Patent Publication Number: US-7912404-B2

Title: Cartridge and electrophotographic image forming apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a cartridge detachably mountable to an electrophotographic image forming apparatus for forming an image on a recording medium, and the electrophotographic image forming apparatus. 
     2. Related Background Art 
     Conventionally, in an electrophotographic image forming apparatus employing an electrophotographic image forming process, a process cartridge, into which an electrophotographic photosensitive member and a process unit acting on the electrophotographic photosensitive member are integrally incorporated as a unit, is detachably mountable to a main body of the image forming apparatus. Furthermore, in Japanese Patent Application Laid-Open No. 05-303242, known is the construction in which, when mounting a process cartridge to an image forming apparatus main body, a guided portion of the process cartridge is guided by a main body guide, and thus the process cartridge is guided to a positioning portion of the image forming apparatus main body. 
     Conventionally, to improve operability upon mounting the process cartridge in the image forming apparatus main body, a main body guide member needs to have a shape to smoothly guide a guided portion. However, there are some cases where downsizing of an electrophotographic image forming apparatus is affected by the shape of the main body guide member. 
     SUMMARY OF THE INVENTION 
     Therefore, the present invention provides a cartridge and an electrophotographic image forming apparatus achieving downsizing of an electrophotographic image forming apparatus main body, and further achieving higher operability when dismounting and mounting the cartridge to the electrophotographic image forming apparatus main body. 
     In addition, the present invention provides a cartridge detachably mountable to an electrophotographic image forming apparatus main body for forming an image on a recording medium, the electrophotographic image forming apparatus main body having: a main body guide; a restraining unit provided movably with respect to the main body guide; and a main body abutting. The cartridge comprises: a frame; a guided portion protruding from the frame so as to be guided by the main body guide, and abutting on the restraining unit as the cartridge is being mounted to the image forming apparatus main body so as to be restrained from moving to a downstream side of the apparatus in a mounting direction; and a moving member provided movably with respect to the frame, abutting on the main body abutting portion so as to be moved to act on the restraining unit, thereby moving the restraining unit on which the guided portion abuts to an allowable position of allowing the guided portion to move to the downstream side in the mounting direction. 
     Further, the present invention provides an electrophotographic image forming apparatus to which a cartridge is detachably mountable for forming an image on a recording medium. The electrophotographic image forming apparatus comprises: (i) a main body guide; (ii) a restraining unit provided movably with respect to the main body guide; (iii) a main body abutting portion; and (iv) a mounting portion to which the cartridge is detachably mountable. The cartridge includes: a frame; a guided portion protruding from the frame so as to be guided by the main body guide, and abutting on the restraining unit as the cartridge is being mounted to an apparatus main body of the electrophotographic image forming apparatus so as to be restrained from moving to a downstream side of the apparatus in a mounting direction; and a moving member provided movably with respect to the frame, abutting on the main body abutting portion so as to be moved to act on the restraining unit, thereby moving the restraining unit on which the guided portion abuts to an allowable position of allowing the guided portion to move to the downstream side in the mounting direction. The apparatus also includes (v) a conveying unit conveying the recording medium. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic sectional view illustrating an overall image forming apparatus in a first embodiment. 
         FIG. 2  is a schematic sectional view of a process cartridge in the first embodiment. 
         FIG. 3  is a schematic perspective view of the process cartridge in the first embodiment. 
         FIG. 4  is a perspective view in the vicinity of a guide groove on the right side in the longitudinal direction of an image forming apparatus main body in the first embodiment. 
         FIG. 5  is a schematic perspective view of the process cartridge in the first embodiment. 
         FIG. 6  is a perspective view in the vicinity of a guide groove on the left side in the longitudinal direction of the image forming apparatus main body in the first embodiment. 
         FIG. 7  is a schematic sectional view when mounting the process cartridge in the image forming apparatus main body in the first embodiment. 
         FIG. 8  is a schematic perspective view at the time of mounting the process cartridge in the image forming apparatus main body in the first embodiment. 
         FIG. 9  is a schematic sectional view illustrating the construction of a guide portion between the process cartridge and the image forming apparatus main body in the first embodiment. 
         FIG. 10  is a schematic sectional view when mounting the process cartridge in the image forming apparatus main body in the first embodiment. 
         FIG. 11  is a schematic perspective view in the state in which the process cartridge abuts on an abutted portion of the image forming apparatus main body in the first embodiment. 
         FIG. 12  is a schematic view illustrating a retreating mechanism of the abutted portion of the image forming apparatus main body in the first embodiment. 
         FIG. 13  is a schematic sectional view in the state in which a moving member of the process cartridge abuts on a releasing member in the first embodiment. 
         FIG. 14  is a schematic sectional view in the state in which the moving member of the process cartridge abuts on the releasing member in the first embodiment. 
         FIG. 15  is schematic perspective view in the state in which the moving member of the process cartridge abuts on the releasing member in the first embodiment. 
         FIG. 16  is a schematic perspective view illustrating the operation of the retreating mechanism of the abutted portion of the image forming apparatus main body in the first embodiment. 
         FIG. 17  is a schematic view illustrating the operation of the retreating mechanism of the abutted portion of the image forming apparatus main body in the first embodiment. 
