Abstract:
A drum cartridge and a method are disclosed. An example drum cartridge includes a photosensitive drum, a first cleaning roller positioned to a side of the photosensitive drum. The drum cartridge includes a lever positioned at an outer surface of the drum cartridge. The outer surface of the drum cartridge is positioned toward the side of the photosensitive drum. The lever is extendable in a second direction different from the first direction, and the lever is pivotable with respect to the outer surface of the drum cartridge about a second axis extending in the first direction. The lever is pivotable between an extended position and a retracted position. The drum cartridge includes an engagement portion movable with pivoting of the lever between an engaged position when the lever is in the extended position and a disengaged position when the lever is in the retracted position.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from Japanese Patent Application No. 2014-071829 filed on Mar. 31, 2014, which is incorporated herein by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The disclosure relates to a photosensitive member cartridge configured to be accommodated in an electrophotographic image forming apparatus. 
       BACKGROUND 
       [0003]    A known drum cartridge includes a photosensitive drum and is accommodated in an electrophotographic image forming apparatus. In the drum cartridge, a developing agent image is carried on a surface of the photosensitive drum during an image forming operation. The developing agent image is transferred on a recording medium. 
         [0004]    A known drum cartridge includes, for example, a cleaning unit configured to clean a surface of the photosensitive drum. In the drum cartridge, the cleaning unit includes a first cleaning roller configured to contact the surface of the photosensitive drum. As an image forming operation is started and the photosensitive drum rotates, the first cleaning roller collects paper powders or fibers on the photosensitive drum. 
       SUMMARY 
       [0005]    In a first example aspect, a drum cartridge includes a photosensitive drum rotatable about an axis extending in a first direction, and a first cleaning roller positioned to a side of the photosensitive drum and including a first shaft extending in the first direction. The drum cartridge further includes a bearing through which the first shaft is inserted and a pressing member configured to press the bearing toward the photosensitive drum. The drum cartridge further includes a lever positioned at an outer surface of the drum cartridge, the outer surface of the drum cartridge positioned toward the side of the photosensitive drum, the lever extendable in a second direction different from the first direction, the lever being pivotable with respect to the outer surface of the drum cartridge about a second axis extending in the first direction, the lever pivotable between an extended position and a retracted position. The drum cartridge further includes an engagement portion movable with pivoting of the lever between an engaged position when the lever is in the extended position and a disengaged position when the lever is in the retracted position. In the engaged position the engagement portion engages the bearing to position the first cleaning roller spaced apart from the photosensitive drum, and in the disengaged position the engagement portion disengages from the bearing and the first cleaning roller contacts the photosensitive drum. 
         [0006]    In a further example aspect, a method is includes pivoting a lever from an extended position to a retracted position, the lever extending from an outer surface at a side of a drum cartridge. The drum cartridge further includes a photosensitive drum, and a first cleaning roller positioned toward the side of the drum cartridge relative to the photosensitive drum and including a first shaft extending in the first direction. The drum cartridge includes a bearing through which the first shaft is inserted, and a pressing member configured to press the bearing toward the photosensitive drum. The drum cartridge further includes an engagement portion movable between an engaged position when the lever is in the extended position and a disengaged position when the lever is in the retracted position. In the engaged position, the engagement portion engages the bearing to position the first cleaning roller spaced apart from the photosensitive drum, and pivoting the lever from the extended position to the retracted position disengages the engagement portion from the bearing, allowing the first cleaning roller to contact the photosensitive drum. 
         [0007]    A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based. 
         [0008]    According to an aspect of the disclosure, when a recording medium gets caught between the cleaning member and the photosensitive member in a photosensitive member cartridge, a recording medium may be readily removed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Reference now is made to the following description taken in connection with the accompanying drawings. 
           [0010]      FIG. 1  is a sectional view of a printer in an illustrative embodiment according to one or more aspects of the disclosure. 
           [0011]      FIG. 2  is a rear view of a drum cartridge depicted in  FIG. 1 . 
           [0012]      FIG. 3  is a sectional view of the drum cartridge depicted in  FIG. 2  taken along a line A-A. 
           [0013]      FIG. 4  is a sectional view of a rear portion of the drum cartridge depicted in  FIG. 3 , illustrating a cover frame being removed from the drum cartridge. 
           [0014]      FIG. 5  is a perspective view of the drum cartridge depicted in  FIG. 2  when viewed from a rear left side, illustrating a state in which a lever is positioned in a first position. 
           [0015]      FIG. 6A  is a perspective view of a driving unit of the drum cartridge depicted in  FIG. 2  when viewed from a rear right side. 
           [0016]      FIG. 6B  is a plan view of the driving unit  60  of the drum cartridge as depicted in  FIG. 2 . 
           [0017]      FIG. 7  is a perspective view of a lever of the drum cartridge when viewed from a rear left side. 
           [0018]      FIG. 8A  is a side view of a photosensitive drum and a first cleaning roller of the drum cartridge as depicted in  FIG. 2 , illustrating a contact state in which a surface of the photosensitive drum contacts a surface of the first cleaning roller. 
           [0019]      FIG. 8B  is a side view of the photosensitive drum and the first cleaning roller of the drum cartridge as depicted in  FIG. 2 , illustrating a separate state in which a surface of the photosensitive drum is separated from a surface of the first cleaning roller. 
           [0020]      FIG. 9  is a perspective view of the drum cartridge depicted in  FIG. 2  when viewed from a rear left side, illustrating a state in which a lever is positioned in a second position. 
           [0021]      FIG. 10  is a sectional view of a rear portion of the drum cartridge depicted in  FIG. 2 , illustrating a state in which a lever is positioned in a second position. 
           [0022]      FIG. 11A  is a sectional view of a rear portion of the drum cartridge depicted in  FIG. 2 , illustrating a state in which the lever in the second position contacts a main casing of the printer. 
           [0023]      FIG. 11B  is a sectional view of a rear portion of the drum cartridge depicted in  FIG. 2 , illustrating a state in which the lever in the first position after the lever contacts the main casing of the printer. 
           [0024]      FIG. 12A  is a side view of the lever of drum cartridge depicted in  FIG. 2  in a second illustrative embodiment according to one or more aspects of the disclosure. 
