Patent Publication Number: US-8971753-B2

Title: Process cartridge

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a process cartridge detachable from an electrophotographic image forming apparatus. The process cartridge is a cartridge having an image bearing member, and at least a charging unit and a developing unit formed integrally as a cartridge and detachable from a main body of an image forming apparatus. Here, the image forming apparatus is an apparatus for forming an image on a recording medium using an electrophotographic forming process, and includes, for example, an electrophotographic copying machine, an electrophotographic printer such as a light emitting diode (LED) printer and a laser beam printer, and an electrophotographic facsimile apparatus. 
     2. Description of the Related Art 
     Conventionally, in the image forming apparatus using the electrophotographic image forming apparatus, a cartridge method has been adapted. In the cartridge method, the image bearing member and a process unit, which acts on the image bearing member, are integrally formed into a cartridge and the cartridge is detachable from the image forming apparatus. According to the cartridge method, a user can perform maintenance of an apparatus by oneself without depending on a serviceman, so that operability of the apparatus can be remarkably increased. Thus, the cartridge method is widely used in the image forming apparatus. 
     According to the cartridge method, the operability is increased, and it becomes possible for a user to easily perform the maintenance of the electrophotographic image forming apparatus by oneself. Thus, the cartridge method is widely used in the image forming apparatus. 
     In many cartridges, a detachable protection member is adopted for protecting a surface of a photosensitive drum from light, dust, fluff, and scratches at a time of shipping (for example, refer to  FIG. 4  in Japanese Application Laid-Open No. 9-127851). A user detaches the protection member before mounting the cartridge to an image forming apparatus, and mounts the cartridge to an image forming apparatus as it is. 
     Further, as a countermeasure of toner leak at a time of shipping, Japanese Patent Laid-Open No. 2000-19839 discusses, in  FIG. 6 , a configuration in which a sealing member is adhered to the protection member itself, and this configuration is adopted in some cartridges. 
     Further, recently, for increasing operability, a configuration for eliminating a toner seal, which closes an opening for supplying a toner to the developing unit has been adopted. This configuration is realized by removing the seal at a time of exchanging a cartridge. To realize this configuration, metal parts are added for increasing strength of a seating surface to which a flexible sheet member is fixed. In this case, the flexible sheet acts to prevent toner leak at a space between a development roller and a development case frame member. 
     The protection members like the conventional examples protect only the surface of the photosensitive drum, and there is a possibility that toner leak and toner dispersion come about near the development roller by a physical distribution at a time of shipping. 
     In a toner seal-less configuration, countermeasures against the toner leak and the toner dispersion is needed only at a time of the physical distribution. Thus, implementing the countermeasure by adding metal parts like the conventional example leads to a cost rise and may become a superfluous measure. Further, like the configuration discussed in Japanese Patent Laid-Open No. 2000-19839, a configuration of providing the sealing member to the protection member also causes a cost rise. 
     Further, when a process cartridge, which has reached the end of useful life, is collected, it is necessary to attach again the protection member to the process cartridge, for preventing the waste toner leak from a waste toner chamber. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to provide a process cartridge which can prevent toner leak and toner dispersion in a period from shipping to an attachment to an image forming apparatus, or in a period from end of useful life to a collection of the cartridge. 
     According to an aspect of the present invention, a process cartridge detachable from an electrophotographic image forming apparatus includes an electrophotographic photosensitive member, a cleaning frame member, a developer bearing member, a development frame member, a flexible sheet member, and a protection member. The electrophotographic photosensitive member forms an electrostatic latent image. The cleaning frame member supports the electrophotographic photosensitive member. The developer bearing member develops the electrostatic latent image using a developer. The development frame member supports the developer bearing member. The flexible sheet member is for preventing leak of a developer from between the developer bearing member and the developer frame member. One end side of the flexible sheet member is fixed onto a seating surface of the developer frame member and the other end side contacts to the developer bearing member. The protection member is attached to the cleaning frame member for protecting the electrophotographic photosensitive member and is detached when the process cartridge is mounted to the electrophotographic image forming apparatus. The protection member includes a pressing portion contacting to a back side of the seating surface for suppressing deformation of the seating surface. 
