Patent Publication Number: US-10782630-B2

Title: Image forming apparatus with movable support member

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119 from Japanese Patent Application No. 2018-202110 filed on Oct. 26, 2018. The entire subject matter of the application is incorporated herein by reference. 
     BACKGROUND 
     Technical Fields 
     The present disclosures relate to an image forming apparatus employing an electrophotographic imaging method. 
     Related Art 
     There has been known an image forming apparatus having a sheet conveying passage extending from a sheet tray to a discharge tray, a part of the sheet conveying passage being curved to be C-shaped (hereinafter, such a C-shaped conveying passage will be simply referred to as a “C-shaped passage”). Among such image forming apparatuses, there are ones in which the C-shaped passage is arranged on a rear wall side of the image forming apparatus. For example, there is known an image forming apparatus, in which a manual insertion tray is provided on a front wall side of a casing of the image forming apparatus. There is also provided a conveyance guide, which is arranged above the sheet tray and is configured to guide the sheet placed on the manual insertion tray to be conveyed from the front wall side to the rear wall side, defining a manual insertion sheet conveying passage. Typically, in such an apparatus, in order to enable jam processing which is processing of dealing with a sheet jam condition, after the sheet tray is removed from the image forming apparatus, the conveyance guide is moved downward into a space which was occupied by the sheet tray before removed, thereby the manual insertion conveying passage being opened. 
     SUMMARY 
     When image forming apparatus is configured such that the sheet tray is arranged at a bottom part of the image forming apparatus, it is necessary that the sheet tray is removed from the image forming apparatus and a user looks into the manual insertion conveying passage through the space located at the bottom part of the image forming apparatus when, for example, the jam processing (e.g., a process of removing a jammed sheet from the passage) is performed. That is, in a conventional image forming apparatus configured as above, it is relatively difficult for the user to visually recognize a portion subject to the jam processing. 
     According to aspects of the present disclosures, there is provided an image forming apparatus configured to form an image in accordance with an electrophotographic image forming method. The image forming apparatus is provided with a casing which has a front wall having an opening, a rear wall and a first conveying guide configured to guide a sheet inserted through the opening in a direction from the front wall toward the rear wall. The image forming apparatus is further provided with a process cartridge having a photosensitive drum, a support member having a second conveying guide configured to guide sheet inserted through the opening, the support member being configured to support the process cartridge, and the support member being slidably movable between an accommodated position at which the process cartridge supported on the supporting member is located inside the casing and a drawn position at which at least a part of the process cartridge supported on the supporting member is located out of the casing through the opening on the front wall, Further, the image processing apparatus is provided with a sheet tray configured to support sheet, the sheet tray being arranged inside the casing at a lower position with respect to the support member when the support member is at the accommodated position, a pair of registration rollers arranged inside the casing at a position closer to the rear wall than the front wall, the pair of registration rollers being configured to convey a sheet. When the supporting member is at the accommodated position, the second conveying guide faces the first conveying guide. 
    
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
         FIG. 1  is a side view schematically illustrating a configuration of an image forming apparatus according to a first embodiment of the present disclosures. 
         FIG. 2  is a side view schematically illustrating the image forming apparatus according to the first embodiment when a supporting member is located at a drawn position. 
         FIG. 3  is a side view schematically illustrating the image forming apparatus according to the first embodiment when the supporting member is located at an accommodated position. 
         FIG. 4  is a front view of the image forming apparatus according to the first embodiment with a cover being removed. 
         FIG. 5  is a cross-sectional view of the image forming apparatus which is take along line A-A of  FIG. 4 . 
         FIG. 6A  illustrates a structure of a first conveying roller when the support member is located at the drawn position. 
         FIG. 6B  illustrates the structure of a first conveying roller when the support member is located at the accommodated position. 
         FIG. 7  is a side view schematically illustrating an image forming apparatus according to a second embodiment when a supporting member is located at a drawn position. 
         FIG. 8  is a side view schematically illustrating the image forming apparatus according to the second embodiment when the supporting member is located at an accommodated position. 
         FIG. 9  is a side view schematically illustrating an image forming apparatus according to a third embodiment. 
         FIG. 10  is a side view schematically illustrating an image forming apparatus according to a fourth embodiment when an MP tray and a guide tray are opened state. 
         FIG. 11  is a side view schematically illustrating the image forming apparatus according to the fourth embodiment when the MP tray and the guide tray are closed state. 
         FIG. 12  is a side view schematically illustrating an image forming apparatus according to a fifth embodiment when a supporting member is located at a drawn position. 
         FIG. 13  is a side view schematically illustrating the image forming apparatus according to the fifth embodiment when the supporting member is located at an accommodated position. 
         FIG. 14  is a side view schematically illustrating an image forming apparatus according to a sixth embodiment when a supporting member is located at a drawn position. 
