Patent Publication Number: US-11656562-B2

Title: Developing device with transporting member and cooling unit fixed to a case

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2021-085595 filed on May 20, 2021, Japanese Patent Application No. 2021-085596 filed on May 20, 2021, and Japanese Patent Application No. 2021-085597 filed on May 20, 2021. 
     BACKGROUND 
     Technical Field 
     The present invention relates to a developing device. 
     Related Art 
     JP-A-2003-114577 discloses a developing device having a developer container in which a developer is contained, an agitator configured to transporting the developer while agitating the developer, a developing sleeve configured to rotate by adsorbing the developer transported by the agitator on a surface thereof, and a developing blade arranged with a uniform minute gap on the surface of the developing sleeve and for thinly and uniformly regulating an adsorption amount of the developer adsorbed on the surface of the developing sleeve; and an image forming apparatus including the developing device, the developing device including at least one cooling unit of a cooling unit in contact with the agitator inside the developer container to absorb the heat of the agitator, a cooling unit in contact with the developing sleeve inside the developer container to absorb the heat of the developing sleeve, and a cooling unit in contact with the developing blade inside the developer container to absorb the heat of the developing blade, in which a heat radiating portion of the cooling unit is disposed outside the developer container and outside a transporting region of a transfer member in a view seen from the top of the image forming apparatus. 
     SUMMARY 
     Aspects of non-limiting embodiments of the present disclosure relate to a developing device in which a cooling member is fixed to a case with a simple structure as compared with a structure in which a cooling member is fixed to a case of a developing device using a dedicate attachment such as a fastening mechanism. 
     Aspects of non-limiting embodiments of the present disclosure further relate to a developing device that may be formed smaller than a developing device including a large heat sink. 
     Aspects of non-limiting embodiments of the present disclosure further relate to a developing device capable of lowering the temperature of a developer passing through the vicinity of a communication pore as compared with a developing device in which a portion of a transporting path adjacent to a communication hole is made of a material having the same heat conductivity as other portions of a case. 
     Aspects of certain non-limiting embodiments of the present disclosure address the above advantages and/or other advantages not described above. However, aspects of the non-limiting embodiments are not required to address the advantages described above, and aspects of the non-limiting embodiments of the present disclosure may not address advantages described above. 
     According to an aspect of the present disclosure, there is provided a developing device including: a case in which a hollow transporting path is formed; a transporting member configured to transport a developer in the transporting path; a support portion fixed to an end portion of the case by a fastening member to support the transporting member at an end portion of the transporting path; and a cooling unit fixed by being sandwiched between the support portion and the case. 
     According to another aspect of the present disclosure, there is provided a developing device including: a transporting path that is hollow and through which a developer is transported, wherein a part of a surface constituting the transporting path is formed by a cooling unit formed of a material having a heat conductivity higher than a heat conductivity of another part of the surface. 
     According to another aspect of the present disclosure, there is provided a developing device including: a case having a first transporting path and a second transporting path adjacent to the first transporting path; a first transporting member and a second transporting member configured to transport a developer so as to circulate the developer between the first transporting path and the second transporting path via a communication hole; and a cooling unit disposed at a position adjacent to the communication hole in the case and formed of a material having a heat conductivity higher than a heat conductivity of the case. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiment(s) of the present invention will be described in detail based on the following figures, wherein: 
         FIG.  1    is a side view illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention; 
         FIG.  2    is an external perspective view illustrating a developing device according to the exemplary embodiment of the present invention; 
         FIG.  3    is an external perspective view illustrating an end portion of the developing device including a support portion according to the exemplary embodiment of the present invention; 
         FIG.  4    is an external perspective view including a longitudinal section of the developing device according to the exemplary embodiment of the present invention; 
         FIG.  5    is a longitudinal sectional view illustrating the developing device according to the exemplary embodiment of the present invention; 
         FIG.  6    is a horizontal sectional view illustrating the developing device according to the exemplary embodiment of the present invention; 
         FIG.  7    is a longitudinal sectional view illustrating a second transporting path from which a cooling unit is removed and a transporting member according to the exemplary embodiment of the present invention; 
         FIG.  8    is a longitudinal sectional view illustrating the second transporting path to which the cooling unit is attached and the transporting member according to the exemplary embodiment of the present invention; 
         FIG.  9    is a rear view illustrating the end portion of the developing device according to the exemplary embodiment of the present invention; and 
         FIG.  10    is an external perspective view illustrating an example of another cooling unit according to the exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an exemplary embodiment of the present invention will be described with reference to the drawings. The same components and processes are denoted by the same reference numerals throughout the drawings, and redundant description thereof will be omitted. 
