Patent Publication Number: US-8532540-B2

Title: Image forming apparatus and toner container

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC §119 from Japanese Patent Application No. 2009-206690 filed Sep. 8, 2009. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to an image forming apparatus and a toner container. 
     2. Related Art 
     Recently, an image forming apparatus, which is capable of preventing toner accumulation or excessive toner feed when the toner is fed to a developing device, has been proposed. 
     SUMMARY 
     According to an aspect of the present invention, there is provided an image forming apparatus including: a feed portion that is fed with toner from above; a transport path that includes an inlet through which the toner fed to the feed portion enters, that allows the toner to be transported therethrough, and that is in a cylindrical shape; and a transporting member provided to continuously extend from the feed portion to the transport path, the transporting member transporting along the transport path the toner fed to the feed portion, wherein an amount of transportation of the toner per unit of time at a part of the transporting member located in the transport path is larger than an amount of transportation of the toner per unit of time at a part of the transporting member located in the feed portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  illustrates an image forming apparatus according to exemplary embodiments of the present invention; 
         FIG. 2  is a cross-sectional view of the image forming apparatus; 
         FIG. 3  illustrates an attachment portion to which the a container is attached; 
         FIG. 4  illustrates the container; 
         FIG. 5  illustrates the attachment portions and the developing devices as viewed from the back side of the attachment portions; 
         FIGS. 6A and 6B  illustrate the arrangement positions of the containers and the developing devices; 
         FIGS. 7A and 7B  illustrate a transporting member; 
         FIG. 8  illustrates a transporting member according to a second exemplary embodiment; 
         FIG. 9  illustrates the transporting member in the third exemplary embodiment; 
         FIG. 10  illustrates the transporting member in the fourth exemplary embodiment; and 
         FIGS. 11A and 11B  illustrate a configuration example in which the transporting member is provided in the container. 
     
    
    
     DETAILED DESCRIPTION 
     First Exemplary Embodiment 
     Hereinafter, a first exemplary embodiment of the present invention is described in detail with reference to the accompanying drawings. 
       FIG. 1  illustrates an image forming apparatus  10  according to exemplary embodiments of the present invention. 
     As shown in this figure, the image forming apparatus  10  includes a housing  20 . This housing  20  is formed in the shape of a rectangular parallelepiped, and includes a first sidewall  20 A on the front side of the image forming apparatus  10 , a second sidewall  20 B on the rear side, a third sidewall  20 C on the left when viewed from the front side, and a fourth sidewall  20 D on the right when viewed from the front side. The housing  20  also has, in an upper surface  20 E thereof, an exit portion  22  through which a sheet having an image formed thereon is outputted. Further, on the upper surface  20 E of the housing  20 , an operation panel  12  is provided to accept operations from a user. 
     Moreover, in the upper surface  20 E of the housing  20 , an openable attachment portion  24  is provided to be openable and closable. Furthermore, in the first sidewall  20 A of the housing  20 , an openable sheet feed portion  26  is provided to be openable and closable. The openable attachment portion  24  is opened and closed when containers  300 Y,  300 M,  300 C, and  300 K are attached in the image forming apparatus  10  and when the containers  300 Y,  300 M,  300 C, and  300 K are detached from the image forming apparatus  10 . On the other hand, the openable sheet feed portion  26  is opened when a sheet is fed from the front side of the image forming apparatus  10 . 
     The image forming apparatus  10  has an attachment portion  30  in which the containers  300 Y,  300 M,  300 C, and  300 K are attached. The containers  300 Y,  300 M,  300 C, and  300 K contain yellow, magenta, cyan, and black toners, respectively. The containers  300 Y,  300 M, and  300 C have the same shape and size to have a capacity of the same volume of toner. The container  300 K is formed to be vertically longer than the containers  300 Y,  300 M, and  300 C, and is larger than the containers  300 Y,  300 M, and  300 C. Accordingly, the container  300 K has a capacity of a larger volume of toner than the containers  300 Y,  300 M, and  300 C. It should be noted that the containers  300 Y,  300 M, and  300 C and the container  300 K have similar configurations and functions, except for toner capacities. It should also be noted that in this specification, any of the containers  300 Y,  300 M,  300 C, and  300 K is representatively referred to as a container  300  in some cases below. 
