Patent Publication Number: US-2022236661-A1

Title: Image forming apparatus and cartridge

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an electrophotographic image forming apparatus. 
     Description of the Related Art 
     Conventionally, as a method of charging a photosensitive drum in an image forming apparatus using an electrophotographic technique, a corona charging method using a charging wire has been known. The corona charging method has a problem in that, when an image forming operation is repeated, a foreign material is deposited on the charging wire, thereby degrading a discharge capability and causing vertical streaks. Accordingly, there is an image forming apparatus provided with a cleaning unit that removes a foreign material deposited on a charging wire (see, e.g., Japanese Patent Application Publication No. H08-227207). According to Japanese Patent Application Publication No. H08-227207, when a cover of a housing of the image forming apparatus is opened, an operation portion for wire cleaning is exposed and, with the operation portion being moved by a user, the charging wire can be cleaned. By thus operating a charging wire cleaning member without taking out a process cartridge from a position in the image forming apparatus where the process cartridge is attached thereto, it is possible to clean the charging wire. 
     SUMMARY OF THE INVENTION 
     However, in the method described in Japanese Patent Application Publication No. H08-227207, the user first widely opens the cover of the image forming apparatus and then manually moves the cleaning member over an entire region of the charging wire to clean the charging wire, resulting in a heavy workload placed on the user. 
     An object of the present invention is to provide a technique which can reduce a workload placed on a user to clean a charging member. 
     To attain the above object, an image forming apparatus of the present invention includes: a photosensitive member; 
     a charging member for charging the photosensitive member; 
     a cleaning member that comes into contact with the charging member and moves relative to the charging member to clean the charging member; and 
     an opening/closing member for exposing an inside of the apparatus, 
     the image forming apparatus further comprising a driving mechanism that moves the charging member and the cleaning member relative to each other in association with opening/closing of the opening/closing member, 
     wherein the driving mechanism moves the cleaning member relative to the charging member that is fixed. 
     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 a cross-sectional view of an image forming apparatus including a process cartridge; 
         FIG. 2  is a cross-sectional view of a development unit; 
         FIG. 3  is a perspective view of the development unit; 
         FIG. 4  is an exploded perspective view of the development unit; 
         FIG. 5  is a cross-sectional view of the process cartridge; 
         FIG. 6  is a top view of the development unit; 
         FIG. 7  is a cross-sectional view of a toner feeding unit; 
         FIG. 8  is a diagram illustrating a resupply of a toner to the toner feeding unit; 
         FIG. 9  is a perspective view of the process cartridge; 
         FIG. 10  is a perspective view of a charging wire and a cleaning member; 
         FIG. 11  is a perspective view of the cleaning member executing a cleaning operation; 
         FIG. 12  is a view illustrating association between an operation of the cleaning member and a side surface cover opening/closing operation; 
         FIG. 13  is a view illustrating the association between the operation of the cleaning member and the side surface cover opening/closing operation; 
         FIG. 14  is a view illustrating the association between the operation of the cleaning member and the side surface cover opening/closing operation; 
         FIGS. 15A and 15B  are illustrative views of a detecting member; 
         FIG. 16  is a perspective view of the development unit; 
         FIG. 17  is a perspective view of the process cartridge; 
         FIGS. 18A and 18B  are partial perspective views of a photosensitive member unit; 
         FIG. 19  is a perspective view of the development unit and the photosensitive member unit; 
         FIG. 20  is a top view of the development unit and the photosensitive member unit; 
         FIGS. 21A and 21B  are perspective views of the process cartridge; 
         FIG. 22  is a partial perspective view of the development unit and a lifting member; 
         FIGS. 23A and 23B  are views illustrating a positional relationship between the lifting member and a pressing member; 
         FIGS. 24A and 24B  are views illustrating detachment of the development unit; 
         FIG. 25  is a view illustrating an operation of a cleaning member in a second embodiment; 
         FIG. 26  is a control block diagram in the second embodiment; and 
         FIG. 27  is a flow chart before a cleaning operation is executed in the second embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, a description will be given, with reference to the drawings, of embodiments (examples) of the present invention. However, the sizes, materials, shapes, their relative arrangements, or the like of constituents described in the embodiments may be appropriately changed according to the configurations, various conditions, or the like of apparatuses to which the invention is applied. Therefore, the sizes, materials, shapes, their relative arrangements, or the like of the constituents described in the embodiments do not intend to limit the scope of the invention to the following embodiments. 
     First Embodiment 
     The following description defines directions based on a user who uses an image forming apparatus  1 . Specifically, a front surface side, a back surface side, an upper surface (top surface) side, and a lower surface (bottom surface) side of the image forming apparatus  1  are defined as “front”, “rear”, “up”, and “down”, respectively. Additionally, a left side and a right side of the image forming apparatus  1  when the image forming apparatus  1  is viewed from the front surface side thereof are defined as “left” and “right”, respectively. For a process cartridge  5  also, directions are defined in the same manner as for the image forming apparatus  1  on the assumption that the process cartridge  5  assumes the same posture as assumed in a state where the process cartridge  5  is attached to the image forming apparatus  1 . In each of the drawings, the individual directions are defined by respective arrows illustrated in the drawing. A front-rear direction, an up-down direction, and a left-right direction indicated by the arrows are perpendicular to each other. These directions refer to the same directions in all the drawings. The up-down direction is parallel with a vertical direction, while the left-right direction and the front-rear direction are parallel with a horizontal direction. Meanwhile, the left-right direction is parallel with each of a rotation axis direction of a photosensitive drum  51  and a rotation axis direction of a development roller  71 . An integrated combination of a development unit  7  and a photosensitive member unit  6  obtained by attaching the development unit  7  to the photosensitive member unit  6  is referred to as the process cartridge  5 . When attached to an apparatus main body  2 , the process cartridge  5  is inserted therein in a direction (insertion direction) indicated by an arrow S 1  in the drawing and detached in a direction indicated by an arrow S 2  in the drawing. 
