Patent Publication Number: US-9417602-B2

Title: Image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is continuation of U.S. patent application Ser. No. 14/663,065, filed Mar. 19, 2015, and further claims priority from Japanese point Patent Application No. 2014-074507, filed on Mar. 31, 2014, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Aspects described herein relate to an electrophotographic image forming apparatus, and more specifically, relates to an image forming apparatus including a process cartridge including a photosensitive body cartridge and a developing cartridge. 
     BACKGROUND 
     Known image forming apparatus include a process cartridge including a photosensitive body cartridge and a developing cartridge. In some image forming apparatus, the photosensitive body cartridge is configured to be attachable to and detachable from a main body of the image forming apparatus, and the developing cartridge is configured to be attachable to and detachable from the photosensitive body cartridge. 
     The photosensitive body cartridge includes a photosensitive drum to which a developing agent is supplied. The photosensitive drum is an example of a photosensitive body. The developing cartridge includes a developing roller for supplying a developing agent to a surface of the photosensitive drum. The main body of the image forming apparatus has an opening that is configured to open upward and enables the process cartridge, in which the developing cartridge is joined to the photosensitive body cartridge, to be attached to and detached from the main body. 
     SUMMARY 
     In the known image forming apparatus, in a case where a waste developing agent storage container for storing a developing agent collected from the surface of the photosensitive drum is disposed at the photosensitive body cartridge, the waste developing agent storage container may be forced to be disposed above and adjacent to the developing cartridge because there is no other space for placing the waste developing agent storage container. 
     Nevertheless, if the waste developing agent storage container is disposed above and adjacent to the developing cartridge, the waste developing agent storage container may obstruct attachment and detachment of the developing cartridge with respect to the photosensitive body cartridge. 
     According to one or more aspects of the disclosure, an image forming apparatus may include a main body and a process cartridge. The process cartridge may include a photosensitive body cartridge and a developing cartridge. The photosensitive body cartridge may include a photosensitive body configured to rotate on an axis and a waste developing agent storage container configured to store a developing agent collected from the photosensitive body. The developing cartridge may include a developing agent carrier configured to supply the developing agent to the photosensitive body. The photosensitive body may be configured to receive the developing cartridge such that the developing cartridge is attached to and detached from the photosensitive body cartridge through a particular space with respect to a direction orthogonal to the axis. The particular space may be defined in the main body. The process cartridge may be configured to pivot, with respect to the main body, between a first position, in which the waste developing agent storage container is positioned outside the particular space entirely, and a second position, in which the waste developing agent storage container at least partially occupies the particular space. 
     According to one or more other aspects of the disclosure, an image forming apparatus may include a main body having a main opening, a process cartridge, a feeding unit, a fixing unit, a discharge tray, and an exposing unit. The process cartridge may include a photosensitive body cartridge and a developing cartridge. The photosensitive body cartridge may include a photosensitive body configured to rotate on an axis. The developing cartridge may include a developing agent carrier configured to supply a developing agent to the photosensitive body. The photosensitive body cartridge may be configured to receive the developing cartridge such that the developing cartridge is attached to the photosensitive body cartridge in a particular direction and detached from the photosensitive body cartridge. The feeding unit may include a feed roller disposed below the process cartridge and a feed tray configured to support one or more recording sheets. The fixing unit may be disposed above the process cartridge. The discharge tray may be configured to support the one or more recoding sheets which have passed the fixing unit. The exposing unit may be disposed between the feed tray and the discharge tray in a vertical direction. The photosensitive body cartridge may include a waste developing agent storage container and a frame. The waste developing agent storage container may extend so as to cover an upper portion of the developing cartridge and may be configured to store therein the developing agent collected from a surface of the photosensitive body. The frame may have a cartridge opening through which the developing cartridge is attached to or detached from the photosensitive body cartridge. The cartridge opening may be defined in a portion upstream of the developing agent carrier in the particular direction. The developing cartridge may be configured to be attached to and detached from the photosensitive body cartridge via the main opening of the main body which is closed and exposed by the discharge tray. The process cartridge may be configured to pivot between a first position and a second position on another axis extending in parallel to the axis. When the process cartridge is located at the first position, the cartridge opening may face the main opening of the main body. When the process cartridge is located at the second position, the exposing unit may be allowed to expose the surface of the photosensitive body via the cartridge opening. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure, needs satisfied thereby, and the objects, features, and advantages thereof, reference now is made to the following descriptions taken in connection with the accompanying drawings. 
         FIG. 1  is a sectional view depicting a general configuration of a laser printer as an example of an image forming apparatus with its top cover opened in an illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 2  is a sectional view depicting the general configuration of the laser printer with its top cover closed in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 3  is a sectional view depicting the laser printer with its top cover opened in the illustrative embodiment according to one or more aspects of the disclosure, wherein a process cartridge is not positioned inside the laser printer. 
         FIG. 4  is a sectional view depicting the laser printer with its top cover closed in the illustrative embodiment according to one or more aspects of the disclosure, wherein the process cartridge is not positioned inside the laser printer. 