         FIG. 18  is a schematic perspective view in the state in which the abutted portion of the image forming apparatus main body is retreated in the first embodiment. 
         FIG. 19  is a schematic sectional view in the state in which mounting of the process cartridge in the image forming apparatus main body has been completed in the first embodiment. 
         FIG. 20  is a schematic sectional view when pulling the process cartridge out of the image forming apparatus main body in the first embodiment. 
         FIG. 21  is a schematic perspective view illustrating the side face of a process cartridge in a second embodiment. 
         FIG. 22  is a schematic sectional view illustrating the construction of a guide portion between the process cartridge and an image forming apparatus main body in the second embodiment. 
         FIG. 23  is a schematic perspective view of a process cartridge in a third embodiment. 
         FIG. 24  is a perspective view in the vicinity of a guide groove on the right side of an image forming apparatus main body in the third embodiment. 
         FIG. 25  is a schematic perspective view of the process cartridge in the third embodiment. 
         FIG. 26  is a perspective view in the vicinity of a guide grove on the left side of the image forming apparatus main body in the third embodiment. 
         FIG. 27  is a schematic sectional view when mounting the process cartridge in the main body in the third embodiment. 
         FIG. 28  is a schematic perspective view when mounting the process cartridge in the main body in the third embodiment. 
         FIG. 29  is a schematic sectional view when mounting the process cartridge in the main body in the third embodiment. 
         FIG. 30  is a schematic sectional view when mounting the process cartridge in the main body in the third embodiment. 
         FIG. 31  is a schematic perspective view when mounting the process cartridge in the main body in the third embodiment. 
         FIG. 32  is a schematic sectional view when mounting the process cartridge in the main body in the third embodiment. 
         FIG. 33  is a schematic sectional view when mounting the process cartridge in the main body in the third embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Embodiment 1 
     Hereinafter, a first exemplary embodiment according to the present invention will be described in detail referring to the accompanying drawings. The longitudinal direction of a process cartridge is the direction (a direction of the axis of rotation of a photosensitive drum or a direction substantially orthogonal to) intersecting the direction of mounting the process cartridge into an electrophotographic image forming apparatus main body. Furthermore, the terms “left” and “right” when used in connection with the process cartridge refer to the left or the right direction as viewed along the direction of mounting the process cartridge into the electrophotographic image forming apparatus main body. In addition, the top face of the process cartridge is the face positioned at the top of the cartridge in the state in which the process cartridge is mounted in the electrophotographic image forming apparatus main body, and the bottom face is the face positioned at the bottom of the cartridge in that state. 
     First, the process cartridge and the electrophotographic image forming apparatus main body into which the process cartridge is detachably mountable will be specifically described with reference to  FIGS. 1 and 2 . Incidentally,  FIG. 1  is a schematic sectional view illustrating the construction of the electrophotographic image forming apparatus main body in which the process cartridge is mounted.  FIG. 2  is a schematic sectional view illustrating the construction of the process cartridge. 
     (Overall Construction) 
     In this electrophotographic image forming apparatus main body (hereinafter referred to as “apparatus main body”) A, as illustrated in  FIG. 1 , information light, generated according to image information, from an optical system  1  functioning as an optical unit, irradiates an electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”)  7  of a drum shape. As a result, an electrostatic latent image is formed on the photosensitive drum  7 . This electrostatic latent image is developed with a developer (hereinafter referred to as “toner”) to form a toner image. Then, in synchronism with the formation of the toner image, a recording medium (a recording sheet, an OHP sheet, cloth and the like)  2  is fed from a sheet feeding portion (cassette)  3   a  and separated one by one by a pickup roller  3   b  and a pressure member  3   c  in pressure contact with the pickup roller  3   b . The toner image having been formed on the photosensitive drum  7  of the process cartridge (hereinafter referred to as a cartridge) B is transferred, by the application of a voltage to a transfer roller  4  acting as a transfer unit, on the recording medium  2  having been conveyed along a conveying guide  3   f   1 . Moreover, the recording medium  2  having been transferred with the toner image is conveyed to a fixing unit  5  along a conveying guide  3   f   2 . This fixing unit  5  includes a drive roller  5   a  and a fixing rotary member  5   d  made of a tubular sheet that contains a heater  5   b  therein and is rotatably supported by a support  5   c . Then, the fixing unit  5  applies heat and pressure to the recording medium  2  being passed to fix the transferred toner image. The recording medium  2  on which the transferred toner image has been fixed is conveyed by a discharge roller  3   d  and discharged to a discharge portion  6  through a reversing and conveying path. Incidentally, although in this embodiment, a conveying unit is formed of the pickup roller  3   b , the pressure member  3   c , the discharge roller  3   d  and the like, the present invention is not limited thereto. 
     (Process Cartridge Construction) 
     The cartridge B is the one that includes the photosensitive drum  7  and at least one process unit. As a process unit, there are, for example, a charging unit charging the photosensitive drum  7 , a developing unit developing an electrostatic latent image that is formed on the photosensitive drum  7 , and a cleaning member for cleaning a toner remaining on the photosensitive drum  7 . In the cartridge B according to this embodiment, as illustrated in  FIG. 2 , the photosensitive drum  7  as an electrophotographic photosensitive member having a photoconductive layer is driven to rotate, and the charging roller  8  as a charging unit has applied thereto a voltage to uniformly charge the surface of the photosensitive drum  7 . The photosensitive drum  7  in this charged state is exposed to information light (light image) based on image information from the optical system  1  through an exposure opening  9   b . Then, it is constructed such that an electrostatic latent image is formed on the surface of the photosensitive drum  7 , and this electrostatic latent image is developed by the developing unit  10 . 