         FIG. 15  is a side view schematically illustrating the image forming apparatus according to the sixth embodiment when the supporting member is located at an accommodated position. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In the following description, a state in which an image forming apparatus  1  is placed as shown in  FIG. 1  so as to be used will be referred to as a reference state. Further, a direction in which a sheet tray  10  is drawn (i.e., a right-hand side in  FIG. 1 ) will be defined as a front side, while an opposite side will be referred to as a rear side. Right and left sides of the image forming apparatus  1  will be defined as directions when the image forming apparatus  1  is viewed from the front side. Furthermore, a discharge tray  82  side with respect to the image forming apparatus  1  will be referred to as an upside, while an opposite side will be referred to as a down side. An up-down direction, a right-left direction and a front-rear direction according to the above definition are indicated on each drawing. 
     First Embodiment 
     &lt;General Configuration of Image Forming Apparatus&gt; 
       FIG. 1  shows an image forming apparatus  1  according to a first embodiment of the present disclosures. The image forming apparatus  1  has a casing  2 , a supplying section  3 , an image forming section  5 , a discharging section  8 , and a support member  9  which constitutes a part the supplying section  3  and a part of the image forming section  5 . The support member  9  is configured to be inserted in and drawn from the casing  2  of the image forming apparatus  1 . 
     The casing  2  has approximately rectangular parallelepiped shape and has a front wall  21  (which is an example of a front wall), a rear wall  22  (which is an example of a rear wall), a left wall  23 , a right wall  24 , an upper wall  25  and a bottom wall  26 . On the front wall  21  and a front portion of the upper wall  25 , an opening  211  is formed. The support member  9  is inserted in or drawn from the casing  2  through the opening  211 . The opening  211  is covered with an openable cover  212 . 
     The supplying section  3  is arranged in a lower part of the image forming apparatus  1  and is configured to feed recording sheets (hereinafter, simply referred to as “sheets”) held by the supplying section  3  toward the image forming section  5  one by one. The image forming section  5  is arranged on a downstream side, in the sheet conveying direction, with respect to the supplying section  3 . The image forming section  5  is configured to form an image on the sheet conveyed from the supplying section  3 . The discharging section  8  is arranged on a downstream side, in the conveying direction, with respect to the image forming section  5 , and is configured to discharge the sheet on which an image has been formed outside the image forming apparatus  1 . 
     The supplying section  3  has a sheet tray  10 , a supplying mechanism  30 , a registration roller  31 , a multipurpose (MP) tray  40 , an MP tray side supplying mechanism  33 , a first conveying guide  34 , a second conveying guide  91 , a first conveying roller  35  and a second conveying roller  37 . 
     The sheet tray  10  is detachably attached to a lower part of the casing  2 . That is, the sheet tray  10  is detachable from and attachable to the lower part of the casing  2 . When the sheet tray  10  is inserted in to the casing  1  rearward from the front side, the sheet tray  10  is attached to the casing  2  and is located at an attached position. When the sheet tray  10  attached to the casing  2  is drawn frontward from the casing  2 , the sheet tray  10  is detached from the casing  2 . 
     The sheet tray  10  has a main body  11  configured to support a plurality of recording sheets and a pressure plate  12  arranged in the main body  11 . The plurality of recording sheets are mounted on the pressure plate  12 . The pressure plate  12  is configured to be displaceable in the up-down direction with mounting the plurality of recording sheets thereon. The pressure plate  12  is rotatably supported about a fulcrum  121 , and is configured to be displaced in the up-down direction by a pressure plate elevating member (not shown). 
     The supplying mechanism  30  is arranged on the rear wall  22  side inside the casing  2 . The supplying mechanism  30  is configured to pick up the recording sheets mounted on the sheet tray  10  one by one in a separated manner and convey the same toward the registration roller  31 . The supplying mechanism  30  has a pickup roller  301 , a separation roller  302  and a retard roller  303 . The separation roller  302  is an example of a feeding roller configured to convey the sheets supported by the sheet tray  10 . 
     The pickup roller  301  is for picking up one of the sheets which are lifted up to a feedable position by the pressure plate  12 . The pickup roller  301  is arranged above the pressure plate  12 . The separation roller  302  is arranged on a downstream side, in the conveying direction, with respect to the pickup roller  301 . The retard roller  303  is arranged to face the separation roller  302  and is urged toward the separation roller  302 , thereby a nip being formed by the separation roller  302  and the retard roller  303 . 
     The sheet(s) picked up by the pickup roller  301  is fed toward the separation roller  302 . Then, only one sheet is separated from the other (if any) at the nip between the separation roller  302  and the retard roller  303 , and conveyed through a conveying passage P 1  toward the registration roller  31 . 
     The registration roller  31  is arranged on the downstream side, in the conveying direction, with respect to the supplying mechanism  30 . The registration roller  31  once regulates movement of a leading end of the sheet conveyed between the registration roller  31  and a registration driven roller  32 , and thereafter, driven again to start conveying the sheet, at a particular timing, toward a transfer position. 
