Patent Publication Number: US-2020301310-A1

Title: Developing device and image forming device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2019-055393 filed Mar. 22, 2019. 
     BACKGROUND 
     (i) Technical Field 
     The present disclosure relates to a developing device and an image forming device. 
     (ii) Related Art 
     Japanese Unexamined Patent Application Publication No. 2011-169931 discloses a developing device provided with a control unit that controls the strength of a magnetic field generated in a portion adjoining a developer rectifying space, in accordance with the development conditions when a toner image is formed on an image carrier. 
     SUMMARY 
     In developing devices, development is sometimes carried out with a rotating body being installed in an opening of the developing device and a developer that has adhered to this rotating body being made to adhere to a development subject. 
     In developing devices, a conveying member that conveys the developer is sometimes provided, and when the developer is supplied directly from this conveying member to the rotating body, the quantity of the developer that adheres to the rotating body is liable to fluctuate. 
     Aspects of non-limiting embodiments of the present disclosure relate to a developing device and an image forming device, a purpose of which is to stabilize the quantity of a developer that is supplied to a rotating member installed in an opening of the developing device, compared to when a developer is supplied directly from a conveying member installed in a developing device to a rotating member installed in an opening of the developing device. 
     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 housing unit that has an opening and houses a developer; a conveying member that is installed within the housing unit and conveys the developer; a first rotating member that has an outer peripheral surface to which the developer conveyed by the conveying member adheres; a regulating unit that protrudes above a movement path of the developer that adheres to the outer peripheral surface and moves due to rotation of the first rotating member, and regulates movement of some of the developer on the outer peripheral surface; and a second rotating member that is installed in the opening and has supplied thereto the developer that has moved through a gap between the first rotating member and the regulating unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An exemplary embodiment of the present disclosure will be described in detail based on the following figures, wherein: 
         FIG. 1  is a drawing depicting the overall configuration of an image forming device; 
         FIG. 2  is a drawing describing a developing device; and 
         FIG. 3  is a drawing depicting another exemplary configuration of the developing device. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an exemplary embodiment of the present disclosure will be described with reference to the appended drawings. 
       FIG. 1  is a drawing depicting the overall configuration of an image forming device  1 . That is to say,  FIG. 1  is a drawing of a case where the image forming device  1  is viewed from the front side of the image forming device  1 . 
     The image forming device  1  is provided with an image forming unit  10 , a paper supply unit  20 , and a fixing unit  30 . 
     The image forming unit  10  forms an image (toner image) that is transferred onto paper P, using what is referred to as an electrophotographic system. The paper supply unit  20  supplies the paper P to the image forming unit  10 . The fixing unit  30  fixes the image formed on the paper P by the image forming unit  10 , to the paper P. 
     The image forming unit  10  is provided with a photoconductor drum  11  that rotates in the direction indicated by arrow A. Furthermore, the image forming unit  10  is provided with a charging roller  12 , an exposing device  13 , a developing device  14 , a transfer roller  15 , and a cleaning device  16 . 
     The photoconductor drum  11 , which serves as an example of the image carrier, is constituted by a cylindrical body. A photosensitive layer (not depicted) is formed on the surface of this cylindrical body. 
     The charging roller  12  is constituted by an electrically conductive rubber roller or the like, and charges the photoconductor drum  11 . 
     The exposing device  13  radiates light from a light source such as a laser light source or an LED (light emitting diode) toward the photoconductor drum  11  that is charged by the charging roller  12 , and forms an electrostatic latent image on the surface of the photoconductor drum  11 . 
     The developing device  14  houses a developer. The developer of the present embodiment is constituted by a magnetic carrier and a colored toner, and is what is referred to as a two-component developer. 
     The developing device  14  causes the developer to adhere to the surface of the photoconductor drum  11 , and develops the electrostatic latent image formed on the photoconductor drum  11 , using the developer having a predetermined color. An image formed using a toner is thereby formed on the surface of the photoconductor drum  11 . 
     The transfer roller  15  functions as a transfer unit and is constituted by a roller-shaped member or the like that is electrically conductive. In the present embodiment, the location where the transfer roller  15  and the photoconductor drum  11  oppose each other serves as a transfer section T, and the image on the surface of the photoconductor drum  11  is transferred to conveyed paper P in this transfer section T. 