     In the developing unit  10 , the toner in a toner containing portion  10   a  is fed out by a rotatable feed member  10   b . Then, a developing roller  10   d  as a developing rotary member (developer carrying member) containing a stationary magnet  10   c  therein is rotated, and a toner layer applied with a triboelectrification charge by a developing blade  10   e  is formed on the surface of the developing roller  10   d . Further, the developing roller  10   d  transfers the toner onto the photosensitive drum  7  based on the electrostatic latent image, thereby forming a toner image to visualize the latent image. 
     Then, the transfer roller  4  is applied with the voltage of a polarity opposite to that of the toner image to transfer the toner image on the recording medium  2 . After the transfer, the toner remaining on the photosensitive drum  7  is scraped off by a cleaning blade  11   a  that is provided at the cleaning member  11 , and is prevented from being leaked to the outside of a removed toner containing portion  11   c  by a scooping sheet  11   b.    
     (Construction of Mounting/Dismounting a Process Cartridge from an Image Forming Apparatus Main Body) 
     A mounting construction for mounting the cartridge B that is assembled as described above in the apparatus main body A will be described referring to the drawings. 
       FIGS. 3 and 5  are schematic perspective views of the cartridge, and  FIGS. 4 and 6  are perspective views in the vicinity of a guide groove on the right side and on the left side in the longitudinal direction of the image forming apparatus main body respectively. 
     As illustrated in  FIG. 3 , at a bearing member  18   c  attached to a cleaning frame  11   d  on the right side in the longitudinal direction of the cartridge B, there are provided a first guided portion  18   c   1  and a second guided portion  18   c   2 . The first guided portion  18   c   1  is of a cylindrical shape that is formed to protrude coaxially with the axis of rotation of the photosensitive drum  7 . In addition, the second guided portion  18   c   2  is a rotation stopper for determining the posture of the cartridge B about the rotation axis of the photosensitive drum  7 . Furthermore, there is provided at a longitudinal direction end portion of the second guided portion  18   c   2  a moving member  14  that is rotatably provided at the longitudinal end of the second guided portion  18   c   2 . 
     Incidentally, the first guided portion  18   c   1  and the second guided portion  18   c   2  are positioned outside of the developing unit  10  in the longitudinal direction. Furthermore, an end face coupling  7   b  receiving a driving force from the apparatus main body A is disposed inside of the bearing member  18   c  in the longitudinal direction. 
     In the apparatus main body A, as illustrated in  FIG. 4 , to guide the first guided portion  18   c   1  and the second guided portion  18   c   2  of the cartridge B to the image forming position (mounting portion Ga 3 , Gc 3 ), there are formed a first guide groove Ga as a first main body guide and a second guide groove Gb as a second main body guide. The guide grooves Ga, Gb include inclined surfaces (upstream-side guide surfaces Ga 1 , Gb 1 ) inclined from the top to the bottom thereof toward the downstream side (into the interior) in the mounting direction of the cartridge B. Further, the guide grooves Ga, Gb further include inclined surfaces (downstream-side guide surfaces Ga 2 , Gb 2 ) at a different angle toward the downstream side (into the interior) in the mounting direction. That is, the first guide groove Ga includes a first bent portion Ga 4 , and the second guide groove Gb includes a second bent portion Gb 4 . Incidentally, the purpose of the guide grooves Ga, Gb including these two inclined surfaces at different angles is to downsize the apparatus main body A and to make the dead space in the apparatus main body A smaller. That is, as illustrated in  FIG. 19 , the optical unit  1  can be disposed below the upstream-side guide surface Gb 1 , thus enabling the efficient use the space in the apparatus main body A. 
     On the other hand, as illustrated in  FIG. 5 , on the other longitudinal direction end side (on the left side), there are formed a first guided portion  11   e  of a cylindrical shape that is provided coaxially with the photosensitive drum  7 , and a second guided portion  11   f  for determining the posture of the cartridge B at the time of mounting. The first guided portion  11   e  and the second guided portion  11   f  are parts of the cleaning frame  11   d . In addition, as with one end side, there is a moving member  15  that is movably (rotatably) provided coaxially with the second guided portion  11   f  at the longitudinal direction end portion of the second guided portion  11   f . Incidentally, the first guided portion  11   e  and the second guided portion  11   f  are positioned outside of the developing unit  10  in the longitudinal direction. Moreover, the first guided portion  11   e  protrudes outward from the one end side of the cleaning frame  11   d  in the longitudinal direction. Furthermore, the second guided portion  11   f  protrudes outward from the other end side of the cleaning frame  11   d  in the longitudinal direction. In addition, in the apparatus main body A, as illustrated in  FIG. 6 , there are provided a first guide groove Gc as a first main body guide and a second guide groove Gd as a second main body guide, which are formed so as to keep, likewise, on the other longitudinal direction end side, a posture when mounting/dismounting the cartridge B, the posture of the cartridge B being determined on the bearing member  18   c  side. As with the guide construction on the right side in the longitudinal direction, the guide grooves Gc, Gd include inclined surfaces (upstream-side guide portions Gc 1 , Gd 1 ) inclined from the top to the bottom thereof toward the downstream side (into the interior) in the mounting direction of the cartridge B. Further, the guide grooves Gc, Gd further include inclined surfaces (downstream-side guide portions Gc 2 , Gd 2 ) at a different angle toward the downstream side (into the interior) in the mounting direction. That is, the first guide groove Gc includes a first bent portion Gc 4 , and the second guide groove Gd includes a second bent portion Gd 4 . 
