Abstract:
An image forming apparatus includes a collection container for collecting toner discharged from an image forming station, the collection container being movable between a mount position in which the collection container is mounted in the apparatus and a removable position in which the collection container is removable from the apparatus; and a door provided on the apparatus to permit access into the apparatus; wherein a track of the collection container when collection container is moved from the mount position to the removable position overlaps a track of the openable member when the openable member is opened and closed, and wherein when the openable member is in the opening position, the collection container is incapable of removing from the main assembly, and when the openable member is in the closing position, the collection container is removable from the main assembly.

Description:
FIELD OF THE INVENTION AND RELATED ART 
       [0001]    The present invention relates to an image forming apparatus which recovers residual toner in its image forming section, and cumulatively stores the recovered toner recovered in its recovery container, by conveying the recovered toner to the recovery container. More precisely, it relates to a structure for taking the recovery container out of a preset position in the casing of the image forming apparatus. 
         [0002]    An image forming apparatus which forms a toner image in its image forming section and directly transfers the tone image onto a sheet of recording medium, or indirectly transfers the toner image by way of an intermediary transferring member, has been widely in use. This type of image forming apparatus is equipped with a container in which transfer residual toner, and the like, which are generated while a toner image is formed in the image forming section, is cumulatively stored. Hereafter, this container will be referred to simply as a “recovery container.” The recovery container is installed in the casing of the image forming apparatus (Japanese Laid-open Patent Application 2008-3294). 
         [0003]    As a recovery container in the casing of an image forming apparatus is filled up with recovered toner, and the like, it is replaced with a new and empty recovery container. In the case of the image forming apparatus disclosed in Japanese Laid-open Patent Application 2008-3294, its recovery container is placed in a preset positioned in the casing of the apparatus so that it can be easily removed from the casing of the image forming apparatus, from the outward side of the casing, and also, so that a replacement recovery container can be easily installed into the preset position. More concretely, the image forming apparatus is structured so that the recovery container can be pulled out of the casing of the apparatus, from the front side of the apparatus, to be replaced with a new and empty recovery container. 
         [0004]    From the standpoint of reducing the frequency with which a recovery container needs to be replaced, the recovery container is desired to be as large as possible. However, a recovery container which is large in bottom area size and low in height is difficult to fill up in such a manner that toner evenly spread across the entirety of the container as it falls into the container. Therefore, a recovery container is desired to be tall, and small in footprint. 
         [0005]    However, equipping the image forming apparatus disclosed in Japanese Laid-open Patent Application 2008-3294, with a tall recovery container requires a larger space for the recovery container to be pulled out frontward, which in turn increases in size the casing of the image forming apparatus. Further, it reduces the apparatus in latitude in terms of the interior design of the casing. Moreover, it becomes impossible to provide the casing with an internal space into which one of the two subassemblies, of which a sheet conveyance passage for reversing a sheet of recording medium is made, can be retracted. Further, when an exposing device, a fixing device, etc., need to be moved out of the casing, they are to be moved in the direction perpendicular to the direction in which the recovery container is to be pulled out. In other words, it makes impossible to properly position an exposing device, a fixing device, etc., in the casing. 
       SUMMARY OF THE INVENTION 
       [0006]    The primary object of the present invention is to provide an image forming apparatus, the casing of which is no larger than that of a conventional image forming apparatus, and yet, can provide an internal passage through which a large recovery container can be pulled out of the casing. 
         [0007]    According to an aspect of the present invention, there is provided an image forming apparatus comprising a main assembly; an image forming station configured to form a toner image; a collection container configured to collect toner discharged from said image forming station, said collection container being movable between a mount position in which said collection container is mounted in said main assembly and a removable position in which said collection container is removable from said main assembly; and an openable member provided on said main assembly to permit access into the main assembly; wherein a track of said collection container at the time when collection container is moved from the mount position to the removable position overlaps a track of said openable member at the time when openable member is opened and closed, and wherein when said openable member is in the opening position, said collection container is incapable of removing from said main assembly, and when said openable member is in the closing position, said collection container is removable from said main assembly. 
         [0008]    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 
         [0009]      FIG. 1  is a drawing for describing the structure of an image forming apparatus in the first embodiment of the present invention. 
           [0010]      FIG. 2  is a drawing for describing the developer recovery system of the image forming apparatus in the first embodiment. 