       FIG.  1    is a side view illustrating a configuration of an image forming apparatus;  FIG.  2    is an external perspective view illustrating a developing device;  FIG.  3    is an external perspective view illustrating an end portion of the developing device including a support portion;  FIG.  4    is an external perspective view including a longitudinal section of the developing device;  FIG.  5    is a longitudinal sectional view illustrating the developing device;  FIG.  6    is a horizontal sectional view illustrating the developing device;  FIG.  7    is a longitudinal sectional view illustrating a second transporting path from which a cooling unit is removed and a transporting member;  FIG.  8    is a longitudinal sectional view illustrating the second transporting path to which the cooling unit is attached and the transporting member;  FIG.  9    is a rear view illustrating the end portion of the developing device; and  FIG.  10    is an external perspective view illustrating an example of another cooling unit. 
     Next, the exemplary embodiment of the present invention will be described with reference to the drawings.  FIG.  1    illustrates an image forming apparatus  10  used in the exemplary embodiment of the present invention. The image forming apparatus  10  includes an image forming apparatus body  12 , and an image forming device  14 , a transfer device  16 , a fixing device  18 , and a sheet feeding device  20  are disposed in the image forming apparatus body  12 . A transporting passage  22  for transporting a recording medium such as a paper sheet is formed in the image forming apparatus body  12 . 
     In this specification and the drawings, for the sake of convenience, a left-right direction of the image forming apparatus  10  in  FIG.  1    is indicated as an X-axis direction, a height direction is indicated as a Y-axis direction, and a direction orthogonal to the X-axis direction and the Y-axis direction is indicated as a Z-axis direction. In  FIG.  1   , the right direction is defined as a positive side in the X-axis direction, the upper direction is defined as a positive side in the Y-axis direction, and the front direction is defined as a positive side in the Z-axis direction. Other drawings are described in the same directions. 
     The image forming device  14  adopts an electrophotographic process to form an image on a recording medium. The image forming device  14  includes, for example, plural image forming units  24 , such as four image forming units  24 . The four image forming units  24  form toner images of different colors such as yellow, magenta, cyan, and black. 
     The image forming unit  24  includes a photoconductor drum  26 . The photoconductor drum  26  is an example of an image carrier. The photoconductor drum  26  carries and rotates the toner image transferred to the recording medium on an outer peripheral surface. The image forming unit  24  is provided with a charging device  28  that charges the photoconductor drum  26 , a developing device  95  that develops the charged latent image with toner, and a cleaning device  32  that cleans the photoconductor drum  26  after the transfer. An optical writing device  48  that forms a latent image on the charged photoconductor drum  26  is further provided. 
     The transfer device  16  includes an intermediate transfer belt  34 . A toner image is primarily transferred from the photoconductor drum  26  to the intermediate transfer belt  34  by a primary transfer member  36 , and the primarily transferred toner image is secondarily transferred to a recording medium by a secondary transfer member  38 . 
     The intermediate transfer belt  34  is supported so as to be rotatable by plural support members  40 . Further, a backup member  42  is provided to face the secondary transfer member  38 . 
     The fixing device  18  fixes the toner image transferred onto the recording medium to the recording medium by using, for example, heat and pressure. 
     The sheet feeding device  20  includes a storage unit  44  that stores recording media in a stacked manner, and a delivery member  46  that delivers a recording medium stored in the storage unit  44  toward the transporting passage  22 . 