     Now, the mounting/dismounting construction of the cartridge B with respect to the apparatus main body A will be described. Incidentally, in this mounting/dismounting construction, the guide grooves Ga, Gb and the guide grooves Gc, Gd of the apparatus main body A, and the first guided portion  18   c   1 ,  11   e  and the second guided portion  18   c   2 ,  11   f  and the moving members  14  and  15  of the cartridge B are in respective similar constructions. Accordingly, here, the construction on the left side when viewed in the mounting direction of the cartridge B into the apparatus main body A will be described. 
       FIGS. 7 and 10  are schematic sectional views when mounting the cartridge B into the apparatus main body A.  FIG. 8  is a schematic perspective view when mounting the cartridge B into the apparatus main body A.  FIG. 9  is a schematic sectional view illustrating the construction of the guide groove. Furthermore,  FIG. 11  is a schematic perspective view in the state in which the cartridge B abuts on an abutted member  25  as an element of a restraining unit  100  of the apparatus main body A.  FIG. 12  is a schematic view illustrating the mechanism of the restraining unit  100  of the apparatus main body A. 
     First, as illustrated in  FIGS. 7 to 9 , an opening/closing door  20  of the apparatus main body A is opened, to expose the guide grooves Gc, Gd. The first guided portion  11   e  is placed on the first guide surface Gc 1 , which is bent to some extent at the front portion toward the apparatus, of the guide groove Gc and the second guided portion  11   f  is inserted into the guide groove Gd. In this state, the cartridge B is pushed into the interior of the apparatus main body A. 
     Here, the restraining unit  100  includes the abutted member  25 , a releasing member  26 , a helical torsion coil spring  27 , a retreating lever  28 , an arm member  29  and an engaging pin  31 . In the vicinity of the first bent portion Gc 4  of the first guided portion  11   e , there is provided the abutted member  25 . Here, the abutted member  25  will be described. As illustrated in  FIGS. 8 and 12 , the abutted member  25  is supported at the apparatus main body A so as to be capable of sliding in the longitudinal direction of the cartridge. Moreover, the abutted member  25  is connected to the retreating lever  28  by the engaging pin  31 . Then, due to the rotating of retreating lever  28  about a shaft  28   a , as described in detail later, the abutted member  25  moves in a sliding manner in the longitudinal direction of the cartridge. In normal operation, before any cartridge is mounted the abutted member  25  protrudes in the guide groove Gc to be in a restraining position for restraining the first guided portion  11   e  from moving to the downstream side in the mounting direction. 
     The releasing member  26  is provided in the proximity of the abutted member  25 , and the releasing member  26  can turn about a rotation center  26   a , and is biased in a counterclockwise direction by the helical torsion coil spring  27 . In addition, the releasing member  26  includes an abutted portion  26   c  that is inclined in the longitudinal direction of the cartridge. 
     Now, the operation of mounting the cartridge B in the apparatus main body A will be described referring to the drawings. 
       FIG. 13  is a schematic sectional view in the state in which the moving member  15  abuts on the releasing member  26 .  FIGS. 14 and 15  are a schematic sectional view and a schematic perspective view, respectively in the state in which the moving member  15  acts on the releasing member  26 . Further,  FIGS. 16 and 17  are a schematic perspective view and a schematic sectional view, respectively, illustrating the operation of a retreating mechanism of the abutted member  25  of the apparatus main body A.  FIG. 18  is a schematic perspective view in the state in which the abutted member  25  of the apparatus main body A is retreated in an allowable position. 
     As described above, the first guided portion  11   e  is placed on the first guide surface Gc 1  and the second guided portion  11   f  is inserted into the guide groove Gd, and thus the cartridge B will be mounted into the interior of the apparatus main body A. 
     Due to the abutment of the first guided portion  11   e  on the abutted member  25 , the cartridge B is temporarily stopped as the cartridge B is being mounted in the apparatus main body A. 
     With the arrangement, a user can adjust the posture of the cartridge B with the first guided portion  11   e  of the cartridge B being as a center in the vicinity of the first bent portion Gc 4 . Then, the posture of the cartridge B can be controlled to follow the guide shape. That is, due to the abutment of the first guided portion  11   e  on the abutted member  25 , the user notices that the cartridge B has not been mounted to the mounting portions Ga 3 , Gc 3 . Further, by the cartridge B being pushed further to the downstream side in the mounting direction by the user, the cartridge B will be reliably mounted to the mounting portion Ga 3 , Gc 3 . In the case where the main body guide is bent as in this embodiment, such a construction that operates as described above is an effective arrangement for reliably mounting the cartridge B in the apparatus main body A. 