           [0011]      FIG. 3  is a plan view of the developer recovery system of the image forming apparatus in the first embodiment. 
           [0012]      FIG. 4  is a perspective view of the recovery container in the first embodiment. 
           [0013]      FIG. 5  is a drawing for describing the structure for pulling the recovery container out of the casing of the image forming apparatus. 
           [0014]      FIG. 6  is a perspective view of the recovery container in the second embodiment of the present invention. 
           [0015]      FIG. 7  is a front view of the developer recovery system of the image forming apparatus in the second embodiment. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]    Hereinafter, embodiments of the present invention are described in detail with reference to the appended drawings. 
       Embodiment 1 
       [0017]    Referring to  FIG. 1 , a recovery container  200  is movable inward or outward of the main assembly of the image forming apparatus to be placed in its preset inside position (installation position) in the main assembly, and also, in its preset outside position (uninstallation position) which makes it possible for the recovery container to be removed from the main assembly. It is in the inside position that the recovery container catches the toner discharged from a discharge pipe  201 , which is a part of the image forming section of the apparatus. The preset inside position is such a position that makes the space, through which the recovery container moves when it is moved from its inside position to its outside position, overlaps with the space, through which the door for accessing the aforementioned sheet reversing passage moves when it is opened or closed. 
         [0018]    A door  150 , which is an example of a component which can be opened or closed, is such a door that allows a user of the image forming apparatus to access the interior of the main assembly of the image forming apparatus. More specifically, the door  150  is for allowing a user to access the sheet reversing passage to remove a jammed sheet of recording medium (paper) or the like. Hereafter, this door  150  will be referred to as a “reversal sheet passage access door, or interior access door”. The interior access door  150  is provided with sheet conveyance rollers, and is pivotally movable about its pivot, relative to one of the lateral walls of the apparatus main assembly  101   a , to enable a user to access the interior of the apparatus main assembly. When the interior access door  150  is open, it is impossible for the recovery container  200  to be moved out of the apparatus main assembly  101   a.  When the interior access door  150  remains closed, it is possible for the recovery container  200  to be moved out of the apparatus main assembly. 
       (Image Forming Apparatus) 
       [0019]      FIG. 1  is a drawing for describing the structure of the image forming apparatus. Referring to  FIG. 1 , the image forming apparatus  100  is a full-color printer of the so-called tandem type, and also, of the so-called intermediary transfer type. It has an intermediary transfer belt  31 , and image forming sections  1 Y,  1 M,  1 C and  1 K for forming yellow, magenta, cyan, and black toner images, respectively. The four image forming sections are sequentially positioned in parallel along the intermediary transfer belt  31 . 
         [0020]    In the image forming section  1 Y, a yellow tone image is formed on its photosensitive drum  11 Y, and is transferred (primary transfer) onto the intermediary transfer belt  31 . In the image forming section  1 M, a magenta toner image is formed on its photosensitive drum  11 M, and is transferred (primary transfer) onto the intermediary transfer belt  31 . In the image forming sections  1 C and  1 M, cyan and black toner images are formed on their photosensitive drums  11 C and  11 K, respectively, and are transferred (primary transferred) onto the intermediary transfer belt  31 . 
         [0021]    Sheets S of recording medium (paper) are moved out of a cassettes  61 - 64  one by one. Then, each sheet S is delivered to a pair of registration rollers  75 , by which it is kept on standby. Then, it is conveyed by the registration rollers  75  to a transfer section T 2 , with such timing that it arrives at the transfer section T 2  at the same time as the toner images on the intermediary transfer belt  31 . In the transfer section T 2 , the toner images on the intermediary transfer belt  31  are transferred (secondary transfer) onto the sheet S. After the transfer (secondary transfer) of the four toner images, different in color, onto the sheet S, the sheet S is conveyed to a fixing device  5 , and is conveyed through the fixing device  5  while being subjected to heat and pressure by the fixing device  5  so that the four toner images on the sheet S are fixed to the sheet S. Then, the sheet S is discharged into a delivery tray  65 . 
       (Image Forming Section) 
       [0022]    Referring to  FIG. 1 , the image forming sections  1 Y,  1 M,  1 C and  1 K are practically the same in structure, although they are different in the color of the toner they use; they use yellow, magenta, cyan and black toners, respectively. Hereafter, therefore, only the image forming section  1 Y, which forms a yellow toner image, is described. That is, the image forming sections  1 M,  1 C and  1 K are not described in order not to repeat the same description. 
