Patent Publication Number: US-2023135180-A1

Title: Process cartridge and image forming apparatus

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a process cartridge including an image bearing member and a developer bearing member, and an image forming apparatus including the process cartridge. 
     Description of the Related Art 
     Hitherto, there is suggested a printer in which a process cartridge is constituted by a photosensitive member cartridge and a development cartridge that is detachably supported to the photosensitive member cartridge, and the process cartridge is detachable from an apparatus body (refer to JP-A-2016-224221). The photosensitive member cartridge includes a photosensitive member of which a surface is scanned with an exposing unit to form an electrostatic latent image, and the development cartridge includes a development roller that develops the electrostatic latent image as a toner image. 
     A release lever for detaching the development cartridge from the photosensitive member cartridge is provided on a left portion of the photosensitive member cartridge. A memory unit is provided on a bottom surface of the development cartridge, and an electric contact portion of the photosensitive member cartridge, which can be electrically connected to an electric contact portion of the memory unit, is provided at a position corresponding to the memory unit of the photosensitive member cartridge. 
     The printer disclosed in JP-A-2016-224221 has a configuration in which the development cartridge can be detached from the photosensitive member cartridge, and thus in accordance with an operation of detaching the development cartridge, the electric contact portion of the memory unit and the electric contact portion of the photosensitive member cartridge are displaced and slide on each other. A displacement amount of the two electric contact portions becomes larger as it is close to the release lever. The two electric contact portions and the release lever are disposed on a left side of the process cartridge, and thus the displacement amount of the electric contact portions is large, and there is a concern that the electric contact portions are abraded and contact failure occurs. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the present invention, a process cartridge includes a first unit including an image bearing member configured to rotate and carry an electrostatic latent image, and a second unit including a developer bearing member configured to rotate while carrying a developer and to develop the electrostatic latent image carried on the image bearing member into a toner image, the second unit being capable of being mounted on the first unit in a mounting direction. The first unit includes a moving member that moves the second unit mounted on the first unit at a mounting position to a detachment position. The second unit includes a storage unit that stores information about the second unit The moving member is disposed on a first side of the process cartridge in a longitudinal direction of the image bearing member. An electrode of the storage unit is disposed on a second side of the process cartridge in the longitudinal direction. 
     According to a second aspect of the present invention, an image forming apparatus includes an apparatus body, and the process cartridge according to claim  1 , the process cartridge being detachably provided in the apparatus body. The apparatus body includes a body electrode that is capable of coming into contact with the electrode of the storage unit 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an overall schematic view illustrating a printer according to a first embodiment. 
         FIG.  2    is a perspective view illustrating a drum unit and a development unit 
         FIG.  3    is a perspective view illustrating the development unit. 
         FIG.  4    is a cross-sectional view illustrating a cross-section  4 - 4  in  FIG.  3   . 
         FIG.  5    is an exploded perspective view illustrating the development unit. 
         FIG.  6    is a plan view illustrating the development unit. 
         FIG.  7 A  is a side view illustrating a development unit that is not used. 
         FIG.  7 B  is a side view illustrating a development unit that is used already. 
         FIG.  8    is a perspective view illustrating the development unit. 
         FIG.  9    is a cross-sectional view illustrating a process cartridge. 
         FIG.  10    is a perspective view illustrating the process cartridge. 
         FIG.  11    is a perspective view illustrating the process cartridge. 
         FIG.  12    is a perspective view illustrating the process cartridge. 
         FIG.  13    is an enlarged perspective view illustrating an operation configuration of a photosensitive drum. 
         FIG.  14    is a plan view illustrating the drum unit and the development unit. 
         FIG.  15 A  is a plan view illustrating a pressing member and a lift member, the lift member being indicated by a broken line. 
         FIG.  15 B  is a plan view illustrating the pressing member and the lift member, the lift member being indicated by a solid line. 
         FIG.  16    is a perspective view illustrating the pressing member and the lift member. 
         FIG.  17 A  is a cross-sectional view illustrating a state in which the development unit is mounted on the drum unit. 
         FIG.  17 B  is a cross-sectional view illustrating the development unit that enters a lift-up state by the lift member. 
         FIG.  18    is a perspective view illustrating a memory and a positioning protrusion of a development unit according to a second embodiment. 
         FIG.  19    is a perspective view illustrating the drum unit and the development unit. 
         FIG.  20    is a perspective view illustrating an arrangement relationship between a memory electrode and the positioning protrusion. 
         FIG.  21    is a cross-sectional view illustrating a preferred configuration for suppressing a displacement of the memory electrode. 
         FIG.  22    is a plan view illustrating an arrangement relationship between the memory electrode and the positioning protrusion. 
         FIG.  23    is a perspective view illustrating a process cartridge according to a third embodiment. 
         FIG.  24    is a perspective view illustrating arrangement of the memory electrode. 
         FIG.  25    is a perspective view illustrating the pressing member and an electrode exposing hole. 
         FIG.  26    is a perspective view illustrating the development unit 
         FIG.  27    is a perspective view illustrating a pressed portion in the development unit. 
         FIG.  28    is a cross-sectional view illustrating an arrangement relationship between the memory electrode and a spring contact portion. 
         FIG.  29    is a perspective view illustrating a process cartridge according to a fourth embodiment. 
         FIG.  30    is a side view illustrating the process cartridge. 
         FIG.  31    is a perspective view illustrating a modification example of the process cartridge according to the fourth embodiment. 
         FIG.  32    is a perspective view illustrating a process cartridge according to a fifth embodiment. 
         FIG.  33    is a side view illustrating the process cartridge. 
         FIG.  34    is a perspective view illustrating the process cartridge. 
         FIG.  35    is a perspective view illustrating a drum unit and a development unit according to a sixth embodiment. 
         FIG.  36    is a perspective view illustrating the drum unit and the development unit. 
         FIG.  37    is a perspective view illustrating the drum unit and the development unit. 
         FIG.  38    is an enlarged perspective view illustrating a lift member and an inner side wall. 
         FIG.  39    is an enlarged perspective view illustrating the lift member and the inner side wall. 
         FIG.  40 A  is a cross-sectional view illustrating a state in which the development unit is mounted on the drum unit. 
         FIG.  40 B  is a cross-sectional view illustrating the development unit that enters a lift-up state by the lift member. 
         FIG.  41 A  is a perspective view illustrating an apparatus body. 
         FIG.  41 B  is an enlarged perspective view illustrating a contact portion of the apparatus body. 
         FIG.  42 A  is a perspective view illustrating a first guide portion and a second guide portion of a right body guide. 
         FIG.  42 B  is a perspective view illustrating a second positioning protrusion and a second guide rib of the drum unit 
         FIG.  43 A  is a perspective view illustrating a third guide portion and a fourth guide portion of a left body guide. 
         FIG.  43 B  is a perspective view illustrating the first guide portion and the second guide portion of the right body guide. 
         FIG.  44 A  is a cross-sectional view illustrating a state in which the development unit is mounted on the drum unit. 
         FIG.  44 B  is a cross-sectional view illustrating the process cartridge in a state in which the lift member is pressed. 
         FIG.  45    is a perspective view for describing a force that acts on the lift member. 
         FIG.  46 A  is a cross-sectional view illustrating a contact state between the memory electrode and an electrode of the apparatus body. 
         FIG.  46 B  is a cross-sectional view illustrating a variation of the contact state between the memory electrode and the electrode of the apparatus body. 
         FIG.  47 A  is a perspective view illustrating an inner side wall. 
         FIG.  47 B  is a cross-sectional view for describing arrangement of the inner side wall. 
         FIG.  48    is a perspective view illustrating a process cartridge according to a seventh embodiment. 
         FIG.  49    is an enlarged perspective view illustrating a lift member and a detection unit. 
         FIG.  50 A  is a side view illustrating the lift member in a state in which the lift member is not pressed and a detection unit. 
         FIG.  50 B  is a side view illustrating a pressing member and a pressed member. 
         FIG.  51 A  is a side view illustrating the lift member in a state in which the lift member is pressed and comes into contact with the detection unit. 
         FIG.  51 B  is a side view illustrating the pressing member and the pressed member. 
         FIG.  52 A  is a side view illustrating the development unit that enters a lift-up state by the lift member. 
         FIG.  52 B  is a side view illustrating the development unit that is maintained in the lift-up state by an end of the pressing member. 
         FIG.  53    is a perspective view illustrating the process cartridge that is to be mounted on the apparatus body. 
         FIG.  54    is a side view illustrating the process cartridge that has begun to be mounted on the apparatus body. 
         FIG.  55 A  is a side view illustrating the process cartridge in a state in which a first guide rib is inserted into a guide space. 
         FIG.  55 B  is a perspective view illustrating the process cartridge in a state in which the first guide rib is inserted into the guide space. 
         FIG.  56    is a side view illustrating the process cartridge that is mounted on the apparatus body. 
         FIG.  57    is a perspective view illustrating an arrangement relationship of a regulation portion. 
         FIG.  58    is a cross-sectional view illustrating a process cartridge according to an eighth embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     First Embodiment 
     Overall Configuration 
     First, a first embodiment of the invention will be described. In the following description, directions are defined on the basis of a user who uses a printer  1 . That is, a front surface side of the printer  1  is set as “front”, a rear surface side thereof is set as “rear”, an upper surface side is set as “up”, and a lower surface side is set as “down”. In addition, when the printer  1  is viewed from the front surface side, a left side of the printer  1  is set as “left”, and a right side thereof is set as “right”. With regard to a process cartridge to be described later, directions are defined in a similar manner as in the printer  1  on the assumption that the process cartridge takes the same posture as in a state of being mounted on the printer  1 . Respective directions in the respective drawings are defined by arrows illustrated in the drawings. For example, in  FIG.  1   , a left side of a paper surface is set to a front side. In addition, an upper-lower direction is parallel to a vertical direction, and a right-left direction and a front-rear direction are parallel to a horizontal direction. The right-left direction is parallel to a rotational axis direction of a photosensitive drum  61  and a rotational axis direction of a development roller  71 . 
     The printer  1  serving as an image forming apparatus according to the first embodiment is an electrophotographic-system laser beam printer. As illustrated in  FIG.  1   , the printer  1  includes a feeding unit  3  that feeds a sheet S accommodated in a cassette  31 , an image forming unit  9  that forms a toner image on the sheet S, a fixing unit  8  that fixes the toner image onto the sheet S, and a sheet discharge roller pair  25 . 
     The feeding unit  3  includes the cassette  31 , a pickup roller  33  that feeds the highest sheet S accommodated in the cassette  31 , and a separation roller pair  32  that separates the sheets S fed by the pickup roller  33  sheet by sheet 
     The image forming unit  9  includes an exposing unit  4  that is provided in an apparatus body  2  of the printer  1 , and a process cartridge  5  that is inserted into the apparatus body  2  in a direction indicated by an arrow S 1  and is detached in a direction indicated by an arrow S 2 . The exposing unit  4  includes a laser emitting component, a polygon mirror, a lens, a reflective mirror, and the like (not illustrated). In the exposing unit  4 , a surface of the photosensitive drum  61  of the process cartridge  5  is scanned at a high speed with laser light that is emitted from the laser emitting component and is based on image data, and thus the surface of the photosensitive drum  61  is exposed. 
