Patent Publication Number: US-6904249-B2

Title: Toner cartridge and image forming apparatus using the same

Description:
BACKGROUND OF THE INVENTION 
   The present invention generally relates to a toner cartridge and an image forming apparatus. 
   DESCRIPTION OF THE RELATED ART 
   An image forming apparatus performs processes of charging, exposing, developing, transferring and fixing in sequence to record an image. The image forming apparatus includes a print process cartridge, which in turn includes a charging unit, a photoconductive drum, and a developing unit. A toner cartridge is detachably received in the print process cartridge and supplies toner to the developing unit. The charging unit charges the surface of the photoconductive drum uniformly. An exposing unit illuminates the charged surface of the photoconductive drum in accordance with print data to form an electrostatic latent image. The developing unit supplies toner to the electrostatic latent image to develop the latent image into a toner image. The toner image is transferred onto print paper by a transferring unit. Then, the print paper advances to a fixing unit where the toner image is fused into a permanent image. Toner that remains on the photoconductive drum after transfer is removed from the photoconductive drum and collected into a waste toner tank provided in the print process cartridge. However, the provision of a waste toner tank requires a space for housing the waste toner tank, leading to a large overall size of the image forming apparatus. Thus, a system is usually employed which collects residual toner into a toner cartridge so that the residual toner can be discarded together with the toner cartridge when the fresh toner in the toner cartridge has been exhausted. 
   However, a conventional toner cartridge requires a space that holds collected residual toner. This in turn reduces a space for holding fresh toner. As a result, when the toner cartridge is replaced, an amount of toner that can be replenished is small. This increases the cost of the toner cartridge per a predetermined number of printed pages. If a toner holding space is to be made larger, the overall size of the toner cartridge becomes large, leading to a larger overall size of an image forming apparatus. 
   BRIEF SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a toner cartridge in which the replacement of the toner cartridge allows replenishment of as large an amount of fresh toner as possible and saving of the running cost of the image forming apparatus. 
   An object of the invention is to provide a toner cartridge that makes it possible to miniaturize an image forming apparatus. 
   A toner cartridge has a first chamber that holds fresh toner and a second chamber that holds waste toner. The cartridge includes a partition provided in the toner cartridge to divide an inner space of the toner cartridge into the first chamber and the second chamber. The partition operates in such a way that a volume of the second chamber increases in accordance with an amount of the waste toner in the second chamber. 
   The partition is such that the first chamber and the second chamber extend substantially in parallel with each other and are partially adjacent to each other horizontally. 
   The partition operates in such a way that the first chamber decreases in volume and the second chamber increases in volume. 
   The partition has a movable portion and a fixed portion that supports the movable portion. The second chamber has a waste toner inlet through which the second chamber receives the waste toner, the inlet being located under the movable portion. 
   The movable portion is a deformable bag-shaped member. 
   The bag-shaped member has a thickness in the range of 0.2 to 0.4 mm. 
   The second chamber has a swingable member therein. The swingable member is urged against the partition in such a way that the swingable member pushes the deformable bag-shaped member toward the first chamber. 
   The partition is detachably inserted into the toner cartridge. 
   The first chamber has a resilient flap extending in the first chamber. 
   The first chamber has an agitator bar that agitates the fresh toner in the first toner chamber. The resilient flap is a film. When the agitator bar agitates the fresh toner, the film moves into engagement with the agitator bar such that the film flexes and subsequently moves out of engagement with the agitator bar. 
   The second chamber extends in a longitudinal direction and has a first transport member therein that extends in the longitudinal direction of the second chamber and a waste toner inlet located at one of opposing ends of the second chamber. The first transport member transports the waste toner from the one of the opposing ends of the second chamber to another one of the opposing ends. 
   The first transport member has a spiral vane formed on it, the spiral vane extending from one end of the first transport member to a part of the first transport member. 
   The second chamber includes a second transport member therein for transporting the waste toner toward the waste toner inlet, the second transporting member extending above the first transport member in the longitudinal direction of the second chamber. 
   The partition operates to increase the second chamber in volume when the amount of waste toner exceeds a certain value. 
   In another aspect, the present invention is directed to an image forming apparatus having a toner cartridge as described above. 
   Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limiting the present invention, and wherein: 
       FIG. 1  is a cross-sectional view, illustrating a general configuration of a color electrophotographic recording apparatus according to the invention; 
       FIG. 2  is a perspective view of a toner cartridge according to a first embodiment; 
       FIG. 3  is a cross-sectional view of the toner cartridge when it remains sealed; 
       FIG. 4  is a cross-sectional view of a toner cartridge that has reached the end of its lifetime; 
       FIG. 5  is a perspective view, illustrating a movable partitioning mechanism having a bag-shaped deformable partition; 
       FIG. 6  is a perspective view of the toner cartridge according to a second embodiment; 
       FIG. 7  is a cross-sectional view of the toner cartridge when it remains sealed; 
       FIG. 8  is a cross-sectional view of the toner cartridge when it is empty of fresh toner; 
       FIG. 9  is a perspective view of a movable partitioning mechanism having a bag-shaped deformable partition; 
       FIG. 10  is a cross-sectional side view, illustrating the interior of a toner cartridge according to the second embodiment; 
       FIG. 11  is a cross-sectional view, illustrating the waste toner held in a waste toner chamber of the toner cartridge according to the second embodiment; 
       FIG. 12  is a perspective view, illustrating the general configuration of a toner cartridge according to a third embodiment; 
       FIG. 13A  is a cross-sectional view, illustrating the toner cartridge according to the third embodiment; 
       FIG. 13B  is a fragmentary side view of a film and a bag-shaped deformable partition; 
       FIGS. 14 and 15  are expanded perspective views, illustrating the detail of a movable partitioning mechanism in  FIG. 12 ; 
       FIG. 16  is a perspective view of the film assembled into the movable partitioning mechanism; 
       FIG. 17  is a perspective view, illustrating the deformable partition provided to the movable partitioning mechanism; 
       FIG. 18  is a perspective view of a side wall when the toner cartridge is seen from outside of the toner cartridge; 
       FIG. 19  is a perspective view of the side wall when the toner cartridge is seen in a direction shown by arrow Q in  FIG. 18 ; 
       FIG. 20  is a side view when the side wall is seen from a direction shown by arrow R in  FIG. 19 ; 
       FIG. 21  illustrates the opening when it is closed by a opening/closing member; and 
       FIG. 22  illustrates the opening when it is opened. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Preferred embodiments of an electrophotographic printer according to the invention will be described. 
   First Embodiment 
     FIG. 1  is a cross-sectional view, illustrating a general configuration of a color electrophotographic recording apparatus  1  according to the invention. Referring to  FIG. 1 , a paper cassette  2  holds print paper  3  therein. A roller  4  feeds the print paper  3  into a transport path P from the paper cassette  2  on a page-by-page basis. Transport rollers  5 ,  6 , and  7  transport the print paper  3  to print process cartridges  8 . The print paper  3  advances to a transfer section of the print process cartridge  8  where a toner image is transferred onto the print paper  3 . Then, the print paper  3  advances to a fixing unit  12  and then discharging roller  13 ,  14 ,  15  and  16  drive the print paper  3  into a paper stacker  17 . 
   Four print process cartridges  8  are disposed along the transport path P of the print paper  3 . The four print process cartridges  8  are of the same configuration and each of the four print process cartridges  8  forms a toner image of a corresponding color. Each print process cartridge  8  includes a photoconductive drum  8   a , a charging roller  8   b , a developing roller  8   c , a toner supplying roller  8   d , a toner cartridge  9 , and a cleaning unit  8   e . The photoconductive drum  8   a  is a photoconductive body driven in rotation by a drum motor, not shown. The charging roller  8   b  charges the surface of the photoconductive drum  8   a . An exposing unit  10  illuminates the charged surface of the photoconductive drum  8   a  to form an electrostatic latent image. The toner cartridge  9  supplies toner to a developing unit. The toner supplying roller  8   d  in the developing unit supplies toner to the developing roller  8   c , which in turn supplies the toner to the electrostatic latent image to develop the electrostatic latent image into a toner image. The cleaning unit  8   e  scrapes the toner off the photoconductive drum  8   a  to clean the photoconductive drum  8   a . A transfer unit  11  has transfer rollers that face corresponding photoconductive drums  8   a  to define transfer points between the photoconductive drums  8   a  and the transfer rollers. When the print paper  3  passes each transfer point, a toner image of a corresponding color is transferred from the photoconductive drum  8   a  onto the print paper  3 . 
   With electrophotographic recording apparatus, some of the toner remains on the surface of the photoconductive drum  8   a  after transfer. The residual toner on the photoconductive drum  8   a  is removed by the cleaning unit  8   e  and is collected into a waste toner chamber of the toner cartridge  9 . 