     The MP tray  40  is rotatably supported by the cover  212  so as to be rotatable between a closing position (indicated by solid lines in  FIG. 1 ) at which the MP tray  40  covers an opening  213  formed to the cover  212  and an opening position (indicated by two-dotted lines in  FIG. 1 ) at which the MP tray  40  uncovers the opening  213  (i.e., the opening  213  is exposed). When located at the opening position, the MP tray  40  is capable of supporting a plurality of sheets thereon. The MP tray side supplying mechanism  33  is configured to pick up a plurality of sheets supported by the MP tray  40  one by one in a separated manner and feeds the picked up sheet toward the first conveying roller  35 . The MP tray side supplying mechanism  33  has an MP tray side pickup roller  331  and an MP tray side separation roller  332 . 
     The MP tray side pickup roller  331  is for picking up one of the sheets which are supported by the MP tray  40 . The MP tray side separation roller  332  is arranged on the downstream side, in the sheet conveying direction, with respect to the MP tray side pickup roller  331 . The sheet(s) picked up by the MP tray side pickup roller  331  is fed toward the MP tray side separation roller  332 . Then, one sheet is separated from the others (if any) by the MP tray side separation roller  332  and conveyed toward the first conveying roller  35 . 
     The first conveying guide  34  is for guiding the sheet supplied from the MP tray  40  along a conveying passage P 2  extending from the front wall  21  of the casing  2  toward the rear wall  22 . The first conveying guide  34  is formed with, for example, ribs, and arranged, between the support member  9  and the sheet tray  10 , to face a bottom wall  95  of the support member  9 . The second conveying guide  91  is a guide having, for example, ribs formed on the bottom wall  95  of the support member  9 . The sheet supplied from the MP tray  40  is guided along the conveying passage P 2  by the first conveying guide  34  and the second conveying guide  9  which face each other. 
     The first conveying roller  35  is provided to the bottom wall  95  of the support member  9 . The first conveying roller  35  is configured to convey the sheet in association with a driving roller  36  which is arranged to face the first conveying roller  35 , the sheet being nipped between the conveying roller  35  and the driving roller  36 . The second conveying roller  37  is provided to the bottom wall  95  of the support member  9  on the rear side with respect to the first conveying roller  35 . The second conveying roller  37  conveys the sheet in association with a driving roller  38  which faces the second conveying roller  37 , the sheet being nipped between the second conveying roller  37  and the driving roller  38 . 
     According to the present embodiment, the image forming section  5  employs an electrophotographic imaging process. Concretely, the image forming section  5  includes a process cartridge  50  configured to transfer an image onto the surface of the sheet which is fed from the supplying section  3 , and a transfer roller  55  arranged to face a photosensitive drum  54  of the process cartridge  50 . The image forming section  5  further includes an exposure section  60  configured to emit light on the surface of the photosensitive drum  54 , and a fixing section  70  configured to fix the image transferred, by the process cartridge  50 , onto the sheet. 
     It is noted that the process cartridge  50  is attachably and detachably supported by the support member  9 . The process cartridge  50  includes a developer storage chamber  51 , a supplying roller  52 , a developing roller  53 , the photosensitive drum  54 , a charging roller  57  and a cleaning roller  58 . 
     The developer storage chamber  51  stores toner as the developer. The toner stored in the developer storage chamber  51  is agitated by an agitating member (not shown) and is sent to the supplying roller  52 . The supplying roller  52  supplies the toner, which has been sent from the developer storage chamber  51 , to the developing roller  53 . 
     The developing roller  53  is arranged to closely contact with the supplying roller  52 . The developing roller  53  carries the toner, which is supplied from the supplying roller  52  and positively charged by a not-shown sliding member. Further, to the developing roller  53 , positive developing bias is applied by a not-shown bias applying device. 
     The photosensitive drum  54  is arranged, inside the casing  2 , at a position closer to the rear wall  22  than the front wall  21 . Further, the photosensitive drum  54  is arranged adjacent to the developing roller  53 . A circumferential surface of the photosensitive drum  54  is uniformly charged by the charging roller  57 . Then, the circumferential surface of the photosensitive drum  54  is exposed to light emitted by the exposure section  60 . The charging roller  57  is cleaned by the cleaning roller  58 . Potential of portions of the photosensitive drum  54  exposed to light is made lower than that of the other portions and an electrostatic latent image is formed, based on image data, on the circumferential surface of the photosensitive drum  54 . Thereafter, as the positively charged toner is supplied from the developing roller  53 , the electrostatic latent image is developed to be a developer image. 
     The transfer roller  55  is provided inside the casing  2 . To the transfer roller  55 , a negative transfer bias is applied by a not-shown bias applying device. When the transfer bias is applied on the surface of the transfer roller  55 , by nipping and conveying the sheet between the photosensitive drum  54  carrying the developer image and the transfer roller  55  at a transfer position (i.e., the nip between the photosensitive drum  54  and the transfer roller  55 ), the developer image formed on the circumferential surface of the photosensitive drum  54  is transferred onto the surface of the sheet. 