     As illustrated in  FIGS. 8 and 13 , the guide portion Ge is provided on the outside in the longitudinal direction of the guide groove Gd. The guide portion Ge is provided in the same position in the longitudinal direction as that of a second abutted portion  15   d  of the moving member  15 . Moreover, a second main body abutting portion Ge 1  of the image forming apparatus main body is provided in the guide portion Ge. When the cartridge B is adjusted to be in the posture capable of being mounted, the second abutted portion  15   d  of the moving member  15  abuts on the second main body abutting portion Ge 1  provided in the guide portion Ge so that the second abutted portion  15   d  is rotated. 
     As illustrated in  FIG. 13 , when the cartridge B is rotated in the clockwise direction with the first guided portion  11   e  as the center, the moving member  15  is rotated in the clockwise direction about a rotation center  15   a , and thus a first abutted portion  15   b  of the moving member  15  abuts on the downstream-side guide portion Gd 2  of the second guide groove Gd. 
     Then, as illustrated in  FIGS. 14 and 15 , the cartridge B is further rotated in the clockwise direction with the first guided portion  11   e  as the center of rotation. Thus, the second guided portion  11   f  of the cartridge B comes to be in the state of abutting on the downstream-side guide portion Gd 2  of the guide grove Gd of the apparatus main body A, and thus the cartridge B will be in such posture as to be capable of being mounted further to the downstream side (into the interior) in the mounting direction. At this time, the moving member  15  is rotated in the clockwise direction about the rotation center  15   a  while the first abutted portion  15   b  abuts on the downstream-side guide portion Gd 2 . As a result, an acting portion  15   c  of the moving member  15  abuts on an abutting portion  26   b  of the releasing member  26  to cause the releasing member  26  to rotate in the clockwise direction about the rotation center  26   a.    
     As illustrated in  FIGS. 16 and 17 , when the releasing member  26  is rotated in the direction indicated by an arrow R, the abutted portion  26   c  abuts on an abutting portion  28   b  of the retreating lever  28 . The abutting portion  28   b  of the retreating lever  28  moves along an inclined surface of the abutted portion  26   c  of the releasing member  26 , and the retreating lever  28  turns about a shaft  28   a  (in the direction indicted by an arrow S). According to the rotation of the retreating lever  28 , the abutted member  25 , which is engaged with the retreating lever  28  via the engaging pin  31 , is moved in a sliding manner outward in the longitudinal direction of the cartridge by a linkage mechanism (in the direction indicated by an arrow T). As a result, the abutted member  25  is retreated from the mounting track of the first guided portion  11   e  being mounted ( FIGS. 17 and 18 ). That is, the abutted member  25  is moved to the allowable position for allowing the first guided portion  11   e  to move to the downstream side in the mounting direction. 
     As a result, the first guided portion  11   e  can move to the downstream-side guide portion Gc 2  of the guide groove Gc (in the direction indicated by an arrow V of  FIG. 17 ). The cartridge B, at the same time, is in such a posture that the second guided portion  11   f  can move further into the interior along the downstream-side guide portion Gd 2  of the guide Gd. Therefore, the first guided portion  11   e  of the cartridge B moves to the downstream-side guide portion Gc 2  of the guide groove Gc and the second guided portion  11   f  thereof moves to the downstream-side guide portion Gd 2  of the guide Gd, and thus the cartridge B moves further to the downstream side (into the interior) in the mounting direction of the apparatus main body A. Finally, the first guided portion  11   e  abuts on the arc-shaped mounting portion Gc 3  of the guide Gc and the second guided portion  11   f  also abuts on the abutting portion Gd 3  of the guide Gd, to complete mounting (refer to  FIG. 19 ). During the movement of the second guided portion  11   f  to the abutting portion Gd 3  of the guide Gd, the second guided portion  11   f  of the cartridge and the first abutting portion  15   b  of the moving member  15  abut on the downstream-side guide portion Gd 2  of the image forming apparatus main body. Moreover, by the movement of the acting portion  15   c  of the moving member  15  while abutting on the abutting portion  26   b  of the releasing member  26 , the abutted member  25  is kept in the state of being retreated from the first guide groove Gc. 
     When the cartridge B moves to the mounting portion Gc 3  (Ga 3 ), the acting portion  15   c  of the moving member  15  is separated from the abutting portion  26   b  of the releasing member  26 . Then, the releasing member  26  is biased in the counterclockwise direction by the helical torsion coil spring  27 , and the abutted member  25  moves to slide inward in the longitudinal direction of the cartridge again to return to the state of blocking the guide groove Gc, that is to the restraining position. 
     Incidentally, the other longitudinal direction end (the right side in the inserting direction) also has the same construction as mentioned above. The first guided portion  18   c   1  abuts on the mounting portion Ga 3  of the guide Ga, and the second guided portion  18   c   2  abuts on the abutting portion Gb 3  (refer to  FIG. 4 ) of the guide Gb. In this state in which mounting has completed, the transfer roller  4  and the photosensitive drum  7  are brought in the abutted state (refer to  FIG. 1 ). 