     Further features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic cross-sectional view illustrating a color electrophotographic image forming apparatus. 
         FIG. 2  is a schematic cross-sectional view illustrating the process cartridge. 
         FIG. 3  is a schematic perspective view illustrating the process cartridge. 
         FIG. 4  is schematic exploded perspective view illustrating the process cartridge. 
         FIG. 5  is a schematic perspective view illustrating a drum protection cover. 
         FIG. 6  is schematic cross-sectional view illustrating the process cartridge when the drum protection cover is mounted. 
         FIG. 7  is a schematic perspective view illustrating the process cartridge viewed from a photosensitive drum unit side when the drum protection cover is mounted. 
         FIG. 8  a schematic perspective view illustrating the process cartridge viewed from a development apparatus side when the drum protection cover is mounted. 
         FIG. 9  is a schematic cross-sectional view illustrating the process cartridge when the drum protection cover is mounted. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the drawings. 
     At first, a schematic configuration of the color electrophotographic image forming apparatus will be described using  FIG. 1 .  FIG. 1  is a schematic cross-sectional view illustrating a color electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) according to the present exemplary embodiment. The main body of image forming apparatus  100  is a four colors full color laser printer and performs color image forming on a recording medium S. The main body of image forming apparatus  100  adopts a process cartridge method and the process cartridge is detachable from the main body of image forming apparatus  100 . The main body of image forming apparatus  100  forms a color image on the recording medium S. 
     In the following description, concerning the main body of image forming apparatus  100 , a side in which an opening/closing door  101  is provided is set to a front face and an opposite face to the front face is set to aback face. Right and left are set as viewed from the front face side of the main body of image forming apparatus  100 . 
     In the main body of image forming apparatus  100 , 4 process cartridges P (PY, PM, PC, PK) can be arranged in a horizontal direction. Each process cartridge P is housed in a cartridge housing portion  102  in the main body of image forming apparatus  100 . The process cartridges P are exchangeable. When the process cartridge P is exchanged, a user opens the opening/closing door  101  in the image forming apparatus main body  100 , pulls out a pullout member  102  in a front face direction, and performs attachment/detachment of each cartridge P. 
     Each process cartridge P includes a similar electrophotographic process mechanism, and a color of a developer (hereinafter referred to as a toner) and a filling amount of the toner are different from each other. To the process cartridges P positioned in the pullout member  102 , rotation driving force is transmitted from a drive input portion (not illustrated) in the image forming apparatus main body  100 . Further, to the process cartridges P, bias voltage (charging bias and developing bias) (not illustrated) is supplied from the image forming apparatus main body  100 . 
     As illustrated in  FIG. 2 , each process cartridge P includes an electrophotographic photosensitive drum  1  (hereinafter referred to as a photosensitive drum) and a photosensitive drum unit  8  including a charging unit which is a process unit acting to the photosensitive drum  1  and a cleaning unit. Further, each process cartridge P includes a development device  9  including a developer bearing member which develops an electrostatic latent image on the photosensitive drum  1 . The photosensitive drum unit  8  and the development device  9  are connected to each other. Further, a charging roller  3  as a charging unit, a cleaning blade  2  as a cleaning unit, and a development roller  4  as a developer bearing unit are used. More detailed configuration of the process cartridge will be described later. 
     A first process cartridge PY houses a yellow (Y) toner in a development container and forms a toner image of a yellow color on a surface of the photosensitive drum  1 . A second process cartridge PM houses a magenta (M) toner in a development container and forms a toner image of a magenta color on a surface of the photosensitive drum  1 . A third process cartridge PC houses a cyan (C) toner in a development container and forms a toner image of a cyan color on a surface of the photosensitive drum  1 . A fourth process cartridge PK houses a black (K) toner in a development container and forms a toner image of a black color on a surface of the photosensitive drum  1 . 
     On an upper side of the process cartridges P (PY, PM, PC, and PK), a scanner unit  105  which is an exposure unit is provided. The scanner unit  105  output laser light L corresponding to image information. Then, the laser light L exposes a surface of the photosensitive drum  1  of the cartridge P. 