         [0023]    The image forming section  1 Y has the photosensitive drum  11 Y, and various drum processing means, more specifically, a charge roller  12 Y, an exposing device  13 Y, a developing device  14 Y, a transfer roller  35 Y, and a drum cleaning device  15 Y, which are disposed in the adjacencies of the peripheral surface of the photosensitive drum  11 Y. The photosensitive drum  11 Y is made up of a substrate, and a photosensitive layer formed on the peripheral surface of the substrate. It rotates leftward of the drawing. The charge roller  12 Y uniformly and negatively charges the peripheral surface of the photosensitive drum  11 Y to a preset potential level VD (pre-exposure level). 
         [0024]    The exposing device  13 Y scans the peripheral surface of the photosensitive drum  11 Y with a beam of laser light which it outputs while modulating (turning on or off) the beam with the image formation signals obtained by separating the image to be formed, into monochromatic images. As a given point of the uniformly charged area of the peripheral surface of the photosensitive drum  11 Y is exposed to the beam of laser light, its potential level (VD) reduces to VL (post-exposure level). Consequently, an electrostatic latent image, which reflects the image to be formed, is effected on the peripheral surface of the photosensitive drum  11 Y. 
         [0025]    The developing device  14 Y stirs developer, which is a mixture of toner and carrier, charging thereby the toner and carrier to the negative and positive polarities, respectively. It causes its development sleeve to bear the developer in such a manner that the developer crests to develop the electrostatic latent image on the photosensitive drum  11 Y. 
         [0026]    The transfer roller  35 Y presses on the inward surface of the intermediary transfer belt  31 . Thus, a transfer section, which transfers the toner image, is formed between the photosensitive drum  11 Y and intermediary transfer belt  31 . As positive DC voltage is applied to the transfer roller  35 Y, the toner image on the photosensitive drum  11 Y is transferred onto the intermediary transfer belt  31 . 
         [0027]    The intermediary transfer belt  31  is suspended and kept tension by a combination of a tension roller  33 , a driver roller  34 , and a secondary transfer inside roller  31 . It circularly moves rightward of the drawing, by being driven by the driver roller  34 . The secondary transfer roller  41  forms the secondary transfer section T 2  by being placed in contact with the intermediary transfer belt  31  backed up by the secondary transfer inside roller  32 . 
       (Developer Recovery Passage) 
       [0028]      FIG. 2  is a drawing for describing the developer recovery system of the image forming apparatus  100 .  FIG. 3  is a plan view of the developer recovery system of the image forming apparatus  100 .  FIG. 3(   a ) is related to a period in which an image is being formed, and  FIG. 3(   b ) is related to a period in which the recovery container in the apparatus main assembly is replaced. Further,  FIG. 3(   c ) is related to a period in which a jammed sheet is removed. 
         [0029]    Referring to  FIG. 2 , as an image is formed by the image forming apparatus  100 , a minute amount toner fails to be transferred, and therefore, remains adhered to the peripheral surface of the photosensitive drum  11 Y. This toner, which hereafter will be referred to as transfer residual toner, is scraped away by the cleaning blade of the drum cleaning device  15 Y, and is conveyed by an unshown conveyance screw to a vertical pipe  203 , which is in the rear side of the casing of the image forming apparatus  100 . 
         [0030]    As the two-component developer is continuously stirred for a long time in the developing device  14 Y, it gradually reduces in chargeability. Therefore, the two-component developer in the developing device  14 Y is taken out by a preset amount (at a preset ratio), and recovered. In order to compensate the developing device  14 Y for the toner consumed by image formation, the developing device  14 Y is replenished with replenishment developer which contains carrier by 10%. During an image forming operation, while the developer in the developing device  14 Y is circularly moved in the developing device  14 Y, it overflows from the developing device  14 Y little by little, more specifically, by an amount (at a ratio) proportional to the amount of the toner consumption, and is conveyed, as deteriorated toner, to the vertical pipe  202 . 