     Next, when the opening/closing door  20  that forms the discharge opening  6  of the apparatus main body A is closed, a drive transmission member of the apparatus main body A moves to the cartridge B side, and then is fitted to the end face coupling  7   b , thus enabling a rotation driving force to be transmitted from the apparatus main body A to the cartridge B. 
     Now, the operation of pulling the cartridge B out of the apparatus main body A will be described referring to the drawings.  FIG. 20  is a schematic sectional view when pulling the cartridge out of the apparatus main body A. 
     As illustrated in  FIG. 20 , when the cartridge B is pulled out of the apparatus main body A, a second abutted portion  15   d  of the moving member  15  abuts on the arm member  29 . Here, the arm member  29  includes a rotation center  29   a  at one end portion and pivotally engages with the apparatus main body A, and on the other end side, includes an engaging hole  29   b  and pivotally engages with an engaging protrusion  26   d  of the releasing member  26 . When the second abutted portion  15   d  of the moving member  15  abuts on the arm member  29 , the arm member  29  is rotated in the counterclockwise direction about the rotation center  29   a . When the arm member  29  is rotated, the releasing member  26  is rotated in the clockwise direction about the rotation center  26   a . The retreating lever  28  abuts on the abutted portion  26   c  of the releasing member  26  and moves along the inclined surface of the abutted portion  26   c , and the retreating lever  28  is rotated in the longitudinal direction of the cartridge about the shaft  28   a . According to the rotation movement of the retreating lever  28 , the abutted member  25  moves to slide outward in the longitudinal direction of the cartridge by the linkage mechanism. In addition, before the guided portion  11   e  reaches the abutted member  25 , the abutted member  25  retreats again from the mounting track of the first guided portion  11   e  to move to the allowable position. Until the guided portion  11   e  passes the abutted member  25 , the second guided portion  11   f  of the cartridge and the first abutting portion  15   b  of the moving member  15  abut on the downstream-side guide portion Gd 2  of the image forming apparatus main body. Furthermore, since the acting portion  15   c  of the moving member  15  moves while abutting on the abutting portion  26   b  of the releasing member  26 , the abutted member  25  is kept in the retreated state. As a result, the cartridge B can be pulled out of the apparatus main body A. 
     Moreover, after the guided portion  11   e  passes the abutted member  25 , the acting portion  15   c  of the moving member  15  is separated from the releasing member  26 , and the releasing member  26  is biased in the counterclockwise direction by the helical torsion coil spring  27 . That is, the abutted member  25  moves to slide and returns to the restraining position of blocking the guide groove Gc again. 
     Embodiment 2 
     Now, a second embodiment according to the present invention will be described referring to the drawings.  FIG. 21  is a schematic perspective view illustrating the side face of a cartridge.  FIG. 22  is a schematic sectional view illustrating the construction of a guide portion between the cartridge and an image forming apparatus main body. 
     Although in the first embodiment, the second guided portion  11   f  is provided on the longitudinally outside portion of the cleaning frame  11   d  of the cartridge B, a moving member  15  may also serve as a second guided portion. 
     That is, as illustrated in  FIGS. 21 and 22 , it is constructed such that a cylindrical guided portion  15   e  is formed coaxially with a rotation center  15   a  of the moving member  15 , and engaged with a guide groove Gd as a second main body guide of the apparatus main body A, to cause the cartridge B to be guided. In addition, a second guided portion on the longitudinally opposite side is of the same construction as well. 
     Due to the cylindrical guided portion  15   e  being provided on the moving member  15  and also serving as the second guided portion, the cartridge B can be further downsized in the longitudinal direction. 
     As described heretofore, according to the first embodiment and the second embodiment, the cartridge can be moved on the limited mounting track without being caught in the guide groove of the image forming apparatus main body, and the posture of the cartridge can be smoothly adjusted and controlled. As a result, high operability of the cartridge can be obtained. 
     Furthermore, due to that arrangement, as is the first embodiment, the apparatus main body A has a guide groove construction having the bent portion, and an unused space in the apparatus main body A can be effectively utilized. In addition, in the apparatus main body A, due to the control of the posture of the cartridge B, the clearance with respect to the apparatus main body A in the vicinity of the mounting track of the cartridge B can be made smaller, so that the apparatus main body A can be downsized. 
     Moreover, in this construction, the guide construction in the cartridge B and the apparatus main body A is described to be symmetrical. However, even if the above-mentioned construction is provided only on one end side, and only the first guided portion that is coaxial with the photosensitive drum  7  is provided at the other end, the similar effect can be obtained. 
     That is, on the occasion when a user mounts the cartridge B on the apparatus main body A, at the first bent portion Ga 4 , the posture of the cartridge B can be adjusted with the first guided portion  11   e  as the center of rotation. Therefore, the posture of the cartridge B can be controlled such that it is easy for the cartridge B to follow the mounting track. Consequently, as is the first embodiment, a high mounting performance of the cartridge B can be achieved. 
     Furthermore, due to the apparatus main body A having the guide grove having the bent portion, the space in the apparatus main body A can be effectively used. In addition, due to the control of the posture of the cartridge B in the apparatus main body A, the clearance with respect to the apparatus main body A in the vicinity of the mounting track of the cartridge B can be made smaller, so that the apparatus main body A can be downsized. 