     FIG. 2  is a perspective view of a toner cartridge  9  according to a first embodiment. 
     FIG. 3  is a cross-sectional view of the toner cartridge  9  when it remains sealed. 
     FIG. 4  is a cross-sectional view of a toner cartridge  9  that has reached the end of its lifetime. 
     FIG. 5  is a perspective view, illustrating a movable partitioning mechanism  18  having a bag-shaped deformable partition  18   b.    
   The toner cartridge  9  according to the embodiment will be described with reference to  FIGS. 2-5 . The toner cartridge  9  has a movable partitioning mechanism  18  that includes a swingable plate  18   a , a bag-shaped deformable partition  18   b , an upper partition wall  18   d , and a lower partition wall  18   c . The movable partitioning mechanism  18  divides an inner space of the toner cartridge  9  into a fresh toner chamber B and a waste toner chamber C. 
   The deformable partition  18   b  is disposed between the lower partition wall  18   c  near the swingable plate  18   a  and an upper portion of the upper partition wall  18   d . The deformable partition  18   b  is fixed at its one end portion to the upper end of the upper partition wall  18   d  and at its other end to the upper end of the lower partition wall  18   c . Thus, the deformable partition  18   b  defines the fresh toner chamber B and the waste toner chamber C that are sealed against each other, preventing the toner in the fresh toner chamber B from being mixed with the toner in the waste toner chamber C. The swingable plate  18   a  is pivotally mounted to the upper end of the lower partition wall  18   c . As shown in  FIG. 3 , a spring, not shown, urges the swingable plate  18   a  in a direction shown by arrow A. 
   As printing is performed repeatedly, the fresh toner in the fresh toner chamber B decreases gradually. The residual toner on the photoconductive drum  8   a  is removed from the photoconductive drum  8   a  and collected into the waste toner chamber C by a toner collecting mechanism provided on a die frame, not shown. As the fresh toner decreases, the swingable plate  18   a  will be inclined gradually by the spring, not shown, in the direction shown by arrow A as shown in FIG.  3 . As a result, the waste toner chamber C increases in volume. 
   The first embodiment has been described with respect to a case in which the waste toner chamber C gradually increases in volume as the amount of waste toner collected in the waste toner chamber C increases. A modification can be made such that when the amount of waste toner exceeds a certain value, the urging force of the spring is large enough to allow the swingable plate  18   a  to swing. The modification allows the volume of the waste toner chamber C to increase when no fresh toner is present in the fresh toner chamber B, preventing toner clump in the waste toner chamber C. 
   Second Embodiment 
   A second embodiment differs from the first embodiment in the interior structure of the toner cartridge  9 . 
     FIG. 6  is a perspective view of the toner cartridge  9  according to the second embodiment. 
     FIG. 7  is a cross-sectional view of the toner cartridge  9  when it remains scaled. 
     FIG. 8  is a cross-sectional view of the toner cartridge  9  when it is empty of fresh toner. 
     FIG. 9  is a perspective view of a movable partitioning mechanism  18  having a bag-shaped deformable partition  19   b.    
   As shown in  FIGS. 6-9 , the toner cartridge  9  has a lower partitioning wall  19   c , an upper partitioning wall  19   a , and a bag-shaped deformable partition  19   b  that defines a fresh toner chamber B and a waste toner chamber C. The bag-shaped deformable partition  19   b , upper partitioning wall  19   a , and lower partitioning wall  19   c  are integral with one another so that a small force can cause the bag-shaped deformable partition  19   b  to displace toward the fresh toner chamber B or toward the waste toner chamber C. 
   When printing is performed repeatedly, the fresh toner in the fresh toner chamber B decreases gradually. The residual toner is removed from the photoconductive drum  8   a , and is collected by the toner collecting mechanism into the waste toner chamber C. The waste toner collected into the waste toner chamber C is moved by a later described spiral shaft from near end to the far end in the waste toner chamber C. The waste toner is gathered toward the middle of the waste toner chamber C and applies pressure against the deformable partition  19   b , so that the deformable partition or bag-shaped partition  19   b  is pushed by the waste toner toward the fresh toner chamber B. Thus, the waste toner chamber C increases in volume by an amount of the movement of the de formable partition  19   b.    