     The process cartridge  5  is disposed bellow the exposing unit  4 , and is inserted into or extracted from the apparatus body  2  in a state in which a door  21  of the apparatus body  2  is opened. The process cartridge  5  mainly includes a drum unit  6  and a development unit  7 , and the drum unit  6  includes a rotatable photosensitive drum  61  serving as an image bearing member, a charging roller  62 , a transfer roller  63 , and the like. The photosensitive drum  61  and the transfer roller  63  form a transfer nip N 1 . The development unit  7  includes a development roller  71 , a supply roller  72 , a blade  73 , a toner storage portion  74  that stores a developer that contains a toner, a first agitator  75 A and a second agitator  75 B which are provided inside the toner storage portion  74 , and the like. 
     Note that, the developer in this embodiment is constituted by a nonmagnetic one-component developer, but a one-component developer including a magnetic component may be used. In addition, the one-component developer may contain an additive (for example, wax or silica particulate) for adjusting fluidity or a charging performance of the toner in addition to toner particles. In addition, as the developer, a two-component developer constituted by a nonmagnetic toner and a magnetic carrier may be used. In the case of using the magnetic developer, as the developer bearing member, for example, a cylindrical development sleeve in which a magnet is disposed on an inner side is used. 
     A developer in the toner storage portion  74  is stirred by the second agitator  75 B and the first agitator  75 A, and is supplied to the development roller  71  by the supply roller  72 . The developer that is supplied to the development roller  71  by the supply roller  72  passes through a gap between the development roller  71  and the blade  73  and is carried on the development roller  71  in a constant layer thickness. The development roller  71  serving as the developer bearing member rotates while carrying the developer and develops an electrostatic latent image carried on the photosensitive drum  61  into a toner image. The fixing unit  8  is disposed on a backward side of the process cartridge  5 , and includes a pressing roller  91  and a heating roller  92 . The heating roller  92  includes a heat source such as a ceramic heater on an inner side. 
     When an image forming command is output to the printer  1 , an image forming process is initiated by the image forming unit  9  on the basis of image information that is input from an external computer connected to the printer  1  or an image reading apparatus or the like that is connected to the printer  1  as an option. The exposing unit  4  emits laser light toward the photosensitive drum  61  on the basis of the image information that is input. At this time, the photosensitive drum  61  is charged in advance by the charging roller  62 , and thus when the photosensitive drum  61  is irradiated with laser light, an electrostatic latent image is formed on the photosensitive drum  61 . Then, the electrostatic latent image is developed by the development roller  71 , and a toner image is formed on the photosensitive drum  61 . 
     In combination with the image forming process, the sheet S stacked on the cassette  31  is sent out by the pickup roller  33 . A plurality of the sheets S fed by the pickup roller  33  are separated sheet by sheet by the separation roller pair  32 , and is conveyed to the transfer nip N 1 . In the transfer nip N 1 , when a transfer bias is applied to the transfer roller  63 , the toner image formed on the photosensitive drum  61  is transferred to the sheet S. The sheet S to which the toner image is transferred at the transfer nip N 1  is heated and pressed by a fixing nip N 2  formed by the pressing roller  91  and the heating roller  92 , and thus the toner image is fixed. In addition, the sheet S to which the toner image is fixed is discharged to a sheet discharge tray  22  by the sheet discharge roller pair  25 . 
     Process Cartridge 
     As illustrated in  FIG.  2   , the process cartridge  5  includes the drum unit  6  serving as a first unit and the development unit  7  serving as a second unit that is detachably supported to the drum unit  6 . The development unit  7  is mounted on the drum unit  6  in a mounting direction AD in a state in which a grip portion  701  is gripped by a user. Note that, in all embodiments to be described below, the mounting direction AD is the same as a direction that substantially face a backward side from a forward side of an apparatus. 
     Development Unit 
     As illustrated in  FIG.  2    to  FIG.  5   , the development unit  7  includes a casing  700 , the development roller  71 , the supply roller  72 , the first agitator  75 A, the second agitator  75 B, a drive train  720 , and a side holder  719 . The casing  700  includes a left side wall  704  and a right side wall  705  which rotatably support both ends of the development roller  71 , the supply roller  72 , the first agitator  75 A, and the second agitator  75 B, and a grip portion  701  that is provided in a front direction of the casing  700  and is gripped by a user. The side holder  719  covers the drive train  720  and is supported to the left side wall  704 . Hereinafter, a rotational axis direction of the development roller  71  is referred to as an axial direction in description. 
     The first agitator  75 A includes a stirring rod  78 A and a stirring sheet  79 A. The stirring rod  78 A stirs the developer inside the toner storage portion  74  in the axial direction, and the stiffing sheet  79 A stirs the developer in a diameter direction orthogonal to the axial direction. Similarly, the second agitator  75 B includes a stiffing rod  78 B and a stirring sheet  79 B. The stirring rod  78 B stirs the developer inside the toner storage portion  74  in the axial direction, and the stirring sheet  79 B stirs the developer in the diameter direction. The supply roller  72  is supplied with the developer by the stirring sheet  79 A. 
     The development roller  71  is rotatably supported by a bearing  746 A provided in the side holder  719 , and a bearing  746 B attached to the right side wall  705  of the casing  700 . As illustrated in  FIG.  3   , the development unit  7  includes a first contact  720 A and a second contact  720 B which are disposed in the vicinity of the bearing  746 B. The first contact  720 A is electrically connected to the development roller  71 , and a voltage applied to the development roller  71  is supplied from the apparatus body  2 . The second contact  720 B is electrically connected to the supply roller  72 , and a voltage applied to the supply roller  72  is supplied from the apparatus body  2 . The first contact  720 A and the second contact  720 B can come into contact with a power supply contact (not illustrated) provided in the apparatus body  2 . 
     As illustrated in  FIG.  5    and  FIG.  6   , the drive train  720  provided on the left side of the development unit  7  includes a development coupling  710 , a supply roller gear  712 , a development roller gear  711 , a first agitator gear  713 , and a second agitator gear  714 . In addition, the drive train  720  includes idle gears  715 A,  715 B, and  715 C. 
     The development coupling  710  is rotatably supported to the left side wall  704  of the development unit  7 , and a drive transmission member (not illustrated) provided in the apparatus body  2  engages with the development coupling  710  in conjunction with an operation of closing the door  21  (refer to  FIG.  1   ) provided in the apparatus body  2 . In contrast, the drive transmission member is spaced apart from the development coupling  710  in conjunction with an operation of opening the door  21 . The drive transmission member is configured to transmit a driving force to the development coupling  710  while permitting a displacement of the development coupling  710  within a predetermined range. In addition, movement of the development coupling  710 , the development roller gear  711 , and the supply roller gear  712  in an axial direction is regulated by the side holder  719 . 
     When the apparatus body  2  operates after the door  21  is closed, the driving force is transmitted from the drive transmission member to the development coupling  710 , and a gear  710   a  provided in a peripheral surface of the development coupling  710  rotates. The gear  710   a  engages with the development roller gear  711  provided in an end of the development roller  71  and the supply roller gear  712  provided in an end of the supply roller  72 , and when the gear  710   a  rotates, the development roller  71  and the supply roller  72  rotate. 
     In addition, the gear  710   a  of the development coupling  710  engages with the first agitator gear  713  through the idle gear  715 A, and when the first agitator gear  713  rotates, the first agitator  75 A rotates. The idle gear  715 B that is provided coaxially with the first agitator  75 A engages with the second agitator gear  714  through the idle gear  715 C, and when the second agitator gear  714  rotates, the second agitator  75 B rotates. 
     In addition, as illustrated in  FIG.  5    to  FIG.  7 B , the second agitator gear  714  is configured to engage with a gear portion  82  of a detection gear  81 . The detection gear  81  is provided with a detection protrusion  83  that is disposed at a position distant from the rotation center by a predetermined distance and extends in an axial direction, and the detection protrusion  83  serving as a detection unit passes through a hole  84  of a detection unit  80  of the side holder  719 . The hole  84  has a long hole shape that is long in a circumferential direction. The apparatus body  2  is provided with a detection mechanism (not illustrated) that detects a position of the detection protrusion  83 , and the detection mechanism outputs a detection signal on the basis of the position of the detection protrusion  83 . According to this, it is possible to determine whether the development unit  7  is an object that is not used, or an object that is used already. 
       FIG.  7 A  is a side view illustrating the development unit  7  that is not used, and  FIG.  7 B  is a side view illustrating the development unit  7  that is used already. The detection gear  81  is a chipped tooth gear and includes the gear portion  82  and a non-gear portion  82   a.  As illustrated in  FIG.  7 A , the second agitator gear  714  of the development unit  7  that is not used engages with the gear portion  82  of the detection gear  81 . At this time, the detection protrusion  83  is located at a position on an upper front side serving as a first position. 
     In addition, when the development unit  7  is used and the second agitator gear  714  rotates in a direction indicated by an arrow R 3 , the detection gear  81  that engages with the second agitator gear  714  rotates in a direction indicated by an arrow R 4 . In addition, as illustrated in  FIG.  7 B , when the gear portion  82  of the detection gear  81  does not engage with the second agitator gear  714 , the detection gear  81  is stopped. At this time, the detection protrusion  83  is located at a position on an upper-rear side serving as a second position. 
     As described above, since the development unit  7  is used, the detection protrusion  83  pivots within in a range of the hole  84  of the detection unit  80 , and a position of the detection protrusion  83  is detected by the detection mechanism provided in the apparatus body  2 . According to this, it is possible to determine whether the development unit  7  is an object that is not used or an object that is used already. 
     In addition, as illustrated in  FIG.  8   , a bottom surface of the development unit  7  is provided with a pair of left and right ribs  718  and  718  which protrudes downward, and a memory  85  and a positioning protrusion  86  which are provided on a left side. More specifically, the memory  85  and the positioning protrusion  86  are provided on a bottom surface of the side holder  719  of the development unit  7 . The memory  85  includes a memory chip (not illustrated) that stores information about the development unit  7 , and a memory electrode  85   a  that is electrically connected to the memory chip. The memory electrode  85   a  comes into contact with an electrode (not illustrated) provided in the apparatus body  2 , and performs communication with the memory chip and the apparatus body  2 . Information that is stored in the memory chip and relates to the development unit  7  includes information about replacement time of the development unit  7 , or information about a residual amount of a toner stored in the development unit  7 . 
     Drum Unit 
     Next, a detailed configuration of the drum unit  6  will be described. As illustrated in  FIG.  2   , and  FIG.  9    to  FIG.  11   , the drum unit  6  mainly includes a frame  610  and the photosensitive drum  61  that is rotatably supported on a rear side of the frame  610 . The frame  610  includes a pair of left side wall  611  and right side wall  612 , and the photosensitive drum  61  is rotatably supported to the left side wall  611  and the right side wall  612 . 