     Overall Configuration of Image Formation Device 
       FIG. 1  is a cross-sectional view of the image forming apparatus  1  having the process cartridge  5  attached thereto. The image forming apparatus  1  mainly includes a sheet feeding unit  3  for feeding a sheet S into the apparatus main body  2 , an exposure device  4 , the process cartridge  5  that transfers a toner image onto the sheet S, a fixation device  8  that thermally fixes the toner image transferred onto the sheet S, and a toner feeding unit  94 . 
     The sheet feeding unit  3  is provided in a lower part of the apparatus main body  2  and mainly includes a sheet feeding tray  31  and a sheet feeding mechanism  32 . The sheet S contained in the sheet feeding tray  31  is fed by the sheet feeding mechanism  32  toward the process cartridge  5  (a gap between the photosensitive drum  51  and a transfer roller  63 ). 
     The exposure device  4  is disposed in an upper part of the apparatus main body  2  and includes a laser light emitting unit not shown and a polygon mirror, a lens, a reflection mirror, and the like which are illustrated without reference numerals. In the exposure device  4 , laser light based on image data which is emitted from the laser light emitting unit rapidly scans a surface of the photosensitive drum  51  to expose the surface of the photosensitive drum  51 . 
     The process cartridge  5  is disposed below the exposure device  4 . The process cartridge  5  is configured to be inserted into a containing portion  23  of the apparatus main body  2  in an insertion direction S 1  through an opening formed when a door (opening/closing member)  21  provided in the apparatus main body  2  is opened (indicated by a two-dot-dash line in  FIG. 1 ) and attached to the apparatus main body  2 . When the process cartridge  5  is detached from the apparatus main body  2 , the process cartridge  5  is moved in the detachment direction S 2  to be taken out. 
     The process cartridge  5  mainly includes the photosensitive member unit  6  and the development unit  7 . The photosensitive member unit  6  mainly includes the photosensitive drum  51  serving as an image bearing member (photosensitive member), a scorotron charger  52 , a cleaning member  54 , and a transfer roller  63 . The development unit  7  is configured to be detachably attached to the photosensitive member unit  6 . The development unit  7  mainly includes the development roller  71 , a feeding roller  72 , a layer thickness control blade  73 , a toner containing portion (developer containing portion)  74  containing a toner (developer) therein, and first and second agitators  75 A and  75 B provided in the toner containing portion  74 . 
     The scorotron charger  52  is disposed to be spaced apart at a predetermined distance from the photosensitive drum  51  so as not to come into contact therewith. In addition, as a charging member extending in the left-right direction, a charging wire  53  is provided. To clean the charging wire  53 , the cleaning member  54  formed of sponge or the like is provided in contact with the charging wire  53 . Note that the cleaning member  54  is movable along a direction (longitudinal direction) in which the charging wire  53  extends. 
     As illustrated in  FIG. 6 , the toner feeding unit  94  is located on a right side of the development unit  7 . The toner feeding unit  94  (described later in detail) is capable of feeding the toner to the development unit  7  of the process cartridge  5 . The toner feeding unit  94  is attached to the apparatus main body  2 . 
     Image Formation Process 
     Next, a description will be given of an image formation process using the process cartridge  5 . The photosensitive drum  51  is driven to rotate while an image formation process is performed. First, the surface of the photosensitive drum  51  is uniformly charged by the scorotron charger  52  and then exposed to the laser light corresponding to the image data which is emitted from the exposure device  4 , resulting in formation of an electrostatic latent image corresponding to the image data on the photosensitive drum  51 . 
     Meanwhile, the toner in the toner containing portion  74  is stirred by the second agitator  75 B and the first agitator  75 A, and then fed to the development roller  71  via the feeding roller  72 . Subsequently, the toner fed to the development roller  71  enters a gap between the development roller  71  and the layer thickness control blade  73  to be carried as a thin layer having a given thickness on the development roller  71 . 
     The toner carried on the development roller  71  is fed to the electrostatic latent image formed on the photosensitive drum  51 . As a result, the toner adheres to the electrostatic latent image to visualize the electrostatic latent image and form the toner image on the photosensitive drum  51 . Then, the sheet S is conveyed to a gap between the photosensitive drum  51  and the transfer roller  63 , and the toner image on the photosensitive drum  51  is transferred onto the sheet S. At this time, the untransferred toner remaining on the photosensitive drum  51  is collected by the development roller  71  to be returned to the development unit  7 . 
     The fixation device  8  is disposed behind the process cartridge  5  and mainly includes a heating roller  92  and a pressing roller  91 . The sheet S having the toner image transferred thereto passes through the fixation device  8 , while being simultaneously heated and pressed between the heating roller  92  and the pressing roller  91 , and the toner image is fixed onto the sheet S. The sheet S having passed through the fixation device  8  is ejected onto a paper receiving tray  22 . 
     Configuration of Process Cartridge 
     Next, a description will be given of each of the units of the process cartridge  5 . As described above, the process cartridge  5  includes the photosensitive member unit  6  and the development unit  7  detachable from the photosensitive member unit  6 . 
     Configuration of Development Unit 
     First, a description will be given of a configuration of the development unit  7 .  FIG. 2  is a cross-sectional view of the development unit  7 , which is a cross-sectional view of an A-A cross section in  FIG. 3 .  FIG. 3  is a perspective view in which the development unit  7  is viewed from above, while  FIG. 9  is a perspective view in which the process cartridge  5  is viewed from above.  FIG. 4  is an exploded perspective view of the development unit  7 .  FIG. 5  is a cross-sectional view of the development unit  7  (process cartridge  5 ) attached to the photosensitive member unit  6 , which is parallel with each of the up-down direction and the front-rear direction.  FIG. 6  is a top view of the development unit  7  illustrating a state from which a top surface of a housing  700  and a side holder  719  are removed for the sake of explanation. 