       FIG. 2  is a cross-sectional view of the image forming apparatus  10 . 
     As shown in this figure, the image forming apparatus  10  of this exemplary embodiment includes, inside the housing  20 , an image forming unit  100  and a sheet feeder  200  for feeding a sheet to the image forming unit  100 . Further, the image forming apparatus  10  includes, inside the housing  20 , a transport path  250  for use in the transportation of a sheet. 
     The image forming unit  100  includes: photoconductive drums  102 Y,  102 M,  102 C, and  102 K; charging devices  104 Y,  104 M,  104 C, and  104 K for charging the photoconductive drums  102 Y,  102 M,  102 C, and  102 K; and a latent image forming device  106  that forms an electrostatic latent image by emitting light to the photoconductive drums  102 Y,  102 M,  102 C, and  102 K charged by the charging devices  104 Y,  104 M,  104 C, and  104 K. The image forming unit  100  further includes developing devices  110 Y,  110 M,  110 C,  110 K (hereinafter referred to as developing devices  110  in some cases) that develop, using toners, electrostatic latent images formed on surfaces of the photoconductive drums  102 Y,  102 M,  102 C, and  102 K by the latent image forming device  106  and thus form yellow, magenta, cyan, and black toner images. The developing devices  110 Y,  110 M,  110 C, and  110 K are fed with yellow, magenta, cyan, and black toners from the containers  300 Y,  300 M,  300 C, and  300 K. 
     The image forming unit  100  further includes a transfer device  140  that transfers yellow, magenta, cyan, and black toner images formed by the developing devices  110 Y,  110 M,  110 C, and  110 K to a sheet; a cleaning device (not shown) that cleans the surfaces of the photoconductive drums  102 Y,  102 M,  102 C, and  102 K; and a fixing device  116  that fixes to the sheet the toner image transferred to the sheet by the transfer device  140 . 
     The transfer device  140  includes an intermediate transfer belt  142  to which yellow, magenta, cyan, and black toner images formed by the photoconductive drums  102 Y,  102 M,  102 C, and  102 K are transferred in a superimposed manner. It should be noted that the intermediate transfer belt  142  is rotatably supported by support rolls  146 ,  148 ,  150 , and  152 . The transfer device  140  further includes primary transfer rolls  156 Y,  156 M,  156 C, and  156 K that transfer the yellow, magenta, cyan, and black toner images formed by the photoconductive drums  102 Y,  102 M,  102 C, and  102 K to the intermediate transfer belt  142 . The transfer device  140  further includes a secondary transfer roll  158  that transfers the yellow, magenta, cyan, and black toner images transferred to the intermediate transfer belt  142  to the sheet. Moreover, the transfer device  140  includes a cleaning device (not shown) that cleans a surface of the intermediate transfer belt  142 . 
     The sheet feeder  200  includes a sheet holding portion  202  in which sheets are held; a delivery roll  204  that sends out sheets among the sheets placed in the sheet holding portion  202  that are located uppermost; and a separation mechanism  206  that separates the sheets sent out by the delivery roll  204 . The separation mechanism  206  includes, for example, a feed roll rotatably disposed and a retard roll whose rotation is limited, and separates the sheets sent out by the delivery roll  204  from each other. Then, one separated sheet is sent out toward registration rolls  260 , which is described later. The sheet holding portion  202  is configured so that it may be pulled out to the front side of the image forming apparatus  10  (to the left in  FIG. 2 ). Pulling out the sheet holding portion  202  to the front side allows the replenishment of sheets. 
     The transport path  250  includes a main transport path  252 , a reverse transport path  254 , and an auxiliary transport path  256 . The main transport path  252  is a transport path for transporting a sheet fed from the sheet feeder  200  toward the exit portion  22 . Along this main transport path  252 , the registration rolls  260 , the secondary transfer roll  158 , the fixing device  116 , and exit rolls  262  are provided in that order from the upstream side toward the downstream side in the sheet transport direction. The registration rolls  260  start rotating with predetermined timing to feed a sheet to a contact portion (secondary transfer portion) between the intermediate transfer belt  142  and the secondary transfer roll  158 . 