         [0031]    During an image forming operation, a small amount of toner in the toner image(s) on the intermediary transfer belt  31  fails to be transferred onto a sheet S of recording medium, and remains adhered to the intermediary transfer belt  31 . This toner, which hereafter will be referred to also as transfer residual toner, is scraped away by the cleaning blade  101  of the belt cleaning device  36 , and is conveyed by an unsown conveyance screw to the vertical pipe  202  which is in the rear portion of the casing of the image forming apparatus  100 . 
         [0032]    After the transfer residual toner and deteriorated developer are conveyed to the vertical pipes  202  and  203 , respectively, they are made to merge into a main recovery pipe  204 . Next, referring to  FIG. 3(   a ), after having merged into the main recovery pipe  204 , the transfer residual toner and deteriorated developer are conveyed by a recovery screw  205  to a discharge pipe  201 , fall through the discharge pipe  201 , and accumulate in the recovery container  200 . 
         [0033]    Providing each of the image forming sections  1 Y,  1 M,  1 C and  1 K, and the belt cleaning device  36 , with its own recovery container makes it difficult and/or complicated to detect whether or not each recovery container is full. Further, it makes complicated the operation for replacing the recovery container in the developing device. Therefore, the transfer residual toner and deteriorated developer are accumulated together in the recovery container  200  as a common recovery container. As the recovery container  200  is filled up with the recovery toner, it is replaced by an empty one. That is, it is a discardable component. In recent years, an image forming apparatus has been substantially improved in image quality and operational speed. Thus, the recovery container  200  has been increased in capacity. From the standpoint of operability, an image forming apparatus is desired to be structured so that a jammed sheet of recording medium, etc., can be removed from the front side of the image forming apparatus, and also, so that the recovery container in the developing device can be replaced from the front side of the image forming apparatus  100 . 
       (Recovery Container) 
       [0034]      FIG. 4  is a perspective view of the recovery container  200  in the first embodiment of the present invention. Referring to  FIG. 3(   b ), the recovery container  200  is mounted on a recovery container tray  210 , in such a manner that it can be moved frontward or rearward in the space in the casing of the image forming apparatus  100 , by the recovery container tray  210 . The recovery container tray  210  is movable between the first tray position, in which it is entirely in the apparatus main assembly, and the second tray position, in which it allows the recovery container  200  to be placed in the tray  210 , or removed from the tray  210 . 
         [0035]    Next, referring to  FIG. 4 , the recovery container  200  is 400 mm in height, 70 mm in depth, and 200 mm in width. Its top-rear portion has an opening  200   b,  as an entrance for the recovered toner (developer). Next, referring to  FIG. 3(   a ), the opening  200   b  is on the rear side of the sheet passage. Therefore, the recovery container  200  can be placed directly under the main recovery pipe  204 . Increasing the distance the waste developer vertically falls through the discharge pipe  201  reduces in angle of rest, the waste developer mass, which the waste developer would form as it accumulates in the recovery container  200 . 
         [0036]    As long as a mass which the waste developer forms in the recovery container  200  as the waste developer falls into the recovery container  200  is relatively small in angle of rest, the recovery container  200  remains high in actual waste toner capacity, even if a screw, a paddle, etc., are not placed in the recovery container  200  to level the waste developer mass in the recovery container  200 . Therefore, the recovery container  200  in this embodiment is smaller in component count, electric power consumption, and simpler in mechanism, than any conventional recovery container, which is equipped with a screw, paddle, etc. 
         [0037]    Referring to  FIG. 4 , the front portion of the recovery container  200  in terms of the direction indicated by an arrow mark A, in which the recovery container  200  is installed or uninstalled, has a angled surface  200   a,  which faces the interior access door  150 , and the angle of which is such that when the interior access door  150  is open widest, the angled surface  200   a  is roughly parallel to the interior access door  150 . Next, referring to  FIG. 3(   b ), the recovery container  200  is shaped so that the angled surface  200   a  becomes roughly parallel to the back surface of the interior access door  150 . This structural arrangement makes the space for the movement of the interior access door  150 , and the space for the movement of the recovery container  200 , overlap with each other. Therefore, it makes it possible to most efficiently use the internal space of the casing of the image forming apparatus. 
       (Structure for Pulling Recovery Container out of Casing of Image Forming Apparatus) 
       [0038]      FIG. 5  is a drawing for describing the structure for allowing the recovery container  200  to be pulled out of the casing of the image forming apparatus  100 .  FIG. 5(   a ) shows the state in which the recovery container  200  and its adjacencies are when the image forming apparatus is forming an image, and  FIG. 5(   b ) shows the state in which the recovery container  200  and its adjacencies are when the recovery container  200  is completely out of the casing of the image forming apparatus  100  to be replaced. 