     A front portion of the frame  610  is provided with a mounting portion  615  (refer to  FIG.  2   ) to which the development unit  7  can be mounted, a grip portion  617  where a user grips the drum unit  6 , a pair of left and right pressing members  640  which presses the development unit  7  to a forward side, and a lift member  642 . In a state in which the development unit  7  is mounted on the drum unit  6 , the toner storage portion  74  of the development unit  7  is disposed between the left side wall  611  and the right side wall  612 . 
     A laser passage hole  616  through which laser light emitted from the exposing unit  4  passes is formed in a rear-upper portion of the frame  610 . In addition, a first positioning protrusion  660  and a first guide rib  662  which protrude to an outer side in an axial direction are provided on the left side wall  611  serving as a second side wall of the frame  610 , and the first positioning protrusion  660  is disposed behind the first guide rib  662 . Similarly, a second positioning protrusion  661  and a second guide rib  663  which protrude to an outer side in the axial direction are provided on the right side wall  612  serving as a first side wall of the frame  610 , and the second positioning protrusion  661  is disposed behind the second guide rib  663 . The first positioning protrusion  660  and the second positioning protrusion  661  are formed in a cylindrical shape, and the first guide rib  662  and the second guide rib  663  extend in a direction along the front-rear direction. 
     As illustrated in  FIG.  2   ,  FIG.  11   , and  FIG.  14   , a concave portion  664  that is concaved downward and the first guide rib  662 , serving as a rib, disposed bellow the concave portion  664  are provided in the left side wall  611  of the drum unit  6 . At least a part of the first guide rib  662  overlaps the concave portion  664  in an insertion direction of the development unit  7  into the drum unit  6 . The detection unit  80  and the detection protrusion  83  further protrude in a longitudinal direction, i.e. axial direction, than the left side wall  611  above the concave portion  664 . Since the concave portion  664  is formed, stiffness of the left side wall  611  decreases. However, since the first guide rib  662  is provided at a position that is located on a downward side of the concave portion  664  and overlaps the concave portion  664  in the front-rear direction, the first guide rib  662  operates as a reinforcing member, and thus it is possible to reduce the decrease in stiffness of the left side wall  611 . 
     By the way, an operational lifespan of the development unit  7  which is determined by a toner amount stored in the development unit  7  is set to be shorter than an operational lifespan of the drum unit  6  which is determined by the thickness of a photosensitive layer of the photosensitive drum  61 . Accordingly, it is preferable to replace only the development unit  7  that has reached the end of the operational lifespan separately from the drum unit  6 . In the case of replacing only the development unit  7 , after opening the door  21  and taking out the process cartridge  5  from the inside of the apparatus body  2 , only the development unit  7  is detached from the drum unit  6 . In addition, a new development unit  7  is inserted in the mounting direction AD illustrated in  FIG.  2    to assemble the development unit  7  to the drum unit  6 . Then, the process cartridge  5  in which the development unit  7  and the drum unit  6  are integrated is mounted on the apparatus body  2 . When the process cartridge  5  is mounted on the apparatus body  2 , the first positioning protrusion  660 , the second positioning protrusion  661 , the first guide rib  662 , and the second guide rib  663  are guided to a guide groove (not illustrated) of the apparatus body  2 , and thus the process cartridge  5  is guided to a mounting position. 
     As illustrated in  FIG.  2   ,  FIG.  10   , and  FIG.  11   , a receiving portion  641  is formed in each of the left side wall  611  and the right side wall  612  of the frame  610 , and the receiving portion  641  is configured to come into contact with a bearing  746 A or  746 B of the development unit  7 . The receiving portion  641  serving as a contact portion is formed in a substantially U-shape of which a front side is opened, and includes a lower surface  641   a  that extends in the front-rear direction, and an abutting surface  641   b  that extends in the vertical direction (refer to  FIG.  10   ). 
     In addition, as illustrated in  FIG.  2   ,  FIG.  8   ,  FIG.  9   , and  FIG.  12   , a sheet passage hole  610   b  through which a sheet passes when being conveyed to the transfer nip N 1 , two protruding portions  643  and  643  which protrude upward, and a positioning hole  68  are formed in the bottom surface  610   a  of the frame  610 . The protruding portions  643  and  643  respectively come into contact with the pair of ribs  718  and  718  formed on the bottom surface of the development unit  7  to support the development unit  7 . As illustrated in  FIG.  12    and  FIG.  13   , the positioning hole  68  is provided on a leftward side of the sheet passage hole  610   b,  and is formed by an electrode exposing hole  68   a  and an engagement hole  68   b.    
     The electrode exposing hole  68   a  is configured to expose the memory electrode  85   a  to a downward side of the drum unit  6  in a state in which the development unit  7  is mounted on the drum unit  6  so as to allow the memory electrode  85  a to come into contact with an electrode (not illustrated) provided in the apparatus body  2 . That is, the electrode exposing hole  68   a  serving as an opening portion and a hole exposes the memory electrode  85   a  of the memory  85  to the outside. The engagement hole  68   b  is formed in dimensions smaller than that of the electrode exposing hole  68   a  in the right-left direction, and engages with the positioning protrusion  86  of the development unit  7  in the right-left direction in a state in which the development unit  7  is mounted on the drum unit  6 . 
     As illustrated in  FIG.  13   , a first photosensitive member gear  65  and a second photosensitive member gear  66  are provided in a left end of the photosensitive drum  61 , and a transfer gear  67  that engages with the second photosensitive member gear  66  is provided in a left end of the transfer roller  63 . When the process cartridge  5  including the drum unit  6  is mounted on the apparatus body  2 , a drive gear provided in the apparatus body  2  engages with the first photosensitive member gear  65 . In this state, when the drive gear rotates, the first photosensitive member gear  65  rotates by the drive gear, and the photosensitive drum  61  and the second photosensitive member gear  66  rotate integrally with the first photosensitive member gear  65 . In addition, rotation of the second photosensitive member gear  66  is transmitted to the transfer gear  67 , and the transfer roller  63  rotates integrally with the transfer gear  67 . 
     In addition, as illustrated in  FIG.  14   ,  FIG.  15 A , and  FIG.  15 B , the pair of pressing members  640  is provided on a front portion of the frame  610  of the drum unit  6 . The pressing members  640  are urged to a forward side by urging springs  644 , and press a pair of pressed ribs  716  which is provided in the casing  700  of the development unit  7  in a state in which the development unit  7  is mounted on the drum unit  6 . According to this, the development roller  71  of the development unit  7  is pressed against the photosensitive drum  61 . 
     Note that, as illustrated in  FIG.  14   , the pair of left and right pressed ribs  716  is provided so that the pressed rib  716  which is disposed on the right side is disposed behind the pressed rib  716  which is disposed on the left side. The reason for this is because the lift member  642  to be described later is disposed to overlap the right pressed rib  716  in the right-left direction as illustrated in  FIG.  15 A  and  FIG.  15 B  so that the lift member  642  that is pivoted and the right pressed rib  716  do not interfere with each other. In this configuration, a rearward protrusion amount of the lift member  642  is suppressed, and thus it is possible to constitute the process cartridge  5  in a small size. 
     Since the drum unit  6  is configured as described above, when the development unit  7  is mounted on the drum unit  6  in the mounting direction AD as illustrated in  FIG.  2   , the bearings  746 A and  746 B of the development unit  7  are guided to the lower surface  641   a  of the receiving portion  641 . In addition, when the development unit  7  is further mounted on the drum unit  6 , the bearings  746 A and  746 B abut the abutting surface  641   b  of the receiving portion  641 . 
     In this state, when a user separates a hand from the grip portion  701  of the development unit  7 , the development unit  7  is supported by the protruding portions  643  and  643  formed on the bottom surface  610   a  of the drum unit  6  and is pressed forward by the pressing member  640 . The bearings  746 A and  746 B of the development unit  7  are pressed against the abutting surface  641   b  due to an urging force of the urging spring  644  that presses the pressing member  640 , and the development unit  7  is positioned with respect to the drum unit  6  in the front-rear direction. In combination with the positioning, the positioning protrusion  86  serving as a protruding portion of the development unit  7  engages with the engagement hole  68   b  of the positioning hole  68 , and thus the development unit  7  is positioned with respect to the drum unit  6  in the right-left direction. 
     The positioning protrusion  86  and the engagement hole  68   b  are provided downstream of the memory electrode  85   a  and the electrode exposing hole  68   a  in the mounting direction AD. According to this, when mounting the development unit  7  on the drum unit  6 , it is possible to easily cause the positioning protrusion  86  to engage with the engagement hole  68   b  without causing the memory electrode  85   a  to come into contact with the drum unit  6 . Accordingly, usability when mounting the development unit  7  on the drum unit  6  is improved, and breakage of the memory electrode  85   a  can be reduced. 
     Development Unit Detachment Configuration 
     Next, a configuration for detaching the development unit  7  from the drum unit  6  will be described. In  FIG.  15 A , the lift member  642  illustrated in  FIG.  15 B  is indicated by a broken line. As illustrated in  FIG.  15 A  to  FIG.  16   , the lift member  642  is provided in a leading edge portion and a right edge portion of the drum unit  6 , and the lift member  642  is supported to the right side wall  612  of the drum unit  6  to be rotatable around the rotational axis  642 X. The rotational axis  642 X extends in parallel to the rotational axis direction of the photosensitive drum  61  and the development roller  71 . The lift member  642  is urged by a compression spring  650  to rotate in a direction indicated by an arrow R 1 , and when an operation portion  642 A provided in a first end portion of the lift member  642  is pressed downward, the lift member  642  pivots against an urging force of the compression spring  650  in a direction indicated by an arrow R 2 . 
     A cylindrical protruding portion  751  that protrudes to a rightward side is provided in the right side wall  705  of the development unit  7 , and a contact portion  642 B that can come into contact with the protruding portion  751  is provided in a second end portion of the lift member  642 . The contact portion  642 B is provided on a side opposite to the operation portion  642 A with the rotational axis  642 X interposed therebetween. 
     By the way, as illustrated in  FIG.  8   , and  FIG.  16    to  FIG.  17 B , the pressing member  640  includes a pressing surface  640   a  that is provided on a front surface of the pressing member  640  and extends in a vertical direction, and an inclined surface  640   b  that is inclined upward from an upper end of the pressing surface  640   a  to a rearward side. The pressed rib  716  in the development unit  7  includes a pressed surface  716   a  which is pressed forward by the pressing surface  640   a,  and an inclined surface  716   b  that is inclined downward from a lower end of the pressed surface  716   a  toward a forward side. 
     As illustrated in  FIG.  17 A , in a state in which the development unit  7  is mounted on the drum unit  6 , the pressing surface  640   a  of the pressing member  640  that is urged by the urging spring  644  presses the pressed surface  716   a  in the pressed rib  716  in the development unit  7 . At this time, the pressing surface  640   a  and the pressed surface  716   a  extend in a substantially vertical direction, and thus an urging force of the urging spring  644  vertically operates on the pressed surface  716   a,  and the development unit  7  is urged to the front direction. According to this, the development unit  7  is locked at a mounting position so as not to be detached from the drum unit  6 . 