     The transporting passage  22  transports a recording medium from the sheet feeding device  20  to between the secondary transfer member  38  and the backup member  42 , transports the recording medium to the fixing device  18 , and further transports the recording medium so as to be discharged to an outside of the image forming apparatus body  12 . 
     In the image forming apparatus  10  configured as described above, the toner image formed on the outer peripheral surface of the photoconductor drum  26  is primarily transferred onto the intermediate transfer belt  34 , the toner image primarily transferred onto the intermediate transfer belt  34  is secondarily transferred onto the recording medium, and the toner image secondarily transferred onto the recording medium is fixed on the recording medium by the fixing device  18 . 
     In the image forming apparatus  10  according to the present exemplary embodiment, the developing device  95  that develops an electrostatic latent image formed on the electrostatic latent image carrier of the photoconductor drum  26  is used. As the developing device  95 , for example, a two-component developer (hereinafter, simply referred to as a developer) including a carrier having magnetism and a toner mainly containing a resin is contained in a case  300  (housing) having a developing opening facing the electrostatic latent image carrier (photoconductor drum  26 ), and a developing roll  190  as a developing carrier is disposed at a position facing the developing opening of the case  300  as the housing. An auger serving as a transporting member that transports the developer in the transporting path in the case  300  (housing) to the developing roll while stirring and transporting the developer is disposed on a back side of the developing roll  190 . 
     As illustrated in  FIGS.  1  to  9   , the developing device  95  according to the present exemplary embodiment includes the housing  300  as a case that is open at a portion facing the photoconductor drum  26  and contains a developer. The developing roll  190  as a developing member, which is a developer carrier, is disposed so as to face the opening of the housing  300 . Inside the housing  300  as an example of the case, a first transporting path  100  that contains the developer so as to be able to supply the developer to the developing roll  190  is provided at a portion adjacent to the developing roll  190 , and a second transporting path  150  that contains the developer so as to be able to supply the developer to the first transporting path  100  is disposed adjacent to the first transporting path  100  and. As illustrated in  FIG.  4   , the first transporting path  100  and the second transporting path  150  are disposed adjacent to each other vertically in the direction of gravity, and the second transporting path  150  is formed so as to be positioned below the first transporting path  100 . 
     Here, the first transporting path  100  and the second transporting path  150  are partitioned from each other via a partition wall, and communicate with each other at both end portions in an axial direction. Specifically, a communication hole  110  (see  FIG.  5   ) is formed at an end portion on a front side, and a communication hole (not shown) is formed at an end portion on a back side. In the housing  300 , the developer circulates in the order of the second transporting path  150 , the communication hole  110  on the front side, the first transporting path  100 , and the communication hole on the back side. 
     The developing device  95  includes a transporting member that applies a transporting force for circulating the developer in the housing  300 . Specifically, the developing device  95  includes a supply auger  120  disposed in the first transporting path  100  and an admix auger  170  disposed in the second transporting path  150 . The supply auger  120  is formed with a main winding portion  180  which is a spiral blade on an outer periphery of a shaft, and the supply auger  120  transports the developer in a predetermined axial direction (for example, a negative side in the Z-axis direction in  FIG.  5   ) while supplying the developer to the developing roll  190  by rotating around the shaft. The admix auger  170  is formed with a main winding portion  180  which is a spiral blade on an outer periphery of a shaft, and the admix auger  170  transports the developer in a direction opposite to that of the supply auger  120  (for example, a positive side in the Z-axis direction in  FIG.  5   ) while stirring the developer by rotating around the shaft. The supply auger  120  is an example of a first transporting member, and the admix auger  170  is an example of a second transporting member. 
     By the rotation of the supply auger  120  and the admix auger  170 , a developer G circulates in the above-described paths. The second transporting path  150  extends to the front side of the communication hole  110 , and in this portion, a portion in which a reverse winding portion  185 , which is a spiral blade, is formed on an outer periphery of the shaft of the admix auger  170  is disposed. The reverse winding portion  185  applies a transporting force in a direction opposite to that of the main winding portion  180  to the developer, so that the developer transported to the communication hole  110  by the main winding portion is promoted to be lifted toward the communication hole  110 . 