     It is noted that the exposure section  60  has a laser diode, a polygonal mirror, lenses and a reflector. The exposure section  60  emits a laser beam, which is modulated based on the image data input to the image forming apparatus  1 , is scanned with use of the polygonal mirror. As mentioned above, the surface of the photosensitive drum  54  is exposed to the scanning laser beam which is modulated based on the image data, thereby the electrostatic latent image being formed on the photosensitive drum  54 . 
     The fixing section  70  has a heat roller  71  and a press roller  72 . The heat roller  71  is driven, by a driving force transmitted from a generally-known motor, to rotate, while the heat roller  71  generates heat as electric power is supplied from a generally-known power source. The press roller  72  is arranged to face the heat roller  71  so as to be press-contacted with each other. As the heat roller  71  rotates, the press roller  72  is driven, by the rotating force of the heat roller  71 , to rotate. When a sheet on which the developer image has been transferred is conveyed to the fixing section  70 , the fixing section  70  conveys the sheet with nipping the sheet between the heat roller  71  and the press roller  72 . As the heat and the pressure are applied to the sheet, the developer image is permanently fixed on the sheet. 
     The discharging section  8  has a discharge roller pair  81  and a discharge tray  82 . The discharge roller pair  81  includes a pair of rollers and configured to discharge the sheet conveyed from the fixing section  70  to outside of the casing  2 . The discharge tray  82  is formed on the upper wall  25  of the casing  2 . On the discharge tray  82 , the sheets discharged, by the discharge roller  81 , to the outside of the casing  2  are stacked. 
     The image forming apparatus  1  according to the present embodiment employs a configuration which enables the user to visually recognize the portion subject to the jam processing. Hereinafter, referring to  FIGS. 2-6 , the configuration which enables the visual recognition of the portion subject to the jam processing will be described in detail. 
       FIG. 2  schematically shows a side view of the image forming apparatus  1  when the support member  9  is located at the drawn position, while  FIG. 3  schematically shows a side view of the image forming apparatus  1  when the support member  9  is located at the accommodated position.  FIG. 4  is a front view of the image forming apparatus  1  with the cover  212  being removed.  FIG. 5  is a cross-sectional view of the image forming apparatus  1  taken along line A-A indicated in  FIG. 4 .  FIGS. 6A and 6B  illustrate a configuration of the first conveying roller  35  and  FIG. 6A  shows a case where the support member  9  is located at the drawn position, while  FIG. 6B  shows a case where the support member  9  is located at the accommodated position. It is noted that, in  FIG. 2 , a guiding member  27  and a positioning member  28  are hatched by oblique lines so as to be visually recognized easily. 
     &lt;Support Member&gt; 
     The support member  9  is configured to detachably and attachably support the process cartridge  50 . Further, the second conveying guide  91  is formed on the support member  9 . The support member  9  is a box-like member which has, as shown in  FIGS. 2-5 , a front wall  92 , a left wall  93 , a right wall  94 , the bottom wall  95  on which the second conveying guide  91  is formed, an opened part  96  exposing the a rear wall and an upper wall, and a grip  97  protruded from the front wall  92 . On the right wall  94  and the left wall  93 , first protruded parts  98 , which are cylindrical parts protruding outward in a horizontal direction (i.e., the right-left direction), are provided respectively and symmetrically with respect to the horizontal direction. 
     The support member  9  is configured to slide between the accommodated position (see  FIG. 3 ) at which the support member  9  is accommodated inside the casing  2  and the drawn position (see  FIG. 2 ) at which the support member  9  is drawn out of the casing  2  through the opening  211 . When the support member  9  is moved to the drawn position, the process cartridge  50  can be exchanged and the jam processing can be performed. 
     &lt;Process Cartridge&gt; 
     The process cartridge  50  is accommodated in a part surrounded by the front wall  92 , the left wall  93 , the right wall  94  and the bottom wall  95  of the support member  9 . According to the above configuration, the photosensitive drum  54  is exposed toward the rear wall  22  through the opened part  96 . To portions of the right and left side faces of the process cartridge  50  which is protruded rearward through the opened part  96  of the support member  9 , second protruded parts  56  which are cylindrical parts protruding outward in the horizontal direction are respectively provided symmetrically with respect to the right-left direction. The second protruded parts  56  are arranged on an upper side with respect to the first protruded parts  98 , respectively. 
     &lt;Guiding Members&gt; 
     On inner surfaces of the left wall  23  and the right wall  24  of the casing  2 , the guiding members  27  configured to guide the support member  9  and the process cartridge  50  are arranged symmetrically with respect to the right-left direction. Each of the guiding members  27  is formed with, as shown in  FIGS. 2 and 3 , a first groove  271  for guiding the first protruded part  98  and a second groove  272  for guiding the second protruded part  56  and a second positioning part  273  for positioning the second conveying roller  37 . 