         FIG. 5  is a sectional view intersecting with an axial direction of a photosensitive drum, depicting the process cartridge that is removed from the laser printer and stands with foot portions in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 6A  is a sectional view intersecting with the axial direction, depicting a configuration of a photosensitive body cartridge constituting the process cartridge of  FIG. 5  in the illustrative embodiment according to one or more aspects of the disclosure 
         FIG. 6B  is a side view intersecting with the axial direction, depicting the photosensitive body cartridge in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 7  is a sectional view taken along line VII-VII of  FIG. 5  in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 8  is a plan view depicting a configuration of the developing cartridge depicted in  FIG. 1  in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 9  is a sectional view of the laser printer including an interlocking mechanism in a variation of the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 10A  is a sectional view intersecting with the axial direction, depicting a photosensitive body cartridge in a first variation of the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 10B  is a sectional view intersecting with the axial direction, depicting a photosensitive body cartridge in a second variation of the illustrative embodiment according to one or more aspects of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Illustrative embodiments will be described with reference to the accompanying drawings. The image forming apparatus according to one of the illustrative embodiments may be implemented by a laser printer  1  depicted in  FIGS. 1 and 2 . Hereinafter, referring to  FIGS. 1 and 2 , a general configuration of the laser printer  1  will be described. 
     In the description made below referring to  FIGS. 1 and 2 , with reference to the laser printer  1 , directions of up, down, right, left, front, and rear are defined with reference to an orientation of the laser printer  1  that is disposed in which it is intended to be used as depicted in  FIG. 1 . 
     &lt;General Configuration of Laser Printer&gt; 
     As depicted in  FIGS. 1 and 2 , the laser printer  1  includes a casing  2  and a top cover  21 . The casing  2  is an example of a main body. The top cover  21  is an example of a cover. The casing  2  has an opening A (as an example of a main opening) in its top. The top cover  21  is pivotably supported by an upper rear portion of the casing  2  via a rear end portion of the top cover  21 . The top cover  21  is capable of pivoting between an open position at which the top cover  21  opens relative to the top of the casing  2  and exposes the opening A (refer to  FIG. 1 ) and a closed position at which the top cover  21  closes the top of the casing  2  and cover the opening A (refer to  FIG. 2 ). 
     The laser printer  1  includes a feeding unit  3 , a scanner unit  4 , a process cartridge  5 , a transfer roller  62 , and a fixing unit  8  within the casing  2 . The feeding unit  3  feeds one or more sheets S (refer to  FIG. 2 ) therefrom. The sheet S is an example of a recording sheet. The scanner unit  4  is an example of an exposing unit. The transfer roller  62  transfers a toner image formed by the process cartridge  5 , onto a sheet S. The fixing unit  8  fixes a transferred toner image onto a sheet S by heat. 
     The feeding unit  3  is disposed in a lower portion of the casing  2 . The feeding unit  3  includes a feed tray  31 , a sheet pressing plate  32 , and a feeding mechanism  33 . The feeding mechanism  33  includes a feed roller  34 , a separation roller  35 , and a separation pad  36 . 
     As depicted in  FIG. 2 , one or more sheets S supported by the feed tray  31  are moved upward by the sheet pressing plate  32  and are fed curvedly upward, one by one, by the feeding mechanism  33  in a rear portion of the casing  2 . The fed sheet S is conveyed to between a photosensitive drum  61  and a transfer roller  62 . The photosensitive drum  61  is included in a photosensitive body cartridge  6  constituting the process cartridge  5 . The photosensitive drum  61  is an example of a photosensitive body. 
     The scanner unit  4  is disposed in front half of the casing  2  and in a middle portion of the casing  2  in an up-down direction. In other words, the scanner unit  4  is disposed between the feed tray  31  and a discharge tray  23  in the vertical direction. The scanner unit  4  includes a scanner body  41 , a supporting portion  42 , and a cover  43 . The scanner body  41  includes a laser emitting portion, a polygon mirror, lenses, and reflectors, which are not depicted. The supporting portion  42  supports the scanner body  41 . The cover  43  covers an upper portion of the scanner body  41 . 
     In the scanner unit  4 , the surface of the photosensitive drum  61  is exposed by high-speed scanning of a laser beam L (refer to  FIG. 2 ) emitted from the laser emitting portion of the scanner body  41  based on image data. 
     For inserting the process cartridge  5  to the casing  2 , the process cartridge  5  is inserted obliquely downward to the rear into the casing  2  via the opening A along an attaching/detaching path B while the top cover  21  is located at the open position to expose the opening A defined in the top of the casing  2  as depicted in  FIG. 1 . Thus, the process cartridge  5  is positioned behind the scanner unit  4  in the casing  2  (e.g., at an inserted position). For removing the process cartridge  5  from the casing  2 , the process cartridge  5  is pulled obliquely upward to the front from the inserted position. Meanwhile, the process cartridge  5  is moved along the attaching/detaching path B and thus removed out of the casing  2  via the opening A. 
     The process cartridge  5  includes the photosensitive body cartridge  6  and a developing cartridge  7 . The photosensitive body cartridge  6  is attachable to and detachable from the casing  2  via the opening A. The developing cartridge  7  is attachable to and detachable from the photosensitive body cartridge  6 . The photosensitive body cartridge  6  includes the photosensitive drum  61 , a charging roller  63 , and a waste toner storage container  64 . The photosensitive drum  61  is supplied with toner on its surface from the developing cartridge  7 . The toner is an example of a developing agent. The charging roller  63  charges the surface of the photosensitive drum  61  before toner is supplied onto the surface of the photosensitive drum  61 . The waste toner storage container  64  collects toner from the surface of the photosensitive drum  61  and stores the collected toner therein. The waste toner storage container  64  is an example of a waste developing agent storage container. 