     On the other hand, the first transporting path  100  extends to the front side of the communication hole  110 , and forms a part of a developer discharge path  186  through which excess developer is discharged. The developer discharge path  186  includes a part extending forward to the positive side in the Z-axis direction beyond the reverse winding portion  185  of the admix auger  170  than the communication hole  110  in the first transporting path  100 , and a part extending downward from an end portion of the above part and vertically penetrating the second transporting path  150 . Since the developer discharge path  186  is formed, a so-called trickle method is adopted in which the deteriorated developer is gradually discharged to the outside of the case  300 . In the part of the developer discharge path  186  extending in the Z-axis direction, a portion in which a reverse winding portion  185  that applies a transporting force in a direction opposite to that of the main winding portion  180  of the supply auger  120  to the developer is formed is disposed. 
     In the present exemplary embodiment, a third transporting path  195  in which a counter auger  196  serving as a third transporting member is disposed is formed in the housing  300 . The counter auger  196  rotates around the axis to return the developer that is not consumed by the developing roll  190  to the second transporting path  150 . 
     The case  300  is formed by joining a body side housing  320  and an end portion side housing  340 . In the body side housing  320 , parts of the first transporting path  100  and the second transporting path  150  slightly closer to the front side than the communication hole  110  are formed. In the end portion side housing  340 , the remaining parts of the first transporting path  100  and the second transporting path  150  are formed. The body side housing  320  and the end portion side housing  340  are fixed to each other by screwing fastening members  342 ,  344 ,  346  into the body side housing  320  (case) from the end portion side housing  340  side in an abutting state in which a seal member  156  is sandwiched between the end portions of the body side housing  320  and the end portion side housing  340 . 
     As illustrated in  FIGS.  3  to  6   , in the present exemplary embodiment, the cooling unit  200  is disposed at a position adjacent to the communication hole  110  of the second transporting path  150 . The cooling unit  200  is disposed on the front side of the communication hole  110  in the second transporting path  150 . The cooling unit  200  is a pipe-shaped member made of aluminum or an aluminum alloy which is a material having a higher heat conductivity than the resin which is a material for the case  300 . The cooling unit  200  is formed so as to cover an inner surface of the second transporting path  150  at an arrangement portion thereof and extend in a peripheral direction of the second transporting path  150 . Specifically, the cooling unit  200  covers the reverse winding unit  185  of the admix auger  170  from the periphery. 
     The cooling unit  200  is fixed to the case  300  by being sandwiched between the body side housing  320  and the end portion side housing  340 . 
     A specific description will be given below. A recessed portion  152  is formed in a portion of the body side housing  320  where the second transporting path  150  is formed. The recessed portion  152  is a portion having an inner diameter larger than that of the transporting path  150 , and reaches an end portion of the end portion side housing  340  in the body side housing  320 . An end portion of the recessed portion  152  on the side opposite to the end portion side housing  340  side is an abutting surface (inner surface)  153  facing the end portion side housing  340  side. A part of the cooling unit  200  on the negative side in the Z-axis direction is internally fitted into the recessed portion  152  in a state where the cooling unit  200  abuts against the abutting surface  153  of the recessed portion  152 . 
     Another part of the cooling unit  200  is internally fitted into the end portion side housing  340 . The seal member  154  is interposed between the end portion side housing  340  and the end portion of the cooling unit  200  opposite to the body side housing  320 . A fastening load by the above-described fastening members  342 ,  344 ,  346  acts on the seal member  154 . That is, as described above, the cooling unit  200  is fixed to the case  300  by being sandwiched between the body side housing  320  and the end portion side housing  340  by the fastening load of the fastening members  342 ,  344 ,  346 . 
     Here, as illustrated in  FIG.  8   , a pipe inner diameter of the cooling unit  200  and an inner diameter of the second transporting path  150  are formed to be the same, and the inner surfaces of both are formed to be continuous without generating a step. However, the pipe inner diameter of the cooling unit  200  may be formed to be smaller than the inner diameter of the second transporting path  150 . As a result, the developer transported by the reverse winding portion  185  is smoothly transported toward the communication hole  110 . 