     The exit rolls  262  output a sheet having a toner image fixed thereon by the fixing device  116  to the exit portion  22 . In the case where images are formed on both sides of a sheet, the exit rolls  262  rotate in a direction opposite to the direction of rotation for outputting a sheet to the exit portion  22 , and thus feed a sheet having an image formed on one side thereof to the reverse transport path  254 . The reverse transport path  254  is used in the case where a sheet having an image formed on one side thereof is fed to the upstream side of the registration rolls  260  again. The reverse transport path  254  has, for example, two pairs of reverse transfer rolls  264  provided along the reverse transport path  254 . 
     The auxiliary transport path  256  is a transport path for use in the case where a sheet is fed through the openable sheet feed portion  26  provided on the front side of the image forming apparatus  10 . This auxiliary transport path  256  has an auxiliary transport roll  266  for transporting a sheet toward the registration rolls  260 , and a separation roll  268  that is in contact with the auxiliary transfer roll  266  and is used to separate sheets, which are provided along the auxiliary transport path  256 . 
       FIG. 3  illustrates the attachment portion  30  (refer to  FIG. 1 ) to which the containers  300 Y,  300 M,  300 C, and  300 K are attached. 
     In the attachment portion  30 , four container chambers  31  are provided which house the respective containers  300 Y,  300 M,  300 C, and  300 K. It should be noted that this figure shows a container chamber  31  for housing the container  300 C (refer to  FIG. 1 ), and that another container chamber  31  is provided adjacent to the shown container chamber  31 . Each container chamber  31  is formed such that an upper portion thereof is open, and has sidewalls in four directions. Further, each container chamber  31  has a bottom portion  311  and an opening  312  in the bottom portion  311 . The toner discharged from each container  300  is fed downward through this opening  312 . 
     In this exemplary embodiment, a transporting member  400  for transporting the toner fed through the opening  312  is provided below the opening  312 . Further, a transport path forming member  500  is provided for holding the transporting member  400  inside thereof and forms a transport path for the toner being transported by the transporting member  400 . The toner being transported by the transporting member  400  moves in the direction indicated by arrow A in the figure. Then, this toner falls downward to be fed to the developing device  110 C (refer to  FIG. 2 , and details are described later). 
       FIG. 4  illustrates the containers  300 Y,  300 M,  300 C, and  300 K. It should be noted that in this figure, the container  300 C is shown as an example. As shown in this figure, the container  300 C, as an example of a toner containing portion, is formed in the shape of a rectangular parallelepiped. The container  300 C has an exit port  302 , as an example of an opening, in a bottom portion  301  thereof so as to discharge the toner contained inside thereof. This exit port  302  is disposed to face the opening  312  when the container  300 C is housed in the container chamber  31 . The container  300 C of this exemplary embodiment discharges toner by utilizing the own weight of the toner. Specifically, the toner contained in the container  300 C falls through the exit port  302  to be fed to the transporting member  400 . 
     The container  300 C also includes a rotary shaft  303  that is rotated by a driving force from an unillustrated motor, and a stirring member  304  that is attached to the rotary shaft  303  and that rotates with the rotation of the rotary shaft  303  to stir the toner contained therein. The container  300 C also includes a moving member  305  provided to extend from the rotary shaft  303  toward an inner wall of the container  300 C with one end thereof attached to the rotary shaft  303 . The moving member  305  moves the toner contained in the container  300 C to the exit port  302 . The moving member  305  is formed in the shape of a plate, and has a length that allows contact with the bottom portion  301  formed to have a curvature. 
     The moving member  305  rotates in the direction indicated by an arrow in the figure with the rotation of the rotary shaft  303  to move the toner contained in the container  300 C to the exit port  302 . The toner discharged from the exit port  302  is fed to the transporting member  400  through the opening  312  (refer to  FIG. 3 ) and then fed to the developing device  110 C (refer to  FIG. 2 ). It should be noted that the container  300 C also includes a handle  306  that is operated by a user, and a lid member  307  that opens or closes the exit port  302  in response to the movement of the handle  306 . 
