG.  25 ). As a result, the conductive member  62  formed of metallic foil is accurately positioned to be pasted to the toner sealing member  21 , across the predetermined area. Thereafter, the conductive member  62  formed of metallic foil is pressed again onto the toner sealing member  21 . With the employment of the above-described method, the conductive member  62  can be perfectly pasted to the toner sealing member  21 , from one longitudinal edge of the toner sealing member  21 , from one longitudinal end of the toner releasing opening  31  to the other, from one longitudinal edge of the toner sealing member  21  to the other, or even from one longitudinal edge of the toner holding frame portion  16  to the other, across the opening  31  in terms of its width direction. 
     The other features of this embodiment are the same as those of the first embodiment. 
     According to the above described structural arrangements, it is possible to easily and accurately position a piece of metallic foil, which tends to tear, on a developer sealing member, across a predetermined area, without deforming the piece of metallic foil. As a result, it becomes possible to automatically remove a developer sealing member, without errors, by transmitting driving force from the image forming apparatus main assembly. Further, the above described structural arrangement simplifies the operation for placing a conductive portion formed of metallic foil, reducing, therefore, operational cost. 
     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 purposes of the improvements or the scope of the following claims.