     The photosensitive drum  61  includes a drum coupling C. The photosensitive drum  61  is configured to rotate on an axis X in response to receipt of driving force by the drum coupling C from a casing coupling  29  (refer to  FIGS. 3 and 4 ) disposed in the casing  2 . The waste toner storage container  64  has a thin box shape extending in a direction that the axis X of the photosensitive drum  61  extends (hereinafter, also referred to as “axial (X) direction”). The waste toner storage container  64  extends so as to cover an upper portion of the developing cartridge  7  when the process cartridge  5  is located at a second position. The waste toner storage container  64  includes a cleaning blade  64 A. The cleaning blade  64 A is in contact with the surface of the photosensitive drum  61  and collects toner from the surface of the photosensitive drum  61 . The waste toner storage container  64  is configured to store therein toner collected from the surface of the photosensitive drum  61  using the cleaning blade  64 A. The cleaning blade  64 A extends in the axial (X) direction. 
     The transfer roller  62  is rotatably supported inside the casing  2 . The transfer roller  62  transfers a toner image onto a sheet S from the surface of the photosensitive drum  61  while the sheet S passing between the photosensitive drum  61  and the transfer roller  62 . 
     The developing cartridge  7  includes a developing roller  71 , a supply roller  72 , a layer-thickness regulating blade  73 , a toner storage portion  74 , and an agitator  75 . The developing roller  71  supplies toner onto the surface of the photosensitive drum  61  from the supply roller  72 . The developing roller  71  is an example of a developing agent carrier. The supply roller  72  supplies toner onto the surface of the developing roller  71  from the toner storage portion  74 . The layer-thickness regulating blade  73  regulates a thickness of a toner layer held by the surface of the developing roller  71  to a certain thickness. The toner layer may be a layer of toner supplied to the surface of the developing roller  71  from the supply roller  72 . The toner storage portion  74  stores therein toner to be supplied. The agitator  75  agitates toner stored in the toner storage portion  74 . 
     The developing cartridge  7  having such a configuration is configured to be attached to and detached from the photosensitive body cartridge  6  through a particular space. The particular space is defined in the casing  2 . The developing cartridge  7  having such a configuration is configured to be solely removed out of the casing  2  via the opening A by pulling along the attaching/detaching path B. More specifically, the developing cartridge  7  is pulled obliquely upward to the front to detach the developing cartridge  7  from the photosensitive body cartridge  6  and is further moved along the attaching/detaching path B while the top cover  21  is located at the open position (refer to  FIG. 1 ) and exposes the opening A defined in the top of the casing  2 . The attaching/detaching path B indicated by a double-headed arrow in  FIG. 1  may be a common attaching/detaching path for the process cartridge  5 , the photosensitive body cartridge  6 , and the developing cartridge  7 . An attaching/detaching path Bd indicated by a double-dotted and dashed line in  FIG. 2  may be an attaching/detaching path for the developing cartridge  7 . The particular space has the attaching/detaching path Bd. 
     In the process cartridge  5 , the charging roller  63  charges the surface of the photosensitive drum  61  uniformly. Then, the surface of the photosensitive drum  61  is exposed by high-speed scanning of a laser beam L emitted from the scanner unit  4 , whereby an electrostatic latent image is formed on the surface of the photosensitive drum  61  based on image data. While toner stored in the toner storage portion  74  is agitated by the agitator  75 , toner is supplied onto the surface of the supply roller  72  and then further supplied onto the surface of the developing roller  71 . Then, toner passes between the surface of the developing roller  71  and the layer-thickness regulating blade  73  and becomes a thin toner layer on the surface of the developing roller  71 . 
     Toner carried by the surface of the developing roller  71  is further supplied onto the electrostatic latent image formed on the surface of the photosensitive drum  61  from the surface of the developing roller  71 . Thus, the electrostatic latent image becomes visualized and a toner image is formed on the surface of the photosensitive drum  61 . Then, while a sheet P passes between the photosensitive drum  61  and the transfer roller  62 , the toner image is transferred onto the sheet S from the surface of the photosensitive drum  61 . 
     Thereafter, the sheet S having the toner image transferred from the surface of the photosensitive drum  61  is further conveyed to the fixing unit  8  while the sheet S passes between the photosensitive drum  61  and the transfer roller  62 . The fixing unit  8  is disposed above the process cartridge  5 . The fixing unit  8  includes a heating roller  81  and a pressing roller  82  that convey the sheet S by pinching the sheet S therebetween. While the heating roller  81  and the pressing roller  82  pinch the sheet S therebetween, the pressing roller  82  applies pressure to the sheet S and the heating roller  81  applies heat to the sheet S using a heat source, such as a built-in halogen lamp. 
     While the sheet S passes between the heating roller  81  and the pressing roller  82  of the fixing unit  8 , the toner image transferred onto the sheet S is fixed by heat. The sheet S having the toner image fixed thereon by heat is further conveyed frontward from an upper rear portion of the casing  2  by the heating roller  81  and the pressing roller  82  while the sheet S is warped toward the front. Then, the sheet S is discharged onto a discharge tray  23  by discharge rollers  22 . The discharge tray  23  is defined at the top of the top cover  21 . 