     An opening portion  360  through which the cooling unit  200  faces the outside of the housing is formed in a portion of the housing  300  located outside the cooling unit  200 . The opening portion  360  is formed in a rectangular window shape penetrating the inside and the outside of the housing, so that the cooling unit  200  is configured to be able to come into contact with the air outside the case  300 . 
     Here, in the present exemplary embodiment, the opening portion  360  is formed at two positions, that is, an upper opening portion  362  facing obliquely upward of the case  300  (housing) as shown in  FIG.  2   , and a lower opening portion  364  facing downward of the case  300  (housing) as shown in the rear view of  FIG.  9   . The opening portion  360  is provided on a surface of the second transporting path  150  parallel to a developer transporting direction (positive side in the Z-axis direction). In this exemplary embodiment, the upper opening portion  362  and the lower opening portion  364  are formed in the end portion side housing  340 , and the seal member  156  is positioned at an edge of the end portion side housing  340  on the body side housing  320  side. 
     In the present exemplary embodiment, as illustrated in  FIG.  2   , an air intake unit  420  that sucks air into the image forming apparatus  10  and an air exhaust unit  430  that exhausts the air are provided. The air intake unit  420  is a portion that opens in the right side plate when the image forming apparatus  10  is viewed from the side illustrated in  FIG.  1   , and the air exhaust unit  430  is a portion that opens in the back side plate when the image forming apparatus  10  is viewed from the side illustrated in  FIG.  1   . In addition, as illustrated in  FIG.  2   , in a state where the developing device  95  is installed in an image processing apparatus  90 , the cooling unit  200  is disposed not on the air exhaust unit  430  side but on the air intake unit  420  side. In addition, the air intake unit  420  includes a blowing device  400  that blows air toward the cooling unit  200 . Therefore, the opening portion  360  is provided at a position in contact with an airflow generated inside the image forming apparatus  10  in a state where the developing device  95  is installed in the image forming apparatus  10 . Here, the air intake unit  420  is the portion that opens in the right side plate when the image forming apparatus  10  is viewed from the side illustrated in  FIG.  1   , and the air exhaust unit  430  is the portion that opens in the back side plate when the image forming apparatus  10  is viewed from the side illustrated in  FIG.  1   . The number of the air intake unit  420  and the air exhaust unit  430  is not limited to one, and may be provided in each developing device  95 . In addition, a duct connected from the air intake unit  420  to the opening portion  360  may be provided so that the air taken in from the air intake unit  420  is able to be easily sent to the cooling unit  200 . 
     (First Aspect) 
     In the developing device  95 , when the supply auger  120  and the admix auger  170  rotate, the developer circulates in the housing  300  in the order of the second transporting path  150 , the communication hole  110  on the front side, the first transporting path  100 , and the communication hole on the back side. 
     In the above-described exemplary embodiment, in order to change the transporting direction of the developer in the second transporting path  150  (from the negative side in the Z-axis direction to the positive side in the Z-axis direction in  FIG.  5   ) to the transporting direction of the developer in the first transporting path  100  (from the positive side in the Z-axis direction to the negative side in the Z-axis direction in  FIG.  5   ) and to move the developer upward into the first transporting path  100  on the upper side, it is necessary to apply pressure to the developer in the vicinity of the communication hole  110  of the second transporting path  150 . At this time, the temperature of the developer and the like increases due to generation of frictional heat accompanying an increase in frictional force between the developers. 
     In addition, when the transporting member such as an auger shaft is rotated at high speed without increasing the diameter in order to save the space of the image forming apparatus, heat is generated in the bearing and the driving system, and heat is likely to be generated in a portion in the vicinity of the communication hole where the developer stays. 
     In the exemplary embodiment, the cooling unit  200  is disposed adjacent to the communication hole  110 . The cooling unit  200  has a heat conductivity higher than that of the housing  300 . 