     The cleaning device  16  is provided with a contact member  16 A that is arranged in contact with the photoconductor drum  11 , and the cleaning device  16  eliminates adhered substances (such as toner) on the photoconductor drum  11 . 
     The paper supply unit  20  is provided with a housing container  21  that houses the paper P, and a feeding mechanism  22  that feeds the paper P from the housing container  21 . 
     In addition, in the present embodiment, there are provided paper conveying mechanisms  23  that convey the paper P that is fed from the housing container  21 , through the transfer section T and the fixing unit  30 . 
     The fixing unit  30  is provided with a pair of rotating bodies  31  that rotate while in contact with each other. 
     A heating source (not depicted) is provided within one rotating body  31  from among this pair of rotating bodies  31 . 
     In the fixing unit  30 , pressure and heat are applied to the paper P by these two rotating bodies  31 , and the toner image on the paper P is fixed to this paper P. 
     An image forming operation in the image forming device  1  will now be described. 
     In the image forming unit  10 , the photoconductor drum  11 , which rotates in the direction of arrow A, is charged by the charging roller  12 . Next, the exposing device  13  carries out exposure, and an electrostatic latent image corresponding to image information is formed on the surface of the photoconductor drum  11 . 
     Thereafter, the developing device  14  carries out developing, and an image (toner image) corresponding to the electrostatic latent image is formed on the surface of the photoconductor drum  11 . 
     The toner image formed on the photoconductor drum  11  moves toward the transfer section T due to the rotation of the photoconductor drum  11 . Furthermore, the paper P fed from the housing container  21  is conveyed to the transfer section T by the paper conveying mechanisms  23 . 
     The toner image on the photoconductor drum  11  is then transferred to the conveyed paper P in the transfer section T. Thereafter, the paper P to which the toner image has been transferred passes through the fixing unit  30  and has heat and pressure thereby applied thereto, and this toner image is fixed on the paper P. 
       FIG. 2  is a drawing describing the developing device  14 . The developing device  14  is provided with a housing unit  141  that houses the developer therein. The housing unit  141  is constituted by a housing casing  142  made of a resin. 
     The housing casing  142  (developing device  14 ) is arranged so as to extend in the direction from the front side of the image forming device  1  to the rear side (direction orthogonal to the page space in  FIG. 2 ), has a rear side end (not depicted) at the rear side, and has a front side end (not depicted) at the front side. 
     In the housing unit  141 , an opening  143 , which serves as an example of the opening, is provided in a location opposing the photoconductor drum  11  (see  FIG. 1 ). 
     A developing roller  145  is provided in this opening  143 . This developing roller  145  causes the developer to adhere to the surface of the photoconductor drum  11 . 
     The developing roller  145  is formed in a cylindrical shape and is arranged so as to extend in the direction from the front side of the image forming device  1  to the rear side (direction orthogonal to the page space in  FIG. 2 ). 
     The developing roller  145  is provided with a developing sleeve  145 A that is constituted by a cylindrical body and rotates in the direction of arrow  2 A in the drawing by means of an undepicted drive source. 
     Furthermore, the developing roller  145  is provided with a magnet roller  145 B arranged at the inner side of the developing sleeve  145 A. 
     The developing sleeve  145 A, which serves as an example of the second rotating member, is a cylindrical member and is formed of a metal such as SUS, for example. 
     In the present embodiment, the developer within the housing unit  141  is supplied to an outer peripheral surface  145 X of the developing sleeve  145 A, and the developer is then supplied to the photoconductor drum  11 . 
     As mentioned above, the developing sleeve  145 A rotates in the direction of arrow  2 A in the drawing. In other words, the developing sleeve  145 A rotates in such a way that the portion facing the inner side of the housing unit  141  (the portion located at the inner side of the housing unit  141 ) moves upward. 
     In addition, in the present embodiment, the developing sleeve  145 A and the photoconductor drum  11  rotate in such a way that the developing sleeve  145 A and the photoconductor drum  11  move in the same direction in an opposing section TK between the developing roller  145  and the photoconductor drum  11 . 