     In such a laser printer  1 , the feeding unit  3  is disposed below the process cartridge  5 , and the fixing unit  8  and the discharge tray  23  are disposed above the process cartridge  5 . The laser printer  1  has a first conveying path and a second conveying path. The first conveying path guides a sheet S fed from the feed tray  31  curvedly upward at a rear portion of the laser printer  1  and further guides the sheet S toward the photosensitive drum  61  at the time of conveying the sheet S. The second conveying path bends the sheet S, which has passed the photosensitive drum  61 , toward the front and further guides the sheet S to the discharge tray  23  at the time of conveying the sheet S. As described above, the first conveying path and the second conveying path forms a C-shaped conveying route within the casing  2 . 
     &lt;Configuration of Guides in Process Cartridge&gt; 
     As depicted in  FIGS. 1, 2, 3, and 4 , the casing  2  includes first guides  25  and third guides  26  (for convenience in drawing, only one of the first guides  25  and one of the third guides  26  are depicted in  FIGS. 1, 2, 3, and 4 ). Each of the first guides  25  extends obliquely downward to the rear from a generally rear half section of the opening A. Each of the third guides  26  extends obliquely downward to the rear from a generally front half section of the opening A. The first guides  25  and the third guides  26  may be grooves. One of the first guides  25  and one of the third guides  26  are defined in an inner surface of one of sidewalls (e.g., right and left sidewalls) of the casing  2  and the other of the first guides  25  and the other of the third guides  26  are defined in an inner surface of the other of the sidewalls of the casing  2 . 
     The first guides  25  and the third guides  26  guide the process cartridge  5  for moving obliquely downward to the rear from the opening A (depicted in  FIG. 1 ) toward a first position at the time of attaching the process cartridge  5  to the casing  2 . The first guides  25  and the third guides  26  also guide the process cartridge  5  for moving obliquely upward to the front from the first position toward the opening A at the time of detaching the process cartridge  5  from the casing  2  via the opening A. 
     The process cartridge  5  includes first guided portions  65 G at respective ends in the axial (X) direction. When the process cartridge  5  is located at the first position, each of the first guided portion  65 G is located at a most downstream portion of a corresponding one of the first guides  25  in an attaching direction (as an example of a particular direction) of the process cartridge  5  to the casing  2 . The casing  2  includes the casing coupling  29  configured to transmit driving force to the photosensitive drum  61  of the process cartridge  5  located at the first position. The casing coupling  29  is disposed so as to face the drum coupling C of the photosensitive drum  61  in the axial (X) direction when the process cartridge  5  is located at the first position. The direction that the common attaching/detaching path B for the process cartridge  5  and the photosensitive body cartridge  6  with respect to the casing  2  may extend in a direction substantially the same as a direction that the first guides  25  and the third guides  26  extend. 
     Each of the first guides  25  has a relatively wide width throughout (e.g., from a front portion to a rear portion). Each of the third guides  26  extends obliquely downward toward the rear and has a funnel shape so as to be tapered toward the bottom from the top. Lower rear portions of the third guides  26  have a width narrower than the width of any portions of the first guides  25 . 
     The casing  2  further includes arc-shaped second guides  27  for guiding a movement of the process cartridge  5  at the time of pivoting the process cartridge  5  between the first position (refer to  FIG. 1 ) and the second position (refer to  FIG. 2 ) (for convenience in drawing, only one of the second guides  27  is depicted in  FIGS. 1, 2, 3, and 4 ). One of the second guides  27  is defined in the inner surface of the one of the sidewalls of the casing  2  and the other of the second guides  28  is defined in the inner surface of the other of the sidewalls of the casing  2 . As depicted in  FIGS. 3 and 4 , each of the second guides  27  has a relatively narrow width and extends downward from a rear end of a corresponding one of the third guides  26 . 
     Each of the second guides  27  has an arc shape which is a portion of a circle having the center through which the axis X of the photosensitive drum  61  passes. The photosensitive body cartridge  6  includes second guided portions  65 H at respective ends in the axial (X) direction. When the photosensitive body cartridge  6  is located at the second position, each of the second guided portions  65 H of the photosensitive body cartridge  6  is located at a lower end portion of a corresponding one of the second guides  27 . The scanner unit  4  exposes the surface of the photosensitive drum  61  by emitting a laser beam L such that the laser beam L travels in a space between the waste toner storage container  64  and the developing cartridge  7  when the process cartridge  5  is located at the second position. 
     &lt;Configuration of Interlocking Mechanism&gt; 
     An interlocking gear mechanism  9  is disposed within the casing  2  as depicted in  FIGS. 3 and 4 . The interlocking gear mechanism  9  functions as an interlocking mechanism for pivoting the process cartridge  5  between the first position (refer to  FIG. 1 ) and the second position (refer to  FIG. 2 ) in response to opening or closing of the top cover  21 . 
     The interlocking gear mechanism  9  includes a sector gear  91 , an intermediate gear  92 , a partially toothed gear  93 , and a fork arm  94  at each side inside the casing  2  in a right-left direction. The same components have the same configuration and features, and therefore, a description will be made on one of the same components. The sector gear  91  is a driving gear and is integrally disposed at a rear end portion of the top cover  21 . The intermediate gear  92  is rotatably supported by the casing  2  in mesh with the sector gear  91 . The partially toothed gear  93  is a driven gear and is rotatably supported by the casing  2  in mesh with the intermediate gear  92 . The fork arm  94  is integral with the partially toothed gear  93  and extends from a missing tooth portion of the partially toothed gear  93 . The fork arm  94  includes a two-pronged fork portion  95  at its distal end. 