     According to the exemplary embodiment, as compared with a structure in which the cooling member  200  is fixed to the case  300  of the developing device  95  using a dedicated attachment such as a fastening mechanism, the cooling unit  200  may be fixed to the developing device  95  without requiring a special fastening mechanism or the like for fixing the cooling unit  200  separately. In addition, the structure of the developing device  95  may be simplified without complicating the structure. 
     According to the exemplary embodiment, as compared with a configuration in which the cooling unit  200  is sandwiched by the support portion  340  in a state where the cooling unit  200  is not pressed, the cooling unit  200  is pressed toward an inner surface of the recessed portion  152 , and the cooling unit  200  is firmly sandwiched and fixed between the support portion  340  and the transporting path without being pushed by a dedicated fastening member. 
     According to the exemplary embodiment, as compared with a configuration in which positioning is not performed by abutting, and a seal member is not provided, positioning is easily performed by abutting the cooling unit  200  against the inner surface of the recessed portion  152 , a gap is less likely to be generated, and entry of the developer is also prevented. 
     According to the exemplary embodiment, as compared with a configuration in which the support portion  340  and the support portion  340  side of the cooling unit  200  are in direct contact with each other, the developer may be prevented from entering between the cooling unit  200  and the support portion  340 . 
     According to the exemplary embodiment, as compared with a configuration in which the cooling unit  200  has a plate shape, the cooling unit  200  is formed in a tubular shape, so that the developer comes into direct contact with the inner surface of the tubular shape, the heat of the developer is efficiently transmitted to the cooling unit  200 , and the temperature of the developer may be efficiently lowered. 
     According to the exemplary embodiment, the image forming apparatus  10  having the function and effect of the developing device  95  according to any one of the aspects described above may be provided. 
     In addition, in the above-described exemplary embodiment, the opening portion  360  is provided not in the body side housing  320  but in the end portion side housing (support portion)  340 . The end portion side housing (support portion)  340  is formed to be shorter than the elongated body side housing  320 , so that the opening portion  360  is opened while maintaining the strength and rigidity of the housing. 
     In addition, in the above-described exemplary embodiment, as illustrated in  FIG.  2   , the air intake unit  420  is provided, so that cold fresh air outside the image forming apparatus  10  is taken into the image forming apparatus  10  from the air intake unit  420  by the blowing device  400 . Then, the air flow directly comes into contact with the cooling unit  200 . 
     As a result, the air, the temperature of which is increased due to taking in the heat released from the surface of the cooling unit  200 , may be discharged from the air exhaust unit  430  to the outside of the image forming apparatus  10 . In addition, a flow of air may be generated as illustrated in  FIG.  2    inside the image forming apparatus  10 , and the cooling effect of the cooling unit  200  may be increased without increasing the air temperature inside the image forming apparatus  10 . 
     In addition, the cooling unit  200  according to the exemplary embodiment has a cylindrical pipe shape as a whole, and an opening, a notch, or the like is not formed, but the cooling unit  200  is not particularly limited to such a shape. Specifically, for example, as illustrated in  FIG.  10   , a cutout portion  210  may be provided at which a position corresponding to the communication hole  110  is cut out. In the case where the cutout portion  210  is provided, it is desirable that the communication hole  110  is disposed so as to be positioned between one side  211  and the other side  212  facing each other of the cutout portion  210 . Note that, in the exemplary embodiment, the cutout portion  210  has a shape that is cut out at an end portion side of the cooling unit  200 , but the position and shape of the cutout portion  210  are not particularly limited to the shape that is cut out at the end portion side, and the cutout portion  210  may be formed in a hole shape that opens further toward an inner side of the cooling unit  200 . 
     As illustrated in  FIG.  10   , when the cooling unit  200  has the cutout portion  210  corresponding to the communication hole  110 , the cooling unit  200  may be disposed close to the periphery of the communication hole  110 , and the temperature increase around the communication hole  110  may be efficiently reduced. 