     Multiple magnetic poles that generate magnetic fields are arranged within the magnet roller  145 B. The developer constituted by a toner and a carrier is adhered to the outer peripheral surface  145 X of the developing sleeve  145 A due to the magnetic fields generated by the magnetic poles. 
     Furthermore, in the present embodiment, due to the developing sleeve  145 A rotating counterclockwise in the drawing, the developer adhered to the outer peripheral surface  145 X of the developing sleeve  145 A moves to the opposing section TK. 
     Furthermore, as depicted in  FIG. 2 , a first conveying member  146 , a second conveying member  147 , and a third conveying member  148  that convey the developer are provided within the housing unit  141 . 
     Each of the first conveying member  146 , the second conveying member  147 , and the third conveying member  148  is provided with a rotating shaft  140 A that rotates by means of an undepicted drive source, and a pushing unit  140 B that is provided around the rotating shaft  140 A and pushes the developer in the axial direction of the rotating shaft  140 A. 
     The pushing unit  140 B is provided around the rotating shaft  140 A. Furthermore, the pushing unit  140 B is formed in a spiral shape. 
     In the present embodiment, when positions in the horizontal direction are compared, the first conveying member  146  is provided at the side nearest the developing roller  145  and the third conveying member  148  is provided at the side furthest from the developing roller  145 . 
     Furthermore, in the horizontal direction, the second conveying member  147  is located between the first conveying member  146  and the third conveying member  148 . 
     Furthermore, in the present embodiment, when positions in the vertical direction are compared, the first conveying member  146  is provided in the lowest position and the third conveying member  148  is provided in the highest position. 
     Furthermore, in the vertical direction, the second conveying member  147  is located between the first conveying member  146  and the third conveying member  148 . 
     In addition, when the rotation center C 1  of each conveying member and the rotation center C 2  of the developing sleeve  145 A are compared, in the present embodiment, the rotation centers C 1  of the first conveying member  146  and the second conveying member  147  are located lower than the rotation center C 2  of the developing sleeve  145 A. 
     Furthermore, the rotation center C 1  of the third conveying member  148  is located higher than the rotation center C 2  of the developing sleeve  145 A. 
     The first conveying member  146  is arranged so as to extend in the direction from the front side of the image forming device  1  to the rear side (arranged so as to extend in the direction orthogonal to the page space in  FIG. 2 ), and conveys the developer in the rear side direction of the page space in  FIG. 2  (conveys to the rear side of the image forming device  1 ), for example. 
     Furthermore, the second conveying member  147  is also arranged so as to extend in the direction from the front side of the image forming device  1  to the rear side (arranged so as to extend in the direction orthogonal to the page space in  FIG. 2 ). 
     The second conveying member  147  conveys the developer in the direction toward the front side of the page space in  FIG. 2  (conveys to the front side of the image forming device  1 ), for example. 
     Furthermore, the third conveying member  148  is also arranged so as to extend in the direction from the front side of the image forming device  1  to the rear side (arranged so as to extend in the direction orthogonal to the page space in  FIG. 2 ). 
     The third conveying member  148  conveys the developer in the rear side direction of the page space in  FIG. 2  (conveys to the rear side of the image forming device  1 ), for example. 
     In addition, in the present embodiment, the space within the housing casing  142  is partitioned by a partition wall  150 , and a first housing space  171  that houses the first conveying member  146 , a second housing space  172  that houses the second conveying member  147 , and a third housing space  173  that houses the third conveying member  148  are provided within the housing casing  142 . 
     The partition wall  150  is not formed across the entire housing casing  142  in the longitudinal direction, and the partition wall  150  is not provided at the rear side end and the front side end of the housing casing  142 . 
     That is to say, a non-formed portion in which the partition wall  150  is not formed is present at both end sections of the housing casing  142  in the longitudinal direction. 
     Thus, in the present embodiment, the developer moves through the first housing space  171 , the second housing space  172 , and the third housing space  173  in this order. 
     Specifically, in the present embodiment, the developer within the first housing space  171  is conveyed in the rear side direction of the page space in  FIG. 2  by the first conveying member  146 . Then, upon reaching the rear side end of the housing casing  142 , this developer moves toward the second housing space  172  through a non-formed portion. 