     As illustrated in  FIG.  16   , when the operation portion  642 A of the lift member  642  is pressed downward, the lift member  642  rotates in a direction indicated by an arrow R 2 , and the contact portion  642 B of the lift member  642  lifts up the protruding portion  751  of the development unit  7  to an upward side. According to this, as illustrated in  FIG.  17 B , a front direction of the development unit  7  mounted on the drum unit  6  pivots upward, and the development unit  7  pivots in a detachment direction LD from the mounting position. According to this, the pressed surface  716   a  in the development unit  7  is separated upward from the pressing surface  640   a,  and the inclined surface  716   b  of the development unit  7  rides on the inclined surface  640   b  of the pressing member  640 . 
     At this time, the bearings  746 A and  746 B of the development unit  7  are in a state of being supported by the receiving portions  641  and  641 . A state of the development unit  7  at this time is referred to as a lift-up state, and a position of the development unit  7  that enters the lift-up state is referred to as a detachment position. When the development unit  7  is in the lift-up state, the inclined surfaces  640   b  and  716   b  are inclined with respect to the front direction that is an urging direction of the pressing member  640 . That is, when the development unit  7  is pivoted in the detachment direction LD by the lift member  642 , the pressed surface  716   a  in the development unit  7  is separated upward from the pressing surface  640   a.  In this case, the inclined surface  716   b  of the development unit  7  can be lifted upward by the inclined surface  640   b  of the pressing member  640  that is urged forward by the urging spring  644 , and thus the development unit  7  further pivots in the detachment direction LD by the urging force of the urging spring  644 . According to this, it is possible to reduce an operation force for setting the development unit  7  to the lift-up state. 
     When the development unit  7  enters the lift-up state, most of the forward urging force of the urging spring  644  is converted as a substantially upward force by the inclined surfaces  640   b  and  716   b,  and thus the development unit  7  is not locked to the drum unit  6 . According to this, a user can detach the development unit  7  from the drum unit  6  only by lifting up the grip portion  701  of the development unit  7  without moving other members or the like. In this manner, the user can mount a new development unit  7  on the drum unit  6  after detaching the drum unit  6  from the development unit  7 . 
     Summary of First Embodiment 
     In the process cartridge  5  in which the development unit  7  is detachably provided in the drum unit  6 , when the memory electrode  85   a  of the memory  85  provided in the development unit  7  is abraded, a contact state between the memory electrode  85   a  and the electrode of the apparatus body  2  becomes unstable. Particularly, when the memory electrode  85   a  is disposed near the lift member  642  for detaching the development unit  7  from the drum unit  6 , an amount of displacement between the memory electrode  85   a  and the electrode of the apparatus body  2  tends to increase in accordance with an operation of the lift member  642 . 
     Here, in this embodiment, in the longitudinal direction, i.e. axial direction, of the photosensitive drum  61  serving as the image bearing member, the lift member  642  serving as the moving member is disposed on a first side of the process cartridge  5 , and the memory electrode  85   a  of the memory  85  serving as a storage unit is disposed on a second side. More specifically, the lift member  642  is disposed on the right side of the process cartridge  5 , and the memory electrode  85   a  serving as an electrode is disposed on the left side of the process cartridge  5 . 
     According to this, when detaching the development unit  7  from the drum unit  6  by pressing the lift member  642  to a downward side, it is possible to reduce a displacement between the memory electrode  85   a  and the electrode of the apparatus body  2 . According to this, abrasion of the memory electrode  85   a  is suppressed, and thus it is possible to stabilize a contact state between the memory electrode  85   a  and the electrode of the apparatus body  2 . 
     In addition, the detection protrusion  83  is disposed on the second side of the process cartridge  5  on a side opposite to the lift member  642 , that is, on the left side in the longitudinal direction, i.e. axial direction, of the photosensitive drum  61 . According to this, by enlarging the size of the lift member  642  and raising the part stiffness, a user&#39;s operation is made to be easy, and the lift member  642  becomes hardly to be bent. When the lift member  642  is bent, the displacement amount between the memory electrode  85   a  and the electrode of the apparatus body  2  increases. However, abrasion of the memory electrode  85   a  can be suppressed by suppressing bending of the lift member  642 . 
     In addition, at least a part of the detection protrusion  83  overlaps the lift member  642  when viewed in a longitudinal direction of the photosensitive drum  61 . According to this, the size of the process cartridge  5  is not enlarged, and thus it is possible to dispose the lift member  642  at a position where a user&#39;s operation is easy. 
     In addition, the concave portion  664  is provided in the left side wall  611  of the drum unit  6  in order for the detection unit  80  and the detection protrusion  83  to protrude in the longitudinal direction. When the concave portion  664  is formed, stiffness of the left side wall  611  decreases. However, since the first guide rib  662  is provided at a position that is located bellow the concave portion  664  and overlaps the concave portion  664  in the front-rear direction, the first guide rib  662  operates as a reinforcing member, and thus it is possible to reduce the decrease in stiffness of the left side wall  611 . 
     Note that, the lift member  642  may be disposed on the left side of the process cartridge  5 , and the memory electrode  85   a  may be disposed on the right side of the process cartridge  5 . In addition, the detection protrusion  83  may be disposed on the same side as in the lift member  642 . 
     Second Embodiment 
     Next, a second embodiment of the invention will be described. In the second embodiment, the positioning protrusion  86  of the first embodiment is disposed at a different position. Accordingly, illustration of the same configuration as in the first embodiment will be omitted, or the same reference numeral will be given to the same configuration in the following description. 
     As illustrated in  FIG.  18   , in a development unit  7 A according to this embodiment, the positioning protrusion  86 A protrudes downward from the bottom surface, and the memory  85  is disposed in a left direction of the positioning protrusion  86 A serving as a protruding portion. The memory  85  includes a memory chip (not illustrated) that stores information about the development unit  7 A, and a memory electrode  85   a  that is electrically connected to the memory chip. 
     In the drum unit  6 A, as illustrated in  FIG.  19   , an engagement hole  102   a  and an electrode exposing hole  103  which are provided to be adjacent in the axial direction, i.e. right-left direction, are formed. The engagement hole  102   a  is configured so that the positioning protrusion  86 A engages with the engagement hole  102   a  in the right-left direction, and the development unit  7 A can be positioned with respect to the drum unit  6 A in the right-left direction. In a state in which the development unit  7 A is mounted on the drum unit  6 A, the electrode exposing hole  103  exposes the memory electrode  85   a  to a downward side of the drum unit  6 A so that the memory electrode  85   a  can come into contact with an electrode (not illustrated) provided in the apparatus body  2 . 
     In contact between the memory electrode  85   a  and the electrode provided in the apparatus body  2 , high positional accuracy is required from the viewpoints of stabilization of an electrode contact situation in communication or mutual abrasion of the electrodes. Accordingly, it is preferable that the positioning mechanism of the development unit  7 A with respect to the drum unit  6 A is provided at a position close to the memory  85 . As in the first embodiment, positioning of the development unit  7 A with respect to the drum unit  6 A in the front-rear direction is performed when the bearings  746 A and  746 B of the development unit  7 A come into press contact with the receiving portions  641  and  641  of the drum unit  6 A. 
     In this embodiment, to improve positional accuracy between the memory electrode  85   a  and the electrode provided in the apparatus body  2  in the right-left direction, as illustrated in  FIG.  20   , the positioning protrusion  86 A is disposed so that at least a part overlaps the memory electrode  85   a  in the front-rear direction. In other words, when viewed in the axial direction, the positioning protrusion  86 A is disposed so that at least a part overlaps the memory electrode  85   a  in the front-rear direction. 
     In addition, in this embodiment, in a state in which the development unit  7 A is mounted on the drum unit  6 A, the positioning protrusion  86 A is disposed on a front side of the drum unit  6 A. The receiving portion  641  that performs positioning of the development unit  7 A in the front-rear direction is also disposed on a front side of the drum unit  6 A. As described above, when the receiving portion  641  of the drum unit  6 A and the memory electrode  85   a  are disposed to be adjacent to each other, the positioning accuracy of the memory electrode  85   a  can be further improved. 
     In addition, as illustrated in  FIG.  21   , it is preferable that the process cartridge  5 A is configured so that a distance L 2  is shorter than a distance L 1 . The distance L 1  is a distance between the central line C 1  of the first positioning protrusion  660  of the drum unit  6 A and the central line C 2  of the bearing  746 A, and the distance L 2  is a distance between the central line C 1  and the memory electrode  85   a  in the upper-lower direction. When the process cartridge  5 A is configured as described above, it is possible to suppress a displacement of the memory electrode  85   a  with respect to swinging of the drum unit  6 A for the apparatus body  2 , and swinging of the development unit  7 A for the drum unit  6 A. That is, a fluctuation of a contact position between the memory electrode  85   a  and the electrode of the apparatus body  2  in the front-rear direction and a contact direction is suppressed, a contact state between the memory electrode  85   a  and the electrode of the apparatus body  2  is stabilized, and abrasion of electrodes is suppressed. 
     Note that, when the development unit  7 A is mounted on the drum unit  6 A, the positioning protrusion  86 A is disposed at a position illustrated in the engagement hole  102   a  in  FIG.  22   . In this embodiment, the positioning protrusion  86 A and the engagement hole  102   a  are located on a further rightward than the memory electrode  85   a  and the electrode exposing hole  103 , but the position of the positioning protrusion  86 A and the engagement hole  102   a  is not limited thereto. For example, as illustrated by a position  102   b  of  FIG.  22   , the positioning protrusion  86 A and the engagement hole  102   a  may be disposed on a further leftward than the memory electrode  85   a  and the electrode exposing hole  103 . On the other hand, when the positioning protrusion  86 A and the engagement hole  102   a  are disposed on a further rightward than the memory electrode  85   a  and the electrode exposing hole  103 , the positioning protrusion  86 A is located at a position closer to the sheet passage hole  610   b  than the memory electrode  85   a.  According to this, it is possible to regulate entrance of a sheet that passes through the sheet passage hole  610   b  to a contact between the memory electrode  85   a  and the electrode on the apparatus body  2  side by the positioning protrusion  86 A, and a contact state of electrodes can be stabilized. 
     In addition, a configuration for positioning the development unit  7 A to the drum unit  6 A is not limited to the above-described positioning protrusion  86 A and the engagement hole  102   a.  For example, the engagement hole may be provided in the development unit  7 A and the positioning protrusion may be provided in the drum unit. 
     Summary of Second Embodiment 
     Recently, in contact between the memory electrode  85   a  and the electrode provided in the apparatus body  2 , high positional accuracy is required from the viewpoints of stabilization of an electrode contact situation in communication or mutual abrasion of the electrodes. Here, in this embodiment, the positioning protrusion  86 A is disposed so that at least a part of the positioning protrusion  86 Aoverlaps the memory electrode  85   a  in the front-rear direction, that is, in a direction orthogonal to the longitudinal direction, i.e. axial direction, of the photosensitive drum  61 . In other words, when viewed in the axial direction, the positioning protrusion  86 A is disposed so that at least a part overlaps the memory electrode  85   a  in the front-rear direction. 