     On a lower side of the process cartridges P (PY, PM, PC, and PK), an intermediate transfer belt unit  11  which is a transfer member is provided. The intermediate transfer belt unit  11  includes an endless transfer belt  12  having flexibility, a drive roller  13  which rotates the transfer belt  12 , a turn roller  14  and tension roller  15  which stretch the transfer belt  12 . A lower surface of the photosensitive drum  1  contacts an upper surface of the transfer belt  12 . The contact portion is a primary transfer portion. On an inner side of the transfer belt  12 , primary transfer rollers  16  ( 16 Y,  16 M,  16 C, and  16 K) are provided, opposing to the photosensitive drums  1 . A secondary transfer roller  17  is provided, contacting the turn roller  14  via the transfer belt  12 . The contact portion of the transfer belt  12  and the secondary transfer roller  17  is a secondary transfer portion. 
     On a lower side of the intermediate transfer belt unit  11 , a feeding unit  18  is provided. The feeding unit  18  includes a sheet feeding tray  18  stacking and storing the recording medium S and a sheet feeding roller  20 . 
     On an upper side of the back side in the image forming apparatus main body  100 , a fixing unit  21  and a discharge unit  22  are provided. An upper face of the image forming apparatus main body  100  is a discharge tray  23 . 
     The each cartridge P (PY, PM, PC, and PK) housed in the pullout member  102  is pressed from upper side by a press mechanism (not illustrated) on the image forming apparatus main body  100  side and fixed to a positioning portion (not illustrated) on the image forming apparatus main body  100  side. Further, a drive output unit on the image forming apparatus main body  100  side connects to a drive input unit of the each cartridge P (not illustrated). Further, an electric power supply system (not illustrated) on the image forming apparatus  100  side conducts to an input electrical contact on the each cartridge P side. 
     The operation for forming a full color image is as follows. In  FIG. 1 , the photosensitive drums  1  of each process cartridge P (PY, PM, PC, and PK) of a first to a fourth are rotationally driven in an arrow direction (A direction in  FIG. 1 ) at a predetermined speed. The transfer belt  12  is also rotationally driven in an arrow direction (B direction in  FIG. 1 ) at a speed corresponding to the speed of the photosensitive drums  1 . The scanner unit  105  is also driven. Synchronizing these dives, in each process cartridge P, the charging roller  3  uniformly charges the surfaces of the photosensitive drum  1  in predetermined polarity and potential. 
     The scanner unit  105  exposes the surface of each photosensitive drum  1  by the laser light L corresponding to an image signal of each color. With this operation, an electrostatic latent image corresponding to the image signal of the corresponded color is formed on the surface of each photosensitive drum  1 . The formed electrostatic latent image is developed by the development roller  4  rotationally driven at a predetermined rate in an arrow C direction. 
     By the aforementioned electrophotographic image forming process operation, a toner image with yellow color corresponding to a yellow component of full color image is formed on the photosensitive drum  1  in the first process cartridge PY. Then, the toner image is primary transferred onto the transfer belt  12 . 
     Similarly, a toner image with magenta color corresponding to a magenta component of full color image is formed on the photosensitive drum  1  in the second process cartridge PM. Then, the toner image is primary transferred, and is superimposed on the toner image of yellow color which is already transferred onto the transfer belt  12 . 
     Similarly, a toner image with cyan color corresponding to a cyan component of full color image is formed on the photosensitive drum  1  in the third process cartridge PC. Then, the toner image is primary transferred, and superimposed on the toner images of yellow color+magenta color which are already transferred onto the transfer belt  12 . 
     Similarly, a black color toner image corresponding to a black component of full color image is formed on the photosensitive drum  1  in the fourth process cartridge PK. 
     Then, the toner image of black color is primary transferred, and is superimposed on the toner images of yellow color+magenta color,+cyan color which are already transferred onto the transfer belt  12 . 
     With these processes, an unfixed toner image with four colors full color of yellow color+magenta color+cyan color+and black color is formed onto the transfer belt  12 . 