           [0025]      FIG. 12B  is a side view of the lever of drum cartridge depicted in  FIG. 2  in a third illustrative embodiment according to one or more aspects of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    In general, the present disclosure relates to a photosensitive drum cartridge usable in an electrophotographic image forming apparatus. In a known drum cartridge, when a recording medium gets caught between the first cleaning roller and the photosensitive drum, the recording medium may be difficult to be removed. More specifically, as an image forming operation is performed with a recording medium, for example, curved, the recording medium being fed may enter between the first cleaning roller and the photosensitive drum after passing through a transfer position of the photosensitive drum. In such case, the recording medium may be difficult to be removed. However, some embodiments of the disclosure address such issues by providing a drum cartridge in which a surface of the first cleaning roller can be spaced apart from a surface of the photosensitive drum when a lever pivots with respect to an outer surface of the drum cartridge. In the drum cartridge according to some aspects of the disclosure, a surface of the first cleaning roller can be spaced apart from a surface of the photosensitive drum when a lever pivots. For example, a lever pivoting with respect to an outer surface of the drum cartridge accommodates such movement of the first cleaning roller. In example embodiments, the lever can be positioned to interact with a surface of an image forming apparatus, to ensure engagement of the cleaning roller and photosensitive drum when the drum cartridge is installed in an image forming apparatus. 
       1. General Structure of Printer 
       [0027]    As depicted in  FIG. 1 , the printer  1  may be an electrophotographic monochrome printer. The printer  1  includes a main casing  2 , a process cartridge  3 , a scanner unit  4 , and a fixing unit  5 . In the description below, the right side of the sheet of  FIG. 1  is defined with reference to the front of the printer  1 , and the left of the sheet of  FIG. 1  is defined with reference to the rear of the printer  1 . The upper side of the sheet of  FIG. 1  is defined with reference to the top of the printer  1 , and the lower side of the sheet of  FIG. 1  is defined with reference to the bottom of the printer  1 . The left and right sides of the printer  1  are determined when viewed from the front side. More specifically, the front side of the sheet of  FIG. 1  is defined with reference to the left side of the printer  1 , and the rear side of the sheet of  FIG. 1  is defined with reference to the right side of the printer  1 . 
         [0028]    The main casing  2  has a generally box shape. The main casing  2  includes an opening portion  6 , a front cover  7 , a sheet supply tray  27 , and a sheet discharge tray  9 . 
         [0029]    The opening portion  6  is positioned at a front end portion of the main casing  2 . The opening portion  6  allows an interior and an exterior of the main casing  2  to communicate with each other in the front-rear direction. The opening portion  6  permits the process cartridge  3  to be passed therethrough. 
         [0030]    The front cover  7  is positioned at a front end portion of the main casing  2 . The front cover  7  has a generally flat plate shape. The front cover  7  extends in the top-bottom direction. The front cover  7  is pivotally supported about a lower end portion thereof by the front wall of the main casing  2 . The front cover  7  is configured to open or close the opening portion  6 . 
         [0031]    The sheet supply tray  8  is positioned at a bottom portion of the main casing  2 . The sheet supply tray  8  is configured to accommodate a recording medium, e.g., a sheet P. 
         [0032]    The sheet discharge tray  9  is positioned at the upper surface of the upper wall of the main casing  2 . The sheet discharge tray  9  is depressed downward from the upper surface of the main casing  2  for receiving the sheets P. 
         [0033]    The process cartridge  3  is accommodated in a generally central portion of the main casing  2  in the top-bottom direction. The process cartridge  3  is configured to be attached to or removed from the main casing  2 , via the opening portion  6 . The process cartridge  3  includes the drum cartridge  11  and a developing cartridge  30 . 
         [0034]    The drum cartridge  11  includes a photosensitive drum  13 , a scorotron charger  14 , a transfer roller  15 , a first cleaning roller  15 , a second cleaning roller  12 , a sponge scraper  23 , partition wall  24 , and a paper dust reservoir  26 . 
         [0035]    The photosensitive drum  13  has a generally tubular shape extending in the left-right direction. The photosensitive drum  13  is rotatably supported at a rear portion of the drum cartridge  11 . Each end portion of the photosensitive drum  13  in the left-right direction is rotatably supported by the drum cartridge  11 . 
         [0036]    The scorotron charger  14  is positioned above the photosensitive drum  13  with a space between the scorotron charger  14  and a surface of the photosensitive drum  13 . 
         [0037]    The transfer roller  15  has a generally tubular shape extending in the left-right direction. The transfer roller  15  is rotatably supported by the drum cartridge at a rear portion of the drum cartridge  11 . Each end portion of the transfer roller  15  in the left-right direction is rotatably supported by the drum cartridge  10 . The transfer roller  15  is disposed below the photosensitive drum  13 . An upper end portion of the transfer roller  15  (e.g., a surface of the transfer roller  15 ) is in contact with a lower end portion of the photosensitive drum  13  (e.g., a surface of the photosensitive drum  13 ). 
         [0038]    The first cleaning roller  16  has a generally tubular shape extending in the left-right direction. The first cleaning roller  16  is rotatably supported by the drum cartridge at a front end portion of the drum cartridge  11 . Each end portion of the first cleaning roller  16  in the left-right direction is rotatably supported by the drum cartridge. A lower front portion of the first cleaning roller  16  (e.g., a surface of the first cleaning roller  16 ) is in contact with an upper rear end portion of the photosensitive drum  13  (e.g., a surface of the photosensitive drum). 
         [0039]    The second cleaning roller  17  is rotatably supported by the drum cartridge at a front end portion of the drum cartridge  11 . Each end portion of the second cleaning roller  17  in the left-right direction is rotatably supported by the drum cartridge  11 . The second cleaning roller  17  is positioned at a rear side of the first cleaning roller  16 . A lower front end portion of the second cleaning roller  17  (e.g., a surface of the second cleaning roller  17 ) contacts an upper rear end portion of the first cleaning roller  16  (e.g., a surface of the first cleaning roller  16 ). 
         [0040]    The sponge scraper  23  is positioned at an upper rear portion of the drum cartridge  11 . More specifically, the sponge scraper  23  is positioned at an upper side of the second cleaning roller  17 . The sponge scraper  23  is in contact with an upper end portion of the second cleaning roller  17  (e.g., a surface of the second cleaning roller  17 ). 
         [0041]    The partition wall  24  is positioned at a lower rear portion of the drum cartridge  11 . More specifically, the partition wall  24  is positioned at a lower portion of the second cleaning roller  17  with a space between the partition wall  24  and a surface of the second cleaning roller  17 . The partition wall  24  has a generally flat plate shape. A film  25  is attached to an upper end portion of the partition wall  24 . The film  25  extends from an upper end portion of the partition wall  24  upwardly. An upper end of the film  25  is in contact with a lower end portion of the second cleaning roller  17  (e.g., a surface of the second cleaning roller  17 ). 
         [0042]    The paper dust reservoir  26  is positioned at a rear portion of the drum cartridge  11 . More specifically, the paper dust reservoir  26  is arranged at a rear side of the second cleaning roller  17 , the sponge scraper  23 , the partition wall  24 , and the film  25  in the drum cartridge  11 . 