       FIG. 5  illustrates the attachment portion  30  and the developing devices  110  as viewed from the back side of the attachment portion  30 . Specifically,  FIG. 5  illustrates the attachment portion  30  and the developing devices  110  as viewed from the direction of arrow V in  FIG. 1 . In this exemplary embodiment, as described above, toners are first discharged from the exit ports  302  (refer to  FIG. 4 ) of the containers  300 . After that, the toners are fed to the transporting members  400  through the openings  312  (refer to  FIG. 3 ) of the container chambers  31  and then fed to the developing devices  110 . 
     The transport routes of toners are further described with reference to  FIG. 5 . It should be noted that the transport route of the black toner is described here as an example. The above-described opening  312  is provided in a region indicated by broken lines in this figure. In other words, the opening  312  is provided on the back side of the attachment portion  30 . More specifically, the opening  312  is provided on the opposite side, in the longitudinal direction of the developing device  110 , of the attachment portion  30  to the side on which the developing device  110  is provided. The toner fed to the inside of the transport path forming member  500  through the opening  312  is transported in the direction indicated by arrow A in  FIG. 5  (to the side on which the developing device  110  is provided) by the transporting member  400  (refer to  FIG. 3 ). After that, this toner is fed to the inside of a cylindrical member  550  disposed to extend downward, and is fed to the developing device  110  (the developing device  110 K) located thereunder. 
     Next, the arrangement positions of the containers  300  and the developing devices  110  are described. 
       FIGS. 6A and 6B  illustrate the arrangement positions of the containers  300  and the developing devices  110 . It should be noted that these figures show the container  300 C and the developing device  110 C as examples.  FIG. 6A  shows a top view, and  FIG. 6B  shows a front view (as viewed from the front side of the image forming apparatus  10 ). 
     As shown in  FIG. 6A , when the image forming apparatus  10  is viewed from above, in this exemplary embodiment, the container  300 C is attached between the third sidewall  20 C (also refer to  FIG. 1 ) of the housing  20  and the developing device  110 C. Further, when the image forming apparatus  10  is viewed from above, the transporting member  400  is provided between the third sidewall  20 C of the housing  20  and the developing device  110 C. 
     More specifically, as shown in  FIG. 6B , the transporting member  400  is formed to have a dimension L 1  smaller than a size W of a gap formed between the third sidewall  20 C and the developing device  110 C. A width L 2  of the container  300 C is also smaller than the size W of the gap. Further, the dimension L 1  of the transporting member  400  is smaller than the width L 2  (width of the container  300 C in the direction in which the transporting member  400  is disposed) of the container  300 C. Specifically, the dimension L 1  of the transporting member  400  has a size that allows the transporting member  400  to be contained in the container  300 C if the transporting member  400  is shifted toward the container  300 C. More specifically, in  FIG. 6B , the transporting member  400  protrudes from the container  300 C in the direction of the width of the container  300 C. However, since the dimension L 1  is smaller than the width L 2 , if the transporting member  400  is moved to the left in the figure, the transporting member  400  does not protrude from the container  300 C. It should be noted that the dimension L 1  and the width L 2  only needs to be smaller than the size W of the gap, and that a part of any one of the transporting member  400  and the container  300 C may be disposed to overlap a part of the developing device  110 C. 
     Further, in this exemplary embodiment, as shown in  FIG. 6A , a dimension L 4  is smaller than a dimension L 3 . The dimension L 3  is the length of a part of the transporting member  400  that is located under the opening  312 . Moreover, the dimension L 4  is the length of a part of the transporting member  400  that is located between an inlet of a cylindrical portion  520  (refer to  FIGS. 7A and 7B ) and the cylindrical member  550 . Specifically, the dimension L 4  is the length of a part of the transporting member  400  that is located downstream of the opening  312  and located upstream of the cylindrical member  550 . 