     According to this, a fluctuation of a contact position between the memory electrode  85   a  and the electrode of the apparatus body  2  in the front-rear direction and a contact direction is suppressed, a contact state between the memory electrode  85   a  and the electrode of the apparatus body  2  is stabilized, and abrasion of electrodes is suppressed. 
     Third Embodiment 
     Next, a third embodiment of the invention will be described. In the third embodiment, arrangement of the pressing member, the memory, and the electrode exposing hole is changed from the arrangement in the first embodiment According to this, illustration of the same configuration as in the first embodiment will be omitted, or the same reference numeral will be given to the same configuration in the following description. 
     As illustrated in  FIG.  23    to  FIG.  25   , a process cartridge  5 B according to this embodiment includes a drum unit  6 B and a development unit  7 B. In a state of being mounted on the drum unit  6 B, the development unit  7 B is locked to the drum unit  6 B by the lift member  642 , and detachment from the drum unit  6 B is prevented. 
     In the drum unit  6 B, an electrode exposing hole  310  is formed in the bottom surface  610   a  of the frame  610 . In addition, a supporting portion  301  protrudes upward at both ends of the bottom surface  610   a  in the axial direction, and the pressing member  640  is disposed on a forward side of the supporting portion  301 . The pressing member  640  is urged forward by a compression spring  302  (refer to  FIG.  28   ) disposed between the pressing member  640  and the supporting portion  301 . A spring contact portion  301   a  of the supporting portion  301  comes into contact with the compression spring  302  and receives an elastic force from the compression spring  302 . The electrode exposing hole  310  is disposed rearward and leftward of the supporting portion  301  and the pressing member  640  which are disposed on a left side of the drum unit  6 B. 
     As illustrated in  FIG.  26    and  FIG.  27   , the development unit  7 B includes a pressed portion  316  which is provided in the left side wall  704  and the right side wall  705  of the casing  700 . The pressed portion  316  which is provided in the left side wall  704  is provided to protrude leftward from the left side wall  704 , and the pressed portion  316  which is provided in the right side wall  705  is provided to protrude rightward from the right side wall  705 . 
       FIG.  28    is a cross-sectional view illustrating the process cartridge  5 B, and a part of the cross-sectional view illustrates a cross-section in the vicinity of the pressing member  640  of the development unit  7 B, and another part of the cross-sectional view illustrates a cross-section in the vicinity of a memory  300 . As illustrated in  FIG.  28   , when viewed in the axial direction, each of the pressed portions  316  includes an arc portion  316   a  that is formed in an arc shape, and an extending portion  316   b  that extends forward from both ends of the arc portion  316   a.  The arc portion  316   a  of the pressed portion  316  is pressed forward by the pressing member  640  in a state in which the development unit  7 B is mounted on the drum unit  6 B. Since the both ends of the arc portion  316   a  are supported by the extending portion  316   b,  even when a pressing force is applied to the arc portion  316   a,  it is possible to reduce deformation of the arc portion  316   a.    
     In addition, when the pressed portion  316  in the development unit  7 B is pressed forward, the development roller  71  of the development unit  7 B is urged to a direction approaching the photosensitive drum  61 , and comes into contact with the photosensitive drum  61 . In a state in which the development roller  71  comes into contact with the photosensitive drum  61 , the above-described image forming process is performed. 
     Next, the memory  300  of the development unit  7 B will be described. As illustrated in  FIG.  24   ,  FIG.  26   , and  FIG.  28   , the memory  300  is attached to the bottom surface of the side holder  719  attached to the left side wall  704  of the development unit  7 B. The memory  300  includes a memory chip (not illustrated) that stores information about the development unit  7 B, and a memory electrode  300   a  that is an electric contact connected to the memory chip, and the memory chip and the memory electrode  300   a  are provided on the same substrate. When the process cartridge  5 B is mounted on the apparatus body  2  (refer to  FIG.  1   ), the memory electrode  300   a  and an electrode  303  serving as a body electrode of the apparatus body  2  come into contact with each other, and the apparatus body  2  reads information about the development unit  7 B and performs various kinds of control. 
     The memory electrode  300   a  of the memory  300  is disposed to face downward, and is disposed at a position corresponding to the electrode exposing hole  310  of the drum unit  6 B in a state in which the development unit  7 B is mounted on the drum unit  6 B. When the process cartridge  5 B is mounted on the apparatus body  2 , the memory electrode  300   a  exposed from the electrode exposing hole  310  comes into contact with the electrode  303  of the apparatus body  2  when viewed from a downward side as illustrated in  FIG.  28   . 
     As illustrated in  FIG.  28   , the pressed portion  316  in the development unit  7 B is disposed in front of the memory electrode  300   a  of the memory  300  and the electrode exposing hole  310  when viewed in the axial direction. That is, the pressed portion  316  is disposed at a position closer to the photosensitive drum  61  than the memory electrode  300   a  of the memory  300  and the electrode exposing hole  310  when viewed in the axial direction. 
     In addition, the pressed portions  316  which are provided on both sides of the development unit  7 B in the right-left direction are disposed so as to overlap each other when viewed in the axial direction, and thus an arrangement relationship between the pressed portion  316  on the both sides and the memory electrode  3   00   a  when viewed in the axial direction of the development roller  71  is the same on the both sides. 
     Summary of Third Embodiment 
     When the pressing member  640  for pressing the development unit  7 B is provided in the drum unit  6 B, the following problem occurs. The development roller  71  comes into contact with the photosensitive drum  61  due to a pressing force applied by the pressing member  640 , but there is a concern that the frame  610  of the drum unit  6 B may be deformed due to a repulsive force of the pressing force applied by the pressing member  640 . Specifically, the compression spring  302  that presses the pressing member  640  comes into contact with the spring contact portion  301   a  of the supporting portion  301  provided in the frame  610 . According to this, the same force as the force of pressing the pressing member  640  by the compression spring  3   02  acts on the supporting portion  301  from the compression spring  302 . 
     In addition, when deformation of the frame  610  due to the repulsive force increases, the pressing force of the pressing member  640  decreases. Therefore, it is difficult to cause the development roller  71  to stably come into contact with the photosensitive drum  61 , and the development roller  71  and the photosensitive drum  61  are separated from each other, and thus there is a concern that image defects may occur. To prevent occurrence of the image defects, it is necessary to suppress deformation of the frame  610  of the drum unit  6 B due to the repulsive force of the pressing member  640 . In addition, to suppress deformation of the frame  610 , it is necessary to secure frame strength of a region in which load occurs in the drum unit  6 B due to the repulsive force of the pressing member  640 . The region in which the load occurs is a region between the supporting portion  311  of the frame  610  that rotatably supports the photosensitive drum  61 , and the spring contact portion  301   a  of the supporting portion  301  that comes into contact with the compression spring  302 . 
     In addition, in this embodiment, as illustrated in  FIG.  28   , the process cartridge  5 B is mounted on the apparatus body  2  in a rearward and downward direction indicated by an arrow  312 . In this case, it is preferable that the memory electrode  300   a  is disposed on a lower surface side of the process cartridge  5 B. The reason for this is as follows. When the memory electrode  300   a  is separated from the electrode  303  of the apparatus body  2  immediately before the process cartridge  5 B is completely mounted on the apparatus body  2 , the memory electrode  300   a  and the electrode  303  do not slide on each other, and thus durability is improved. In addition, it is not necessary to provide an additional device for moving the memory electrode  300   a  or the electrode  303 , and thus the arrangement is preferable in terms of the cost. 
     However, it is necessary to provide a hole or a notch such as the electrode exposing hole  310  in the frame  610  of the drum unit  6 B so as to dispose the memory  300  that records information about the development unit  7 B on a lower surface side of the process cartridge  5 B. The hole or notch becomes a cause for reduction in the frame strength of the frame  610 . 
     Here, in this embodiment, the process cartridge  5 B is configured as follows. The spring contact portion  301   a  of the supporting portion  301  that comes into contact with compression spring  302  of the drum unit  6 B is disposed at a position closer to the photosensitive drum  61  than the memory electrode  300   a  and the electrode exposing hole  310  when viewed in the axial direction of the development roller  71 . 
     According to this, the electrode exposing hole  310  that is the cause for reduction in the frame strength of the drum unit  6 B can be provided out of a range of the region for which the frame strength of the drum unit  6 B is necessary. Accordingly, it is possible to secure the frame strength of the drum unit  6 B, and the development roller  71  is caused to stably come into contact with the photosensitive drum  61 , and thus it is possible to reduce occurrence of image defects. 
     In addition, in this embodiment, the pressed portion  316  in the development unit  7 B is disposed at a position closer to the photosensitive drum  61  than the memory electrode  300   a.  Due to the arrangement relationship in the development unit  7 B, it is possible to realize a condition for securing the frame strength of the drum unit  6 B. Accordingly, the development roller  71  is caused to stably come into contact with the photosensitive drum  61 , and thus occurrence of the image defects can be reduced. 
     Fourth Embodiment 
     Next, a fourth embodiment of the invention will be described. In the fourth embodiment, arrangement of the memory is changed from the third embodiment. Accordingly, illustration of the same configuration as in the third embodiment will be omitted, or the same reference numeral will be given to the same configuration in the following description. 
     As illustrated in  FIG.  29    and  FIG.  30   , the frame  610  of a drum unit  6 C of this embodiment includes the left side wall  611 , and a notch  305  concaved downward and having a rectangular shape with one side open is formed in the left side wall  611 . In addition, a memory supporting portion  306  that protrudes leftward, i.e. in an axial direction, is formed in the side holder  719  of a development unit  7 C. A memory  1300  is supported to a lower surface of the memory supporting portion  306 , and the memory  1300  is disposed so that a memory electrode  1300   a  faces downward. 
     When the development unit  7 C is mounted on the drum unit  6 C, the memory supporting portion  306  protrudes leftward from the notch  305  of the frame  610  of the drum unit  6 C. In this state, the memory electrode  1300   a  of the memory  1300  supported to the memory supporting portion  306  is located on a further leftward than the left side wall  611  of the frame  610 . In other words, the memory electrode  1300   a  of the memory  1300  is disposed on a side opposite to the development roller  71  with the left side wall  611  interposed therebetween in the longitudinal direction, i.e. axial direction. In addition, when a process cartridge  5 C in which the development unit  7 C and the drum unit  6 C are integrated is mounted on the apparatus body  2  (refer to  FIG.  1   ), the electrode  303  provided in the apparatus body  2  and the memory electrode  1300   a  come into contact with each other, and information of the memory  1300  is read to the apparatus body  2 . 
     Note that, as illustrated in  FIG.  31   , a memory  2300  may be provided on a left side surface of the memory supporting portion  306 , and a memory electrode  2300   a  of the memory  2300  may be disposed to face leftward. Even in this embodiment, as in the third embodiment, the spring contact portion  301   a  and the pressed portion  316  are disposed at a position closer to the photosensitive drum  61  than the memory electrodes  1300   a  and  2300   a  when viewed in the axial direction. 