         [0039]    Referring to  FIG. 5(   a ), the main assembly of the image forming apparatus  100  is provided with a three-piece slide rail. It is the frontmost piece of the slide rail that the recovery container tray  210  is fixed. The recovery container tray  210  is provided with a tray handle  211 , which is fixed to the front side of the tray  210 . 
         [0040]    Next, referring to  FIG. 5(   b ), in order for a user to replace the recovery container  200  in the image forming apparatus  100 , the user is to grasp the tray handle  211 , and pull the tray handle  211 . As the tray handle  211  is pulled, the recovery container tray  210 , on which the recovery container  200  is present, moves frontward of the image forming apparatus  100  while being guided by the slide rail  212 . 
         [0041]    Referring to  FIG. 4 , the recovery container  200  has a container handle  200   c,  which is on the front side of the recovery container  200 . Thus, a user can easily lift the recovery container  200  by grasping the container handle  200   c,  and place an empty (new) recovery container  200  on the recovery container tray  210 . 
       (Jam Solution) 
       [0042]    Referring to  FIG. 1 , the sheet passage of the image forming apparatus  100  has a section which turns a sheet S of recording medium over, and re-feed the sheet S back into the secondary transfer section T 2 . This section of the sheet passage is made up of multiple combinations of sheet driving roller  76   a  and idler rollers  76   b,  which are placed along the interior access door  150 . In a case where a paper jam or the like occurred in the above described section of the sheet passage, the jammed sheet S has to be manually removed while the driver rollers  76   a  and idler rollers  76   b  are kept stationary. Thus, the interior access door  150  of the image forming apparatus  100  is to be horizontally and pivotally opened leftward, from the front side of the apparatus main assembly, as shown in  FIG. 1 , so that the nips which the multiple combinations of driver roller  76   a  and idler roller  76   b  form can be eliminated all at once. 
         [0043]    Referring to  FIG. 3(   c ), the interior access door  150  can be pivotally moved about a vertical hinge  151 , which is on the rear side of the interior access door  150 , so that it can be placed in the first position, in which the interior access door  150  makes the idler rollers  76   b  form the nips, or in the second position, in which it does not makes the idler rollers  76   b  form the nips. The interior access door  150  can be pivotally moved about the hinge  151  as much as roughly 25°. 
         [0044]    By the way, it is possible to increase the angle by which the interior access door  150  can be pivotally moved, in order to make it easier for a user to see the jammed paper or the like in the apparatus main assembly. However, increasing the angle by which the interior access door  150  can be opened requires the image forming apparatus  100  to be increased in width in terms of the direction parallel to the front panel of the image forming apparatus  100 . In this embodiment, therefore, the angle by which the interior access door  150  can be horizontally opened was set to 25°, in order to optimize the relationship between the space for dealing with paper jam or the like, and the apparatus width. 
         [0000]    (Structure for Preventing Interference between Interior Access Door and Recovery Container) 
         [0045]    Referring to  FIG. 5(   a ), the interior access door  150  is precisely positioned relative to the recovery container tray  210  by being fitted into the recess, with which the contact preventing portion  213  of the recovery container tray  210  is provided. The contact preventing portion  213  is provided with an angled surface  213   a,  which is positioned so that when the interior access door  150  is in the aforementioned recess, the angled surface  213   a  it will be slightly outwardly offset from the recovery container  200 . The contact preventing portion  213  prevents the interior access door  150  from making direct contact with the recovery container  200 . 
         [0046]    Even if the interior access door  150  happens to be open, as the recovery container tray  210  is moved frontward of the apparatus main assembly, the angled surface  213   a  is made to push the interior access door  150 , causing thereby the interior access door  150  to close. Therefore, the interior access door  150  is prevented from coming into contact (colliding with) the interior access door  150 . That is, the angled surface  213   a  is angled in such a direction that as the recovery container tray  210  is moved frontward of the image forming apparatus  100 , the angled surface  213   a  presses the interior access door  150  in the direction to close the interior access door  150 . In other words, the angled surface  213   a  is made to close the interior access door  150  by the outward movement of the recovery container tray  210 . Therefore, even if the interior access door  150  is open, it has no effect upon the operation for replacing the recovery container  200 . That is, this structural arrangement can improve the image forming apparatus  100  in operability in terms of the operation for replacing the recovery container  200 . 