     Embodiment 3 
     Now, a third embodiment according to the present invention will be described with reference to  FIGS. 23 to 33 . 
     The construction in an internal part of a process cartridge B is the same as that of the first embodiment, so that descriptions thereof will be omitted. 
     (Construction of Mounting/Dismounting a Process Cartridge from an Apparatus Main Body) 
     A mounting construction of mounting a process cartridge (hereinafter referred to as a cartridge) B on an image forming apparatus main body A will be described with reference to  FIGS. 23 to 26 . 
     A bearing member  18   c  is attached to a cleaning frame  11   d  of the cartridge B. Furthermore, at the bearing member  18   c , as a mounting guide onto the apparatus main body A, there are provided a first guided portion  18   c   1  of a cylindrical shape that is formed to be coaxial with the rotation axis of the photosensitive drum  7  and a second guided portion  18   c   2  as a rotation stopper. The second guided portion  18   c   2  determines the posture of the cartridge B about the axis of the photosensitive drum  7 . 
     Moreover, at the longitudinal direction end portion of the second guided portion  18   c   2 , there is a moving member  14  that is rotatably provided at the longitudinal end of the second guided portion  18   c   2 . Incidentally, the first guided portion  18   c   1  and the second guided portion  18   c   2  are positioned longitudinally outside of the developing unit  10 . In addition, an end face coupling  7   b  that receives a driving force from the apparatus main body A is positioned on the inside side of the bearing member  18   c  in the longitudinal direction. 
     In the apparatus main body A, as illustrated in  FIG. 24 , there are formed a guide groove Ga as a first main body guide and a guide groove Gb as a second main body guide for guiding the first guided portion  18   c   1  and the second guided portion  18   c   2  of the cartridge B to mounting portions Ga 3 , Gc 3 , being an image forming position. The guide grooves Ga, Gb includes inclined surfaces (upstream-side guide portions Ga 1 , Gb 1 ) inclined from the top to the bottom thereof toward the downstream side (into the interior) in the mounting direction of the cartridge B. Moreover, the guide grooves Ga, Gb includes inclined surfaces (downstream-side guide portions Ga 2 , Gb 2 ) at a different angle toward the downstream side (into the interior) in the mounting direction. That is, the guide groove Ga includes a first bent portion Ga 4 , and the guide groove Gb includes a second bent portion Gb 4 . Incidentally, the purpose of the guide grooves Ga, Gb including these two inclined surfaces at different angles is to downsize the image forming apparatus, and to make the dead space in the image forming apparatus smaller. 
     On the other hand, as illustrated in  FIG. 25 , on the other longitudinal direction end side, there are formed a first guided portion  11   e  of a cylindrical shape that is provided coaxially with the photosensitive drum  7  and a second guided portion  11   f  for determining the posture of the cartridge B at the time of mounting. The first and second guided portions  11   e ,  11   f  are parts of the cleaning frame  11   d . Furthermore, as with the other end, there is a moving member  15  that is rotatably provided at the longitudinal direction end portion of the second guided portion  11   f . Incidentally, the first guided portion  11   e  and the second guided portion  11   f  are positioned on the outside side of the developing unit  10  in the longitudinal direction. 
     In addition, in the apparatus main body A, as illustrated in  FIG. 26 , there are provided a guide grooves Gc, Gd that are formed so as to likewise keep the posture in mounting/dismounting of the cartridge B having been determined on the bearing member  18   c  side on the other longitudinal direction end side as well. As with the guide construction on the right side, the guide grooves Gc, Gd include inclined surfaces (upstream-side guide portions Gc 1 , Gd 1 ) inclined from the top to the bottom thereof toward the downstream side (into the interior) in the mounting direction of the cartridge B. Further, the guide grooves Gc, Gd include inclined surfaces (downstream-side guide portions Gc 2 , Gd 2 ) at a different angle toward the downstream side (into the interior) in the mounting direction. 
     Now, a mounting/dismounting construction of the cartridge B with respect to the apparatus main body A will be described referring to  FIGS. 27 to 31 . Incidentally, in this mounting/dismounting construction, the guide portions Ga, Gb, Gc, and Gd of the apparatus main body A, and the first guided portions  18   c   1 ,  11   e , the second guided portions  18   c   2 ,  11   f , and the moving members  14 ,  15  of the cartridge B have respective similar constructions. Therefore, the construction on the left side in the inserting direction of the cartridge B into the apparatus main body A will be described. 
     First, as illustrated in  FIGS. 27 and 28 , the opening/closing door  20  of the apparatus main body A is opened, and the guide grooves Gc, Gd are exposed. The first guided portion  11   e  is placed on the first guide surface Gc 1  of which an upstream side in the mounting direction is bent to some extent, of the guide groove Gc and the second guided portion  11   f  is placed on the upstream-side guide portion Gd 1  of the guide groove Gd. In this state, the cartridge B is mounted into the interior of the apparatus main body A. 
     Next, as illustrated in  FIG. 29 , in this embodiment, a restraining unit  200  includes a shield member  225 , a releasing lever  226 , a compression spring  227  and a spring  228  biasing the releasing lever  226 . 