     When the top cover  21  is located at the open position (refer to  FIG. 3 ), the interlocking gear mechanism  9  enables the fork arm  94  to extend frontward in substantially the horizontal direction such that the fork portion  95  of the fork arm  94  is positioned at an upper end portion of the arc-shaped second guide  27 . In response to pivoting of the top cover  21  on a pivot  24  to the closed position (refer to  FIG. 4 ), the sector gear  91  rotate along with the top cover  21  on the pivot  24 , whereby the fork arm  94  pivots downward so as to extend obliquely downward to the front. Meanwhile, the fork portion  95 , which is the distal end portion of the fork arm  94 , moves to the lower end portion of the second guide  27  along the arc-shaped second guide  27 . 
     &lt;Detailed Configuration of Photosensitive Body Cartridge&gt; 
     As depicted in  FIG. 5 , the photosensitive body cartridge  6  includes the photosensitive drum  61 , a frame  65 , and foot portions  66 . The frame  65  supports the photosensitive drum  61  so as to be rotatable. As depicted in  FIG. 7 , the photosensitive drum  61  includes a drum body  61 A, a first flange  61 B, and a second flange  61 C. 
     The first flange  61 B is fixedly attached to one end of the drum body  61 A in the axial (X) direction and the second flange  61 C is fixedly attached to the other end of the drum body  61 A in the axial (X) direction. The first flange  61 B and the second flange  61 C rotate integrally with the drum body  61 A on the axis X. The first flange  61 B includes a shaft portion  61 D and the second flange  61 C includes a shaft portion  61 E. 
     As depicted in  FIG. 7 , the first flange  61 B includes the shaft portion  61 D, a body portion BB, the drum coupling C, and a drum gear DG. The body portion BB has a diameter larger than the shaft portion  61 D and is positioned inside the drum body  61 A. The drum coupling C is configured to engage the casing coupling  29  to drive the photosensitive drum  61 . The drum coupling C is disposed at a distal end portion of the shaft portion  61 D. The drum coupling C includes a plurality of, for example, two, protrusions facing across the axis X. The drum gear DG is provided at a portion of a peripheral surface of the body portion BB closer to the shaft portion  61 D. The drum gear DG transmits driving force, which is inputted into the first flange  61 B from the casing coupling  29  via the drum coupling C, to the developing roller  71  and the charging roller  63 . 
     As depicted in  FIG. 5 , the frame  65  has an opening  65 A for exposing a portion of the surface of the photosensitive drum  61 . The opening  65 A may be a long narrow opening extending along the axis X of the photosensitive drum  61  in the frame  65 . The foot portions  66  protrude relative to one (e.g., a lower surface when the process cartridge  5  stands vertically) of peripheral surfaces of the photosensitive drum  61 . The foot portions  66  are disposed facing across the opening  65 A. The foot portions  66  enable the process cartridge  5  to stand vertically while the photosensitive drum  61  is positioned at a lower portion of the frame  65  as depicted in  FIG. 5  after the process cartridge  5  is removed out of the casing  2  via the opening A along the attaching/detaching path B of  FIG. 1 . 
     The frame  65  of the photosensitive body cartridge  6  includes a lower wall  65 B, sidewalls  65 C, and attachment/detachment guides  65 D. The lower wall  65 B extends along the axial (X) direction while facing the waste toner storage container  64 . The sidewalls  65 C connect the waste toner storage container  64  and the lower wall  65 B to each other near the end portions of the photosensitive drum  61 . The attachment/detachment guides  65 D are defined in the respective sidewalls  65 C. The photosensitive body cartridge  6  accommodates the developing cartridge  7  in a space defined therein by the waste toner storage container  64 , the lower wall  65 B, and the sidewalls  65 C. In a state where the process cartridge  5  is located at the second position (refer to  FIG. 2 ) while the developing cartridge  7  is positioned (e.g., accommodated) within the photosensitive body cartridge  6 , the lower wall  65 B is positioned opposite to the waste toner storage container  64  across the developing cartridge  7  in the vertical direction. The photosensitive drum cartridge  6  has an opening  65 E (as an example of a cartridge opening). The opening  65 E is defined by a front edge of the waste toner storage container  64 , a front edge of the lower wall  65 B, and front edges of the sidewalls  65 C. The opening  65 E is an example of attachment/detachment opening. The developing cartridge  7  is attached to or detached from the photosensitive body cartridge  6  via the opening  65 E. The opening  65 E is defined in a position opposite to the photosensitive drum  61  across the developing cartridge  7  in a front-rear direction. 
     The attachment/detachment guides  65 D guide respective end portions of a shaft  71 A of the developing roller  71  of the developing cartridge  7  at the time of attaching or detaching the developing cartridge  7  with respect to the photosensitive body cartridge  6 . The attachment/detachment guides  65 D are defined in the inner surfaces of the respective sidewalls  65 C (for convenience in drawing, only one of the attachment/detachment guides  65 D is depicted in  FIG. 6A .). Each of the attachment/detachment guides  65 D includes a first portion  65 D 1  and a second portion  65 D 2 . The first portion  65 D 1  extends in the front-rear direction when the process cartridge  5  is located at the second position. The second portion  65 D 2  extends obliquely upward toward the rear from the first portion  65 D 1  when the process cartridge  5  is located at the second position. 