         [0047]    Referring to  FIG. 3(   c ), if it is necessary for a jammed sheet of paper or the like to be removed, the interior access door  150  is to be opened to separate the idler rollers  76   b  from the driver rollers  76   a.  As the interior access door  150  is opened, the contact preventing portion  213  plays the role of a stopper for preventing the interior access door  150  from colliding with the recovery container  200 . The contact preventing portion  213  surrounds the entirety of the bottom edge portion of the recovery container  200 . Therefore, even when the interior access door  150  and/or recovery container tray  210  is somewhere in their range of movement, it does not occur that the interior access door  150  and interior access door  150  interfere with each other. 
         [0048]    If an attempt is made to pull the recovery container tray  210  out of the apparatus main assembly  101   a  when the interior access door  150  is open, the contact preventing portion  213  presses the interior access door  150  in the direction to close the interior access door  150 . Therefore, it is possible to prevent the problem that when the recovery container tray  210  is pulled out of the apparatus main assembly  101   a,  or pushed back into the apparatus main assembly, or when the interior access door  150  is opened or closed, the recovery container  200  is felled, and/or the contents of the recovery container  200  is spilled, by the collision between the interior access door  150  and recovery container  200 . 
         [0049]    Referring to  FIG. 5(   a ), a component  214  for regulating the movement of the interior access door  15  is fixed to the rear end of the mid section of the three-piece slide rail  212 . The door movement regulating component  214  is a component for preventing the interior access door  150  from being opened when the recovery container tray  210  has been frontwardly moved out of the apparatus main assembly, far enough for the angled surface  213   a  to be prevented from holding the interior access door  150 . That is, the door movement regulating component  214  prevents the problem that when the interior access door  150  is open widest, the recovery container tray  210 , on which the recovery container  200  is present, is pushed into the apparatus main assembly, and collides with the interior access door  150 . 
         [0050]    Further, the door movement regulating component  214  prevents the problem that the interior access door  150  opens when the recovery container tray  210  is in the second tray position. While the recovery container tray  210  is out of the apparatus main assembly, the interior access door  150  does not open. Therefore, it can be avoided that the recovery container tray  210  is pushed into the apparatus main assembly while the interior access door  150  is open. Further, if the recovery container tray  210  happens to be pulled outward of the apparatus main assembly  101   a  while the interior access door  150  is open, the interior access door  150  is automatically closed by the outward movement of the recovery container tray  210 . 
       (Effects of Embodiment 1) 
       [0051]    In the first embodiment, the image forming apparatus  100  is structured so that the space through which the recovery container  200  moves while being guided by the slide rail  212  overlaps with the space through which the interior access door  150  pivotally moves about the hinge  151 . Therefore, its main assembly can be smaller in footprint and volume than that of an image forming apparatus structured so that the two spaces do not overlap with each other. 
         [0052]    In the first embodiment, the recovery container  200  is made up of the first section which will be on the rear side of the interior access door  150  when the recovery container  200  is in its preset inside position (installation position), and the interior access door  150  is open, and the second section which will be on the front side of the first section and extends to the immediate adjacencies of the interior access door  150  when the interior access door  150  is open. Therefore, the recovery container  200  is greater in capacity, being therefore longer in replacement interval than a conventional recovery container. 
         [0053]    In the first embodiment, the slide rail  212 , which is an example of a supporting mechanism, supports the recovery container  200  in such a manner that the recovery container  200  can be moved to the preset outside position (uninstallation position) while being supported by the slide rail  212 . Thus, it is unnecessary for a user to bear the weight of the recovery container  200  while the user is moving the recovery container  200  inward or outward of the apparatus main assembly. 
         [0054]    In the first embodiment, the contact preventing portion  213  and door movement regulating component  214 , which are examples of a regulating member, are attached to the slide rail  212 . Thus, as the recovery container  200  is moved to the preset outside position (uninstallation position), the contact preventing portion  213  and door movement regulating component  214  are moved by the movement of the slide rail  212  to their position in which they regulate the opening movement of the interior access door  150 . Therefore, it does not occur that the interior access door  150  and recovery container  200  are made to collide with each other, even if a user absent-mindedly opens the interior access door  150 . 