     Meanwhile, the recording media S is fed one by one with being separated from each other at predetermined control timing. The recording media S is introduced to a secondary transfer portion at a predetermined control timing. At the secondary transfer portion, the secondary transfer roller  17  abuts on the transfer belt  12 . According to this process, in the process in which the recording medium S is conveyed to the secondary transfer portion, the toner image in which four colors are superimposed on the transfer belt  12  is transferred collectively onto the recording medium S successively. 
     The recording medium S is separated from the surface of the transfer belt  12  and introduced to a fixing unit  21 . Then, the recording medium S is heated and pressed at the fixing nip portion. By this process, each color toner image is fixed to the recording medium S. Then, the recording medium S goes out from the fixing unit  21  and is discharged, as a full color image formed sheet, on a discharge sheet tray  23  by the discharging unit  22 . 
     Then, the process cartridge P will be described using  FIG. 2 ,  FIG. 3 , and  FIG. 4 .  FIG. 2  is a schematic cross-sectional view illustrating the process cartridges P (PY, PM, PC, and PK).  FIG. 3  is a schematic perspective view illustrating the process cartridges P (PY, PM, PC, and PK).  FIG. 4  is an exploded perspective view illustrating the process cartridges P (PY, PM, PC, and PK). 
     As illustrated in  FIG. 3 , the process cartridges P (PY, PM, PC, and PK) have a oblong shape with a longitudinal direction which is a rotation axis line T direction of the photosensitive drum  1 . As viewed from the front side of the image forming apparatus main body, a right side is a drive side and a left side is a non-drive side. The cartridge P includes a photosensitive drum unit  8 , development device  9 , a drive side cover member  61 , and non-drive side cover member  62 . 
     The photosensitive drum unit  8  includes a cleaning frame member  50  including a cleaning blade  2  and a scooping sheet  52 , a photosensitive drum  1 , and a charging roller  3 . 
     As illustrated in  FIG. 3  and  FIG. 4 , the photosensitive drum  1  is rotatably supported by a photosensitive drum support portion  61   a  of the drive side cover member  61  on the drive side, and by a photosensitive drum support portion  62   a  on a rotation axis line T of the non-drive side cover member  62  on the non-drive side. A drum drive coupling  1   a  is a photosensitive drum drive input portion. At an end of the drive side of the photosensitive drum  1 , the drum drive coupling (drive transmission portion)  1   a  is attached coaxially with the photosensitive drum  1 . A coupling which is a drum drive output portion (not illustrated) engages to the drum drive coupling  1   a . Then, driving force of a drive motor of the main body of apparatus (not illustrated) is transmitted and the photosensitive drum  1  is rotationally driven in the A direction (in  FIG. 1  and  FIG. 2 ) at a predetermined speed. 
     The charging roller  3  is a charging member of a contact charging type which contacts the photosensitive drum  1  and rotates. The charging roller  3  is provided by causing the axis ends thereof on the drive side and the non-drive side to be rotationally supported via bearing portions (not illustrated) which are provided between side plates of the cleaning frame member  50 . 
     The cleaning blade  2  which is a cleaning member has an elastic rubber blade and removes the toner remaining on the photosensitive drum  1 . The remaining toner, which is removed from periphery surface of the photosensitive drum  1  by the cleaning blade  2 , is guided by the scooping sheet  52  which is a flexible sheet member and stored in a waste toner chamber  51  positioned in the cleaning frame member  50 . 
     The scooping sheet  52  is fixed onto a seating surface  53 , which is provided in the cleaning frame member  50 , by attaching one end thereof using a double-stick tape. Another one end contacts to the photosensitive drum  1 . A contact direction of the scooping sheet  52  is set to become a forward direction to the rotation direction A of the photosensitive drum  1 . The reason for this is that the remained toner on the photosensitive drum  1  rotating in the arrow A direction passes through the contact portion of the photosensitive drum  1  and the scooping sheet  52  but the scooping sheet  52  prevents the remained toner removed from the periphery surface of the photosensitive drum  1  by the cleaning blade  2  from moving in a opposite direction of the rotation direction A. 