     As illustrated in  FIG. 2 , the development unit  7  has, in front of the housing  700  serving as a development frame body, a holding portion  701  to be held by the user, while having the development roller  71  rotatively supported behind the holding portion  701 . A description will be given below of the configuration of the development unit  7  in which the rotation axis direction of the development roller  71  is referred to as an axial direction. 
     As illustrated in  FIGS. 4 and 6 , the development roller  71 , the feeding roller  72 , the first agitator (first stirring member)  75 A, and the second agitator (second stirring member)  75 B have respective both ends rotatively supported by a left side wall  704  and a right side wall  705  of the housing  700 . On a left side of the left side wall  704  of the housing  700 , a development coupling  710 , a development roller gear  711 , a feeding roller gear  712 , a first agitator gear  713 , a second agitator gear  714 , a development screw gear  715 A, and idle gears  715 B and  715 C are provided. The development roller gear  711  is fixed to an end portion of the development roller  71 , while the feeding roller gear  712  is fixed to an end portion of the feeding roller  72 . The first agitator gear  713  is fixed to an end portion of a stirring rod  78 A (see  FIG. 5 ) of the first agitator  75 A, while the second agitator gear  714  is fixed to an end portion of a stirring rod  78 B (see  FIG. 5 ) of the second agitator  75 B. 
     As illustrated in  FIG. 6 , inside the toner containing portion  74  of the development unit  7 , a screw  96  is provided. 
     The screw  96  extends through the right side wall  705  of the toner containing portion  74  to overlap a connection cylinder  98  when viewed in the left-right direction and communicate with the connection cylinder  98 . Note that, between the toner containing portion  74  and the connection cylinder  98 , a sealing member  99  is interposed. A description will be given later of the connection cylinder  98 . 
     The sealing member  99  has a substantially cylindrical shape. The sealing member  99  prevents a toner leakage through a gap between the toner containing portion  74  and the connection cylinder  98 . Even when the development unit  7  rotates with respect to the photosensitive member unit  6  and the toner containing portion  74  and the connection cylinder  98  are displaced from each other when viewed in the left-right direction, the sealing member  99  connects the toner containing portion  74  and the connection cylinder  98  to prevent the toner leakage through the gap between the toner containing portion  74  and the connection cylinder  98 . 
     As illustrated in  FIG. 2 , the screw  96  is located in the toner containing portion  74 . The screw  96  extends in the left-right direction. The screw  96  is an auger screw. The screw  96  has a left end portion extending through the left side wall  704  of the toner containing portion  74  and connected to the development screw gear  715 A. The screw  96  has a right end portion rotatively supported by the right side wall  705  of the toner containing portion  74 . 
     As illustrated in  FIG. 3 , the development unit  7  is provided with a first electric contact point  720 A which is electrically connected to the development roller  71  and to which a voltage to be applied to the development roller  71  is fed and a second electric contact point  720 B which is electrically connected to the feeding roller  72  and to which a voltage to be applied to the feeding roller  72  is fed. Through contact of these electric contact points with power supply contact points provided in the apparatus main body  2  and not shown, power is fed to the development roller  71  and to the feeding roller  72 . 
     In association with an operation of closing the front door  21  provided in the apparatus main body  2 , a development driving transmission member provided in the apparatus main body  2  and not shown moves to a position for engagement with the development coupling  710 . Conversely, in association with an operation of openings the front door  21 , the development driving transmission member moves to a position for disengagement from the development coupling  710 . 
     After the front door  21  is closed, when the apparatus main body  2  operates, a driving force is transmitted (input) from the development driving transmission member to the development coupling  710  serving as a driving force receiving member to allow the development roller  71  to rotate via a gear provided on a peripheral surface of the development coupling  710  and the development roller gear  711  and allow the feeding roller  72  to rotate via the feeding roller gear  712 . The development driving transmission member is configured to be able to tolerate a displacement of the development coupling  710  within a predetermined range and transmit the driving force to the development coupling  710 . Each of the development coupling  710 , the development roller gear  711 , and the feeding roller gear  712  has axial movement thereof restricted by the side holder  719  attached to the housing  700 . 
     The development unit  7  uses two agitators, i.e., the first and second agitators  75 A and  75 B to stir the toner in the toner containing portion  74 . The first agitator  75 A includes the stirring rod  78 A and a stirring sheet  79 A. The first agitator  75 A is configured to be able to receive, at the first agitator gear  713 , the driving force from the development coupling  710  via the development screw gears  715 A and rotate. The second agitator  75 B includes the stirring rod  78 B and a stirring sheet  79 B. The second agitator  75 B is configured to be able to receive, at the second agitator gear  714 , the driving force from the first agitator gear  713  via the idle gears  715 B and  715 C and rotate. 
     The second agitator  75 B feeds the toner in the toner containing portion  74  toward the first agitator  75 A. The toner located near the first agitator  75 A in the toner containing portion  74  is stirred by the first agitator  75 A, then fed toward the feeding roller  72 , and further fed by the feeding roller  72  to the development roller  71 . 
     As illustrated in  FIGS. 4 and 9 , at a left end portion of the development unit  7 , a detecting unit  80  is provided. The detecting unit  80  is provided so as to allow a detecting mechanism (not shown) provided in the apparatus main body  2  to detect a state of a detecting member  81  provided in the detecting unit  80 . It is possible to determine whether the development unit  7  has not been used yet or has already been used based on the state of the detecting member  81 . 
     Referring to  FIGS. 15A and 15B , an operation of the detecting member  81  will be described.  FIGS. 15A and 15B  are views in which the development unit  7  is viewed from a left side surface. For the sake of explanation, the side holder  719  has been removed from each of  FIGS. 15A and 15B . As illustrated in  FIG. 15A , the detecting member  81  is provided with a detecting projection  83  and a detecting gear  82 . As illustrated in the drawings, the detecting gear  82  is a chipped tooth gear. The detecting member  81  receives, at the detecting gear  82 , the driving force from the second agitator gear  714 . 