     In this exemplary embodiment, as described above, the length of the transporting member  400 , which is denoted by L 1 , is set short. This makes the space in the image forming apparatus  10  occupied by the transporting member  400  small and makes the image forming apparatus  10  smaller. Setting the length of the transporting member  400  short makes toner transported to the developing device  110 C prone to fluctuations in the amount thereof. Specifically, even when fluctuations have occurred in the amount of toner fed from the container  300 C, the amount of toner is averaged in the course of transporting the toner if the length of the transporting member  400  is long. However, if the length of the transporting member  400  is short, the amount of toner is less likely to be thus averaged. 
     Accordingly, in this exemplary embodiment, the container  300 C that feeds toner by causing the toner to fall is employed so that a sufficient amount of toner may be always fed to the transporting member  400 . Specifically, the container  300 C that feeds toner by causing the toner to fall is employed so that a sufficient amount of toner may always exist under the opening  312  (refer to  FIG. 3 ). If the amount of toner under the opening  312  is short, the amount of toner being transported temporarily decreases, and the above-described fluctuations occur. However, if a sufficient amount of toner exists under the opening  312 , the above-described fluctuations are less likely to occur. 
       FIGS. 7A and 7B  illustrate the transporting member  400 . 
     As shown in  FIG. 7A , the transporting member  400  includes a rotary shaft  410  rotated by an unillustrated motor, and a protruding portion  420  provided to protrude from the rotary shaft  410 . The protruding portion  420  is provided in the form of a blade around the rotary shaft  410 . Further, the protruding portion  420  is provided from one end side toward the other end side of the rotary shaft  410  and provided in a helical shape (shape of a screw). The protruding portion  420 , which functions as a moving portion, presses toner with the rotation of the rotary shaft  410  to move the toner in the axial direction of the transporting member  400 . The diameter of the rotary shaft  410  varies in the axial direction thereof, and the rotary shaft  410  has a large-diameter portion  411  on the upstream side in the toner transport direction, and a small-diameter portion  412  having a smaller diameter than that of the large-diameter portion  411  on the downstream side in the toner transport direction. 
     Here, the large-diameter portion  411  is disposed inside the transport path forming member  500 , and is provided under the opening  312  (also refer to  FIG. 3 ). On the other hand, the small-diameter portion  412  is provided inside the transport path forming member  500  and downstream of the opening  312  in the toner transport direction. Specifically, the transport path forming member  500  has an opening formation portion  510 , which has an opening formed in an upper portion thereof, and a cylindrical portion  520 , which is formed in the shape of a cylinder without an opening formed therein. Further, in this exemplary embodiment, the large-diameter portion  411  is provided in the opening formation portion  510 , and the small-diameter portion  412  is provided in the cylindrical portion  520 . In this exemplary embodiment, a cross-section of the cylindrical portion  520  is formed in a U-shape. It should be noted that a cylindrical transport path formed by the cylindrical portion  520  is not limited to a U-shape but may be in the shape of a cylinder or a prism. The opening formation portion  510  may be captured as a feed portion through which toner is fed. 
     It should be noted that though not described in the above description, an exit port  530  is provided in an end and lower part of the cylindrical portion  520 , and toner transported by the transporting member  400  is fed to the cylindrical member  550  (also refer to  FIG. 5 ) through the exit port  530 . The cross-sectional shape of the opening formation portion  510  may be similar to that of the cylindrical portion  520 , or may be a shape formed along the outer edge of the transporting member  400  (outer edge of the protruding portion  420 ). 
     In the case where the container  300  that feeds toner by causing the toner to fall is employed as described above so that a sufficient amount of toner may be fed to the transporting member  400 , clogging (packing/blocking) of toner is likely to occur. For example, in the case where the transporting member  400  shown in  FIG. 7B  is used, toner is transported to the inlet of the cylindrical portion  520  by the transporting member  400 . This inlet is also fed with toner from above. In this case, the cylindrical portion  520  does not have enough room to allow all toner to enter therein. Accordingly, an overflow of toner occurs, and clogging of toner may occur at an inlet indicated by broken line A. In other words, when the toner in the feed portion to which the toner has been fed is transported along the cylindrical transport path, the toner concentrates at the inlet of the transport path, and thereby the toner may result in clogging at the inlet. Further, in a configuration in which toner falls from above as in this exemplary embodiment, the falling toner and the toner being transported to the transporting member  400  would enter the cylindrical portion  520  in a lump. Such a configuration tends to cause a large amount of toner to be squeezed into the cylindrical portion  520 . As a result, clogging of toner is also likely to occur in the cylindrical portion  520  (refer to broken lines B). Specifically, the pressure exerted on the toner in the transport path becomes higher due to increase of the toner fed to the feed portion, and thereby clogging of toner is likely to occur. 