     The direction that second portion  65 D 2  extends when the process cartridge  5  is located at the second position is substantially the same as a direction that pressing portions  10  press the developing cartridge  7  toward the photosensitive drum  61 . The direction that the first portion  65 D 1  extends when the process cartridge  5  is located at the first position is substantially the same as a direction that the first guides  25  and the third guides  26  extend. 
     The lower wall  65 B of the frame  65  has slits  65 F that allow the respective pressing portions  10  (only one of the pressing portions  10  is depicted in  FIG. 6A ) to pass through the lower wall  65 B. As depicted in  FIG. 7 , the slits  65 F are defined at respective end portions of the frame  65  in a direction that longer sides of the frame  65  extend (hereinafter, referred to as “elongated direction of the frame  65 ”). 
     The waste toner storage container  64  includes a handle  67  used for attaching and detaching the photosensitive body cartridge  6  alone or the process cartridge  5  with respect to the casing  2 . The handle  67  extends from one of ends of the waste toner storage container  64 , which is the end disposed on the same side as the end of the frame  65  in which the opening  65 E is defined. In a state where the process cartridge  5  is located at the first position (refer to  FIG. 1 ) and the top cover  21  is located at the open position (refer to  FIG. 1 ), the handle  67  extends from the waste toner storage container  64  toward the opening A of the casing  2 . In a state where the process cartridge  5  is located at the second position (refer to  FIG. 2 ) and the top cover  21  is located at the closed position (refer to  FIG. 2 ), the handle  67  is positioned closer to the opening A (refer to  FIG. 1 ) of the casing  2  than an optical path of a laser beam L. 
     As depicted in  FIGS. 6B and 7 , each of the sidewalls  65 C, which define respective ends of the frame  65  in the elongated direction of the frame  65 , includes a first guided portion  65 G and a second guided portion  65 H. One of the first guided portions  65 G protrudes from an outer surface of one of the sidewalls  65 C along the axial (X) direction, and the other of the first guided portions  65 G protrudes from an outer surface of the other of the sidewalls  65 C along the axial (X) direction. As depicted in  FIG. 7 , the shaft portion  61 D of the first flange  61 B and the shaft portion  61 E of the second flange  61 C, which are disposed at the respective ends of the photosensitive drum  61  in the axial (X) direction, are in engagement with the corresponding first guided portions  65 G so as to be rotatable. Each of the first guided portions  65 G may be a hollow cylindrical protrusion having the axis X of the photosensitive drum  61  as its center. As depicted in  FIGS. 1 and 3 , the first guided portions  65 G are guided along the respective first guides  25  at the time of attaching or detaching the photosensitive drum  6  alone or the process cartridge  5  with respect to the casing  2 . 
     As depicted in  FIG. 7 , one of the second guided portions  65 H protrudes from an outer surface of the one of the sidewalls  65 C along the axial (X) direction and the other of the second guided portions  65 H protrudes from the outer surface of the other of the sidewalls  65 C along the axial (X) direction. As depicted in  FIG. 6B , each of the second guided portions  65 H is disposed at a lower end portion of the corresponding one of the sidewalls  65 C of the frame  65  closer to the handle  67 . As depicted in  FIGS. 1 and 3 , each of the second guided portion  65 H is guided along a corresponding one of the third guides  26  and a corresponding one of the second guides  27  at the time of attaching or detaching the photosensitive body cartridge  6  alone or the process cartridge  5  with respect to the casing  2 . 
     &lt;Detailed Configuration of Pressing Portions&gt; 
     Each of the pressing portions  10  includes a support pin  11 , a pivot lever  12 , and a spring member  13  (only one of the pressing portions  10  is depicted in  FIG. 6A ) Both of the pressing portions  10  have the same configuration and features, and therefore, a description will be made on one of the pressing portions  10 . The support pin  11  extends along the axial (X) direction. The pivot lever  12  is supported so as to be pivotable on the support pin  11 . The spring member  13  urges counterclockwise the pivot lever  12  of which distal end directs obliquely upward toward the front. The pressing portions  10  press the developing cartridge  7  toward the photosensitive drum  61 . As depicted in  FIGS. 1 and 3 , the pressing portions  10  are disposed within the casing  2  and above the feeding mechanism  33  of the feeding unit  3 . 
     &lt;Detailed Configuration of Developing Cartridge&gt; 
     As depicted in  FIG. 5 , the developing cartridge  7  includes a frame  76  and a developing roller gear RG. The frame  76  of the developing cartridge  7  may be a casing extending in a direction that an axis Xd of the developing roller  71  extends (hereinafter, also referred to as “axial (Xd) direction”). The frame  76  of the developing cartridge  7  includes a handle  78  protruding relative to the opening  65 E of the frame  65  of the photosensitive body cartridge  6  in a state where the developing cartridge  7  is joined to the photosensitive body cartridge  6 . The handle  78  is used at the time of attaching or detaching the developing cartridge  7  with respect to the photosensitive body cartridge  6 . The frame  76  of the developing cartridge  7  further includes auxiliary pressing portions  79 . The auxiliary pressing portions  79  press the developing roller  71  against the photosensitive drum  61  of the photosensitive body cartridge  6 . As depicted in  FIG. 8 , the auxiliary pressing portions  79  protrude from outer surfaces of respective sidewalls  76 A of the frame  76  of the developing cartridge  7  along the axial (Xd) direction. The auxiliary pressing portions  79  have a circular shape in cross section. 