       FIG. 15A  illustrates a state where the development unit  7  has not been used yet. The detecting projection  83  is located in an upper front portion of the detecting member  81 . The detecting gear  82  meshes with the second agitator gear  714 . When the development unit  7  is used, by the driving force received by the development coupling  710  from the development driving transmission member of the apparatus main body  2 , the second agitator gear  714  rotates in a direction indicated by an arrow R 3  in  FIG. 15A . At this time, due to the detecting gear  82  meshing with the second agitator gear  714 , the detecting member  81  rotates in a direction indicated by an arrow R 4  in  FIG. 15A .  FIG. 15B  illustrates a state after the detecting member  81  is rotated. Since the detecting gear  82  is a chipped tooth gear, the detecting member  81  is rotated in a direction indicated by an arrow R 4  in  FIG. 15B  and, when there is no more gear tooth meshing with the second agitator gear  714 , the rotation of the detecting member  81  stops. At this time, the detecting projection  83  is located in an upper rear portion of the detecting member  81 . 
     Through detection of a position of the detecting projection  83  of the detecting member  81  by a detecting mechanism (not shown) provided in the apparatus main body  2 , it is possible to determine whether the development unit  7  has not been used yet or has already been used. 
       FIG. 16  is a perspective view in which the development unit  7  is viewed from below. As illustrated in  FIG. 16 , a bottom surface of the development unit  7  includes a memory  85  and a positioning projection  86 . The memory  85  includes a memory chip (not shown) storing therein information related to the development unit  7  and a memory electrode  85 A conductive with the memory chip. The memory electrode  85 A comes into contact with an electrode provided in the apparatus main body  2  and not shown to provide communication between the memory chip and the apparatus main body  2 . 
     Configuration of Photosensitive Member Unit and Supporting of Development Unit 
     Next, a description will be given of a detailed configuration of the photosensitive member unit  6 .  FIG. 17  is a perspective view of the process cartridge  5 .  FIG. 18A  is a partial perspective view of the photosensitive member unit  6 , while  FIG. 18B  is a cross-sectional view of a B-B cross section in  FIG. 18A .  FIG. 19  is a perspective view of the development unit  7  and the photosensitive member unit  6 .  FIG. 20  is a top view illustrating layout relationships among the photosensitive member unit  6 , the development unit  7 , and the development roller  71  in the left-right direction.  FIG. 21A  is a perspective view in which the process cartridge  5  is viewed from below, while  FIG. 21B  is a perspective view of the development unit  7  and a positioning portion in the axial direction of the photosensitive drum  51  of the photosensitive member unit  6 . For the sake of explanation,  FIG. 21B  illustrates only the positioning projection  86  and the memory  85  of the development unit  7 . 
     As illustrated in  FIG. 17 , the photosensitive member unit  6  mainly includes a frame  610  having a pair of a left side wall  611  and a right side wall  612  and the photosensitive drum  51  rotatively supported behind the frame  610 . In front of the frame  610 , an attachment portion  615  (see  FIG. 19 ) to which the development unit  7  can be attached, a holding portion  617  with which the user holds the photosensitive member unit  6 , pressing members  640  that press the development unit  7 , and a lifting member (movement member)  642  that lifts up the development unit  7  are provided. The lifting member  642  lifts up the development unit  7  attached to the attachment portion  615 . Between the left side wall  611  and the right side wall  612  in the left-right direction, the toner containing portion  74  of the development unit  7  attached to the attachment portion  615  is disposed. 
     Behind the frame  610 , a first positioning projection  660  projecting coaxially with the photosensitive drum from the left side wall  611  and a first guide rib  662  are provided. Likewise, a second positioning projection  661  projecting coaxially with the photosensitive drum from the right side wall  612  and a second guide rib  663  are provided (see  FIGS. 20 and 17 ). 
     A life of the development unit  7  which is determined by an amount of the toner contained in the development unit  7  is set shorter than a life of the photosensitive member unit  6  determined by a thickness of a photosensitive layer of the photosensitive drum  51 . Accordingly, it is necessary to exchange only the development unit  7  that has reached the end of the life thereof separately from the photosensitive member unit  6 . In that case, the front door  21  is opened, the process cartridge  5  is taken out of the inside the apparatus main body  2 , the development unit  7  that has reached the end of the life is detached from the photosensitive member unit  6 , and then another development unit  7  is attached to the photosensitive member unit  6 , as indicated by an attachment direction AD in  FIG. 19 . Then, the photosensitive member unit  6  having the development unit  7  attached thereto is attached as the process cartridge  5  to the apparatus main body  2 . 
     As illustrated in  FIGS. 9, 17, and 19 , the left side wall  611  and the right side wall  612  of the frame  610  have respective receiving portions  641  for receiving rotation bearing members  746 A and  746 B of the development roller  71  which are formed in front of the photosensitive drum  51 . Each of the receiving portions  641  is a recessed portion having a substantially U-shaped shape having a front side thereof open when viewed from the left side. In a process of the attachment of the development unit  7  to the photosensitive member unit  6 , a rotation shaft  746  of the development roller  71  is inserted into the receiving portions  641 . The receiving portions  641  guide movement of the development unit  7  in the attachment direction AD illustrated in  FIG. 19 , while supporting the development unit  7  with respect to the photosensitive member unit  6 . 
     As illustrated in  FIG. 20 , respective projecting portions  643  projecting upward are provided at both end portions of a bottom surface  613  of the frame  610  in the left-right direction. The projecting portions  643  come into contact with ribs  718  provided on a bottom portion of the housing  700  of the development unit  7  illustrated in  FIG. 16  to movably support the development unit  7 . 