     Then, the developer that has moved into the second housing space  172  is conveyed to the front side end of the housing casing  142  by the second conveying member  147 . Then, this developer moves into the third housing space  173  through the non-formed portion at the front side end. 
     Then, this developer that has moved into the third housing space  173  is conveyed to the rear side end of the housing casing  142  by the third conveying member  148 . 
     It should be noted that, out of the developer conveyed by the third conveying member  148 , developer that has moved to the rear side end of the housing casing  142  without being supplied to a movement roller (described later) moves toward the second housing space  172  through the non-formed portion provided at the rear side end. 
     Then, this developer that has moved to the second housing space  172  is once again supplied to the third housing space  173  via this second housing space  172 . 
     In the present embodiment, the second housing space  172  and the third housing space  173  form a configuration provided with an annular path along which the developer moves. 
     In addition, in the present embodiment, a movement roller  200  for moving the developer from the third conveying member  148  to the developing roller  145  is provided in a location adjacent to the third conveying member  148 . 
     The movement roller  200  is arranged so as to extend in the direction from the front side of the image forming device  1  to the rear side (arranged so as to extend in the direction orthogonal to the page space in  FIG. 2 ). 
     Furthermore, the movement roller  200  is arranged along the third conveying member  148 . 
     Furthermore, the movement roller  200  is provided with a movement sleeve  210  that is constituted by a cylindrical body and rotates by means of an undepicted drive source, and a magnet roller  220  that is arranged at the inner side of the movement sleeve  210 . 
     The movement sleeve  210 , which serves as an example of the first rotating member, is a cylindrical member and is formed of a metal such as SUS, for example. 
     In the present embodiment, developer conveyed by the third conveying member  148  adheres to an outer peripheral surface  210 A of this movement sleeve  210  due to a magnetic force generated by the magnet roller  220 . 
     Then, in the present embodiment, the developer that has adhered to the outer peripheral surface  210 A of the movement sleeve  210  moves downstream due to rotation of the movement sleeve  210 . 
     The movement sleeve  210  rotates in the direction of arrow  2 B in the drawing. In other words, the movement sleeve  210  rotates in such a way that the portion located near the third conveying member  148  moves upward. 
     Multiple magnetic poles that generate magnetic fields are arranged within the magnet roller  220 . In the present embodiment, the developer adheres to the outer peripheral surface  210 A of the movement sleeve  210  due to the magnetic fields generated by these magnetic poles. 
     Furthermore, in the present embodiment, the developer that has adhered to the outer peripheral surface  210 A of the movement sleeve  210  moves downstream due to the movement sleeve  210  rotating in the direction of arrow  2 B in the drawing. 
     In addition, in the present embodiment, a regulating unit  300  that regulates the movement of the developer on the outer peripheral surface  210 A of the movement sleeve  210  is provided in a position opposing the outer peripheral surface  210 A of the movement sleeve  210 . 
     The regulating unit  300  protrudes above a movement path R of the developer that moves due to the rotation of the movement sleeve  210 , and regulates the movement of some of the developer located on this movement path R. 
     That is to say, the regulating unit  300  protrudes above this movement path R from a side of the movement path R, and regulates the movement of some of the developer that moves downstream. 
     The regulating unit  300  is provided at the opposite side of the movement roller  200  to the side where the developing roller  145  is installed. 
     Furthermore, the regulating unit  300  is provided with a regulating surface  310  with which moving developer collides, and the movement of some of the developer is regulated using this regulating surface  310 . 
     The regulating surface  310  faces upstream in the movement direction of the developer. Furthermore, the regulating surface  310  faces downward in the vertical direction. 
     In addition, the regulating surface  310  (regulating unit  300 ) is arranged with there being a gap G 1  between the regulating surface  310  and the outer peripheral surface  210 A of the movement sleeve  210 , and is arranged so as to extend in the direction away from the outer peripheral surface  210 A. 
     That is to say, in the present embodiment, the gap G 1  is provided between the outer peripheral surface  210 A of the movement sleeve  210  and an end of the regulating surface  310  (the end at the outer peripheral surface  210 A side). 