     Further, in the exemplary embodiment, the first transporting path  100  and the second transporting path  150  are arranged adjacent to each other vertically in the direction of gravity, that is, in a so-called vertical arrangement, but the present invention is not particularly limited to such a vertical arrangement. Specifically, for example, even in a horizontal arrangement in which plural transporting paths are arranged on the left and right in the direction of gravity instead of the vertical arrangement in which plural transporting paths are arranged vertically in the direction of gravity as described above, the same function and effect may be obtained and applicable even when the cooling unit  200  as described above is provided in a developing device in which a high speed rotation is performed to increase the efficiency and the temperature of the developer is expected to increase due to a frictional force. 
     (Second Aspect) 
     According to the exemplary embodiment, the developing device  95  that may be formed smaller than a developing device including a large heat sink is provided. Here, the cooling unit  200  is provided on a part of the inner surface of the second transporting path  150 . For this reason, the cooling unit  200  may directly absorb heat from the developer whose temperature has increased, and further diffuse and dissipate the absorbed heat to the periphery of the case, so that the concentration of heat is reduced and the temperature increase of the developer and the like is reduced. 
     According to the exemplary embodiment, the cooling effect may be increased as compared with a case where the cooling unit  200  does not face the outside of the housing  300 . 
     According to the exemplary embodiment, the opening portion  360  may be opened while maintaining the strength of the housing  300  as compared with a case where the opening portion  360  is provided in the elongated body side housing  320 . That is, the end portion side housing (support portion)  340  is formed to be shorter than the elongated body side housing  320 , so that the opening portion  360  is opened while maintaining the strength and rigidity of the housing. 
     According to the exemplary embodiment, leakage of the developer from a gap may be prevented as compared with a case where a seal member is disposed only between the body side housing  320  and the cooling unit  200 . 
     According to the exemplary embodiment, the cooling effect of the cooling unit  200  may be increased as compared with a case where an airflow does not contact the cooling unit  200  facing the opening portion  360 . 
     According to the exemplary embodiment, the cooling effect may be increased as compared with a case where the opening portion  360  is provided on a surface of the second transporting path  150  other than the surface parallel to the transporting direction of the developer. 
     According to the exemplary embodiment, the cooling effect may be increased as compared with a case where the cooling unit  200  is provided only at a part in the peripheral direction. 
     According to the exemplary embodiment, the cooling effect of the cooling unit  200  may be increased as compared with a case where the air from the blowing device  400  does not come into contact with the cooling unit  200 . 
     According to the exemplary embodiment, the cooling effect of the cooling unit  200  may be increased as compared with a case where the cooling unit  200  is disposed on the air exhaust unit  430  side. That is, as illustrated in  FIG.  2   , the air intake unit  420  is provided, so that the cold fresh air outside the image forming apparatus  10  is taken into the image forming apparatus  10  from the air intake unit  420  by the blowing device  400 . Then, the air flow directly comes into contact with the cooling unit  200 . As a result, the air, the temperature of which is increased due to taking in the heat released from the surface of the cooling unit  200 , may be discharged from the air exhaust unit  430  to the outside of the image forming apparatus  10 . In addition, a flow of air may be generated as illustrated in  FIG.  2    inside the image forming apparatus  10 , and the cooling effect of the cooling unit  200  may be increased without increasing the air temperature inside the image forming apparatus  10 . 
     In the above-described exemplary embodiment, as illustrated in  FIGS.  5  and  6   , the cooling unit  200  is provided from a position adjacent to the communication hole  110  to a position corresponding to the developer discharge path  186 . As a result, an increase in temperature in the vicinity of the developer discharge path  186  may be reduced, the developer discharge path  186  to which the developer is discharged may be prevented from becoming functional failure, and the function of discharging excess developer may be maintained. 
     In the above-described exemplary embodiment, as illustrated in  FIGS.  3 ,  5 , and  6   , when the support portion  340  is fixed to the end portion of the case  300  by the fastening members ( 342 ,  344 , and  346 ), the cooling unit  200  is sandwiched between the support portion  340  and the case  300 , and the support portion  340  is fixed to the case  300  by the fastening members ( 342 ,  344 , and  346 ). 
     Accordingly, as compared with a structure in which the cooling unit  200  is fixed to the case  300  of the developing device  95  using a dedicated attachment such as a fastening mechanism, the cooling unit  200  may be fixed to the developing device  95  without requiring a special fastening mechanism or the like for fixing the cooling unit  200  separately. In addition, the structure of the developing device  95  may be simplified without complicating the structure. 