         [0043]    The developing cartridge  30  is configured to be accommodated in the drum cartridge  11  in front of the photosensitive drum  13 . The developing cartridge  30  includes a developing roller  31 , a supply roller  32 , a layer thickness regulation blade  33 , and a toner chamber  34 . 
         [0044]    The developing roller  31  has a generally cylindrical shape extending in the left-right direction. The developing roller  31  is rotatably supported at a rear end portion of the developing cartridge  30 . A rear end portion of the developing roller  31  (e.g., a surface of the developing roller  31 ) is in contact with a front end portion of the photosensitive drum  13  (e.g., a surface of the photosensitive drum  13 ). 
         [0045]    The supply roller  32  has a generally cylindrical shape extending in the left-right direction. The supply roller  32  is rotatably supported at a rear end portion of the developing cartridge  30 . The supply roller  32  is positioned at a front lower portion of the developing roller  31 . An upper rear end portion of the supply roller  32  (e.g., a surface of the supply roller  32 ) contacts a lower front end portion the developing roller  31  (e.g., a surface of the developing roller  31 ). 
         [0046]    The layer thickness regulation blade  33  is positioned at front and upper side of the developing roller  31 . The layer thickness regulation blade  33  contacts a front end portion of the developing roller  31  (e.g., a surface of the developing roller  31 ). 
         [0047]    The toner chamber  34  is positioned at front side of the supply roller  32  and the layer thickness regulation blade  33 . The toner chamber  34  is configured to accommodate toner. The toner chamber  34  includes an agitator  35 . 
         [0048]    The agitator  35  is rotatably supported by the developing cartridge  30  in the toner chamber  34 . 
         [0049]    The scanner unit  4  is positioned upper side of the process cartridge  3 . The scanner unit  4  is configured to emit laser beam toward the photosensitive drum  13  based on image data. 
         [0050]    The fixing unit  5  is positioned rear side of the process cartridge  3 . The fixing unit  5  includes a heat roller  36  and a pressure roller  37  pressed against a lower end portion of the heat roller  36  (e.g., a surface of the heat roller  36 ). 
         [0051]    As the printer  1  starts an image forming operation, the scorotron charger  14  positively and uniformly charges a surface of the photosensitive drum  13 . The scanner unit  4  exposes the surface of the photosensitive drum  13  with light based on the image data. Thus, an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum  13 . 
         [0052]    The agitator  35  agitates the toner in the toner chamber  34  and supplies the toner to the supply roller  32 . The supply roller  32  supplies the toner supplied by the agitator  35  to the developing roller  31 . At this time, the toner is positively charged between the developing roller  31  and the supply roller  32  by friction, and is carried on the developing roller  31 . The layer thickness regulation blade  33  regulates the thickness of the toner layer carried on the developing roller  31  to a constant thickness. 
         [0053]    Then, the toner carried on the developing roller  31  is supplied to the electrostatic latent image on the surface of the photosensitive drum  13 . Thus, the toner image is carried on the surface of the photosensitive drum  13 . 
         [0054]    The sheets P are supplied one by one at a predetermined timing from the sheet supply tray  27  between the photosensitive drum  13  and the transfer roller  15 , with the rotation of various rollers. The toner image on the surface of the photosensitive drum  13  is transferred to the sheet P when the sheet P passes between the photosensitive drum  13  and the transfer roller  15 . 
         [0055]    Thereafter, heat and pressure are applied to the sheet P when the sheet P passes between the heat roller  36  and the pressure roller  37 . Thus, the toner image on the sheet P is thermally fixed on the sheet P. Thereafter, the sheet P is discharged onto the sheet discharge tray  9 . 
         [0056]    The first cleaning roller  16  and the second cleaning roller  17  are charged to a positive polarity greater than the potential of the surface of the photosensitive drum  13 . More specifically, the second cleaning roller  17  is charged to have a greater positive polarity than the first cleaning roller  16 . 
         [0057]    Paper powders or fibers attached to the photosensitive drum  13  are collected on the first cleaning roller  16  when the paper powders or fibers contact the first cleaning roller  16 . In other words, the first cleaning roller  16  cleans a surface of the photosensitive drum  13 . Paper powders or fibers collected on the first cleaning roller  16  are collected on the second cleaning roller  17  when the paper powders or fibers contact the second cleaning roller  17 . 
         [0058]    Thereafter, the paper powders or fibers collected on the second cleaning roller  17  are scraped by the sponge scraper  23  and stored in the paper dust reservoir  26 . 
       2. Details of Drum Cartridge 
       [0059]    As depicted in  FIGS. 2 and 3 , the drum cartridge  11  includes a base frame  20 , a cover frame  21 , and a cleaning unit  22 . The base frame  20  and the cover frame  21  are one of examples of a frame of the drum cartridge  11 . 
         [0060]    (1) Base Frame 
         [0061]    The base frame  20  has a generally rectangular shape in plane view. The base frame  20  has a bottomed frame shape. The base frame  20  is integrally provided with a pair of side walls  41 , a front wall  42 , a rear wall  43 , and a bottom wall  44 . 
         [0062]    Each side wall  41  is disposed at a respective end portion of the base frame  20  in the left-right direction. Each side wall  41  has a generally rectangular flat plate shape in side view. Each side wall  41  extends in the front-rear direction. 
         [0063]    The front wall  42  extends between front end portions of the side walls  41 . The front wall  42  has a generally rectangular flat plate shape in front view. The front wall  42  extends in the left-right direction. The front wall  42  includes a drum cartridge holding portion  45  (e.g., grip). 
         [0064]    The rear wall  43  extends between rear end portions of the side walls  41 . The rear wall  43  has a generally rectangular flat plate shape in front view. The rear wall  43  extends in the left-right direction. 
         [0065]    The bottom wall  44  extends between lower end portions of the side walls  41 , a lower end portion of the front wall  42  and a lower end portion of the rear wall  43 . The bottom wall  44  has a generally rectangular flat plate shape in plane view. The bottom wall  44  extends in the left-right direction. A rear end portion of the bottom wall  44  extends upward. 
         [0066]    A pair of lower guide ribs  46  is positioned at a rear portion of the bottom wall  44 . More specifically, each lower guide rib  46  protrudes upward from a respective end portion of a rear portion of the bottom wall  44  in the left-right direction. Each lower guide rib  46  has a generally rectangular plate shape in side view. The upper edge of each lower guide rib  46  serves as a lower guide portion  46 A. The lower guide portion  46 A of each lower guide rib  46  is inclined along a direction that connects the upper-rear side and the lower-front side when projected in the left-right direction. 
         [0067]    (2) Cover Frame 
         [0068]    The cover frame  21  has a generally rectangular plate shape in plane view. The cover frame  21  covers the upper end of a rear portion of the base frame  20 . The cover frame  21  includes a pair of upper guide ribs  47 . 