     FIG. 10  is a cross-sectional side view, illustrating the interior of a toner cartridge  9  according to the second embodiment. 
     FIG. 11  is a cross-sectional view, illustrating the waste toner held in the waste toner chamber C of the toner cartridge  9  according to the second embodiment. 
   For efficient utilization of the space in the waste toner chamber C, a spiral shaft  9   e  is rotated to move a pile of waste toner  20  toward the middle of the waste toner chamber C. A conventional spiral shaft has a vane  9   f  that spans across the entire length of the spiral shaft  9   e  so as to move the waste toner to the end of waste toner chamber C. The spiral shaft  9   e  according to the second embodiment has the vane  9   f  shaft so that the bag-shaped deformable partition  19   b  efficiently deforms into the adjacent fresh toner chamber B. There is provided a spiral shaft  9   g  over the spiral shaft  9   e  and these two spiral shafts  9   e ,  9   g  rotate. The spiral shaft  9   g  has a vane that describes a spiral in the opposite direction to the spiral shaft  9   e , the vane causing the top of the pile of the waste toner  20  to fall toward a waste toner inlet  9   b.    
   During printing, the toner in the fresh toner chamber B is used in developing and residual toner is removed from the photoconductive drum  8   a  and collected by the toner collecting mechanism, not shown into the waste toner chamber C. The spiral shaft  9   e  causes the waste toner  20  in the waste toner chamber C to move to the end of the waste toner chamber C. Because the vane  9   f  extends only as far as the middle of spiral shaft  9   e , the waste toner  20  begins to pile up at a longitudinal middle of the bag and the pile will grow there. As a result, the waste toner will produce a pressure that causes the bag to extend toward the fresh toner chamber B easily and the pile of the waste toner  20  to fall toward the waste toner inlet  9   b . Thus, the waste toner  20  is distributed all over the floor in the waste toner chamber C, allowing efficient use of the toner holding space. 
   The deformable partition  19   b  that defines the boundary between the fresh toner chamber B and the waste toner chamber C deforms substantially uniformly across the length of the waste toner chamber C, ensuring that a space holding the waste toner  20  is enlarged. Because the collected waste toner  20  is distributed all over floor in the waste toner chamber C, a limited small space can be efficiently utilized. 
   Third Embodiment 
     FIG. 12  is a perspective view, illustrating the general configuration of a toner cartridge  9  according to a third embodiment. 
     FIG. 13A  is a cross-sectional view, illustrating the toner cartridge  9  according to the third embodiment. 
     FIG. 13B  is a fragmentary side view of a film and a bag-shaped deformable partition  40   a.    
   As shown in  FIG. 12 , the toner cartridge  9  includes an outer case  9   a , a movable partitioning mechanism  40  slidably assembled into the outer case  9   a , and a side wall  9   b  that closes the side of the outer case  9   a . The movable partitioning mechanism  40  has a bag-shaped deformable partition  40   a , which is assembled in a unitary construction. When the movable partitioning mechanism  40  is slidably assembled into the outer case  9   a , a fresh toner chamber B and waste toner chamber C are defined in the outer case  9   a  as shown in FIG.  13 A. It is to be noted that the movable partitioning mechanism  40  can disassembled from the outer case  9   a  so that the movable partitioning mechanism  40  can be re-used by simply replacing a later described sealing member  24 . 
     FIGS. 14 and 15  are expanded perspective views, illustrating the detail of the movable partitioning mechanism  40  in FIG.  12 . 
     FIG. 16  is a perspective view of the film  22  assembled into the movable partitioning mechanism  40 . 
     FIG. 17  is a perspective view, illustrating the deformable partition  40   a  provided to the movable partitioning mechanism  40 . 
   The bag-shaped deformable partition  40   a  ( FIG. 17 ) is inserted in a recess  40   e  ( FIG. 14 ) formed in the movable partitioning mechanism  40 . An outer peripheral portion  40   d  of the deformable partition  40   a  is welded to an end portion  40   c  ( FIGS. 13A and 14 ) of the frame  40   b . The deformable partition  40   a  defines the fresh toner chamber B and the waste toner chamber C. The movable partitioning mechanism  40  also has a film  22  having its tip attached to the bag-shaped deformable partition  40   a  by means of a tape  22   f  as shown in FIG.  13 B and FIG.  14 . The film  22  is movable with the bag-shaped deformable partition  40   a  in the direction shown by an arrow. The material and thickness of the deformable partition  40   a  are selected such that the deformable partition  40   a  can easily deform into the adjacent fresh toner chamber B. The deformable partition  40   a  is vacuum-molded from a sheet of polyethylene or polypropylene by using a concave mold. The thickness t of the deformable partition  40   a  is in the range of 0.2 mm≦t≦0.4 mm. 