     That is, the notch  305  serving as an opening portion formed in the frame  610  of the drum unit  6 C becomes a cause for reduction in the frame strength, but the notch  305  is provided out of a range of the region for which the frame strength in the frame  610  is necessary. Accordingly, the frame strength of the region of the frame  610  that receives the repulsive force of the pressing member  640  and the compression spring  302  as described in the third embodiment is secured, the development roller  71  is caused to stably come into contact with the photosensitive drum  61 , and thus occurrence of the image defects can be reduced. 
     Summary Fourth Embodiment 
     A load due to the repulsive force of the pressing member  640  acts on the frame  610  of the drum unit  6 C in a region particularly between the supporting portion  311  and the spring contact portion  301   a  of the supporting portion  301  that comes into contact with the compression spring  302 . When the frame  610  is deformed due to the load, there is a concern that the pressing force of the pressing member  640  decreases, the development roller  71  cannot be caused to stably come into contact with the photosensitive drum  61 , the development roller  71  and the photosensitive drum  61  are separated from each other, and thus the image defects may occur. 
     Here, in this embodiment, a hole or a notch that becomes a cause for reduction in the frame strength is not provided in the region, and the notch  305  is provided in the left side wall  611 . In addition, the memory electrodes  1300   a  or  2300   a  is exposed to the outside from the notch  305 . According to this, deformation of the frame  610  is suppressed, and the image defects can be reduced. 
     Fifth Embodiment 
     Next, a fifth embodiment of the invention will be described. In the fifth embodiment, a configuration of the development unit and the casing, i.e. frame, of the drum unit, and arrangement of the memory are different from the configuration and the arrangement in the third embodiment. Accordingly, illustration of the same configuration as in the third embodiment will be omitted, or the same reference numeral will be given to the same configuration in the following description. 
     As illustrated in  FIG.  32    to  FIG.  34   , a drum unit  6 D of this embodiment includes a front wall  614  of the frame  610 . A notch  308  that is concaved downward is formed in the front wall  614 . According to this, the drum unit  6 D of this embodiment is not provided with the grip portion  617  described in the first embodiment. 
     A development unit  7 D includes an extending portion  307  that protrudes forward. That is, the extending portion  307  extends more upstream of the mounting direction AD (refer to  FIG.  2   ) than the frame  610  of the drum unit  6 D. The extending portion  307  is disposed on both sides in the right-left direction with the grip portion  701  interposed therebetween. A toner that is used in image formation is stored in the extending portion  307 . A memory  3300  is supported to a lower surface of the extending portion  307  on the left side, and the memory  3300  is disposed so that a memory electrode  3300   a  faces downward. 
     When the development unit  7 D is mounted on the drum unit  6 D, the extending portion  307  protrudes forward from the notch  308  formed in the front wall  614  of the drum unit  6 D, and the memory  3300  that is supported to the lower surface of the extending portion  307  on the left side is located behind the front wall  614 . In addition, when a process cartridge  5 D in which the development unit  7 D and the drum unit  6 D are integrated is mounted on the apparatus body  2  (refer to  FIG.  1   ), the electrode  303  provided in the apparatus body  2  and the memory electrode  3300   a  come into contact with each other, and information of the memory  3300  is read to the apparatus body  2 . 
     Even in this embodiment, as in the third embodiment, the spring contact portion  301   a  and the pressed portion  316  are disposed at a position closer to the photosensitive drum  61  than the memory electrode  3   300   a  when viewed in the axial direction. 
     Summary of Fifth Embodiment 
     In the case of enlarging capacity of a toner stored in the development unit  7 D, there is the following problem. If a width or a height of the development unit  7 D is not changed, the development unit  7 D is necessary to protrude forward. In this embodiment, the extending portion  307  that extends forward is formed, and the toner is stored in the extending portion  307 . In addition, the notch  308  is formed in the front wall  614  and the extending portion  307  extends into the notch  308  so that the extending portion  307  does not interfere with the front wall  614  of the drum unit  6 D. However, the notch  308  becomes a cause for reduction in the frame strength of the frame  610  of the drum unit  6 D. 
     Here, in this embodiment, the memory  3300  including the memory electrode  3300   a  is disposed on the lower surface of the extending portion  307 , and the memory electrode  3300   a  is disposed at a position distant from the photosensitive drum  61 . That is, as illustrated in  FIG.  28   , the spring contact portion  301   a  and the pressed portion  316  in the drum unit  6 D are disposed at a position closer to the photosensitive drum  61  than the memory electrode  3300   a  when viewed in the axial direction. 
     According to this, the notch  308  that is the cause for reduction in the frame strength of the drum unit  6 D can be provided out of a range of the region for which the frame strength of the drum unit  6 D is necessary. Accordingly, it is possible to secure the frame strength of the drum unit  6 D while increasing the capacity of the toner stored in the development unit  7 D, and the development roller  71  is caused to stably come into contact with the photosensitive drum  61 , and thus it is possible to reduce occurrence of image defects. 
     In addition, when mounting the process cartridge  5 D on the apparatus body  2 , the development unit  7 D and the drum unit  6 D are integrated by the lift member  642 . According to this, even in a case where the grip portion is not provided in the drum unit  6 D, it is possible to easily attach and detach the process cartridge  5 D to and from the apparatus body  2  by gripping the grip portion  701  of the development unit  7 D without detaching the development unit  7 D from the drum unit  6 D. 
     Note that, in this embodiment, the memory electrode  3300   a  is provided in the extending portion  307  of the development unit  7 D, but there is no limitation thereto. For example, the memory electrode  3300   a  may be disposed at any one position among the memory electrodes described in the first to fourth embodiments. Even in this disposition of the memory electrode, it is possible to secure strength relating to a region for which frame strength of the drum unit  6  is necessary. 
     Sixth Embodiment 
     Next, a sixth embodiment of the invention will be described. In the sixth embodiment, a configuration in which rotation, deformation, and falling of the lift member can be regulated is added to the first embodiment Accordingly, illustration of the same configuration as in the first embodiment will be omitted, or the same reference numeral will be given to the same configuration in the following description. 
     As illustrated in  FIG.  35    to  FIG.  37   , a process cartridge  5 E according to this embodiment includes a drum unit  6 E and a development unit  7 E. The drum unit  6 E includes the frame  610 , and the photosensitive drum  61  that is rotatably supported to the frame  610 . The development unit  7 E is pressed forward by the pressing members  640  and  640  in a state of being mounted on the drum unit  6 E, and according to this, the development roller  71  (refer to  FIG.  9   ) supported to the development unit  7 E also comes into contact with the photosensitive drum  61 . 
     The frame  610  of the drum unit  6 E includes the left side wall  611  and the right side wall  612 , and the bottom surface  610   a  and the front wall  614  which connect the left side wall  611  and the right side wall  612 . The pressing members  640  and  640  are supported to the front wall  614 , and the lift member  642 E is rotatably supported to the right side wall  612 . 
     The development unit  7 E includes the casing  700  including the left side wall  704  and the right side wall  705 , and the side holder  719  that is supported to the left side wall  704 . The detection unit  80  described in the first embodiment is provided in the side holder  719 , and a hole  719   a  from which the development coupling  710  is exposed to the outside is formed in the side holder  719 . The memory  85  and the positioning protrusion  86  are provided in the bottom surface of the side holder  719 . The cylindrical protruding portion  751  that protrudes rightward is provided on the right side wall  705 . 
     As illustrated in  FIG.  38    and  FIG.  39   , a lift member  642 E is rotatably supported to the right side wall  612  with a rotation shaft  403   b  set as the center, and an inner side wall  403   f  supported to the right side wall  612  is disposed on a leftward side of the lift member  642 E. The lift member  642 E includes an operation portion  410   b  that is provided in a first end portion of the lift member  642 E and can be pressed downward by a user, and a contact portion  410   a  that is provided in a second end portion of the lift member  642 E and can come into contact with the protruding portion  751 . The operation portion  410   b  is disposed in front of the rotation shaft  403   b,  and the contact portion  410   a  is disposed behind the rotation shaft  403   b.  That is, the operation portion  410   b  and the contact portion  410   a  are disposed to be opposite to each other with the rotation shaft  403   b  interposed therebetween in the front-rear direction. 
     In addition, the lift member  642 E includes a regulation portion  410   c  that is provided integrally with the operation portion  410   b,  and the regulation portion  410   c  is disposed on a rightward side of the operation portion  410   b  to further protrude rightward than the right side wall  612 . The inner side wall  403   f  is disposed adjacent to the operation portion  410   b  on a leftward side of the operation portion  410   b.  In other words, the inner side wall  403   f  is disposed on an inner side of the operation portion  410   b  in an axial direction of the photosensitive drum  61 . The compression spring  650  is contracted between the operation portion  410   b  of the frame  610  and a seating surface  403   g  provided in the frame  610 , and the compression spring  650  presses the operation portion  410   b  to an upward side. 
     Next, description will be given of an operation when detaching the development unit  7 E from the drum unit  6 E. As illustrated in  FIG.  40 A , the lift member  642 E is held at a predetermined standby position in a state in which the operation portion  410   b  is pressed upward, and comes into contact with, for example, a stopper (not illustrated). At this time, the contact portion  410   a  of the development unit  7 E mounted on the drum unit  6 E is spaced apart from the protruding portion  751 , and does not come into contact with the protruding portion  751 . 
     When a user presses the operation portion  410   b  to a downward side, as illustrated in  FIG.  40 B , the contact portion  410   a  swings upward, and the protruding portion  751  of the development unit  7 E is pressed upward by the contact portion  410   a.  According to this, the development unit  7 E rotates in a clockwise, i.e. CW direction, around the bearing  746 B ( 746 A) that is disposed on a lateral side in the axial direction of the development roller  71 , and is detached from the drum unit  6 E. At this time, the pair of left and right ribs  718  and  718  of the development unit  7 E that is supported to the protruding portions  643  and  643  of the drum unit  6 E is spaced apart from the protruding portions  643  and  643 . 
     As described above, the user completes the work for detaching the development unit  7 E by taking out the development unit  7 E from the drum unit  6 E while gripping the grip portion  701  (refer to  FIG.  35   ) of the development unit  7 E that enters the lift-up state as described above. 
     Next, description will be given of a configuration for mounting the process cartridge  5 E on the apparatus body  2 .  FIG.  41 A  is a perspective view illustrating the apparatus body  2  according to this embodiment, and  FIG.  41 B  is an enlarged perspective view illustrating a peripheral configuration of the lift member  642 E. Note that, in  FIGS.  41 A and  41 B , the door  21  illustrated in  FIG.  1    is omitted. 
     As illustrated in  FIG.  41 A  to  FIG.  43 B , the apparatus body  2  includes a right body guide  420  and a left body guide  421 . The right body guide  420  is disposed on a right side of a storage portion of the apparatus body  2  in which the process cartridge  5 E is stored, and the left body guide  421  is disposed on a left side of the storage portion. The right body guide  420  includes a first guide portion  420   b  and a second guide portion  420   c  which respectively guide the second positioning protrusion  661  and the second guide rib  663  of the process cartridge  5 E. The first guide portion  420   b  and the second guide portion  420   c  have a groove shape. In addition, the right body guide  420  includes a contact portion  420   a  that is disposed on an upward side of the first guide portion  420   b  and can come into contact with the regulation portion  410   c  of the lift member  642 E. 