     As shown in  FIG. 2 , the size of the first groove  271  is defined such that the first protruded part  98  is movably supported by the first groove  271 . The first groove  271  includes a front end part  271 A which is a closed portion located in the vicinity of the front wall  21  of the casing  2 . The first groove  271  further includes a horizontal part  271 B extending rearward and horizontally, from the front end part  271 A, an inclined part  271 C inclining rearward and downward from the horizontal part  271 B, a horizontal part  271 D extending rearward and horizontally from the inclined part  271 C, and a rear end part  271 E which is a closed part following the horizontal part  217 D and located in the vicinity of the rear wall  22  of the casing  2 . The front end part  271 A serves as a stopper which contacts the first protruded part  98  of the support member  9  to prevent the support member  9  from coming off from the drawing position. Further, when the rear end part  271 E contacts the first protruded part  98  of the support member  9 , the support member  9  is positioned. 
     The size of the second groove  272  is defined such that the second protruded part  56  is movably supported by the second groove  272 . The second groove  272  is formed on an upper side with respect to the first groove  271  and extends along the first groove  271 . That is, the second groove  272  includes a front end part  272 A which is located in the vicinity of the rear wall  22  of the casing and formed to be opened frontward, a horizontal part  272 B horizontally extending rearward from the front end part  272 A, an inclined part  272 C inclined rearward and downward from the horizontal part  272 B, a horizontal part  272 D horizontally extending rearward from the inclined part  272 C and a rear end part  272 E connected to the horizontal part  272 D and located in the vicinity of the rear wall  22  of the casing and formed to be closed. As shown in  FIG. 3 , as the second protruded part  56  contacts the rear end part  272 E, the process cartridge  50  is positioned. 
     As shown in  FIG. 2 , the second positioning part  273  is formed in the vicinity of the driving roller  38 . The second positioning part  273  has a vertical surface, which is perpendicular to the front-rear direction. When the support member  9  is located at the accommodated position, the second conveying roller  37  contacts the vertical surface of the second positioning part  273  as shown in  FIG. 3 . Further, the second positioning part  273  is provided with a torsion coil spring  274  which is arranged such that one end of the torsion coil spring  274  protrudes frontward with respect to the second positioning part  273 . 
     &lt;Positioning Member&gt; 
     As shown in  FIG. 4 , on inner surfaces of the left wall  23  and right wall  24  of the casing  2 , positioning members  28  are arranged symmetrically with respect to the right-left direction. As shown in  FIG. 2 , each positioning member  28  has a first positioning part  281  which is used for positioning of the first conveying roller  35 . The first positioning part  281  is located on the front side with respect to the second positioning part  273  and in the vicinity of the driving roller  36 . The height position of the first positioning part  281  is the same as the height position of the second positioning part  273 . The first positioning part  281  has a vertical surface which is perpendicular to the front-rear direction. When the support member  9  is located at the accommodated position, the first conveying roller  35  contacts the vertical surface of the first positioning part  281  as shown in  FIG. 2 . Further, the first positioning part  281  is provided with a torsion coil spring  282  which is arranged such that one end of the torsion coil spring  281  protrudes frontward with respect to the first positioning part  281 . 
     &lt;First Conveying Roller and Second Conveying Roller&gt; 
     As shown in  FIG. 6A , the first conveying roller  35  has an engaging part  351  which engages with a hole  951  formed on the bottom wall  95  of the support member  9 , a rotatable shaft  352  which extends in the right-left direction and is rotatably supported by the engaging part  351  and a roller part  353  provided on a circumferential surface of the rotatable shaft  352 . On an upper end of the engaging part  351 , a claw part  351 A is formed to engage with the hole  951  of the support member  9 . 
     The first conveying roller  35  is movable in the up-down direction. When the support member  9  is located at the drawn position, the first conveying roller  35  is located at its lowermost position by its own weight as shown in  FIG. 6A . When the support member  9  is located at the accommodated position, as shown in  FIG. 6B , the first conveying roller  35  contacts the driving roller  36  and is lifted up thereby, while urged downward by the torsion coil spring  282 . Thus, the first conveying roller  35  and the driving roller  36  form a nip therebetween. It is noted that the structure of the second conveying roller  37  is the same as that of the first conveying roller  35 , and a detailed description thereof will be omitted for brevity. 
     &lt;Effects&gt; 
     According to the above-described configuration, as shown in  FIG. 2 , by moving the support member  9  to the drawn position, the second conveying guide  91  moves frontward and the upper part of the conveying passage P 2  is exposed to outside. Accordingly, the user can visually recognize a portion subject to the jam processing from an obliquely upper side thereof. That is, according to the above-described configuration, it is easy to visually recognize the portion subject to the jam processing in comparison with a conventional configuration of completely removing the sheet tray. 
     Further, only by one operation of sliding the support member  9  from the accommodated position to the drawn position, the conveying passage P 2  defined by the first conveying guide  34  and the second conveying guide  91  is exposed to outside. Therefore, in comparison with a conventional configuration in which two operations (i.e., a first operation of drawing the sheet tray and a second operation of moving down the conveyance guide) are required, the jam processing can be done easily. 