   If the thickness t is such that t≦0.2 mm, there may be a large variation of thickness, making it difficult to properly mold the deformable partition  40   a  If the thickness t is in the relation that t&gt;0.4 mm, the bag-shaped deformable partition  40   a  loses flexibility significantly to such an extent that a small pressure applied by the waste toner  20  is not enough to cause the bag-shaped deformable partition  40   a  to deform. Therefore, a sufficient amount of waste toner cannot be collected. 
   As shown in  FIGS. 14 and 15 , the frame  40   b  has an outer end on which a sealing member (sponge)  24  is provided, shown by hatching. The sealing member  24  seats between the outer end and the outer case  9   a  when the movable partitioning mechanism  40  is inserted into the toner cartridge  9 . The sealing member  24  isolates the fresh toner chamber B from the waste toner chamber C completely, so that the toners in the chambers are not mixed with each other. 
   As shown in  FIGS. 14 and 15 , the frame  40   b  of the movable partitioning mechanism  40  has guides  21   a - 21   d . As shown in  FIG. 13A , there are provided guides  20   a - 20   d  on the inner wall surface of the outer case  9   a . When the movable partitioning mechanism  40  is inserted into or pulled out of the outer case  9   a , the aforementioned guides  21   a - 21   d  of the frame  40   b  engage the aforementioned guides  20   a - 20   d  of the outer case  9   a , thereby allowing the outer case  9   c  to smoothly guide the frame  40   b . Upon completion of insertion of the frame  40   b , the frame  40   b  is accurately positioned in the outer case  9   a.    
   The guides  21   a - 21   d  of the frame  40   b  serve to add mechanical strength to the frame  40   b.    
     FIG. 17  illustrates the bag-shaped deformable partition  40   a  before it is attached to the movable partitioning mechanism  40 . The deformable partition  40   a  has an outer peripheral portion  40   d  bonded to the frame  40   b  by an adhesive. As shown in  FIG. 16 , the film  22  has, three large holes  22   e , three slits  22   b , three holes  22   c , and one hole  22   d , which are fitted to guides  23  of the frame  40   b . The film  22  is disposed on the inside of the fresh toner chamber B. 
   The film  22  is detachably mounted at a portion near tips  22   a  for reasons which will be described later. As shown in  FIG. 13A , the tips  22  project into a rotational path of an agitator bar  21  to agitate the toner in the fresh toner chamber B. The film  22  is configured to the deformable partition  40   a , i.e., the film  22  is bent as shown in  FIGS. 15 and 16 . As shown in  FIG. 13A , the agitator bar  21  rotates to engage the tips  22   a , causing the tips  22   a  to flex. The agitator bar  21  further rotates to subsequently release the tips  22   a , so that the film  22  vibrates lightly in its entirety. The film  22  is mounted to the movable partitioning mechanism  40  in such a way that it will not come off the frame  40   b  when the agitator bar  21  continues to rotate, cycling to move into and out of engagement with the tips  22   a.    
   As shown in  FIG. 13A , the agitator bar  21  rotates in a direction shown by an arrow to agitate the toner, thereby supplying the toner to the developing unit, not shown, at all times. The film  22  is made of, for example, polyester and has a thickness tin the range of 0.05 mm≦t≦0.25 mm, and preferably t≦0.1 mm. A thickness t less than 0.05 mm cannot make the film  22  resilient enough to add vibration to the toner in the fresh toner chamber B when the tips  22   a  are released from the agitator bar  21 . A thickness t greater than 0.25 mm makes the film  22  too rigid, so that the pressure given by the waste toner is not large enough to cause the deformable partition  40   a  to deform toward the fresh toner chamber B. Thus, the waste toner chamber C cannot hold a large amount of waste toner  20 . 
   Because the film  22  is detachably mounted to the frame  40   b , the film  22  can be disassembled for cleaning. 