     Accordingly, in this exemplary embodiment, as shown in  FIG. 7A , the diameter of a part of the rotary shaft  410  that is located inside the cylindrical portion  520  is set small (refer to the small-diameter portion  412 ), the amount of transportation (amount of transportation per unit time) of toner inside the cylindrical portion  520  is set larger than the amount of transportation (amount of transportation per unit time) of toner in the opening formation portion  510 . This makes clogging of toner less likely to occur inside the cylindrical portion  520 . Moreover, a part of the rotary shaft  410  that is located under the opening  312  is set larger (refer to the large-diameter portion  411 ), thus reducing the amount of toner transported toward the inlet of the cylindrical portion  520  in comparison with the mode shown in  FIG. 7B . This also makes clogging of toner less likely to occur at the inlet of the cylindrical portion  520 . In this exemplary embodiment, the position at which the diameter of the rotary shaft  410  switches from a large diameter to a small diameter (hereinafter referred to as a “diameter change position” in some cases) coincide, in the axial direction of the transporting member  400 , with the boundary (junction) between the opening formation portion  510  and the cylindrical portion  520 . However, the diameter change position and the boundary may not coincide with each other in the axial direction of the transporting member  400 . 
     Second Exemplary Embodiment 
       FIG. 8  illustrates the transporting member  400  in the second exemplary embodiment. 
     In the transporting member  400  in this exemplary embodiment, the diameter (outer diameter) of the protruding portion  420  varies in the axial direction of the transporting member  400  to increase the amount of transportation of toner in the cylindrical portion  520  compared to the amount of transportation of toner in the opening formation portion  510 . More specifically, by making the diameter of the part of the protruding portion  420  located inside the cylindrical portion  520  larger than the diameter of the part of the protruding portion  420  located inside the opening formation portion  510 , the amount of transportation (amount of transportation per unit time) of toner inside the cylindrical portion  520  is made larger than the amount of transportation (amount of transportation per unit time) of toner in the opening formation portion  510 . Further, by setting the diameter of the part of the protruding portion  420  located inside the opening formation portion  510  small, the amount of transportation (amount of transportation per unit time) of toner proceeding toward the inlet of the cylindrical portion  520  is reduced compared to the amount of transportation (amount of transportation per unit time) of toner in the opening formation portion  510 . 
     Similar to the above description, in this exemplary embodiment, clogging of toner inside the cylindrical portion  520  is less likely to occur. Also, clogging of toner which may appear at the inlet of the cylindrical portion  520  is less likely to occur. Further, since the diameter of the part of the protruding portion  420  located in the opening formation portion  510  is set small in this exemplary embodiment, a space located beneath the opening  312  is expanded, that is, a space where toner is accumulated is expanded. As a result, the amount of toner fed to the cylindrical portion  520  becomes more stable. Moreover, in the case where the diameter of the part of the protruding portion  420  located in the opening formation portion  510  is set smaller, rotational resistance of the transporting member  400  may be made small, thus making a torque required for rotating the transporting member  400  small. In other words, if the diameter of the part of the protruding portion  420  located in the opening formation portion  510 , where a large amount of toner exists, is set large, the torque required for rotating the transporting member  400  has a tendency to be large. Accordingly, making the diameter of the part of the protruding portion  420  located in the opening formation portion  510  small may reduce the torque required for rotating the transporting member  400 . 
     Third Exemplary Embodiment 
       FIG. 9  illustrates the transporting member  400  in the third exemplary embodiment. 