     According to the above-described configuration, the opened part  96  is formed to the support member  9 . By forming the rear wall  22  side of the support member  9  as the opened part  96  which does not have walls, the support member  9  does not obstacles the jam processing after the support member  9  is slid do the drain position and the process cartridge  50  is removed (as indicated by two-dotted lines in  FIG. 2 ). Thus, in comparison with a case where the rear wall  22  side of the support member  9  is formed to have walls, the jam processing can be performed much easier. 
     According to the above-described configuration, by positioning the first conveying roller  35  with use of the positioning member  28  provided to the casing  2 , the first conveying roller  35  can be positioned with high accuracy. The same effects can be achieved by the second positioning part  273 . It is noted that one of the first positioning part  281  and the second positioning part  273  may be omitted. 
     According to the first conveying roller  35  and the second conveying roller  37 , conveyance resistance of the sheet in the conveying passage P 2  can be reduced, thereby the sheet being conveyed smoothly. Further, by configuring the first conveying roller  25  and the second conveying roller  37  as driven rollers, it become unnecessary to provide a complex mechanism to transmit a driving force to the rollers which are provided to the movable support member  9 . 
     Second Embodiment 
       FIG. 7  shows an image forming apparatus  101  according to a second embodiment of the present disclosures. It is noted that  FIG. 7  shows a state where the support member  9  is located at the drawn position, while  FIG. 8  shows the image forming apparatus  101  when the support member  9  is located at the accommodated position. In  FIG. 7 , a guiding member  27 A and a positioning member are hatched with oblique lines so as to be easily recognized. In the following description, configurations different from those in the first embodiment are mainly described. The components same as those in the first embodiment are assigned with the same reference numbers and detailed descriptions thereof will be omitted for brevity. 
     The image forming apparatus  101  has, as configurations different from those of the image forming apparatus  1  according to the first embodiment, a first conveying guide  34 A, a first conveying roller  35 A, a second conveying roller  37 A, a second conveying guide  91 A, a driving roller  36 A arranged to face the first conveying roller  35 A, a driving roller  38 A arranged to face the second conveying roller  37 A and a guiding member  27 A. 
     In a state shown in  FIG. 8 , the first conveying guide  34 A and the second conveying guide  91 A are arranged to face each other, both being inclined such that rear sides thereof are higher than front sides thereof. Further, the second conveying roller  37 A and the driving roller  38 A are arranged at higher levels than the first conveying roller  35 A and the driving roller  36 A, respectively. In accordance with the first conveying roller  35 A being arranged at a relatively lower position, the MP tray side supplying mechanism  33  is also arranged at a lower position. 
     According to the above configuration, when the support member  9  is slid horizontally for insertion or removal, the second conveying roller  37 A and the driving roller  36 A may hardly interfere with each other. Therefore, the guiding member  27 A may be configured such that an inclined part  271 F and an inclined part  272 F can be made shorter than the inclined part  271 C and the inclined part  272 C of the first embodiment, respectively. According to the above configuration, moving amount in the up-down direction (i.e., a difference of heights of the support member  9  shown in  FIG. 7  and in  FIG. 8 ) when the support member  9  is slid is suppressed, thereby an operability being improved. 
     Third Embodiment 
       FIG. 9  shows an image forming apparatus  102  according to a third embodiment of the present disclosures. In the following description, configurations different from those of the third embodiment will be mainly described, while configurations similar to those of the first embodiment are assigned with the same reference numbers and detailed description thereof will be omitted for brevity. As the configurations different from the image forming apparatus  1  according to the first embodiment, the image forming apparatus  102  has a sheet insertion section  41 , a curved guide  99  (which an example of a third conveying guide) and a sheet sensor  39 . 
     The sheet insertion part  41  is an opening through which the sheets are to be inserted one by one. The sheet insertion part  41  is formed on the MP tray  40  at a position facing the support member  9  when the MP tray  40  is located at the closing position. The sheet insertion part  41  is formed to penetrate through the MP tray  40  in the front-rear direction, and has a size allowing the sheets to pass through. 
     The curved guide  99  is formed on a front part of the support member  9 . The curved guide  99  has ribs and is for guiding the sheet inserted through the sheet insertion part  41  to the conveying passage P 2 . One end  99 A of the curved guide  99  is arranged at a position facing the sheet insertion part  41  formed on the front wall  92  of the support member  9 , while the other end  99 B of the curved guide  99  is arranged on the bottom wall  95  of the support member  9  at a position on a front side with respect to the first conveying roller  35 . A portion between the one end  99 A and the other end  99 B is formed as a curved surface (i.e., each rib has a curved surface) in order that the sheet is conveyed smoothly. 
     The sheet sensor  39  is a mechanical sensor for detecting a sheet being conveyed, and is arranged on the conveying passage P 2  at a position on the front side with respect to the first conveying roller  35 . As the leading end of the sheet inserted through the sheet insertion part  41  pushes down the sheet sensor  39 , the image forming apparatus  102  detects insertion of the sheet and drives the driving roller  36 . 