         [0069]    Each upper guide rib  47  is positioned at a respective end portion of a rear portion of the cover frame  21  in the left-right direction. Each upper guide rib  47  has a generally rectangular plate shape in side view. Each upper guide rib  47  extends downward from the cover frame  21 . The lower edge of each upper guide rib  47  serves as an upper guide portion  47 A. The upper guide portion  47 A of each upper guide rib  47  is inclined along a direction that connects the upper-rear side and the lower-front side when projected in the left-right direction. The upper guide portion  47 A of each upper guide rib  47  is positioned above the corresponding lower guide portion  46 A of each lower guide rib  46  with a space. The upper guide portion  47 A of each upper guide rib  47  and the corresponding lower guide portion  46 A of each lower guide rib  46  extend parallel to each other when projected in the left-right direction. 
         [0070]    The photosensitive drum  13  is positioned between the cover frame  21  and a rear portion of the base frame  20 . More specifically, the photosensitive drum  13  is accommodated by the cover frame  21  and a rear portion of the base frame  20 . 
         [0071]    As depicted in  FIG. 3 , the photosensitive drum  13  includes a drum shaft  3 A extending in the left-right direction, and a drum body  3 B having a generally tubular shape and covering an outer peripheral surface of the drum shaft  3 A. Each end portion of the drum shaft  3 A of the photosensitive drum  13  in the left-right direction is rotatably supported by the relevant side wall  41 , and the photosensitive drum  13  is configured to rotate about a first axis extending in the left-right direction. 
         [0072]    (3) Cleaning Unit 
         [0073]    The cleaning unit  22  is positioned between the cover frame  21  and a rear portion of the base frame  20 . More specifically, the cleaning unit  22  is positioned behind the photosensitive drum  13 . As depicted in  FIGS. 3 and 5 , the cleaning unit  22  includes the cleaning frame  50 , the first cleaning roller  16 , the second cleaning roller  17 , and a pair of bearings  51 . 
         [0074]    The cleaning frame  50  has a generally U-shape in side view. The cleaning frame  50  has a generally box shape extending in the left-right direction and a front end portion of the cleaning frame  50  is open. The cleaning frame  50  accommodates the first cleaning roller and the second cleaning roller rotatably. The sponge scraper  23 , the partition wall  24 , the film  25 , and the paper dust reservoir  26  is positioned in the cleaning frame  50  (not depicted). 
         [0075]    The first cleaning roller  16  is positioned at a front end portion of the cleaning frame  50 . The first cleaning roller  16  includes a first cleaning shaft  16 A and a first cleaning body  16 B. 
         [0076]    The first cleaning shaft  6 A has a generally cylindrical shape extending in the left-right direction. A diameter of the first cleaning shaft  6 A is smaller than a distance between the lower guide portion  46 A and the upper guide portion  47 A. As depicted in  FIG. 5 , each end portion of the first cleaning shaft  16 A in the left-right direction is exposed from a respective end portion of the cleaning frame  50  in the left-right direction. 
         [0077]    The first cleaning body  16 B covers a portion of the first cleaning shaft  16 A except each end portion of the first cleaning shaft  16 A in the left-right direction. A lower front portion of the first cleaning body  16 B (e.g., a surface of the first cleaning body  16 B) contacts an upper rear portion of the photosensitive drum  13  (e.g., a surface of the photosensitive drum  13 ). 
         [0078]    The second cleaning roller  17  is positioned at an upper rear portion of the first cleaning roller  16  in the cleaning frame  50 . The second cleaning roller  17  includes a second cleaning shaft  17 A and a second cleaning body  17 B. 
         [0079]    The second cleaning shaft  17 A has a generally cylindrical shape extending in the left-right direction. A diameter of the second cleaning shaft  17 A is smaller than a distance between the lower guide portion  46 A and the upper guide portion  47 A. As depicted in  FIG. 5 , each end portion of the second cleaning shaft  17 A in the left-right direction is exposed from a respective end portion of the cleaning frame  50  in the left-right direction. 
         [0080]    The second cleaning body  17 B covers a portion of the second cleaning shaft  17 A except each end portion of the second cleaning shaft  17 A in the left-right direction. A lower front portion of the second cleaning body  17 B (e.g., a surface of the second cleaning body  17 B) contacts an upper rear portion of the first cleaning body  16 B (e.g., a surface of the first cleaning body  16 B). 
         [0081]    As depicted in  FIGS. 3 and 4 , each bearing  51  is positioned at a respective end portion of the cleaning frame  50  in the left-right direction. More specifically, each bearing  51  is mounted on a respective end portion of the first cleaning shaft  16 A and a respective end portion of the second cleaning shaft  17 A. Each bearing  51  rotatably receives a respective end portion of the first cleaning shaft  16 A in the left-right direction and a respective end portion of the second cleaning shaft  17 A in the left-right direction. 
         [0082]    As depicted in  FIG. 6B , each bearing  51  includes a first holding member  52 , a second holding member  53 , and a bearing connecting member  54 . 
         [0083]    A depicted in  FIGS. 3 and 4 , the first holding member  52  of each bearing  51  is a generally cylindrical shape. The first holding member  52  of each bearing  51  rotatably holds a respective end portion of the first cleaning shaft  16 A in the left-right direction. As depicted in  FIG. 3 , the first holding member  52  of each bearing  51  is positioned between the lower guide portion  46 A of the respective lower guide rib  46  and the upper guide portion  47 A of the respective upper guide rib  47 . 
         [0084]    A depicted in  FIGS. 3 and 4 , the second holding member  53  of each bearing  51  is a generally cylindrical shape. The second holding member  53  of each bearing  51  rotatably holds a respective end portion of the second cleaning shaft  17 A in the left-right direction. As depicted in  FIG. 3 , the second holding member  53  of each bearing  51  is positioned between the lower guide portion  46 A of the respective lower guide rib  46  and the upper guide portion  47 A of the respective upper guide rib  47 . 
         [0085]    As depicted in  FIGS. 3 and 4 , the bearing connecting member  54  of each bearing  51  connects the first holding member  52  and the second holding member  54 . 
         [0086]    Therefore, the first cleaning roller  16  is configured to rotate about an axis line L 2  extending in the left-right direction. Furthermore, the second cleaning roller  17  is configured to rotate about an axis line L 3  extending in the left-right direction. Each bearing  51  keep a certain distance between the axis line L 2  and the axis line L 3 . 
         [0087]    As depicted in  FIG. 3 , the cleaning unit  22  is configured to move along the direction that connects the upper-rear side and the lower-front side, as the first holding member  52  and the second holding member  53  of each bearing  51  are guided by the lower guide portion  46 A of the respective lower guide ribs  46  and the upper guide portion  47 A of the respective upper guide ribs  47 . As depicted in  FIG. 4 , a pressing member, e.g., a spring  55 , is positioned a rear portion of each end portion of the cleaning unit  22  in the left-right direction. 