     The first guided portion  11   e  abuts on the shield member  225  in the vicinity of the first bent portion Gc 4 . Here, the shield member  225  will be described. The shield member  225  is supported so as to be capable of vertically sliding, and biased downward by the compression spring  227 . 
     Below the shield member  225 , there is provided the releasing lever  226  that can rotate about a rotation center  226   a , and is biased in the clockwise direction by the spring  228 . A shield member abutting portion  226   b  of this releasing lever  226  presses the shield member  225  upward. Incidentally, the biasing force of the releasing lever  226  is larger than the biasing force of the shield member  225 , and normally, a shield portion  225   a  of the shield member  225  is positioned in a restraining position of blocking the guide groove Gc. 
     Due to abutting of the first guided portion  11   e  on the shield member  225 , the cartridge B is temporarily stopped as the cartridge B is being mounted in the apparatus main body A. 
     As a result, a user can easily control the posture of the cartridge B with the first guided portion  11   e  of the cartridge B as the center in the vicinity of the first bent portion Gc 4 . That is, as with the first embodiment, the cartridge B can be reliably mounted in the apparatus main body A. 
     As illustrated in  FIGS. 30 to 32 , on the outside in the longitudinal direction of the second guide portion Gd, there is a guide portion Ge guiding the moving member  15 . Then, when the cartridge B is postured to be capable of being mounted, a first abutting portion  15   a  of the moving member  15  abuts on a protrusion Ge 1  (main body abutting portion) that is provided at the guide portion Ge. Then, the moving member  15  is rotated in the clockwise direction about a rotation center  15   b , and an acting portion  15   c  of the moving member  15  abuts on the releasing lever  226 . 
     Subsequently, the releasing lever  226  is rotated in the counterclockwise direction about the rotation center  226   a  so that the shield member  225  is moved downward by the biasing force of the spring  227  to move the shield member  225  to an allowable position in which the shield portion  225   a  of the shield member  225  is retreated from the mounting track of the first guided portion  11   e . As a result, the first guided portion  11   e  can move to the downstream-side guide portion Gc 2  of the guide groove Gc. At the same time, the cartridge B is postured to be capable of being mounted, so that the second guided portion  11   f  moves to the downstream-side guide portion Gd 2  of the guide Gd as well, and finally the first guided portion  11   e  abuts on the mounting portion Gc 3  of the guide Gc. Furthermore, the second guided portion  11   f  also abuts on the abutting portion Gd 3  of the guide Gd, to complete mounting (refer to  FIG. 32 ). 
     Incidentally, the other longitudinal direction end (right side in the inserting direction) is likewise in the above-mentioned construction, the first guided portion  18   c   1  abuts on a mounting portion Ga 3  of the guide Ga and the second guided portion  18   c   2  abuts on an abutting portion Gb 3  of the guide Gb (as to the mounting portion Ga 3  and the abutting portion Gb 3 , refer to  FIG. 24 ). In this mounting completion state, the transfer roller  4  and the photosensitive drum  7  are in the abutted state. 
     Then, when the opening/closing door  20  that forms the discharge opening  6  of the apparatus main body A is closed, a drive transmission member of a twisted and substantially recessed-triangular shape of the apparatus main body A moves to the cartridge B side. Then, the drive transmission member is fitted to the end face coupling  7   b  of the cartridge B, and thus a rotation driving force is transmitted to the cartridge B from the apparatus main body A. 
     As illustrated in  FIG. 33 , when the cartridge B is pulled out of the image forming apparatus A, the first guided portion  11   e  pushes downward an inclined surface  225   b  of the shield member  225  and passes through the guide groove Gc. Furthermore, at the same time, the second guided portion  11   f  passes through the guide portion Gd, and eventually the cartridge B can be pulled out of the apparatus main body A. 
     As described heretofore, the posture of the cartridge B can be controlled such that the cartridge B can easily follow the limited mounting track. As a result, high operability of the cartridge B can be obtained. 
     Moreover, due to the inclusion in the apparatus main body A of the guide groove having the bent portion, the unused space in the image forming apparatus main body A can be effectively utilized. In addition, due to the control of the posture of the cartridge B in the apparatus main body A, the clearance with respect to the apparatus main body A in the vicinity of the mounting track of the cartridge B can be made smaller, so that the apparatus main body A can be downsized. 
     Moreover, in this construction, the guide construction in the cartridge B and the apparatus main body A is described to be symmetrical. However, even if the above-mentioned construction is provided only on one end side, and only the first guided portion that is coaxial with the photosensitive drum  7  is provided on the other end, the similar effect can be obtained. 
     Embodiment 4 
     In the above-described embodiments 1 to 3, descriptions are provided using a process cartridge including a photosensitive drum and a process unit. However, it is preferable to be a developing cartridge including a developing unit for developing an electrostatic latent image that is formed on an electrophotographic photosensitive member, the developing cartridge being detachably mountable to an image forming apparatus main body provided with the electrophotographic photosensitive member. 
     Heretofore, according to the present invention, the electrophotographic image forming apparatus main body can be downsized, and further, high operability on the occasion when the cartridge is mounted or dismounted from the electrophotographic image forming apparatus main body can be achieved. 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application Nos. 2006-336008, filed Dec. 13, 2006, and 2007-304501, filed Nov. 26, 2007 which are hereby incorporated by reference herein in their entirety.