         [0055]    In the first embodiment, the recovery container  200  is provided with the opening, which is a part of its top wall, and can be connected to, or disconnected from, the discharge pipe  201 . Its vertical dimension is greater than its horizontal dimension. Therefore, it can be placed in a narrow space, and yet, can be substantial in capacity. 
         [0056]    In the first embodiment, it is the top wall of the recovery container  200  that is provided with the opening. Further, the opening is on the rear side of the sheet conveyance passage. Therefore, the opening can be connected to, or disconnected from, the discharge pipe  201 , in the direction perpendicular to the recovered toner conveying passage. That is, this embodiment can make the recovery container  200  simpler in structure, and low in cost. 
         [0057]    In the first embodiment, the recovery container  200  is made up of the first section, which is similar to a conventional recovery container, and the second section which is provided with the angled surface  200   a  and is positioned so that when the recovery container  200  is in the preset inside position (installation position) and the interior access door  150  is open, the second section extends frontward to the immediate adjacencies of the interior access door  150 , with the angled surface  200   a  being roughly parallel to the interior access door  150 . Therefore, the recovery container  200  in this embodiment is substantially greater in capacity that a conventional recovery container. Further, being provided with the angled surface  200   a,  the recovery container  200  does not interfere with the opening or closing of the interior access door  150 , nor affect the angle by the maximum angle by which the interior access door  150  can be opened, even though it has been elongated in the depth direction of the apparatus main assembly to be increased in capacity. 
         [0058]    In the first embodiment, the image forming apparatus  100  is structured so that the space through which the recovery container  200  moves overlaps with the space through which the interior access door  150  is opened or closed. Therefore, the recovery container  200  in this embodiment is substantially greater in capacity than a conventional recovery container, even though it is no greater in size than a conventional recovery container. That is, this embodiment can increase the recovery container  200  in capacity without requiring the apparatus main assembly to be increased in overall size. In other words, not only can this embodiment increase the recovery container  200  in capacity, but also, can improve the image forming apparatus  100  in terms of the efficiency with which a jammed paper or the like can be removed. 
         [0059]    In the first embodiment, the recovery container  200  is moved out of the apparatus main assembly, or moved into the apparatus main assembly, together with the recovery container tray  210 . Therefore, the image forming apparatus  100  is superior to a conventional image forming apparatus, in terms of ease and efficiency with which the recovery container  200  in the apparatus main assembly can be replaced. 
         [0060]    In the first embodiment, the contact preventing portion  213  surrounds the entirety of the bottom edge portion of the recovery container  200 . Therefore, the recovery container  200  is safe even if it is subjected to a force which comes from an unexpected direction. 
         [0061]    This embodiment makes it unnecessary to employ such a structure that when it is necessary to remove a jammed sheet of paper or the like, it is required for the conveyance guide to be frontwardly pulled out of the apparatus main assembly, the conveyance guide to be opened or closed in the opposite direction from the recovery container  200 , and/or the recovery container  200  to be install or uninstall. Therefore, it does not require an image forming apparatus to be increased in size and/or complicated in structure, and/or does not complicate the process of removing a jammed sheet of paper or the like. 
         [0062]    In the first embodiment, the recovery container  200  is allowed to be taller, being therefore naturally higher in the amount by (ratio at) which it is filled with developer. Therefore, it is unnecessary for the recovery container  200  to be equipped with an internal screw or the like in order for the recovery container  200  to be increased in fill factor. Therefore, it does not invite the cost increase attributable to structural complication and increase in component count. 
       Embodiment 2 
       [0063]      FIG. 6  is a perspective view of the recovery container in the second embodiment of the present invention.  FIG. 7  is a front view of the developer recovery system of the image forming apparatus.  FIG. 7(   a ) is related to a period in which an image is being formed, and  FIG. 7(   b ) is related to a period in which the apparatus is ready for removal of a jammed sheet of paper or the like. 
         [0064]    Referring to  FIG. 3(   c ), in the first embodiment, the interior access door  150  was horizontally and pivotally moved about the vertical hinge  151  to be opened or closed. In comparison, in the second embodiment, the interior access door  150  is vertically and pivotally moved about a horizontal hinge  151  to be opened or closed. Otherwise, the second embodiment is the same as the first one. Thus, the structural components, their parts, etc., in the second embodiment, which are the same as the counterparts in the first embodiment, are given the same referential codes as those given to the counterparts, in order not to repeat the same descriptions. 