     As described above, with the image forming apparatus  102  according to the third embodiment, the sheet can be supplied through the sheet insertion part  41  easily without deteriorating easiness of exchangeability of the process cartridge  50 . Further, operability of the image forming apparatus  102  is improved since the number of the sheet supplying passages is increased. 
     Fourth Embodiment 
       FIG. 10  shows an image forming apparatus  103  according to a fourth embodiment of the present disclosures. The image forming apparatus  103  employs another configuration to introduce the sheet to the conveying passage P 2  instead of the curved guide  99  employed in the image forming apparatus  102  according to the third embodiment.  FIG. 10  shows a state where the MP tray  40  and a guide tray  991  are opened, while  FIG. 11  shows a state where the MP tray  50  and the guide tray  991  are closed. As the configurations different from the image forming apparatus  1  according to the first embodiment, the image forming apparatus  103  has the guide tray  991 , which is an example of a third conveying guide, and the sheet sensor  39 , which is the same as that of the third embodiment. 
     The guide tray  991  is formed on a front side of the support member  9  and is configured to guide the sheet supplied through an opening  213  to the conveying passage P 2 . The guide tray  991  is rotatably supported by the support member  9  such that the guide tray  991  is rotatable between a closing position at which the guide tray  991  stands upright (i.e., a position shown in  FIG. 11 ) and an opening position (i.e., a position shown in  FIG. 10 ) at which the guide tray  991  inclines toward the opening  213 , or falls frontward through the opening  213 . The guide tray  991  is configured to guide the sheet toward the first conveying roller  35  when located at the opening position. 
     With the image forming apparatus  103  according to the fourth embodiment, a sheet can be supplied through the guide tray  991 . Further, since the number of the sheet supplying passages is increased, the operability of the image forming apparatus is improved. 
     Fifth Embodiment 
       FIG. 12  shows an image forming apparatus  104  according to a fifth embodiment.  FIG. 12  shows a state where a support member  9 A is located at the drawn position, while  FIG. 13  shows a state where the support member  9 A is located at the accommodated position. In  FIG. 12 , the guiding member  27  and the positioning member are hatched with oblique lines so as to be visually recognizable easily. In the following description, configurations different from those of the first embodiment are mainly described. Configurations the same as those of the first embodiment are assigned with the reference numbers same as those used in the first embodiment and the detailed description thereof will be omitted for brevity. It is noted that the image forming apparatus  104  has, as configurations different from those in the first embodiment, the support member  9 A. 
     The support member  9 A has a transfer roller  55 A which is arranged to face the photosensitive drum  54 . It is noted that, according to the first embodiment, the transfer roller  55  of the first embodiment provided to the casing  2 . In contrast, according to the fifth embodiment, the transfer roller  55 A is provided to the support member  9 A and is movable together with the support member  9 A. 
     According to the fifth embodiment, when the support member  9 A is moved to the drawn position, the transfer roller  55 A is also drawn out of the casing  2 . Accordingly, the sheet jammed between the photosensitive drum  54  and the transfer roller  55 A can be drawn, together with the support member  9 A, out of the casing  2 . Thus, the jam processing can be performed easily. 
     Sixth Embodiment 
       FIG. 14  shows an image forming apparatus  105  according to a sixth embodiment of the present disclosures.  FIG. 14  shows a state where a support member  9 B is located at the drawn position, while  FIG. 15  shows a state where the support member  9 B is located at the accommodated position. In  FIG. 14 , the guiding member  27  and the positioning member are hatched with oblique lines so as to be easily recognized. In the following description, configurations different from those of the first embodiment will be mainly described. Configurations the same as those of the first embodiment will be assigned with the same reference numbers and the detailed description thereof will be omitted for brevity. The image forming apparatus  105  has a support member  9 B which is a configuration different from that of the image forming apparatus  1  according to the first embodiment. 
     The support member  9 B has an MP tray side supplying mechanism  33 A at a lower front portion thereof. The MP tray side supplying mechanism  33 A has an MP tray side pickup roller  331 A and an MP tray side separation roller  332 A. It is noted that, in the first embodiment, the MP tray side supplying mechanism  33  is provided to the casing  2 . In contrast, according to the sixth embodiment, the MP tray side supplying mechanism  33 A is provided to the support member  9 B. According to this configuration, the MP tray side supplying mechanism  33 A is movable together with the support member  9 B. 
     Since the MP tray side supplying mechanism  33 A is drawn as the support member  9 B is moved to the drawn position. Therefore, when the support member  9 B is inserted into or drawn from the casing  2 , it does not interfere with the MP tray side supplying mechanism  33 A and the operability is improved. 