     The developing roller  71  includes a shaft  71 A that extends along the axial (Xd) direction while having the axis Xd as its center. End portions of the shaft  71 A in the axial (Xd) direction protrude beyond the frame  76  of the developing cartridge  7 . The developing roller gear RG is fixed to one of the end portions of the shaft  71 A. The developing roller gear RG is configured to mesh with the drum gear DG in a state where the developing cartridge  7  is joined to the photosensitive body cartridge  6 . The developing roller gear RG rotates the developing roller  71  upon receipt of driving force from the drum gear DG. The supply roller  72  and the agitator  75  are configured to rotate by input of driving force into the developing roller gear RG. 
     The auxiliary pressing portions  79  are disposed so as to come into engagement with the pivot levers  12  of the respective pressing portions  10  that are configured to enter the respective slits  65 F of the frame  65  as depicted in  FIG. 6A . As depicted in  FIG. 2 , the auxiliary pressing portions  79  are pressed obliquely upward toward the rear while being in engagement with the respective pivot levers  12 , thereby pressing the developing roller  71  against the photosensitive drum  61 . 
     In the laser printer  1  having the above-described configuration, when the top cover  21  is located at the open position where the top cover  21  exposes the opening A of the casing  2  (refer to  FIG. 3 ), the fork portion  95  of each of the fork arms  94  constituting the interlocking gear mechanism  9  is located at the upper end portion of the corresponding second guide  27  defined in one of the inner surfaces of the sidewalls of the casing  2 . In this state, the photosensitive body cartridge  6  of the process cartridge  5  is inserted into the casing  2  obliquely downward toward the rear along the attaching/detaching path B via the opening A of the casing  2 . During the insertion of the photosensitive body cartridge  6 , the first guided portions  65 G (refer to  FIG. 6B ) of the photosensitive body cartridge  6  are guided by the respective first guides  25  defined in the inner surfaces of the respective sidewalls of the casing  2  and the second guided portions  65 H (refer to  FIG. 6B ) of the photosensitive body cartridge  6  are guided by the respective third guide  26  defined in the inner surfaces of the respective sidewalls of the casing  2 . Thus, the process cartridge  5  is moved to the first position (refer to  FIG. 1 ) smoothly. 
     When the process cartridge  5  is located at the first position (refer to  FIG. 1 ), the waste toner storage container  64  of the photosensitive body cartridge  6  is positioned out of the attaching/detaching path Bd for the developing cartridge  7  (e.g., above the attaching/detaching path Bd) and the opening  65 E of the photosensitive body cartridge  6  is positioned on the attaching/detaching path Bd. In other words, the opening  65 E faces the opening A of the casing  2 . Therefore, when the process cartridge  5  is located at the first position (refer to  FIG. 1 ), the developing cartridge  7  may be detached from the casing  2  via the opening A along the attaching/detaching path Bd smoothly. When the process cartridge  5  is located at the first position (refer to  FIG. 1 ), the developing cartridge  7  is positioned so as to obstruct a laser beam L emitted from the scanner body  41  of the scanner unit  4  and the waste toner storage container  64  traverses a portion of the conveying path extending from the photosensitive drum  61  to the fixing unit  8 . 
     When the process cartridge  5  is located at the first position (refer to  FIG. 1 ), the fork portion  95  of each of the fork arms  94  of the interlocking gear mechanism  9  is positioned at the upper end portion of the corresponding second guide  27  of the casing  2  and each of the second guided portion  65 H of the photosensitive body cartridge  6  is in engagement with a recessed portion of a corresponding one of the fork portions  95 . Under this state, the top cover  21  is pivoted to the closed position (refer to  FIG. 2 ). In response to this, each fork portion  95  that is in engagement with the corresponding one of the second guided portions  65 H of the photosensitive body cartridge  6  moves to the lower end portion of the corresponding one of the second guides  27  along the curve of the second guide  27 , and the process cartridge  5  pivots on the axis X of the photosensitive drum  61  extending the centers of the shaft portions  61 D and  61 E that are rotatably in engagement with the respective first guided portions  65 G of the photosensitive body cartridge  6 . Thus, the process cartridge  5  is located at the second position (refer to  FIG. 2 ). 
     As described above, when the process cartridge  5  is located at the second position (refer to  FIG. 2 ), the waste toner storage container  64  of the photosensitive body cartridge  6  is positioned above the attaching/detaching path Bd for the developing cartridge  7  and the opening  65 E of the photosensitive body cartridge  6  is not positioned on the attaching/detaching path Bd. Under this situation, the waste toner storage container  64  of the photosensitive body cartridge  6  and the developing cartridge  7  are located at respective positions such that the waste toner storage container  64  and the developing cartridge  7  allow a laser beam L emitted from the scanner body  41  of the scanner unit  4  to travel in the space therebetween toward the photosensitive drum  61 . In other words, when the process cartridge  5  is located at the second position, the scanner unit  4  is able to expose the surface of the photosensitive drum  61  via the opening  65 E of the photosensitive body cartridge  6 . Thus, the process cartridge  5  becomes enabled to transfer a toner image onto a sheet S. 