         [0088]    One end portion of each spring  55  is supported by an upper end portion of the rear wall  43 . The opposite end portion of each spring  75  is engaged with the respective second holding member  53  of each bearing  51 . Thus, each spring  55  is positioned in a compressed state between an upper end portion of the rear wall  43  and the respective bearing  51 . Each bearing  51  is constantly urged by the respective spring  55  toward a lower-front side. In other words, the cleaning unit  22  is constantly urged by the springs  55  toward a lower-front side. Thus, the first cleaning roller  16  is constantly pressed against the photosensitive drum  13  by the springs  55 . 
         [0089]    (4) Drive Unit 
         [0090]    As depicted in  FIGS. 6A and 6B , a drive unit  60  is disposed at the left side of the photosensitive drum  13 , the first cleaning roller  16 , and the second cleaning roller  17 . 
         [0091]    The drive unit  32  includes a gear holder  61 , a drum gear  62 , a first idle gear  63 , a second idle gear  64 , a slider  65 , a second cleaning gear  66 , and a first cleaning gear  67 . 
         [0092]    The gear holder  61  has a generally rectangular plate shape in side view. The gear holder  61  is configured to be attached to a rear end of the side walls  41 . The gear holder  61  is not described in the  FIG. 2-5 ,  FIG. 6B , and  FIG. 9A . As depicted in  FIG. 6A , the gear holder  61  includes a first boss  68  and a second boss  69 . The first boss protrudes toward the right direction from a center of a right surface of the gear holder  61 . The second boss  69  protrudes toward the right direction from a rear portion of a right surface of the gear holder  61 . The second boss  69  is positioned at rear side of the first boss  68  with a space between the first boss  68  and the second boss  69 . 
         [0093]    As depicted in  FIGS. 6A and 6B , the drum gear  62  has a generally cylindrical shape extending in the left-right direction. The drum gear  62  is connected to the left end of the drum shaft  13 A so as not to be rotatable relative to the drum shaft  13 A. 
         [0094]    The first idle gear  63  has a generally cylindrical shape extending in the left-right direction. The first idle gear  63  is connected to the first boss  68  of the gear holder  61  so as to be rotatable relative to the first boss  68 . A lower front portion of the first idle gear  63  meshes with an upper rear portion of the drum gear  96 . 
         [0095]    The second idle gear  64  has a generally cylindrical shape extending in the left-right direction. The second idle gear  64  includes a closed portion  64 A and a projection  64 B. 
         [0096]    The closed portion  64 A is positioned at left end portion of the second idle gear  64 . The closed portion  64 A has a generally disc shape in side view and closes a left end of the second idle gear  64 . 
         [0097]    The projection  64 B protrudes toward the right direction from a right surface of the closed portion  64 A. The projection  64 B has a generally rectangular cylinder shape. The projection  64 B extends along a diametric direction of the closed portion  64 A. 
         [0098]    A through hole  64 C penetrates through substantially centers of the closed portion  64 A and the projection  64 B in the left-right direction. The through hole  64 C has a generally circular shape in side view. 
         [0099]    The second idle gear  64  is connected to the second boss  69  of the gear holder  61  so as to be rotatable relative to the second boss  69 , by engaging the second boss  68  with the through hole  64 C. An upper end portion of the second idle gear  64  meshes with a lower end portion of the first idle gear  63 . 
         [0100]    The slider  65  has a generally cylindrical shape extending in the left-right direction. The slider  65  includes a left slide part  65 A and a right slide part  65 B. 
         [0101]    The left slide part  65 A is groove which is recessed rightward relative to a left surface of the slider  65  and extends along a diametric direction of the slider  65 . A width of the left slide part  65 A is slightly wider than a width of the projection  64 B of the second idle gear  64 . 
         [0102]    The right slide part  65 B is groove which is recessed leftward relative to a right surface of the slider  65  and extends along a diametric direction of the slider  65 . The right slide part  65 B extends in a direction perpendicular to a direction that the left slide part  65 A extends as viewed in the left-right direction. 
         [0103]    The left slide part  65 A engages with the projection  64 B of the second idle gear  64 . Therefore, the slider  65  can slide along the projection  64 B of the second idle gear  64 . 
         [0104]    The second cleaning gear  66  includes a gear portion  66 A, a circular plate  66 B, and a projection  66 C. 
         [0105]    The gear portion  66 A has a generally cylindrical shape extending in the left-right direction. The gear portion  66 A is connected to the left end of the second cleaning shaft  17 A so as not to be rotatable relative to the second cleaning shaft  17 A. 
         [0106]    The circular plate  66 B is positioned at a left end of the gear part  66 A. 
         [0107]    The circular plate  66 B has a generally circular shaped plate, and a circumference of the circular plate  66 B is larger than a circumference of the gear part  66 A. The circular plate  66 B closes the left end portion of the gear part  66 A. 
         [0108]    The projection  66 C protrudes toward the left direction from a left surface of the circular plate  66 B. The projection  66 C has a generally rectangular cylinder shape. The projection  66 C extends along a diametric direction of the circular plate  66 B. A width of the projection  66 C is slightly smaller than a width of the right slide part  65 B. The projection  66 C engages with the right slide part  65 B. Therefore, the slider  65  can slide along the projection  66 C of the second cleaning gear  66 . 
         [0109]    The first cleaning gear  67  has a generally cylindrical shape extending in the left-right direction. The first cleaning gear  67  is connected to the left end of the first cleaning shaft  16 A so as not to be rotatable relative to the first cleaning shaft  16 A. An upper end portion of the first cleaning gear  67  meshes with the gear part  66 A of the second cleaning gear  66 . 
         [0110]    An Oldham coupling  70  in the drive unit  60  is configured by the second idle gear  64 , the slider  65  and the cleaning gear  66 . 
         [0111]    (5) Lever 
         [0112]    Levers  80  are disposed at both end portions of the cleaning unit  22  in the left-right direction. One of the levers  80  is disposed at one end portion of the cleaning unit  22  in the left-right direction, and other of the levers  80  is disposed at other end portion of the cleaning unit  22  in the left-right direction. 
         [0113]    More specifically, as depicted in  FIG. 5 , the levers  80  are attached to both end portions of the rear wall  43  in the left-right direction corresponding to both end portions of the cleaning unit  22  in the left-right direction. In the description below, the levers  80  will be explained with reference to a state in which the release levers  80  are separated from the bearings  51 . 
         [0114]    As depicted in  FIG. 7 , each of the levers  80  includes a proximal portion  81 , a hook  82 , and a handle  83 . 