     The left body guide  421  includes a third guide portion  421   a  and a fourth guide portion  421   b  which respectively guide the first positioning protrusion  660  and the first guide rib  662  of the process cartridge  5 E. The third guide portion  421   a  and the fourth guide portion  421   b  have a flat plate shape. A drive transmission member  422  that can engage with the development coupling  710  is disposed on an upward side of the third guide portion  421   a,  and the development coupling  710  is driven when the drive transmission member  422  is driven by a drive source (not illustrated) that is provided in the apparatus body  2 . In addition, the electrode  303  that can come into contact with the memory electrode  85   a  of the memory  85  provided in the development unit  7 E is disposed on a lower-left portion of the apparatus body  2 . 
     Next, description will be given of an operation of the lift member  642 E in a state in which the process cartridge  5 E is mounted on the apparatus body  2 . In a state in which the process cartridge  5 E is mounted on the apparatus body  2 , as illustrated in  FIG.  44 A  and  FIG.  45   , the contact portion  420   a  is disposed immediately below the regulation portion  410   c  of the lift member  642 E. In a state in which the lift member  642 E is not operated by a user, the regulation portion  410   c  is spaced apart from the contact portion  420   a  with a slight gap. In addition, the contact portion  410   a  of the lift member  642 E is spaced apart from the protruding portion  751  with a slight gap. According to this, the contact portion  420   a  does not hinder the work for mounting the process cartridge  5 E on the apparatus body  2 . Note that, in a state in which the lift member  642 E is not operated by the user, the regulation portion  410   c  may be in contact with the contact portion  420   a.    
     As illustrated in  FIG.  44 B , when the user presses the operation portion  410   b  of the lift member  642 E to a downward side, the lift member  642 E is apt to pivot against an urging force of the compression spring  650 . However, when the lift member  642 E slightly pivots, the regulation portion  410   c  of the lift member  642 E comes into contact with the contact portion  420   a,  and thus pivoting of the lift member  642 E in a counterclockwise, i.e. in a direction indicated by an arrow CCW, is regulated. 
     According to this, the rib  718  formed on a lower surface of the development unit  7 E is maintained in a state of being supported to the protruding portion  643  formed in the drum unit  6 E. In addition, the contact portion  410   a  of the lift member  642 E is kept in a state of being spaced apart from the protruding portion  751  or a state of slightly coming into contact with the protruding portion  751 . However, the development unit  7 E is not moved in a direction in which the development unit  7 E is detached from the drum unit  6 E. 
     As described above, in a state in which the process cartridge  5 E is mounted on the apparatus body  2 , a pivoting operation of the lift member  642 E is regulated by the contact portion  420   a  provided in the apparatus body  2 . That is, the contact portion  420   a  regulates movement of the development unit  7 E to a detachment position by coming into contact with the lift member  642 E. According to this, even in a case where the user erroneously operates the lift member  642 E in a state in which the process cartridge  5 E is mounted on the apparatus body  2 , the lift member  642  does not lift up the protruding portion  751  of the development unit  7 E to an upward side. Accordingly, it is possible to prevent the development unit  7 E from being erroneously detached from the drum unit  6 E. 
     When the lift member  642 E is operated by a user in a state in which the process cartridge  5 E is mounted on the apparatus body  2 , there is the following problem.  FIG.  45    is a view illustrating a force that acts on the lift member  642 E and a deformation direction of the lift member  642 E when the user operates the lift member  642 E with a strong force in a state in which the process cartridge  5 E is mounted on the apparatus body  2 . 
     As illustrated in  FIG.  45   , when the user presses the operation portion  410   b  of the lift member  642 E to a downward side with a force f 1 , the regulation portion  410   c  of the lift member  642 E comes into contact with the contact portion  420   a  of the apparatus body  2 . In addition, the regulation portion  410   c  receives a repulsive force f 2  from the contact portion  420   a  and is stopped. At this time, the force f 1  which the lift member  642 E receives acts on a further inner side of the apparatus, i.e. left side, in the axial direction of the rotation shaft  403   b  than the repulsive force f 2 . According to this, the lift member  642 E falls or deforms to the left side, and the left side of the lift member  642 E is moved to a direction indicated by an arrow m 1 . 
     Since the lift member  642 E is held by the rotation shaft  403   b,  the contact portion  410   a  of the lift member  642 E is moved to a direction indicated by an arrow m 2  which is opposite to the direction indicated by the arrow m 1 . As a result, the contact portion  410   a  lifts up the protruding portion  751 , and a contact state between the memory electrode  85   a  of the memory  85  and the electrode  303  of the apparatus body  2  varies. When the variation repeats, there is a concern that abrasion of the memory  85  is promoted, and thus a contact resistance between electrodes may vary or contact failure may occur. 
     Here, according to this embodiment, in an axis direction of the rotation shaft  403   b,  the memory  85  is disposed on a side opposite to the protruding portion  751  of the development unit  7 E which is lifted up by the lift member  642 E, and the inner side wall  403   f  is disposed adjacent to the lift member  642 E. As illustrated in  FIG.  46 A , in the development unit  7 E, the bearing  746 A is supported by the receiving portion  641  of the drum unit  6 E on a side opposite to the protruding portion  751  in the axis direction of the rotation shaft  403   b.  As illustrated in  FIG.  46 B , when the lift member  642 E is pressed by a user, the protruding portion  751  is lifted up by the contact portion of the lift member  642 E by falling or deformation of the lift member  642 E. 
     At this time, the development unit  7 E is lifted up in an arrow direction by the lift member  642 E with a contact portion between the bearing  746 A provided on a side opposite to the protruding portion  751  and the receiving portion  641  set as a fulcrum. In addition, the memory  85  is close to the fulcrum in the axis direction of the photosensitive drum  61  and the rotation shaft  403   b,  and as it is distant from a contact portion that is an acting point between the contact portion  410   a  of the lift member  642 E and the protruding portion  751 , a displacement is small in the operation of lifting up the development unit  7 E. According to this, in this embodiment, the memory  85  is disposed at a position closer to the bearing  746 A than the contact portion  410   a  of the lift member  642 E in the axis direction of the photosensitive drum  61  and the rotation shaft  403   b,  and thus it is possible to reduce abrasion of the memory  85 . 
     In addition, as illustrated in  FIG.  47 A , the inner side wall  403   f  is disposed on the leftward side of the lift member  642 E with a slight gap from the lift member  642 E. The lift member  642 E approaches the inner side wall  403   f  due to the falling or deformation of the lift member  642 E. In addition, when the lift member  642 E comes into contact with the inner side wall  403   f,  the falling or deformation is regulated. According to this, in a state in which the process cartridge  5 E is mounted on the apparatus body  2 , a lift-up amount of the development unit  7 E by the lift member  642 E decreases, and thus it is possible to reduce abrasion of the memory  85 . 
     The inner side wall  403   f  is disposed on a side opposite to a contact portion between the regulation portion  410   c  and the contact portion  420   a  with respect to the operation portion  410   b  in the axis direction of the development roller  71  and the rotation shaft  403   b.  For example, in a case where the contact portion between the regulation portion  410   c  and the contact portion  420   a  is disposed on a rightward side of the operation portion  410   b,  the inner side wall  403   f  is disposed on a leftward side of the operation portion  410   b.    
     Preferably, as illustrated in  FIG.  47 B , when viewed in the axis direction, the inner side wall  403   f  is provided on a side opposite to the contact portion  410   a  with respect to the rotation shaft  403   b  in the front-rear direction. More preferably, the inner side wall  403   f  is disposed so that at least a part overlaps the operation portion  410   b  or the regulation portion  410   c  when viewed in the axis direction. According to this, the falling or deformation of the lift member  642 E is regulated, and it is possible to further reduce abrasion of the memory  85 . 
     In addition, when viewed in the axis direction, the lift member  642 E is disposed so that at least a part overlaps the detection unit  80  and the detection protrusion  83 . According to this, the process cartridge  5 E effectively uses a limited space, and the size of the lift member  642 E is secured to maintain stiffness. Accordingly, the deformation or falling of the lift member  642 E can be suppressed, or operability for a user can be improved. 
     Summary of Sixth Embodiment 
     In a state in which the process cartridge  5 E is mounted on the apparatus body  2 , when the development unit  7 E is detachable from the drum unit  6 E, there is a concern that the apparatus body  2  and the development unit  7 E may come into contact with each other, and thus there is a concern that the apparatus body  2  or the development unit  7 E may be damaged. 
     Here, according to this embodiment, in a state in which the process cartridge  5 E is mounted on the apparatus body  2 , a pivoting operation of the lift member  642 E is regulated by the contact portion  420   a  provided in the apparatus body  2 . That is, when the process cartridge  5 E is detached from the apparatus body  2 , the contact portion  420   a  of this embodiment does not contact with the lift member  642 E, and permits the lift member  642 E to move by a first amount In addition, when the process cartridge  5 E is mounted on the apparatus body  2 , the contact portion  420   a  comes into contact with the lift member  642 E and regulates pivoting of the lift member  642 E so that the lift member  642 E can move by a second amount smaller than the first amount. According to this, on an inner side of the apparatus body  2 , the development unit  7 E is prevented from being erroneously detached from the drum unit  6 E, and thus breakage of the apparatus body  2  or the development unit  7 E can be reduced. 
     In addition, in the configuration in which the pivoting operation of the lift member  642 E is regulated by the contact portion  420   a,  when a user presses the operation portion  410   b  of the lift member  642 E with a strong force, there is a concern that the lift member  642 E may fall down or may be deformed. In addition, when the lift member  642 E falls down or is deformed, the memory electrode  85   a  and the electrode  303  on the apparatus body  2  side may be displaced and abraded, and thus there is a concern that contact failure may occur. 
     Here, according to this embodiment, the lift member is disposed on a first side, i.e. right side, of the process cartridge  5 E and the memory electrode  85   a  is disposed on a second side, i.e. left side, of the process cartridge  5 E in the longitudinal direction, i.e. axial direction, of the photosensitive drum  61 . In addition, the inner side wall  403   f  that regulates falling down or deformation of the lift member  642 E is provided on a side opposite to the contact portion  420   a  with the lift member  642 E interposed therebetween. According to this, the lift-up amount of the development unit  7 E due to the lift member  642 E decreases, falling down or deformation of the lift member  642 E is regulated, and thus it is possible to further reduce abrasion of the memory  85 . 
     Seventh Embodiment 
     Next, a seventh embodiment of the invention will be described. The seventh embodiment is different from the first embodiment in disposition of the lift member and a peripheral configuration. Accordingly, illustration of the same configuration as in the first embodiment will be omitted, or the same reference numeral will be given to the same configuration in the following description. 
     As illustrated in  FIG.  48    and  FIG.  49   , a support hole  520  and a guide hole  521  that is formed in an arc shape around a rotation shaft L 515  are formed in the left side wall  611  of a drum unit  6 F according to this embodiment. A rotation shaft  502  of a lift member  642 F is inserted into the support hole  520 . That is, the lift member  642 F is provided on a left side of a drum unit  6 F, and is supported to the left side wall  611  to be rotatable around the rotation shaft L 515 . 