     As illustrated in  FIG. 18A , the photosensitive member unit  6  has a positioning hole  68  provided in the frame  610  and a contact opening  69  provided on one end side in the rotation axis direction (left-right direction) of the photosensitive drum  51 . The one end side mentioned herein indicates the same side of a bisector of a length of the photosensitive drum  51  in the left-right direction. When the development unit  7  is disposed on the photosensitive member unit  6 , as illustrated in  FIGS. 18A and 18B , the positioning projection  86  of the development unit  7  is inserted into the positioning hole  68  of the photosensitive member unit  6 . The positioning projection  86  and the positioning hole  68  are engaged with each other in the axial direction (left-right direction) of the photosensitive drum  51  to determine a position of the development unit  7  with respect to the photosensitive member unit  6  in the left-right direction. The memory  85  of the development unit  7  is exposed in the lower part of the process cartridge  5  via the contact opening  69  of the photosensitive member unit  61 . 
     It is to be noted herein that, as illustrated in  FIGS. 18A and 18B , in the frame  610  of the photosensitive member unit  6 , a box-shaped recessed portion  90 L is provided on one end side in the rotation axis direction (left-right direction) of the photosensitive drum  51 . The recessed portion  90 L is provided at a position overlapping the positioning hole  68  when viewed in the rotation axis direction (left-right direction) of the photosensitive drum  51 . The recessed portion  90 L reinforces a portion around the positioning hole  68  having a strength reduced by the positioning hole  68  provided therein and enhances the strength thereof. As illustrated in  FIG. 18B , a depth D 2  of the recessed portion  90 L is larger than a depth D 1  of the positioning hole  68  to increase a reinforcing effect. This configuration enhances the strength of a periphery of the positioning hole  68  of the photosensitive member unit  6  and increases accuracy of positioning of the development unit  7  and the photosensitive member unit  6  in the left-right direction by the positioning projection  86  of the development unit  7  and the positioning hole  68  of the photosensitive member unit  6 . As a result, positional accuracy of the memory electrode  85 A of the memory  85  and the electrode provided in the apparatus main body  2  is increased to be able to achieve reliable contact between the electrodes. 
     As illustrated in  FIGS. 18A and 18B , on a photosensitive drum  51  side of the recessed portion  90 L, a sheet member  93 L is provided. The sheet member  93 L has a tip portion  93 LA in contact with the photosensitive drum  51 . This configuration allows the tip portion  93 LA to scrape off a foreign material such as the unneeded toner or paper powder deposited on the surface of the photosensitive drum  51  during image formation and thereby prevent a defective image. In this configuration, the foreign material scraped off such as the unneeded toner or paper powder falls into the recessed portion  90 L to be collected. Consequently, it is possible to prevent a defective image from being formed by contamination of the process cartridge  5  due to scattering of the foreign material or by the falling of the foreign material onto the sheet S. By thus using the recessed portion  90 L for structure reinforcement and foreign material collection, there is no more need to provide a configuration for foreign material collection other than the recessed portion  90 L, and it is possible to reduce a size of the cartridge and simplify the configuration thereof. 
     As illustrated in  FIG. 19 , on the opposite side of the positioning hole  68  of the photosensitive member unit  6  in the left-right direction, a foreign material box  90 R including a box-shaped recessed portion is provided. On the photosensitive drum  51  side of the foreign material box  90 R, a sheet member  93 R is provided. The sheet member  93 R has a tip portion  93 RA in contact with the photosensitive drum  51 . Similarly to the sheet member  93 L described above, the sheet member  93 R uses the tip portion  93 RA to scrape off the foreign material such as the unneeded toner or paper powder deposited on the surface of the photosensitive drum  51  during the image formation to prevent a defective image. The foreign material scraped off such as the unneeded toner or paper powder falls into the foreign material box  90 R to be collected in the box. 
     As illustrated in  FIG. 19 , the pressing members  640  are located in front of the frame  610  and provided at both end portions of the frame  610  in the left-right direction. The pressing members  640  are biased in a direction from the front to the rear by compression springs  640 A each serving as a biasing member. Consequently, biasing forces of the compression springs  640 A cause the pressing members  640  to press pressing target ribs  716 A and  716 B provided in the housing  700  of the development unit  7 . By using the pressing members  640  to press the development unit  7 , the development roller  71  is biased toward the photosensitive drum  51 . 
     As illustrated in  FIGS. 19 and 9 , in the left side wall  611  of the photosensitive member unit  6 , a recessed portion  664  is provided, and the detecting unit  80  of the development unit  7  is located therein. Since the recessed portion  664  reduces rigidity of the frame  610 , the first guide rib  662  is disposed under the recessed portion  664  such that a portion of the first guide rib  662  overlaps the recessed portion  664 . The first guide rib  662  functions as a reinforcing member and can thus reduce the reduction in the rigidity of the frame  610 . 
     As illustrated in  FIGS. 18A and 18B , a photosensitive member gear (first gear)  65  and a transfer gear (second gear)  66  are configured to be fixed to a left end portion of the photosensitive drum  51  and rotate integrally with the photosensitive drum  51 . When the process cartridge  5  is attached to the apparatus main body  2 , a drive gear (not shown) of the apparatus main body  2  meshes with the photosensitive member gear  65  to transmit a driving force to each of the photosensitive drum  51  and the transfer gear  66  and provide a rotative state. In addition, the transfer gear  66  meshes with a transfer roller gear (third gear)  67  fixed to a left end portion of the transfer roller  63  to bring even the transfer roller  63  into a rotative state. 
     Lifting Mechanism of Development Unit  7   
       FIG. 22  is a partial perspective view of the development unit  7  and the lifting member  642 .  FIGS. 23A and 23B  are top views of the photosensitive member unit  6  having the development unit  7  attached thereto.  FIG. 23A  illustrates the lifting member  642  in a see-through state, while  FIG. 23B  illustrates the lifting member  642  in a non-see-through state.  FIGS. 24A and 24B  are cross-sectional views of the photosensitive member unit  6  and the development unit  7 , and respective cross sections thereof are parallel with the up-down direction and in the front-rear direction.  FIG. 24A  illustrates a state where the development unit  7  is attached to the photosensitive member unit  6 .  FIG. 24B  illustrates a state where the development unit  7  is placed on the photosensitive unit  6 . 