     That is, according to the illustrative embodiment, in the laser printer  1 , the process cartridge  5  is supported by the casing  2  so as to be pivotable between the first position and the second position along with the waste toner storage container  64  of the photosensitive body cartridge  6 . When the process cartridge  5  is located at the first position, the waste toner storage container  64  of photosensitive body cartridge  6  is positioned out of the attaching/detaching path Bd for the developing cartridge  7 . Therefore, the waste toner storage container  64  may be positioned without obstructing the attachment and detachment of the developing cartridge  7 . 
     The description has been made as to the laser printer  1  as the example of the image forming apparatus according to the illustrative embodiment. Nevertheless, the image forming apparatus is not limited to the laser printer  1  according to the illustrative embodiment, and the configuration of the laser printer  1  may be changed or modified appropriately. For example, in other embodiments, the process cartridge  5  may include a photosensitive body unit that may be configured not to be attached to and detached from the casing  2  easily. 
     In other embodiments, for example, an interlocking mechanism  100  depicted in  FIG. 9  may be adopted for pivoting the process cartridge  5  between the first position (refer to  FIG. 1 ) and the second position (refer to  FIG. 2 ) in response to opening or closing of the top cover  21 . 
     As depicted in  FIG. 9 , the interlocking mechanism  100  includes a fork arm  102  and a pressure spring  103  at each side inside the casing  2  in the right-left direction, as a mechanism for urging the process cartridge  5  to the first position (refer to  FIG. 1 ). The same components have the same configuration and features, and therefore, a description will be made on one of the same components. The fork arm  102  includes a fork portion  101  at its distal end similar to the fork portion  95  depicted in  FIG. 3 . The pressure spring  103  urges the fork arm  102  upward such that the fork portion  101  is retained at the upper end portion of the second guide  27 . The top cover  21  includes an inclined pressing surface  104  at its inner surface. The inclined pressing surface  104  functions as a mechanism for pressing the process cartridge  5  to the second position (refer to  FIG. 2 ) and is engageable with the tip end of the handle  67  of the photosensitive body cartridge  6  of  FIG. 1 . 
     According to the interlocking mechanism  100 , in response to pivoting of the top cover  21  to the closed position, the inclined pressing surface  104  of the top cover  21  presses the distal end portion of the handle  67  of the photosensitive body cartridge  6  (refer to  FIG. 1 ) downward on the route to the closed position. With this pressing by the inclined pressing surface  104 , the process cartridge  5  is pressed downward to the second position (refer to  FIG. 2 ). In response to pivoting of the top cover  21  to the open position, each of the fork arm  102  pivots upward by upward urging force from the corresponding one of the pressure springs  103  and thus each of the fork portions  101  of the form arms  102  is located at the upper end portion of the corresponding one of the second guides  27 . In response to this, the process cartridge  5  pivots to the first position (refer to  FIG. 1 ) while the second guided portions  65 H of the photosensitive body cartridge  6  engaged in the respective fork portions  101  move upward to the upper end portions of the respective second guides  27 . 
     In other embodiments, for example, as depicted in  FIG. 10A , the frame  65  of the photosensitive body cartridge  6  may have no lower wall and a lower portion of the frame  65  may be opened. In this case, the developing cartridge  7  may be attached to and detached from the photosensitive body cartridge  6  via the opening  65 E that is defined by the front edges of the sidewalls  65 C and the front edge of the waste toner storage container  64 . 
     In other embodiments, for example, as depicted in  FIG. 10B , the frame  65  may include an intermediate wall  65 J for positioning the developing cartridge (not depicted) between the lower wall  65 B and the intermediate wall  65 J and the right and left sidewalls of the frame  65  may be cut out largely from the opening  65 E. In this case, the developing cartridge  7  may be attached to and detached from the photosensitive body cartridge  6  via the opening  65 E that is defined by the front edge of the lower wall  65 B and the front edge of the waste toner storage container  64 . 
     An entire portion of the opening  65 E might not necessarily be enclosed by one or more edges entirely. That is, the one or more edges defining the opening  65 E might not necessarily connect with each other. In an example depicted in  FIG. 10B , a laser beam L entering the photosensitive body cartridge  6  via the opening  65 E may travel in a space between the intermediate wall  65 J and the waste toner storage container  64  and irradiates the surface of the photosensitive drum  61 . 
     In other embodiments, for example, the process cartridge  5  may be a process cartridge of noncontact developing type in which the developing roller  71  of the developing cartridge  7  is not in contact with the surface of the photosensitive drum  61  of the photosensitive body cartridge  6 . The developing cartridge  7  may include a developing sleeve in which a magnet roller is disposed, instead of the developing roller  71 . 
     The waste toner storage container  64  may be configured to store waste toner collected from the surface of the charging roller  63 . The waste toner storage container  64  and the handle  67  may have a one-piece body or may be separate parts. The handle  78  of the developing cartridge  7  and the frame  76  of the developing cartridge  7  may have a one-piece body or may be separate parts. 
     The photosensitive drum  61  may include a metal rotating shaft that passes through the drum body  61 A in the elongated direction of the photosensitive drum  61 , and the photosensitive body cartridge  6  may be rotated on the rotating shaft with respect to the casing  2 . Driving force may be inputted directly to the developing cartridge  7  from the casing  2 . 
     In the illustrative embodiment, the process cartridge  5  is configured to be pivotable on the axial (X) direction. Nevertheless, in other embodiments, for example, the process cartridge  5  may be configured to be pivotable on another axis that is different from the axis X of the photosensitive drum  61  and extends in parallel to the axis X of the photosensitive drum  61 .