     In the transporting member  400  in this exemplary embodiment, similar to the transporting member  400  in the second exemplary embodiment, the diameter of the part of the protruding portion  420  located on the downstream side in the toner transport direction is set larger, and the diameter of the part of the protruding portion  420  located on the upstream side in the toner transport direction is set smaller. However, in this exemplary embodiment, the part of the protruding portion  420  whose diameter is set larger is not only located inside the cylindrical portion  520 , but also partially located in the opening formation portion  510 . In other words, the part of the protruding portion  420  whose diameter is set larger is provided to extend from an end portion (an end portion on the downstream side in the toner transport direction) of the opening formation portion  510  to the exit port  530  formed in the cylindrical portion  520 . In addition, the part of the protruding portion  420  whose diameter is set larger is provided so that a part thereof is positioned beneath the opening  312 . The part of the transporting member  400  located in the opening formation portion  510  is formed such that the amount of transportation of toner per unit of time is larger at the location on the downstream side in the toner transport direction than at the location on the upstream side in the toner transport direction. 
     In this exemplary embodiment, the toner transportation capacity is increased on the upstream side of the cylindrical portion  520  in the toner transport direction. Consequently, toner located at the inlet of the cylindrical portion  520  and above the transporting member  400  is taken into the transporting member  400  more compared to toner in other locations. As a result, clogging of toner which may occur on the upstream side of the cylindrical portion  520  (clogging of toner that occurs at the region indicated by broken line A in  FIG. 7B ) is more suppressed. 
     It should be noted that the diameter of the large-diameter part of the protruding portion  420  is not necessarily constant in the axial direction of the transporting member  400 . For example, in the large-diameter part of the protruding portion  420 , the diameter of the part located beneath the opening  312  may be set smaller than the diameter of the part located inside the cylindrical portion  520 . Specifically, for example, the diameter of the part of the protruding portion  420  located beneath the opening  312  may be set to 9 mm and the diameter of the part of the protruding portion  420  located inside the cylindrical portion  520  may be set to 10 mm. The diameter of the small-diameter part of the protruding portion  420  may be set to, for example, 5 mm. 
     Fourth Exemplary Embodiment 
       FIG. 10  illustrates the transporting member  400  in the fourth exemplary embodiment. 
     The transporting member  400  in the exemplary embodiment is in a mode partially different in the shape from the transporting member  400  shown in  FIG. 8 . In the transporting member  400  shown in  FIG. 8 , the diameter of the part of the protruding portion  420  located in the cylindrical portion  520  is set larger than the diameter of the part of the protruding portion  420  located in the opening formation member  510 . In this exemplary embodiment, in addition to setting the diameter of the part of the protruding portion  420  located in the cylindrical portion  520  large, the diameter of the part of the protruding portion  420  located in the opening formation portion  510  is also set large partially. Specifically, the diameter of the part of the protruding portion  420  located on the upstream side of the opening formation portion  510  in the toner transport direction is set large. In other words, in the transporting member  400  of this exemplary embodiment, the diameter of the part of the protruding portion  420  located on the upstream side of the cylindrical portion  520  in the toner transport direction is set smaller, and the diameter of the parts of the protruding portion in other locations is set larger. The part of the transporting member  400  located in the opening formation portion  510  is formed such that the amount of transportation of toner per unit of time is larger at the location on the upstream side in the toner transport direction than at the location on the downstream side in the toner transport direction. 
     In the case where the diameter of the part of the protruding portion  420  located in the opening formation portion  510  is small, the amount of transportation of toner is decreased, thereby possibly causing insufficiency in the amount of transportation of toner to the cylindrical portion  520 . Therefore, in this exemplary embodiment, the diameter of the part of the protruding portion  420  located on the upstream side of the cylindrical portion  520  in the toner transport direction is set large as described above, thus increasing the amount of toner proceeding toward the cylindrical portion  520 . Further, in this exemplary embodiment, the diameter of the part of the protruding portion  420  located on the upstream side of the cylindrical portion  520  in the toner transport direction is set smaller to reduce the amount of transportation of toner on the upstream side of the cylindrical portion  520 . Accordingly, toner accumulation in which toner is temporarily accumulated is formed, thereby stably feeding toner to the cylindrical portion  520 . Moreover, by reducing the diameter of the part of the protruding portion  420  located on the upstream side of the cylindrical portion  520  in the toner transport direction, the toner transportation speed is lowered on the upstream side of the cylindrical portion  520 , and therefore clogging of toner, which may appear on the upstream side of the cylindrical portion  520 , is less likely to occur. 