     The development unit  7  attached to the photosensitive member unit  6  is brought into a lift-up state by a lifting mechanism and then detached from the photosensitive member unit  6 . A detailed description will be given below of the lifting mechanism. 
     As illustrated in  FIGS. 22, 24A, and 24B , at least a portion of the lifting member  642  is disposed in front of the housing  700  of the development unit  7  and rotatively supported by the right side wall  612 , while receiving the force of a compression spring  650 . Also, at least a portion of the lifting member  642  is disposed to overlap the right side wall  705  of the housing  700  containing therein the toner and the pressing members  640  in the front-rear direction. A rotation axis  642 X of the lifting member  642  is parallel with the left-right direction (axial direction of the photosensitive drum  51 ). The lifting member  642  is biased by the force of the compression spring  650  to rotate in a direction R 1 . 
     The user presses an operation portion  642 A of the lifting member  642  against the force of the compression spring  650  to rotate the lifting member  642  in a direction R 2 , and consequently the lifting member  642  presses a projecting portion  751  to move the development unit  7  in a detachment direction LD in which the development unit  7  is detached from the photosensitive member unit  6 . This provides a state where the development unit  7  can be detached from the photosensitive member unit  6 . The operation portion  642 A is disposed on a right end side (one end side) of the photosensitive member unit  6 . 
     As illustrated in  FIG. 24A , in an attached state where the development unit  7  is attached to the photosensitive member unit  6 , the pressing members  640  press the housing  700  and thus press the development roller  71  against the photosensitive drum  51 . In addition, the pressing members  640  lock the development unit  7  to prevent the development unit  7  from being detached from the photosensitive member unit  6 . 
     As illustrated in  FIG. 22 , one end of the lifting member  642  upwardly moves a contact surface (contact portion)  751 A of the projecting portion  751  of the housing  700 . This moves the development unit  7  from an attachment position where the development unit  7  is attached to the attachment portion  615  (see  FIGS. 24A and 24B ) in the detachment direction LD and allows the development unit  7  to be detached from the photosensitive member unit  6 . 
     As illustrated in  FIG. 24B , when a front portion of the development unit  7  is detached from the photosensitive member unit  6 , the development unit  7  is held at a provisional support position at which a support target surface  700 c of the housing  700  is supported by a holding portion  640 B of each of the pressing members  640 . The development unit  7  at the provisional support position is in a state where the rotation bearing member  746 B ( 746 A) of the development roller  71  is supported by the receiving portions  641 . This state is referred to as the lift-up state. At this time, the lock (restriction of detachment of the development unit  7  from the photosensitive member unit  6 ) has been undone. When the user holds the holding portion  701  and immediately lifts up the development unit  7  in the lift-up state, the user can detach the development unit  7  from the photosensitive member unit  6  without involving movement of another member or the like. Thus, the user can detach the development unit  7  from the photosensitive member unit  6  and attach a new development unit  7  to the photosensitive member unit  6 . 
     Cleaning Member for Scorotron Charger 
     A description will be given of the cleaning member  54  for cleaning the charging wire  53  of the scorotron charger  52 . As illustrated in  FIG. 10 , to clean the charging wire  53  extending in the left-right direction, the cleaning member  54  formed of sponge  55  or the like is provided in contact with the charging wire  53 . The sponge  55  is configured to have a slit to allow the charging wire  53  to be held in the slit in sandwiched relation or configured such that the sponge in the form of a flat plate is folded back so as to hold the charging wire  53 . As the cleaning member  54  moves along the longitudinal direction of the charging wire  53 , the sponge  55  in which the charging wire  53  is held in sandwiched relation rubs off a deposit around the charging wire  53 . A leftmost position of the cleaning member  54  in a movable range as illustrated in  FIG. 20  is assumed to be a home position, and the cleaning member  54  is at this position when the cleaning member  54  does not execute a cleaning operation. 
     Mechanism in Which Cleaning Member Moves in Association with Opening/Closing of Side Surface Cover 
     A description will be given of a mechanism in which the cleaning member  54  moves in association with an opening/closing operation of a side surface cover  101  serving as the opening/closing member to execute a cleaning operation. As illustrated in  FIG. 11 , the apparatus main body  2  includes, as a driving mechanism of moving the cleaning member  54  relative to the charging wire  53 , a first arm  56 , an arm connection pin  57 , a second arm  58 , and a rail  59 . A left end portion of the first arm  56  is connected (rotatively coupled) to the second arm  58  by using the arm connection pin  57 . Meanwhile, a right end portion  60  of the first arm  56  is connected (rotatively coupled) to the side surface cover  101 , as illustrated in  FIGS. 12 to 14 . A lower end portion of the second arm  58  has an inverted U shape to be able to be connected, as an engagement portion, to a projecting portion of an upper part of the cleaning member  54  as illustrated in  FIG. 10 . The arm connection pin  57  is connected also to the rail  59  to be movable along the rail  59  in parallel therewith in the left-right direction. 