         [0065]    Referring to  FIG. 6 , the recovery container  200  has an opening  200   b  and an angled surface  200   a . The opening is a part of the top wall of the recovery container  200 . The angled surface  200   a  is a part of the front section of the recovery container  200 . It is angled in such a direction that it makes the top portion of the front section portion of the recovery container  200  narrower than the bottom portion of the front portion of the recovery container  200 . 
         [0066]    Referring to  FIG. 7(   a ), during the insertion or removal of the recovery container  200 , the interior access door  150  is kept closed, maintaining thereby the nips for sheet conveyance. Further, the interior access door  150  remains retracted from the space through which the recovery container  200  is moved. Therefore, the recovery container  200  can be frontwardly pulled out of the apparatus main assembly, together with the recovery container tray  210 , without any interference. 
         [0067]    Referring to  FIG. 7(   b ), when a jammed sheet of paper or the like needs to be removed, the interior access door  150  is to be pivotally moved outward roughly 25° about the hinge  151 . That is, during the removal of a jammed sheet of paper or the like, the interior access door  150  is in the space for the movement of the recovery container  200 . 
         [0068]    However, the recovery container  200  is provided with the angled surface  200   a,  which is angled so that it will be outside the space for the movement of the interior access door  150 . Therefore, it does not occur that the recovery container  200  interferes with the pivotal movement of the interior access door  150 . That is, a user is free to open the interior access door  150  to create the space for the removal of the jammed sheet of paper of the like, in order to make it easier to remove the jammed sheet of paper of the like. 
         [0069]    The recovery container  200  is greater in capacity than a conventional recovery container, because it has been increased in depth by the addition of its second section (front section) which has the angled surface  200   a,  being therefore out of the space for the movement of the interior access door  150 . The space for the movement of the recovery container  200  overlaps with the space through which the interior access door  150  moves when it is opened or closed. However, it does not occur that the recovery container  200  and interior access door  150  contact with each other during an image forming operation in which a jam might occur. 
         [0070]    The second embodiment shows that even an image forming apparatus, the interior access door  150  of which is hinged along its bottom edge, can be reduced in cost by the simplification of its recovery container  200 . 
       Miscellanies 
       [0071]    The present invention is applicable to image forming apparatuses which are partially or entirely different in structure from those in the preceding embodiment, as long as they are structured so that at least a part of the space through which their movable component moves overlaps with the space through which their recovery container moves. 
         [0072]    In other words, the present invention is also applicable to a sheet conveyance passage, other than the above described sheet reversing passage, which is made up of two sub-assemblies separable at the sheet conveyance nips, a fixing device, an exposing device, an intermediary transfer unit, and the like. The application of the present invention is not limited to those in the above-described embodiments. That is, the present invention is applicable regardless of whether an image forming apparatus is of the drum type or tandem type, whether an image forming apparatus uses single-component developer or two-component developer, and whether an image forming apparatus is of the intermediary transfer type or direct transfer type. Further, the present invention is applicable regardless of image bearing member count, method for charging an image bearing member, method for forming an electrostatic image, developing method, transfer method, fixing method, etc. In the foregoing, only the portions of the image forming apparatus, which are primarily related to the formation and transfer of a toner image, were described. However, the present invention is also applicable to various image forming apparatuses other than those in the preceding embodiments, for example, a printer other than those in the preceding embodiment, a copying machine, a facsimile machine, a multifunction machine, that is, a combination of one of the image forming apparatuses in the preceding embodiment, and additional devices, equipments, casing, etc. 
         [0073]    The image forming apparatus in accordance with the present invention is structured so that the space through which a “door” moves in the apparatus main assembly overlaps with the space through which the recovery container moves in the apparatus main assembly. Therefore, it is smaller in the size of its main assembly than an image forming apparatus structured so that above-described two spaces do not overlap with each other. That is, the present invention can provide an image forming apparatus with an internal passage through which a recovery container can be pulled of the apparatus main assembly, without increasing the apparatus main assembly in size. 
         [0074]    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. 
         [0075]    This application claims priority from Japanese Patent Application No. 193728/2013 filed Sep. 19, 2013, which is hereby incorporated by reference.