   The toner cartridge  9  according to the third embodiment operates as follows: As printing is performed repeatedly, the fresh toner in the fresh toner chamber B is consumed gradually and the residual toner is removed from the photoconductive drum  8   a  and collected into the waste toner chamber C. The waste toner  20  in the waste toner chamber C is moved further into the waste toner chamber C by the spiral shaft  9   e  (FIG.  10 ). Thus, the waste toner  20  will pile up with its top located in the middle of the longitudinally extending waste toner chamber C. The pile of the waste toner  20  produces pressure to push the deformable partition  40   a  toward the fresh toner chamber B. As the waste toner  20  increases, the bag-shaped deformable partition  40   a  will extend toward the fresh toner chamber B as shown in  FIG. 17 , so that a larger amount of waste toner  20  can be held in the waste toner chamber C. 
   With the third embodiment, the opening, through which the waste toner is introduced into the waste toner chamber C, is located below a swelled portion of the bag-shaped deformable partition  40   a . The deformable partition  40   a  is caused to extend toward the fresh toner chamber B after the waste toner  20  piles up in the waste toner chamber C. This feature will be described in more detail with reference to  FIGS. 18-22 . 
     FIG. 18  is a perspective view of a side wall  17  when the toner cartridge  9  is seen from outside of the toner cartridge  9 . 
   Referring to  FIG. 18 , there is provided a support  34  to surround an opening  37 . The support  34  receives a resilient foaming sponge  35  having a thickness of several millimeters. An outer cover  36  is attached in the outer surface of the side wall  17 , thereby preventing the foaming sponge  35  from disengaging from the side wall  17 . The foaming sponge  35  has a hole  35   a  formed in the middle through which a toner discharging beak  42  enters into the waste toner chamber C through the opening  37 . When the toner discharging beak  42  ( FIG. 21 ) enters the opening  37 , the foaming sponge  35  engages the toner discharging beak  42 . This structure substantially eliminates the gap between the toner discharging beak  42  and the opening  37  which would otherwise cause the toner spillage from the toner cartridge  9  when the toner discharging beak  42  is pushed into the waste toner chamber C and pulled out of the waste toner chamber C. 
     FIG. 19  is a perspective view of the side wall  17  when the toner cartridge  9  is seen in a direction shown by arrow Q in FIG.  18 .  FIG. 19  illustrates the opening  37  closed by an opening/closing member  28   a , i.e., when the toner-discharging beak  42  is not pushed into the toner cartridge  9 . 
   As shown in  FIG. 19 , an inner plate  27  is fixed to the inner surface of the side wall  17  by means of a fitting member, not shown. The inner plate  27  has an opening/closing mechanism  28  mounted thereto. The opening/closing mechanism  28  includes the opening/closing member  28   a  that closes the opening  37  from the inside of the toner cartridge  9 , a frame  28   c  that movably holds the opening/closing member  28   a , a spring  28   b  that urges the opening/closing member  28   a  outwardly, and a movable member  28   d  to which one end of the spring  28   b  is secured. 
     FIG. 20  is a side view when the side wall  17  is seen from a direction shown by arrow R in FIG.  19 . 
     FIG. 21  illustrates the opening  37  when the opening/closing member  28   a  closes the opening  37 . 
     FIG. 22  illustrates the opening  37  when it is opened. 
   As shown in  FIG. 21 , the opening  37  remains closed until the toner cartridge  9  has been attached to the image forming apparatus  1 . When the toner cartridge  9  is attached to the image forming apparatus  1 , the toner discharging beak  42  pushed the opening/closing member  28   a  in a direction shown by arrow P. The opening/closing member  28   a  moves along a slide against the urging force of the spring  28   b , so that the toner transport path of the image forming apparatus  1  communicates with the waste toner chamber C of the toner cartridge  9 . The toner-discharging beak  42  enters the waste toner chamber C by a predetermined distance and is maintained where it is. This ensures that the residual toner delivered to the toner cartridge  9  falls into the waste toner chamber C. 
   When the toner cartridge  9  is detached from the image forming apparatus  1 , the toner discharging beak  42  is withdrawn from the opening  37 , so that the opening/closing member  28   a  is urged by the spring  28   b  to close the opening  37 . Thus, the toner in the waste toner chamber C will not leak. 
   The opening  37  through which the waste toner chamber C receives the residual toner is located below the bag-shaped deformable partition  40   a . Therefore, the waste toner chamber C can be disposed as close to the image forming section below the toner cartridge  9  as possible. This configuration provides a shorter toner-transporting path, reducing the possibility of waste toner being clogged in the toner-transporting path. 
   The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art intended to be included within the scope of the following claims.