     As illustrated in  FIG. 3 , the development device  9  has an oblong shape with a longitudinal direction which is a rotation axis direction of the development roller  4 , which is the developer bearing member. As illustrated in  FIG. 2 , the development device  9  includes, other than the development roller  4 , a development frame member  30 , a development blade  6 , a developer supply roller  5 , an end seal member  40 , and a gush prevention sheet  37  which is a flexible sheet member. The developer supply roller  5  includes a core member made of a metal and a cylindrical elastic member made of urethane foam. The developer supply roller  5  is provided in a development chamber  33  facing an opening  31   a  in the toner chamber  31 , and abuts on the development roller  4 . The core members of the development roller  4  and the developer supply roller  5  are respectively arranged in the development chamber  33 , and both ends of each core member are rotatably supported by a bearing member  44  and  45  attached to both sides of the drive side and the non-drive side of the development frame member  30 . 
     Coupling (not illustrated), which is development drive output portions on the main body of apparatus  100  side, engage to drive output unit  75 , and transmit driving force of the drive motor (not illustrated) of the main body of apparatus  100  to the development roller  4  and the developer supply roller  5 . Each roller driven rotates in C direction or D direction at a predetermined speed. 
     At a time of developing, the developer supply roller  5  rotates, and friction against the development roller  4  causes a toner  70  in the toner chamber  31  which is provided in the development frame member  30  to be applied on the development roller  4  in the development chamber  33 . The development blade  6  is provided, whose end portion thereof abuts on the development roller  4  in a counter direction to the rotation direction of the development roller  4 . The toner applied on the development roller  4  is charged by the development blade  6  with rotation of the development roller  4  and is controlled to be a predetermined toner thin layer. Then, at a contact portion between the development roller  4  and the photosensitive drum  1 , the toner on the development roller  4  adheres to an electrostatic latent image on the photosensitive drum  1  and develops the latent image. 
     The toner not contributing to the development and remaining on the development roller  4  is returned in the development chamber  33  by the rotation of the development roller  4 , exfoliated by the development roller at a friction portion with the developer supply roller  5 , and collected. The collected toner is mixed with the remaining toner in the development chamber  33 . 
     At both ends of the opening of the development room  33 , end sealing members  40  are provided in a state of abutting on the development roller  4 , and prevent toner from leaking from the gaps between the development chamber  33 , and the development blade  6  and the development roller  4 . Further, in the longitudinal direction of opening portion of the development chamber  33 , the gush prevention sheet  37  is provided to abut on the development roller  4  and prevents toner from leaking from between the development chamber  33  and the development roller  4 . More specifically, at this place, one end side of the gush prevention sheet  37  adheres and is fixed onto the seating surface  32  provided in the development frame member  30  by a double-stick tape. The other end side of the gush prevention sheet  37  abuts on the development roller  4 . 
     Further, as illustrated in  FIG. 3  and  FIG. 4 , the development device  9  is swingably supported between a drive side cover member  61  and a non-drive side cover member  62 , centering around an axis line V parallel to a drum axis line T. On the drive side of the development device  9 , a cylinder portion  48   a  of a development side cover  48  is rotatably supported by a cylinder bearing hole  61   b  of the drive side cover member  61  and becomes a swing center. On the non-drive side, a side face hole (not illustrated) of the development frame member  30  is rotatably supported by an axis  62   b  of the non-drive side cover member  62  and becomes a swing center. More specifically, the development device  9  is rotatably connected to the photosensitive drum unit  8  and always biased by a pressure spring  90  which is a biasing member, so as to rotate the development roller  4  in a direction of contacting the photosensitive drum  1 . The pressure springs  90  are provided at both sides of the drive side and the non-drive side. Specifically, the development device  9  can move between a contact position for contacting the development roller  4  to the photosensitive drum  1  and a separation position for separating the development roller  4  from the photosensitive drum  1 . 
     A protection member (hereinafter referred to as a drum protection cover), which is an exemplary embodiment of the present invention will be described using  FIG. 5 ,  FIG. 6 ,  FIG. 7 ,  FIG. 8 , and  FIG. 9 . 
       FIG. 5  is a schematic perspective view illustrating the drum protection cover.  FIG. 6  is a cross-sectional view illustrating a process cartridge when the drum protection cover is mounted.  FIG. 7  is a schematic perspective view illustrating the process cartridge when the drum protection cover is mounted, as viewed from the photosensitive drum unit side.  FIG. 8  is a schematic perspective view illustrating the process cartridge when the drum protection cover is mounted, as viewed from the development device side.  FIG. 9  is a schematic cross-sectional view illustrating the process cartridge when the drum protection cover is mounted. 