         [0115]    The proximal portion  81  has a generally obtuse triangular plate shape in side view. The proximal portion  81  has an obtuse-angled portion at its upper rear end in side view. The proximal portion  81  has an engagement hole  84 . 
         [0116]    The engagement hole  84  is defined in the obtuse-angled portion of the proximal portion  81  and has a circular shape in side view. The engagement hole  84  penetrates through the proximal portion  81 . 
         [0117]    The hook  82  is contiguous to a front end portion of the proximal portion  81  in side view. The hook  82  has a generally arc shape in side view. The hook  82  extends downward and curved in side view from a front end of the proximal portion  81 . The hook  62  includes a curved portion  82 A and a front edge portion  82 B. 
         [0118]    The curved portion  82 A a portion of the hook  82  from one end portion of the proximal portion  81  to approximately a front edge portion of the hook  82 . The curved portion  82 A has a generally arc shape in side view. An inner surface of the curved portion  82 A a holding portion  82 C. The holding portion  82 C has a shape following a shape of the second holding member  53 . 
         [0119]    The front edge portion  82 B is a front edge portion of the hook  82 . The front edge portion  82 B extends from a front edge of the curved portion  82 A along a tangential direction of the curved portion  82 A in side view. 
         [0120]    The handle  83  is contiguous to a rear end of the proximal portion  81  in side view. That is, the handle  83  is disposed at opposite side of the hook  82  with respect to the engagement hole  84 . The handle  83  has a generally rectangular plate shape in rear view. The handle  83  extends downwardly from other end portion of the proximal portion  81  in side view, and the handle  83  extends in a direction perpendicular to a direction that the proximal portion  81  extends. The handle  83  includes a plurality of first protrusions  83 A and a second protrusion  83 B. 
         [0121]    The plurality of first protrusions  83 A prevent the handle  83  from sipping, when an user operates the handle  83 . The plurality of first protrusions  83 A protrudes from a rear surface of the handle  83  and extends in the left-right direction. 
         [0122]    The second protrusion  83 B is disposed at down end portion of the rear surface of the handle  83 . The second protrusion  83 B protrudes from the rear surface of the handle  83  toward the rear direction. 
         [0123]    As depicted in  FIG. 3  and  FIG. 5 , engagement protrusions  90  are disposed at both end portions of rear wall  43  in the left-right direction. One engagement protrusion  90  is disposed at one end portion of rear wall  43  in left-right direction, and other engagement protrusion  90  is disposed at other end portion of rear wall  43  in left-right direction. 
         [0124]    The engagement protrusions  90  protrude from upper end portion of the rear wall  43  in the left-right direction and the engagement protrusions  90  are protrudes from both end portions of the rear wall  43  in the left-right direction. Each of the engagement protrusions  90  has a substantially a circular cylindrical shape extending in the left-right direction. A diameter of each of the engagement protrusions  90  is smaller than a diameter of the engagement hole  84 . 
         [0125]    The engagement hole  84  of each of the levers  80  engages with the respective engagement protrusions  90 . This configuration enables each of the release levers  80  to pivot about axis line L 4  extending in the left-right direction. Each of the levers  80  pivots clockwise about the axis line L 4  in left side view, and each of levers  80  can engage with the respective bearing  51  in a first position. 
         [0126]    On the other hand, each of the levers  80  pivots anticlockwise about the axis line L 4  in left side view, and an engagement of each of levers  80  and the respective bearing  51  can be released in a second position. 
         [0127]    As depicted in  FIG. 10 , the holding member  82 C of each of the levers  80  extends along the second holding member  53  of the respective bearing  51  in a state in which each of the levers  80  engages with the respective bearing  51 . 
       3. Driving of Driving Unit 
       [0128]    As depicted in  FIG. 1 , when the printer  1  starts to image forming movement, driving force is transmitted to the photosensitive drum  13  from a motor (not depicted) of the printer  1 , and the photosensitive drum  13  rotates about the axis line L 1  counterclockwise in left side view. 
         [0129]    As depicted in  FIGS. 6A and 6B , the drum gear  62  rotates clockwise in left side view with a rotation of the photosensitive drum  13 . 
         [0130]    The first idle gear  63  rotates anticlockwise in left side view with a rotation of the drum gear  62 , and the second idle gear  64  rotates clockwise in left side view with a rotation of the first idle gear  63 . 
         [0131]    The projection  64 B engages with the left slide part  65 A, and the slider  65  rotates clockwise in left side view with a rotation of the second idle gear  64 . 
         [0132]    The right slide part  65 B engages with the projection  66 C, and the second cleaning gear  66  rotates clockwise in left side view with a rotation of the slider  65 . And then, the first cleaning gear rotates anticlockwise in left side view. 
         [0133]    Therefore, the second cleaning roller  17  can rotates clockwise in left side view, and the first cleaning roller  16  can rotate anticlockwise in left side view. 
         [0134]    In some case, a position of the cleaning unit  22  (e.g., a position of the first cleaning roller  16  and a position of the second cleaning roller  17 ) is shifted in a direction perpendicular to the left-right direction. In other words, as depicted in  FIG. 3 , the axis line L 2  and the axis line L 3  are sifted in a direction perpendicular to the left-right direction. 
         [0135]    In this case, the projection  66 C slides along the right slide part  65 B with engaging the projection  66 C and the right slide part  65 B and/or the slider  65  slides along the projection  64 B with engaging the slider  65  and the projection  64 B. 
         [0136]    For this reason, even though the cleaning unit is shifted in a direction perpendicular to the left-right direction, in other words, the first cleaning roller  16  is shifted relative to the photosensitive drum  13 , the driving force can transmit sequentially the slider  65 , the second cleaning gear  66  and the first cleaning gear  67  from the second idle gear  64 . 
       4. Movement of Lever 
       [0137]    As depicted in  FIGS. 5 and 8A , when the printer  1  forms an image, each of the levers  80  does not engage with the respective bearing  51 . 
         [0138]    In this state, each handle  83  corresponding to each of the levers  80  is adjacent the rear wall  83  (e.g., each of the levers  80  extends along the real wall  83 ). Each hook  82  corresponding to each of the levers  80  is far away from the respective bearing  51 . 
         [0139]    Each of the bearings  51  is pressed toward the photosensitive drum  13  by pressing force of the respective spring  55 . That means that cleaning unit  22  is pressed toward the photosensitive drum  13  by pressing force of each of the springs  55 . And then, the first cleaning roller  16  contacts a surface of the photosensitive drum  13  and press a surface of the photosensitive drum  13  by constant pressing force. At this time, the first cleaning roller  16  is positioned at a contacting position. 