     (Third Aspect) 
     According to the exemplary embodiment, the temperature of the developer passing through the vicinity of the communication hole  110  may be lowered as compared with a case where a portion of the second transporting path  150  adjacent to the communication hole  110  is made of a material having the same heat conductivity as other portions of the case  300 . 
     According to the exemplary embodiment, an increase in temperature may be effectively reduced as compared with a case where the cooling unit  200  is disposed only in the first transporting path  100 . 
     According to the exemplary embodiment, in the configuration in which the second transporting path  150  is disposed on the lower side of the first transporting path  100  in the direction of gravity, the temperature of the developer passing through the vicinity of the communication hole  110  may be lowered as compared to a configuration in which the second transporting path  150  is made of a material having the same heat conductivity as that of a portion of the transporting path adjacent to the communication hole  110 . 
     According to the exemplary embodiment, as compared with a configuration in which the cooling unit is disposed only adjacent to the communication hole  110  through which the developer moves from the first transporting path  100  to the second transporting path  150 , the temperature is likely to increase in the vicinity of the communication hole  110  through which the developer is lifted up and transported, and therefore, the temperature of the developer passing through the vicinity of the communication hole  110  may be efficiently lowered. 
     According to the exemplary embodiment, as compared with a configuration in which the cooling unit has a plate shape, the cooling portion  200  is a pipe-shaped member, so that the developer comes into direct contact with the cooling unit  200 , and therefore, the temperature of the developer passing through the vicinity of the communication hole  110  may be lowered. 
     According to the exemplary embodiment, as compared with a configuration in which the cooling unit  200  is disposed to be shifted from the communication hole  110 , the cooling unit  200  may be disposed close to the periphery of the communication hole  110 , and the temperature of the developer passing through the vicinity of the communication hole  110  may be lowered. 
     According to the exemplary embodiment, as compared with a configuration in which the cooling unit is disposed so as to be shifted from the reverse winding portion, a temperature increase in a portion where the temperature increase due to collision and friction of the developer becomes large is reduced, and the temperature of the developer passing through the vicinity of the communication hole may be reduced. 
     According to the exemplary embodiment, as compared with a case where the cooling unit  200  is disposed only in the vicinity of the communication hole  110 , the temperature increase in the vicinity of the developer discharge path  186  may be reduced, and the discharge failure of the excess developer may be prevented. 
     According to the exemplary embodiment, the image forming apparatus  10  including the developing device  95  according to any one of the aspects described above may be provided. 
     In the exemplary embodiment, the communication hole  110  through which the developer is lifted upward and moves from the second transporting path  150  to the first transporting path  100 , and the communication hole (not illustrated) through which the developer falls down and moves from the first transporting path  100  to the second transporting path  150  are provided. As illustrated in  FIG.  5   , the cooling unit  200  is provided at a position adjacent to, among the two communication holes, the communication hole  110  through which the developer is lifted upward and moves from the second transporting path  150  to the first transporting path  100 . Since the developer may move by natural dropping through the communication hole (not illustrated) through which the developer falls down without applying a special pressure or the like to the developer, a large frictional load is not applied to the developer, and the generation of frictional heat is also small. Therefore, it is not necessary to provide the cooling unit  200  on the side of the communication hole (not illustrated) through which the developer falls down, and the cooling unit  200  is not provided. On the other hand, in the vicinity of the communication hole  110  through which the developer is lifted upward and moves from the second transporting path  150  to the first transporting path  100  via the communication hole  110 , it is necessary to apply pressure by pressing the developer in order to lift the developer from the second transporting path  150  on the lower side to the first transporting path  100  on the upper side against gravity. At such a position, the frictional force between the developers increases, and the temperature in the vicinity tends to increase due to the frictional heat. By providing the cooling unit  200  at a position adjacent to the communication hole  110  where the temperature easily increases, the temperature increase in the vicinity of the communication hole  110  may be efficiently reduced. 
     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.