     The cleaning member  54  assembled to the photosensitive member unit  6  of the process cartridge  5  and the driving mechanism provided in the apparatus main body  2  have respective engagement means to be drivingly connected to each other when the process cartridge  5  is attached to the apparatus main body  2 . The engagement means can be configured to include, e.g., a projecting portion and a depressed portion which are provided in either one of the cleaning member  54  and the driving mechanism and in the other thereof and can be engaged with each other. In the first embodiment, the projecting portion is provided in the cleaning member  54  and the depressed portion having the inverted U shape is provided in a lower end portion of the second arm  58  of the driving mechanism. However, the projecting portion and the depressed portion may also be configured in a reverse combination. The depressed portion is configured to have a groove shape extending in an attachment/detachment direction when the cartridge  5  is attached to the apparatus main body  2  and having open both ends in the attachment/detachment direction so as to allow the projecting portion to fit in (enter) the depressed portion when the cartridge  5  moves to be attached/detached to/from the apparatus main body  2 . The depressed portion and the projecting portion are configured to be able to come into contact with each other in a direction perpendicular to the attachment/detachment direction. The cleaning member  54  is assembled to a frame body of the photosensitive member unit  6  to be movable along a guide slit  654  provided in the frame body of the photosensitive member unit  6 , and the guide slit  654  extends in a direction perpendicular to the attachment/detachment direction. This direction coincides with a direction of movement in which the second arm  58  is guided by the rail  59  in the apparatus main body  2 . Accordingly, in a state where the cartridge  5  is attached to the apparatus main body  2 , the contact (engagement) between the depressed portion and the projecting portion described above in a direction perpendicular to the attachment/detachment direction described above allows the driving force of the driving mechanism of the apparatus main body  2  to be transmitted to the cleaning member  54 . In other words, in response to an operation of the second arm  58 , the cleaning member  54  moves along a direction in which the guide slit  654  extends. 
     As a result, when the side surface cover  101  is closed and the photosensitive member unit  6  is attached to the apparatus main body in a state where the cleaning member  54  is at the home position, the upper projecting portion of the cleaning member  54  and the inverted-U-shaped portion of the second arm  58  are brought into a connected state. Accordingly, as illustrated in  FIGS. 12 to 14 , the first arm  56  moves in response to an opening/closing operation of the side surface cover  101 , and the second arm moves along the rail  59  in parallel therewith in the left-right direction, and consequently the cleaning member  54  also moves in the left-right direction in association therewith to be able to clean the charging wire  53 . 
     Toner Feeding Unit and Connection Cylinder 
     As illustrated in  FIG. 6 , the image forming apparatus  1  includes the toner feeding unit  94  and the connection cylinder  98 . 
     The toner feeding unit  94  is disposed on a right side of the connection cylinder  98 . The toner feeding unit  94  has a generally box-like shape. The toner feeding unit  94  includes a projecting portion  100  ( FIG. 7 ). 
     The projecting portion  100  is located on an upper end portion of the toner feeding unit  94 . The projecting portion  100  upwardly projects from a center portion of an upper wall of the toner feeding unit  94 . 
     The side surface cover  101  is located to extend from an upper part of the toner feeding unit  94  to a right side surface thereof, and has an inverted L shape as illustrated in  FIG. 13 . An upper end portion of the side surface cover  101  is located above the projecting portion  100 . The side surface cover  101  can be opened/closed in a rightward direction around a lower position on a right side surface of the image forming apparatus. In response to the opening/closing operation of the side surface cover  101 , the cleaning member  54  for the charging wire  53  described later can be moved. 
     As illustrated in  FIG. 6 , the connection cylinder  98  is disposed to extend in the left-right direction and have a right end portion connected to a left end portion of the toner feeding unit  94 , while having a left end portion connected to a right end portion of the toner containing portion  74  of the development unit  7 . The connection cylinder  98  cannot be detached from the apparatus main body  2 . As illustrated in  FIG. 6 , the connection cylinder  98  has an inlet port  104  and an outlet port  105 . 
     As illustrated in  FIG. 6 , the inlet port  104  is located at the right end portion of the connection cylinder  98 . The inlet port  104  extends through the right end portion of the connection cylinder  98  in the left-right direction. 
     As illustrated in  FIG. 6 , the outlet port  105  is located at the left end portion of the connection cylinder  98 . The outlet port  105  extends through the left end portion of the connection cylinder  98  in the left-right direction. The outlet port  105  communicates with the right end portion of the toner containing portion  74  via the sealing member  99 . 
     A screw  103  is located in the connection cylinder  98  and in the toner feeding unit  94 . The screw  103  is an auger screw extending in the left-right direction. A left end portion of the screw  103  is rotatively supported by a left wall of the connection cylinder  98 . A right end portion of the screw  103  extends through a right wall of the toner feeding unit  94  to be connected to a motor not shown. 
     As illustrated in  FIG. 7 , the toner feeding unit  94  includes a receiving hole  106  and a lid  107 . The receiving hole  106  is located in an upper end portion of the toner feeding unit  94  and has a substantially cylindrical shape. The lid  107  is detachably attached to the receiving hole  106 . 
     Resupply of Toner to Toner Feeding Unit 
     A description will be given of a resupply of the toner to the toner feeding unit  94 . 
     The user opens the side surface cover  101  in the rightward direction, as illustrated in  FIG. 14 . Then, the user detaches the lid  107  from the receiving hole  106  of the toner feeding unit  94 , as illustrated in  FIG. 8 . Then, the user inserts a toner resupplier  108  into the receiving hole  106  to resupply the toner to the toner feeding unit  94 . When the resupply of the toner is completed, the user attaches the lid  107  to the receiving hole  106  of the toner feeding unit  94 . Then, the user closes the side surface cover  101  to thus return the side surface cover  101  to an original position. By this operation, the cleaning member  54  is moved as described above to clean the charging wire  53 . 
     Effect of Invention in First Embodiment 
     By using a configuration as used in the first embodiment, the opening/closing operation of the side surface cover  101  when the toner is resupplied to the toner feeding unit  94  allows the cleaning operation to be executed on the charging wire  53 . Consequently, it is possible to reduce the cleaning operation manually executed thus far by the user on the charging wire  53  by taking out the photosensitive member unit  6  from the apparatus main body and also prevent formation of a defective image due to deposition of the foreign material on the charging wire  53 . In addition, since the charging wire  53  is automatically cleaned with the timing of resupplying the toner, the cleaning is periodically executed, and therefore it is possible to reduce a workload placed on the user in the cleaning of the charging wire. Moreover, it becomes easier to maintain an excellent state against the deposition of the foreign material on the charging wire  53 . 
     Modification of First Embodiment 
     In the first embodiment, the photosensitive member unit  6  is detachable from the apparatus main body  2 , but the configuration is not limited thereto. 