     The drum protection cover will be described using  FIG. 4  and  FIG. 5 . The drum protection cover  80  is made of a molded resin and typically protects a surface of a photosensitive drum from light, dust, fluff, and cracks at a time of shipping and collecting. 
     When a user uses the process cartridge P by mounting it in the main body of image forming apparatus  100 , the user can remove the drum protection cover  80  by pushing downward a handhold portion  83 . 
     A fixing method of the drum protection cover  80  to the process cartridge P will be described. An engaging portion  86  of the drum protection cover  80  engages with an engaging hole  61   c  of a drive side cover member  61  and further, an engaging portion  87  engages with an engaging hole  62   c  of a non-drive side cover member  62  respectively, so that a position in a short side direction (W direction in  FIG. 6 ) is determined. Furthermore, the engaging portions  88  and  89  engage with engaging holes  50   c  and  50   d  of the cleaning frame member  50  respectively, so that a position in a up and down direction (U direction in  FIG. 6 ) is determined. As another exemplary embodiment apart from the present exemplary embodiment, only a part supporting the photosensitive drum  1  can be configured with a cover member, and all of the aforementioned engaging holes can be provided in the cleaning frame member  50 . 
     In the present exemplary embodiment, a shipping form in a state in which the development roller  4  and the photosensitive drum  1  are separated is adopted. As illustrated in  FIG. 6 , when the drum protection cover  80  is mounted, development position determination portions  84  and  85  abut on a part of bearing members  44  and  45  of the development device  9 . In this case, the development device  9  is held in a state in which the development device  9  is rotated in a clockwise direction by a predetermined angle centering around a swing center, so that a state in which the photosensitive drum  1  and the development roller  4  are separated is realized. In another words, the development device  9  is positioned at a separation position. 
     The separation state in the present exemplary embodiment is a state in which the development position determination portions  84  and  85 , and the photosensitive drum  1  are not in contact with each other. However, the development position determination portions  84  and  85  and the photosensitive drum  1  can be separated in a state in which the development position determination portions  84  and  85  are in contact with both the development drum  1  and the bearing members  44  and  45 . 
     Conventionally, inner pressure of a container increases by deformation of a gush prevention sheet seating surface or a scooping sheet seating surface. The deformation is generated by impact at a time of shipping, collecting, and transporting. Thus, by the increased inner pressure, there is a possibility that toner leaks from a part between the gush prevention sheet and the development roller, and a part between the scooping sheet and the development drum, where the abutment pressure is small. 
     Therefore, as for a countermeasure against the toner leak, it is simple and effective to give a function for preventing deformation of these seating surfaces of each sheet member to the drum protection cover  80 , which is mounted only at a time of shipping and collecting. 
     As illustrated in  FIG. 8 , as for the countermeasure against deformation of the gush prevention sheet seating surface  32 , the development frame member  30  in the development apparatus  9  includes a plurality of reinforcing ribs  34  provided on the back side  32   b  of the seating surface. These reinforcing ribs extend in a vertical or a cross direction with respect to the back side of the seat face  32   b , and are provided in line in a development roller axis direction (T direction in  FIG. 8 ). In the present exemplary embodiment, pressing portions  82  directly abuts on the back side  32   b  of the seating surface between each rib. More specifically, a pressing portion  82   a  is provided between the ribs  34   a  and  34   b , a pressing portion  82   b  is provided between the ribs  34   b  and  34   c , a pressing portion  82   c  is provided between the ribs  34   c  and  34   d , a pressing portion  82   d  is provided between the ribs  34   d  and  34   e , and a pressing portion  82   e  is provided between  34   e  and  34   f . The pressing portion  82  is an elastic portion which is elastic deformable, so that a size variation of the back side  32   b  of the seating surface can be compensated. 