         [0140]    In this state, the photosensitive drum  13 , the first cleaning roller  16 , and the second cleaning roller  17  are arranged in a direction from the upper-rear side to the lower-front side. That means that the axis line L 1  of the photosensitive drum  13 , the axis line L 2  of the first cleaning roller  16 , and the axis line L 3  of the second cleaning roller  17  are arranged in a direction from the upper-rear side to the lower-front side. 
         [0141]    In the above-described image forming operation, when the sheet is, for example, curved, a leading end portion of the sheet P may enter between the photosensitive drum  13  and the first cleaning roller  16 , after passing the transfer position  13 C of the photosensitive drum  13 , as depicted in  FIG. 8A . In this case, an operator stops the image forming operation in the printer  1  and pulls or removes the sheet P from a portion between the photosensitive drum  13  and the first cleaning roller  16 . 
         [0142]    More specifically, an operator first removes the process cartridge  3  from the main casing  2 . Then, as represented by an arrow B in in  FIGS. 9 and 10 , the operator lifts up each handle  83 . 
         [0143]    When each handle  83  is lifted up, each of the levers  80  pivots clockwise about the axis line L 4  in left side view. And then, each hook  82  corresponding to each of the levers  80  engages with the respective bearings  51 . More specifically, each holding portion  82 C corresponding to each of the levers  80  engages with the respective second holding member  53  corresponding to each of the bearings  51 . 
         [0144]    As depicted in  FIG. 8B , each hook  82  of each of the levers  80  lift up the respective bearing  51  upward and rearward against the pressing force of the springs  55 . 
         [0145]    At this time, the bearings  51  of the cleaning unit  22  are guided by the lower guide portions  46 A of the corresponding lower guide ribs  46  and the upper guide portions  47 A of the corresponding upper guide ribs  47 , so that the cleaning unit  22  moves rearward and upwardly. As a result, the cleaning unit  22  is placed at a position where the cleaning unit  22  is separated from a surface of the photosensitive drum  13 . That means that a surface of the first cleaning roller  16  is separated from a surface of the photosensitive drum  13 . 
         [0146]    At this time, each engagement hole  84  corresponding to each of the levers  80 , each holding portion  82 C corresponding to each of the levers  80 , and each second holding member  53  corresponding to each of the bearing  51  are arranged in a direction that connects the upper-rear side and the lower-front side in side view. In other words, each engagement hole  84  corresponding to each of the levers  80 , each holding portion  82 C corresponding to each of the levers  80 , and each second holding member  53  corresponding to each of the bearing  51  are arranged in a pressing direction in which the springs  55  press. Each second holding member  53  presses the respective holding portion  82 C by the pressing force of the springs  55 . 
         [0147]    Therefore, a state in which each holding portion  82 C engages with the respective second holding member  53  keeps. 
         [0148]    In this state, the operator pulls the sheet P forwardly from the process cartridge  3 , and removes the sheet P from a portion between the photosensitive drum  13  and the first cleaning roller  16 . 
         [0149]    Thereafter, the operator presses each handle  83  corresponding to each of the levers  80  forwardly. 
         [0150]    When the operator presses each handle  83  corresponding to each of the levers  80  forwardly, as depicted in  FIG. 3 , each of the levers  80  pivots anticlockwise about the axis line L 4  in left side view. And then, an engagement each of the levers  80  and each of the bearings  51  is released. That means that each of the levers  80  does not engage with each of the bearings  51 . 
         [0151]    Alternatively, when the operator installs the process cartridge  3  in the main casing  2 , each of the levers  80  may be lifted up and each holding portion  82 C corresponding to each of the levers  80  may engage with each second holding member  53  corresponding to each of the bearings  51 . 
         [0152]    In this case, as depicted in  FIG. 11A , each second protrusion  83 B corresponding to each of the levers  80  can contact a contact portion  100  of the main casing  2 , when the operator installs the process cartridge  3  in the main casing  2 . 
         [0153]    And then, as represented by an arrow C in  FIG. 11A , the operators further moves the process cartridge  3  in the main casing  2 , each second protrusion  83 B corresponding to each of the levers  80  is pressed forwardly by contacting the contact portion  100 . 
         [0154]    Therefore, as represented by an arrow D in  FIG. 11A , each of the levers  80  pivots anticlockwise about the axis line L 4  in left side view. And then, an engagement each of the levers  80  and each of the bearings  51  is released. That means that each of the levers  80  does not engage with each of the bearings  51 . 
       5. Effects 
       [0155]    (1) In the drum cartridge  11 , as depicted in  FIG. 10 , the first cleaning roller  16  is configured to move between a contact position in which a surface of the first cleaning roller  16  contacts a surface of the photosensitive drum  13  and a separate position in which a surface of the first cleaning roller  16  is separated from a surface of the photosensitive drum  13 . Each of levers  80  engages with the respective bearings  51 , and each of levers  80  move the first cleaning roller  16  from the contact position to the separate position. Furthermore, an engagement each of the levers  80  and each of the bearings  51  is released, and then, the first cleaning roller  16  is moved from the separate position to the contact position. 
         [0156]    Therefore, when the sheet P gets caught between the first cleaning roller  16  and the photosensitive drum  13 , the first cleaning roller  16  is moved from the contact position to the separate position by operating each of the levers  80  and engaging each of the levers  80  with the respective bearings  51 , and the operator can removes the sheet P from a portion between the photosensitive drum  13  and the first cleaning roller  16 . 
         [0157]    (2) In the drum cartridge  11 , as depicted in  FIG. 10 , each of the levers  80  pivots about the axis line L 4  and each of the levers  80  is configured to move the first cleaning roller  16  between the contact position and the separate position. 
         [0158]    Therefore, each of the levers  80  can move the first cleaning roller  16  between the contact position and separate position smoothly. 
         [0159]    (3) In the drum cartridge  11 , as depicted in  FIG. 10 , when the operator operates the handle  83 , each of the levers  80  pivots about the engagement hole  84 . And then, each hook  82  engages with each of the bearings  51  or each hook  82  is released from an engagement with each of the bearings  51  with a pivoting of each of the levers  80 . 
         [0160]    Therefore, each of the levers  80  help the operator to engage each hook  82  and the each of the bearings  51  easily, and each of the levers  80  help the operator to release an engagement each hook  82  and the each of the bearings  5  easily. 
         [0161]    (4) In the drum cartridge  11 , as depicted in  FIG. 10 , each holding portion  82 C can keep an engagement state in which each of the levers  80  and the respective bearings  51 . 
         [0162]    Therefore, each holding portion  82 C can keep the first cleaning roller  16  in the separate position. 
         [0163]    Therefore, when the sheet P gets caught between the first cleaning roller  16  and the photosensitive drum  13 , it is much easier for the operator to remove the sheet P from a portion between the photosensitive drum  13  and the first cleaning roller  16  further easily. 