     As will be described in detail, in the case where the above-described large-diameter part of the protruding portion  420  is not provided in the opening formation portion  510 , that is, all the parts of the protruding portion is of small diameter, the toner accumulation is not formed on the upstream side of the cylindrical portion  520  in some cases. If the amount of toner fed through the opening  312  is temporarily decreased with this situation, the amount of toner fed to the inside of the cylindrical portion  520  is decreased, and thereby variations arise in the density of toner fed to the developing device  110 . In the configuration of this exemplary embodiment, formation of the toner accumulation may bring stable toner transportation and suppresses clogging of toner as described above. In this exemplary embodiment, the diameter of the protruding portion  420  is partially reduced to lower the amount of transportation of toner on the upstream side of the cylindrical portion  520  in the toner transport direction. However, the amount of transportation of toner may also be reduced by increasing the diameter of the rotary shaft  410  on the upstream side of the cylindrical portion  520 . It should be noted that, if the length of the cylindrical portion  520  in the longitudinal direction is considerably extended, fluctuation in the amount of toner transported inside the cylindrical portion  520  may be suppressed, and thereby variations in toner density in the developing device  110  may also be suppressed. 
     In the above-described first to fourth exemplary embodiments, the case where the transporting member  400  is provided to the main body of the image forming apparatus  10  is described as an example. However, the transporting member  400  may be provided to the container  300 . 
       FIGS. 11A and 11B  illustrate a configuration example in which the transporting member  400  is provided in the container  300 . Here,  FIG. 11A  shows a top view and  FIG. 11B  shows a front view (as viewed from the front side). Further, these figures show the container  300 C and the developing device  110 C as examples. 
     In the image forming apparatus  10  in these figures, the transport path forming member  500  that has an opening  580  in an upper portion and that is formed in the shape of a cylinder is attached to a lower part of the container  300 C (refer to  FIG. 11B ). The transporting member  400  is housed in the transport path forming member  500 . Toner (cyan toner) contained in the container  300 C falls downward through the opening  580  formed in the transport path forming member  500  to be fed to the transporting member  400 . The toner fed to the transporting member  400  is transported to the developing device  110 C. It should be noted that in the configuration example shown in these figures, the cylindrical member  550  (refer to  FIG. 5 ) is not provided. 
     In the configuration example shown in these figures, as shown in  FIG. 11B , the transporting member  400  is also formed to have a dimension L 1  smaller than a size W of the gap formed between the third sidewall  20 C and the developing device  110 C. Further, a width L 2  of the container  300 C is also smaller than the size W of the gap. Moreover, the dimension L 1  of the transporting member  400  is smaller than the width L 2  of the container  300 C (width of the container  300 C in the direction in which the transporting member  400  is disposed). Furthermore, in the configuration example shown in these figures, as shown in  FIG. 11B , the transporting member  400  does not protrude from the container  300 C, and the transporting member  400  is inside the width of the container  300 C. 
     It should be noted that though in the above-described first to fourth exemplary embodiments, a description is made of an example in which the transporting member  400  is provided in a transport route for transporting toner to the developing devices  110 , the transporting member  400  may, of course, be provided in, for example, a transport route for transporting waste toner produced in the cleaning of the photoconductive drums  102 Y,  102 M,  102 C, and  102 K. Further, though in the above-described first to fourth exemplary embodiments, the case where the transporting member  400  is provided in a lower part of the container  300  is exemplified, the attachment position of the transporting member  400  is not limited to a lower part of the container  300 . For example, in the mode shown in  FIGS. 6A and 6B , toner transported through the cylindrical member  550  is transported to the developing device  110 C using a second cylindrical member  560 . The transporting member  400  may be provided in the second cylindrical member  560 . 
     The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.