     For example, even when the photosensitive member unit  6  cannot be detached from the apparatus main body  2 , it is possible to move the cleaning member  54  in association with the opening/closing operation of the side surface cover  101  in the same manner as in the first embodiment. 
     Alternatively, even when the configuration is such that the scorotron charger  52  is a member separate from the photosensitive member unit  6  and cannot be taken out of the apparatus main body  2 , it is possible to move the cleaning member  54  for the charging wire  53  in association with the opening/closing operation of the side surface cover  101  in the same manner as in the first embodiment. 
     It may also be possible to move the cleaning member  54  in association with not the side surface cover  101 , but another opening/closing member of the apparatus main body, such as the front door  21 . 
     In addition, the configuration is not limited to a configuration in which the cleaning member  54  is moved in association with a constituent member assembled to an apparatus frame body to expose the inner portion of the apparatus, such as the side surface cover  101 . In other words, the configuration described in the first embodiment is such that the side surface cover  101  has both the function of opening the inner portion of the apparatus to the outside of the apparatus and the function of a to-be-operated portion for controlling the cleaning operation of the cleaning member  54 . Unlike this, the configuration may also be such that the to-be-operated portion exposed to the outside of the apparatus is disposed as the to-be-operated portion dedicated to the control of the cleaning operation of the cleaning member  54 , and a driving mechanism which allows movement of the cleaning member  54  relative to the charging wire  53  through the operation of the to-be-operated portion by the user is provided. Since the user can clean the charging wire  53  by merely operating the to-be-operated portion, there is no more need for such opening/closing of the cover as performed previously, and it is possible to reduce the workload. 
     Note that, in the first embodiment, the configuration is such that the cleaning member  54  is moved relative to the fixed charging wire  53 , but the configuration may also be such that the charging wire  53  is moved relative to the fixed cleaning member  54 . Alternatively, the configuration may also be such that both the cleaning member  54  and the charging wire  53  are moved relative to each other. 
     Also, in the first embodiment, the description has been given of the cleaning operation in the single process cartridge  5  but, in a multi-color image forming apparatus in which a plurality of process cartridges are arranged also, it is similarly possible to allow the cleaning operation to be executed in association with the opening/closing operation of the side surface cover. 
     Second Embodiment 
     A second embodiment uses a configuration in which a detecting member  110  detects the opening/closing of the side surface cover  101 , and a cleaning motor  111  attached to the apparatus main body  2  subsequently drives a belt  112  to allow the cleaning member  54  to move along the charging wire  53  and clean the charging wire  53 . In such a configuration also, there is no more need for the user to directly clean the charging wire, and therefore it is possible to reduce labor of the user. Since other components in the second embodiment are the same as the components in the first embodiment, a description thereof is omitted. 
     Cleaning Member Movement Mechanism in Second Embodiment 
     Referring to  FIG. 25 , a description will be given of a mechanism of moving the cleaning member  54  in the second embodiment. In the second embodiment, unlike in the first embodiment, the first arm  56  is not provided and instead, as illustrated in  FIG. 25 , the cleaning motor  111  serving as a power source, the belt  112  serving as a transmission means for transmitting a driving force of the motor, a drive roller  113 , and a facing roller (not shown) are additionally provided. The annular belt  112  is wound in tension around the drive roller  113  and the facing roller (not shown) to be fixed, and is movable in the left-right direction with rotation of the drive roller  113 . 
     The cleaning member  54  is connected to the belt  112  and moves with movement of the belt  112  to be able to execute an operation of cleaning the charging wire  53 . 
     Block Diagram 
     Next, referring to a control block diagram of  FIG. 26 , a description will be given of a control configuration in the second embodiment. A control unit  109  includes a CPU (central processing unit) that performs arithmetic processing, a memory serving as a storage means, and I/F that inputs/outputs information to/from a peripheral device, and the like. The control unit  109  is a control means for generally controlling an operation of the image forming apparatus  1  and connected to each of control targets in the image forming apparatus  1  via the input/output I/F. As illustrated in  FIG. 26 , based on information from the detecting member  110 , the control unit  109  determines whether the side surface cover  101  is open or closed and controls driving of the cleaning motor  111 . As the detecting member  110  that detects the opening or closing of the side surface cover  101 , conventionally known detecting means of a contact type, an optical type, or the like can appropriately be used. 
     Execution Process of Cleaning Operation 
     Next, a process before a toner feeding step is performed in the second embodiment will be described with reference to a flow chart of  FIG. 27 . When the image forming apparatus  1  is brought into an operable state, the flow chart illustrated in  FIG. 27  is started (S 1 ). 
     When the detecting member  110  detects opening/closing of the side surface cover  101  (YES in S 2 ), the control unit  109  starts to control the driving of the cleaning motor  111  (S 3 ). The cleaning member  54  is caused to reciprocate once in the left-right direction to execute the cleaning operation (S 4 ), which is then ended (S 5 ). 
     In S 2 , when the opening/closing of the side surface cover  101  is not detected, the process is immediately ended (S 5 ). 
     As has been described above, even a configuration as used in the second embodiment allows the opening/closing operation of the side surface cover  101  when the toner is resupplied to the toner feeding unit  94  to implement the operation of cleaning the charging wire  53 , in the same manner as in the first embodiment. Therefore, it is possible to reduce the operation of cleaning the charging wire  53  manually executed thus far by the user by taking out the photosensitive member unit  6  from the apparatus main body and also prevent formation of a defective image due to the deposition of a foreign material on the charging wire  53 . In addition, since the charging wire  53  is automatically cleaned with the timing of resupplying the toner, cleaning is periodically executed, and it is easier to maintain an excellent state against the deposition of the foreign material on the charging wire  53 . 
     According to the present invention, it is possible to reduce a workload placed on the user in cleaning of the charging member. 
     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. 2020-102715, filed on Jun. 12, 2020, which is hereby incorporated by reference herein in its entirety.