     The lift member  642 F includes a regulation portion  501 , the rotation shaft  502 , a contact portion  503 , and an operation portion  504 , and is urged in a direction indicated by an arrow  8510  by the compression spring  650 . The regulation portion  501  is formed to protrude to a leftward side, and is provided to pass through the guide hole  521 . 
     In a state in which the lift member  642 F is not operated by a user, as illustrated in  FIG.  50 A , the lift member  642 F is in a state in which the contact portion  503  is spaced apart from a lower portion  80   a  of the detection unit  80  with a slight clearance. At this time, as illustrated in  FIG.  50 B , the pressed rib  716  in the development unit  7 F is urged toward a rearward side by the pressing member  640  that is urged by the urging spring  644 . More specifically, the pressed surface  716   a  in the pressed rib  716  is pressed rearward by the pressing surface  640   a  of the pressing member  640 . 
     When the operation portion  504  is pressed downward by a user, as illustrated in  FIG.  50 A  and  FIG.  5     1 A, the lift member  642 F rotates against the urging force of the compression spring  650  in a direction indicated by an arrow R 511  which is opposite to the direction indicated by the arrow R 510 . According to this, the regulation portion  501  moves inside the guide hole  521 , and the contact portion  503  moves upward. The contact portion  503  lifts up the lower portion  80   a  of the detection unit  80  to an upward side, and a leading edge side of the development unit  7 F is lifted up in a direction indicated by an arrow R 512 . 
     According to this, as illustrated in  FIG.  51 B , the pressed surface  716   a  in the development unit  7 F is spaced apart from the pressing surface  640   a  to an upward side, and the inclined surface  716   b  of the development unit  7 F rides on an end  522  of the pressing member  640 . In this case, the inclined surface  716   b  of the development unit  7 F is lifted up in a direction indicated by an arrow R 513  by the end  522  of the pressing member  640  urged forward by the urging spring  644 , and the development unit  7 F further pivots in the direction indicated by the arrow R 512  by the urging force of the urging spring  644 . According to this, it is possible to reduce an operation force for causing the development unit  7 F to enter a lift-up state. 
       FIG.  52 A  and  FIG.  52 B  are cross-sectional views illustrating the development unit  7 F that has entered the lift-up state. In the state in which the development unit  7 F has entered the lift-up state, if the pressing operation for the lift member  642 F is released, the lift member  642 F returns to a standby position due to an operation of the compression spring  650 . In addition, since the development unit  7 F is lifted up in the direction indicated by the arrow  8513  by the end  522  of the pressing member  640 , the leading edge side can be further lifted up in comparison to the state illustrated in  FIG.  51 B . 
     Next, description will be given of a configuration and an operation for mounting the process cartridge  5 F on the apparatus body  2 . As illustrated in  FIG.  53   , the apparatus body  2  is provided with the right body guide  420  (refer to  FIG.  42 A ) and the left body guide  421  for guiding the process cartridge  5 F. Note that, in this embodiment, description of the right body guide  420  will be omitted, and only the left body guide  421  will be described. 
     The left body guide  421  includes the third guide portion  421   a  and the fourth guide portion  421   b  which respective guide the first positioning protrusion  660  and the first guide rib  662  of the process cartridge  5 E As illustrated in  FIG.  54   , when the process cartridge  5 F starts to be mounted on the apparatus body  2 , the first positioning protrusion  660  of the process cartridge  5 F comes into contact with a guide surface  555  of the third guide portion  421   a,  and is guided to a rearward side of the apparatus. 
     When the process cartridge  5 F is further inserted into the apparatus body  2 , as illustrated in  FIGS.  55 A and  55 B , the first guide rib  662  enters a guide space SP formed by an upper surface  553  and a lower surface  554  of the fourth guide portion  421   b.  Here, when the process cartridge  5 F is inclined upward, the first guide rib  662  comes into contact with the upper surface  553 , and upward movement of the process cartridge  5 F is regulated. According to this, it is possible to stably mount the process cartridge  5 F on the apparatus body  2 . On the other hand, the detection unit  80  of the development unit  7 F is provided to protrude to a leftward side from the left side wall  611  of the drum unit  6 F, and passes through an upward side of the guide surface  555  of the third guide portion  421   a.    
     When the process cartridge  5 F is further inserted into the apparatus body  2 , as illustrated in  FIG.  56   , the first positioning protrusion  660  abuts a positioning surface  556  of the third guide portion  421   a,  and movement of the process cartridge  5 F in an insertion direction is regulated. That is, positioning of the process cartridge  5 F in the front-rear direction is performed. 
     In addition, a protruding portion  557  that protrudes upward is formed on the lower surface  554  of the fourth guide portion  421   b,  and the height of the guide space SP at a position of the protruding portion  557  is narrowed. In a state in which the process cartridge  5 F is mounted on the apparatus body, and gripping by a user is released, a leading edge portion  662   a  of the first guide rib  662  is supported to the protruding portion  557 . The leading edge portion  662   a  bulges in a circular cross-sectional shape. The leading edge portion  662   a  hardly moves in a height direction in the guide space SP due to the shape of the leading edge portion  662   a  and the protruding portion  557 , and positioning of the process cartridge  5 F in a rotation direction, that is, in the height direction is performed. 
     In a state in which the process cartridge  5 F is mounted on the apparatus body  2  as described above, as illustrated in  FIG.  57   , the regulation portion  501  provided in the lift member  642 F is disposed on an upward side of the guide surface  555  of the third guide portion  421   a  with a slight clearance. In this state, even when a user erroneously presses downward the lift member  642 F, since the regulation portion  501  comes into contact with the guide surface  555 , the lift member  642 F pivots only in a slight amount That is, in a state of being mounted on the process cartridge  5 F, the lift member  642 F can pivot only by the clearance. According to this, the development unit  7 F hardly moves to enter the lift-up state, and thus the development unit  7 F is not detached from the drum unit  6 F at the inside of the apparatus body  2 . 
     According to this, it is possible to reduce a mechanical operation failure that occurs due to detachment of the development unit  7 F, and a communication problem between the memory chip and the apparatus body  2  which occurs due to a contact failure between the memory electrode  85   a  and the electrode  303  of the apparatus body  2 . 
     In addition, as illustrated in  FIG.  49    and  FIG.  57   , the regulation portion  501  of the lift member  642 F is disposed bellow a rotation center L 516  of the detection gear  81  of the detection unit  80 , that is, the rotation center L 516  of the detection protrusion  83 . According to this, the guide surface  555  can be disposed on a lower side of the apparatus body  2 , and when mounting the process cartridge  5 F on the apparatus body  2 , the first positioning protrusion  660  of the process cartridge  5 F can be allowed to smoothly pass through the third guide portion  421   a.  Particularly, undulation of the guide surface  555  is small, and thus it is not necessary to greatly lift up the entirety of the process cartridge  5 F, and usability can be improved. In addition, it is not necessary to provide a space necessary for lifting up the entirety of the process cartridge  5 F in the apparatus body  2 , and thus it is possible to realize a reduction in size of the apparatus body  2  in the height direction. 
     Summary of Seventh Embodiment 
     In recent years, there has been a demand for a reduction in size of a process cartridge and a printer serving as an image forming apparatus. Here, according to this embodiment, the detection unit  80 , including detection protrusion  83 , the memory electrode  85   a,  and the lift member  642 F are disposed on a left side where the development coupling  710  of the process cartridge  5 F is provided. According to this, the detection unit  80 , including detection protrusion  83 , the memory electrode  85   a,  and the lift member  642 F are disposed in a compact manner, and thus the size of the process cartridge and the image forming apparatus can be reduced. 
     In addition, the regulation portion  501  that protrudes to an outer side in the axial direction of the photosensitive drum  61  is provided in the lift member  642 F, and in a state in which the process cartridge  5 F is mounted on the apparatus body  2 , the regulation portion  501  is configured to come into contact with the guide surface  555  provided in the apparatus body  2 . According to this, in a state in which the process cartridge  5 F is mounted on the apparatus body  2 , even in a case where the operation portion  504  of the lift member  642 F is pressed downward, since the regulation portion  501  comes into contact with the guide surface  555 , pivoting of the lift member  642 F is regulated. According to this, the development unit  7 F is prevented from being erroneously detached from the drum unit  6 F at the inside of the apparatus body  2 , and thus it is possible to reduce breakage of the apparatus body  2  or the development unit  7 F. 
     Eighth Embodiment 
     Next, an eighth embodiment of the invention will be described. The eighth embodiment is different from the first embodiment in a process configuration of the drum unit Accordingly, illustration of the same configuration as in the first embodiment will be omitted, or the same reference numeral will be given to the same configuration in the following description. 
     As illustrated in  FIG.  58   , the process cartridge  5 G according to this embodiment includes a drum unit  6 G and a development unit  7 G that is mounted on the drum unit  6 G. The drum unit  6 G includes the photosensitive drum  61 , a corona charger  62 G, the transfer roller  63 , a front exposure unit  201 , and a collection roller  202 . 
     The corona charger  62 G is a charging unit that charges a surface of the photosensitive drum  61  in a non-contact manner. The front exposure unit  201  includes a light-emitting diode serving as a light source, and a light guide serving as a light guiding member. Light emitted from the light-emitting diode is guided by the light guide, and the surface of the photosensitive drum  61  is irradiated with the light. A current that is supplied to the light-emitting diode is supplied from the apparatus body  2 . The surface of the photosensitive drum  61  is discharged through the light irradiation by the front exposure unit  201 . In addition, a predetermined voltage is applied to the collection roller  202  from the apparatus body  2  to collect foreign substances such as paper dust and a waste and a toner which adhered to the surface of the photosensitive drum  61 . With regard to a rotation direction of the photosensitive drum  61  during image formation, that is, a direction indicated by an arrow  61   a  in the drawing the transfer roller  63 , the front exposure unit  201 , the collection roller  202 , the corona charger  62 G, and the development roller  71  are arranged in this order from an upstream side to a downstream side. 
     Summary of Eighth Embodiment 
     In recent years, there has been a demand for various charging types of process cartridges. In this embodiment, the corona charging type corona charger  62 G is provided in the process cartridge  5 G. 
     Note that, in any of the above-described embodiments, the development roller  71  comes into contact with the photosensitive drum  61 , but the development roller  71  may not come into contact with the photosensitive drum  61 . That is, it is possible to employ a configuration in which the development roller  71  is disposed to face the photosensitive drum  61  with a minute gap, and a toner is developed in the photosensitive drum  61  through the minute gap. 
     In addition, in any of the above-described embodiments, description has been made with reference to an electrophotographic system monochrome printer, but the invention is not limited thereto. For example, the present invention is also applicable to a full-color printer using an intermediate transfer belt, or an inkjet type image forming apparatus that forms an image on a sheet by ejecting an ink liquid from the nozzle. Note that, any of the above-described embodiments and modification examples may be appropriately combined. 
     Other Embodiments 
     Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiments) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g, central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     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 such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2019-084040, filed Apr. 25, 2019, which is hereby incorporated by reference herein in its entirety.