         [0164]    (5) In the drum cartridge  11 , as depicted in  FIG. 10 , each of the bearings engages with the each holding portion  82 C corresponding to each of the levers  80 , and the first cleaning roller  16  is held in the separate position. 
         [0165]    When an engagement each of the bearings  51  and each holding portion  82 C corresponding to each of the levers  80  is released, the first cleaning roller  15  is surely moved to the contact position by the pressing force of the springs  55 . 
         [0166]    (6) In the drum cartridge  11 , as depicted in  FIG. 10 , the base frame  2  includes the lower guide portions  46 A, and the cover frame  21  includes the upper guide portions  47 A. 
         [0167]    The lower guide portions  46 A and the upper guide portions  47 A extend along the pressing direction in which the springs  75  press the first cleaning roller  16 . The lower guide portions  46 A and the upper guide portions  47 A constitute guide portions configured to guide the movement of the first cleaning roller  16  between the contact position and the separate position. 
         [0168]    Therefore, the lower guide portions  46 A and the upper guide portions  47 A can smoothly move the first cleaning roller  16  between the contact position and the separate position. 
         [0169]    (7) In the drum cartridge  11 , as depicted in  FIG. 8A , each of the levers  80  includes the hook  82  having a generally arc shape in side view. Each hook  82  corresponding to each of the levers  80  engages with the respective bearing  51 . 
         [0170]    Therefore, each of the levers  80  is configured to engage with the respective bearing  51  easily. 
         [0171]    (8) In the drum cartridge  11 , as depicted in  FIG. 2 , one of the levers  80  is disposed at a left end portion of the cleaning unit  22  in the left-right direction, and other of the levers  80  is disposed at a right end portion of the cleaning unit  22  in the left-right direction. 
         [0172]    Therefore, each of the levers  80  can engage with the respective bearing  51 . 
         [0173]    Consequently, a surface of the first cleaning roller  16  can contact and/or separate a surface of the photosensitive drum  13  in a well-balanced state in the left-right direction. 
         [0174]    (9) In the drum cartridge  11 , as depicted in  FIG. 6A , the drive unit  60  includes the drum gear  62 , the first idle gear  63 , the second idle gear  64 , the slider  65 , the second cleaning gear  66 , and the first cleaning gear  67 . The Oldham coupling  70  is configured by the second idle gear  64 , the slider  65 , and the second cleaning gear  66 . 
         [0175]    Therefore, even though a position of the cleaning unit  22  is shifted (e.g., the first cleaning roller  16  is shifted relative to the photosensitive drum  13 ), the driving force can transmit from the drum gear  62  to the second cleaning gear  66  via the first idle gear  63 , the second idle gear  64 , and the slider  65 . 
         [0176]    Therefore, the first cleaning roller can be rotated stably. 
         [0177]    (10) In the drum cartridge  11 , as depicted in  FIG. 11A , each of the levers  80  includes the second protrusion  83 B. The second protrusion  83 B can contact a contact portion  100  of the main casing  2 , and then each of the levers  80  pivots anticlockwise about the axis line L 4  in left side view. When each of the levers  80  pivots anticlockwise about the axis line L 4  in left side view, the first cleaning roller is moved from the separation position to the contact position. 
         [0178]    Therefore, even though each of the levers  80  is lifted up and the first cleaning roller  16  is in the separate position when the operator installs the process cartridge  3  in the main casing  2 , the second protrusion  83 B can contact a contact portion  100  of the main casing  2 , and the first cleaning roller is moved from the separation position to the contact position. 
         [0179]    Consequently, a surface of the first cleaning roller  16  surely contacts a surface of the photosensitive drum  13 , when the process cartridge  3  is installed in the main casing  2 . 
       6. Second Illustrative Embodiment 
       [0180]    Referring to  FIG. 12A , the drum cartridge  11  according to a second illustrative embodiment will be described. Like reference numerals may be used for like corresponding components and a detailed description thereof with respect to the second illustrative embodiment may be omitted herein. 
         [0181]    In the first illustrative embodiment, as depicted in  FIG. 2 , each of the levers  80  is different component and each of the levers  80  is attached to the rear wall  43 . That means that each of the levers  80  can pivot respectively. On the other hand, in the second illustrative embodiment, each of the can pivot integrally. More specifically, the proximal portion  81  includes an attachment portion  201  instead of the engagement hole  84  at the obtuse-angled portion. The attachment portion  201  has a circular plate shape in side view. Each of the levers  80  is connected to a connecting portion  202 . 
         [0182]    The connecting portion  202  has a cylindrical shape extending in the left-right direction. A left end portion of the connecting portion  202  is connected to one lever  80  on the left side (hereinafter, is referred to as “left lever”). More specifically, a left end portion of the connecting portion  202  is connected to a right end portion of the attachment portion  201  in the left lever and rotates with pivoting of the left lever. A right end portion of the connecting portion  202  is connected to other lever  80  on the right side (hereinafter, is referred to as “right lever”). More specifically, a right end portion of the connecting portion  202  is connected to a left end portion of the attachment portion  201  in the right lever and rotates with pivoting of the right lever. 
         [0183]    Therefore, the left lever and the right lever is connected to the connecting portion  202  and the left lever and the right lever can pivot with a rotation of the connecting portion  202 . 
         [0184]    In the second illustrative embodiment, the drum cartridge  11  further includes the connecting portion  202  connecting the left lever and the right lever. 
         [0185]    Consequently, the left lever and the right lever can pivot with a rotation of the connecting portion  202 . When the operator operates at least one of the right lever and the left lever, both right lever and left lever can engage with the respective bearing  51  simultaneously. When the operator operates at least one of the right lever and the left lever, engaging both right lever and left lever with the respective bearing  51  can be released simultaneously. 
       6. Third Illustrative Embodiment 
       [0186]    Referring to  FIG. 12B , the drum cartridge  11  according to a third illustrative embodiment will be described. Like reference numerals may be used for like corresponding components and a detailed description thereof with respect to the third illustrative embodiment may be omitted herein. In the second illustrative embodiment, each of the levers  80  includes the handle  83  respectively, and each of the levers  80  is connected to the connecting portion  202 . 
         [0187]    In the third illustrative embodiment, the left lever includes the handle  83 , and the right lever does not include the handle  83 . In other words, only the left lever includes the handle  83 . 
         [0188]    In the third illustrative embodiment, when the operator operates the handle  83  of the left lever, the connecting portion  202  can rotate, and the right lever can pivot with a rotation of the connecting portion  202 . 
         [0189]    While the disclosure has been described in detail with reference to the specific embodiments thereof, this is merely an example, and various changes, arrangements and modifications may be applied therein without departing from the spirit and scope of the disclosure.