     Effects of the Embodiments 
     The image forming apparatus according to the first embodiment is the image forming apparatus  1  employing the electrophotographic imaging method and has the casing  2 . The casing  2  has the front wall  21  on which the opening  211  is formed and the rear wall  22  arranged to face the front wall  21 . The image forming apparatus  1  further includes the photosensitive drum  54 , which is arranged, inside the casing  2 , at the position closer to the rear wall  22  than the front wall  21 . The image forming apparatus  1  further includes the support member  9  which supports the photosensitive drum  54  and is slidably movable between the accommodated position at which the photosensitive drum  54  is located inside the casing  2  and the drawn position at which the photosensitive drum  54  is drown out of the casing  2  through the opening  211  formed on the front wall  21 . The image forming apparatus  1  further includes the sheet tray  10  arranged, inside the casing  2 , at the position lower than the support member  9 . The sheet tray  10  supports the sheets. Still further, the image forming apparatus  1  has the separation roller  302  which is arranged, inside the casing  2 , at the position closer to the rear wall  22  than the front wall  21  and is configured to feed the sheet supported by the sheet tray  10 . The image forming apparatus  1  is further provided with the first conveying guide  34  which is arranged to face the support member  9  between the support member  9  and the sheet tray  10  and is configured to guide, inside the casing  2 , the sheet inserted through the opening  213  from the front wall  21  to the rear wall  22 . Furthermore, the image forming apparatus  1  is provided with the second conveying guide  91  which is arranged to support member  9  at the position facing the first conveying guide  34  and is configured to guide the sheet inserted through the opening  213 . 
     According to the above configuration, by moving the support member  9  to the drawn position, the second conveying guide  91  moves out of the casing  2  and the upper portion of the conveying passage P 2  is opened. Accordingly, the user can visually recognize the portion subject to the jam processing from an obliquely upper position thereof. In comparison with the conventional configuration in which the sheet tray is withdrawn and the user look into the casing through the opening from which the sheet tray  10  is withdrawn, the user can visually recognize the portion easier. Further, with only one operation of sliding the support member  9  from the accommodated position to the drawn position, the conveying passage P 2  defined by the first conveying guide  34  and the second conveying guide  91  is opened, the jam processing can be performed much easier in comparison with a conventional case where two operations of withdrawing the sheet tray and then moving the conveying guide downward are necessary to perform the jam processing. 
     The image forming apparatus  1  according to the first embodiment is configured that the second conveying guide  91  of the support member  9  includes the first conveying roller  35  for conveying the sheet. 
     According to the above configuration, with use of the first conveying roller  35 , the conveying resistance of the sheet can be reduced, thereby the sheet being conveyed smoothly. 
     The image forming apparatus  1  according to the first embodiment is configured such that the driving roller  36  which forms a nip in association with the first conveying roller  35  is provided to the casing  2 . The first conveying roller  35  is a driven roller which is driven by the rotation of the driving roller  36 . 
     According to the above configuration, a complex mechanism for inputting the driving force to the first conveying roller  35  provided to the support member  9  is not necessary. 
     In the image forming apparatus  1  according to the first embodiment, the casing  2  has the first positioning part  281  which is configured to position the first conveying roller  35  when the support member  9  is located at the accommodated position. 
     According to the above configuration, by positioning the first conveying roller  35  with use of the first positioning part  281  provided to the casing  2 , the first conveying roller  35  can be positioned with high accuracy. 
     The image forming apparatus  101  according to the second embodiment is configured such that the support member  9  has the second conveying roller  37 A. When the support member  9  is located at the accommodated position, the second conveying roller  37 A conveys the sheet guided by the second conveying guide  91 A on the rear wall  22  side with respect to the first conveying roller  35 A and on an upper level with respect to the first conveying roller  35 A. 
     According to the above configuration, since the second conveying roller  37 A is arranged at the upper level than the first conveying roller  35 A, an operability in sliding the support member  9  is excellent. 
     In the image forming apparatus  1  according to the first embodiment, on the rear wall  22  side portion of the support member  9 , an opened part exposing the photosensitive drum  54  without covering the same is provided. 
     According to the above configuration, the opened part  96 , which does not have any walls, is formed on the support member  9  at the position on the rear wall  22  side thereof. With this configuration, by sliding the support member  9  to the drawn position and then removing the process cartridge  50  from the support member  9 , the jam processing can be performed easier in comparison with a case where there remains walls which may obstacle the jam processing. 
     With the image forming apparatus  102  according to the third embodiment or  103  according to the fourth embodiment, the support member  9  is provided with the curved guide  99  or the guide tray  991  configured to guide the sheet toward the portion between the first conveying guide  34  and the second conveying guide  91 . 
     According to the above configuration, the sheets can be supplied through the curved guide  99  or the guide tray  991 . Further, the number of the sheet supplying passages is increased, thereby operability being improved. 
     In the image forming apparatus  104  according to the fifth embodiment, the transfer roller  55 A for transferring the toner image onto the sheet is arranged on the support member  9 A at the position facing the photosensitive drum  54 . 
     According to the above configuration, by moving the support member  9 A to the drawn position, the transfer roller  55 A is also drawn, it becomes possible to withdraw the sheet jammed at the position between the photosensitive drum  54  and the transfer roller  55 A and the jam processing can be performed easily.