     In the photosensitive drum unit  8 , as illustrated in  FIG. 7 , a pressing portion  81  also abuts on a back side  53   b  of the seating surface as a countermeasure to deformation of the scooping sheet face  53 . Since the pressing portion  81  is an elastic portion, a size variation at the back side  53   b  of the seat is absorbable. In the present exemplary embodiment, although the pressing portion  81  is divided into  81   a ,  81   b ,  81   c ,  81   d , and  81   e , if the pressing portions have elasticity, these portions can be integrally formed. 
     In the present exemplary embodiment, ribs are not provided at the back side  53   b  of the scooping sheet face  53 . However, even when the ribs are provided, the similar effect to the development device  9  can be obtained by allowing pressing portions  81   a ,  81   b ,  81   c ,  81   d , and  8   e  to abut on corresponding back side  53   b  of the seating surface between each rib. 
     In the present exemplary embodiment, the pressing portions  82  are provided between each rib. However, as illustrated in  FIG. 9 , the similar effect can be obtained by allowing the pressing portion  82  to abut on an end portion  35  of each rib  34  directly provided from the back side  32   b  of the seating surface. In this case, the smaller an interval of a plurality of ribs  34  is, the more the effect increases (the second exemplary embodiment). 
     Further, as described above, when the back side  32   b  of the seating surface is not directly pressed, it is effective to allow the pressing portion  82  to abut on the more top end side of the seating surface than a root  36  of apart which forms the seating surface  32 . 
     In the photosensitive drum unit  8 , as illustrated in  FIG. 9 , the similar effect is obtained by allowing the pressing portion  81  to abut on a rib top surface  54 . When the back side  53   b  of the seating surface is not directly pressed, it is effective to abut the pressing portion  81  on the more top end side of the seating surface than a root  55  of apart which forms the seating surface  53 . 
     In this case, it is not necessary to form a plurality of pressing portions, adjusting gaps between a plurality of ribs, so that freedom of a position of the pressing portion and number of the pressing portion increases. 
     In the present exemplary embodiment, the process cartridge has the configuration which is integrated by the photosensitive drum unit  8  at least including the photosensitive drum  1  and charging roller  3 , and the development device  9  at least including the development roller  4 . However, even when the photosensitive drum unit  8  and the development device  9  are configured independently, the similar effect to the present exemplary embodiment can be obtained. 
     For example, in a case of an independent development device, the following configuration is realized. Specifically, the protection cover of the development roller is positioned to the bearing member  45  and the development side cover  48  in the development device  9 , and the pressing portion abuts on the gush prevention sheet seating surface. In this case, the development protection cover can be positioned with respect to the development frame member  50 . 
     Further, in a case of an independent photosensitive drum unit, the drum protection cover is positioned with respect to the photosensitive drum unit, and the pressing portion abuts on the scooping sheet seat face. 
     In addition, the present exemplary embodiment is described on an assumption that the photosensitive drum  1  and the development roller  4  are separated. However, the similar effect is also obtained in the state in which the photosensitive drum  1  and the development roller  4  are not separated. 
     For example, as described above, the drum protection cover  80  is positioned by the cleaning frame member  50 , the drive side cover member  61 , and the non-drive side cover member  62  which configure the photosensitive unit  8 . In the state in which the photosensitive drum  1  and the development roller  4  are not separated, the development position determination portions  84  and  85  are not necessary in the drum protection cover  80 . In this configuration, the development device  9  is rotated centering around the swing center, and the development roller  4  abuts on the photosensitive drum  1 , so that the position of the development device  9  is determined. Then, the pressing portion  82  of the drum protection cover  80  abuts on the back side  32   b  of the seating surface of the gush prevention sheet seating surface  32 . 
     According to the above description, the process cartridge according to the present invention obtains the following effects.
     (1) At a time of shipping, by attaching a protection member, the process cartridge can suppress deformation of a seating surface which fixes a flexible sheet member, and decrease toner leak and toner dispersion as much as possible.   (2) At a time of collecting a used cartridge, by attaching a protection member, the process cartridge can suppress deformation of a seating surface which fixes a flexible sheet member, and decrease toner leak and toner dispersion as much as possible.   

     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures, and functions. 
     This application claims priority from Japanese Patent Application No. 2010-139961 filed Jun. 18, 2010, which is hereby incorporated by reference herein in its entirety.