     Furthermore, in the present embodiment, the regulating surface  310  is arranged in the radial direction of the movement sleeve  210 . 
     Furthermore, in the present embodiment, the regulating unit  300  is arranged in a position opposing the magnetic poles with the movement sleeve  210  therebetween. That is to say, in the present embodiment, multiple magnetic poles that generate magnetic fields are provided in the magnet roller  220 ; however, the regulating unit  300  is arranged in a position opposing one magnetic pole included in these multiple magnetic poles. 
     Napping of the developer easily occurs in a position opposing a magnetic pole, and the movement of the developer in a napped state is regulated when the regulating unit  300  is provided in a position opposing a magnetic pole. 
     In addition, in the present embodiment, the regulating unit  300  is arranged above the third conveying member  148 . More specifically, in the present embodiment, the regulating unit  300  and the third conveying member  148  are arranged in such a way that the regulating unit  300  and the third conveying member  148  overlap when the regulating unit  300  and the third conveying member  148  are viewed from above or below in the vertical direction. 
     In addition, in the present embodiment, a rotation center C 3  of the movement sleeve  210  is located higher up than the rotation center C 1  of the third conveying member  148 . 
     In the present embodiment, when developer adheres to the outer peripheral surface  210 A of the movement sleeve  210 , this developer moves downstream due to the rotation of the movement sleeve  210 . 
     That is to say, in the present embodiment, assuming there is a horizontal plane H passing through the rotation center C 3  of the movement sleeve  210 , developer from the third conveying member  148  adheres to the portion located below this horizontal plane H of the outer peripheral surface  210 A of the movement sleeve  210 . 
     The developer that has adhered to the outer peripheral surface  210 A of the movement sleeve  210  moves upward due to the rotation of the movement sleeve  210 . 
     Then, in the present embodiment, this developer reaches the regulating unit  300  arranged above the horizontal plane H. When the developer reaches the regulating unit  300 , the downstream movement of some of the developer is regulated. 
     Furthermore, the rest of the developer moves downstream through the gap G 1  between the movement sleeve  210  and the regulating unit  300 . 
     Here, regarding when developer is supplied to the developing roller  145 , a form is also feasible in which the developing roller  145  is provided adjacent to the third conveying member  148  and developer is supplied directly from the third conveying member  148  to the developing roller  145 , for example. 
     Incidentally, in this case, unevenness is liable to occur in the developer that is supplied from the developing roller  145  to the photoconductor drum  11 . 
     Specifically, when developer is conveyed by the third conveying member  148 , a state is entered in which the developer is conveyed while agitated, and when developer is supplied from the third conveying member  148  to the developing roller  145  in this state, unevenness is liable to occur in the developer that adheres to the developing roller  145 . In particular, this unevenness is liable to occur when the third conveying member  148  conveys the developer at a high speed. 
     Then, in this case, unevenness is liable to occur also in the developer that is supplied from the developing roller  145  to the photoconductor drum  11 . 
     In contrast, when the regulating unit  300  that regulates the movement of the developer is provided as in the present embodiment, the developer is smoothed out and unevenness in the developer supplied to the developing roller  145  is reduced. 
     Then, in this case, unevenness in the developer that is supplied from the developing roller  145  to the photoconductor drum  11  is reduced. 
     It should be noted that, in the present embodiment, because the regulating surface  310  of the regulating unit  300  faces downward, developer that collides with this regulating surface  310  and has the movement thereof regulated drops downward. 
     Furthermore, in the present embodiment, the third conveying member  148  is located below the regulating unit  300 , and developer that has had the movement thereof regulated by the regulating unit  300  and has dropped is supplied to the third conveying member  148 . 
     In addition, in the present embodiment, as mentioned above, the regulating unit  300  and the third conveying member  148  are arranged in such a way that the regulating unit  300  and the third conveying member  148  overlap when the regulating unit  300  and the third conveying member  148  are viewed from above or below in the vertical direction. 
     In this case, developer can be supplied to the third conveying member  148  merely by developer that has had the movement thereof regulated by the regulating unit  300  simply dropping downward. 
     Here, if a configuration is adopted in which the regulating unit  300  and the third conveying member  148  do not overlap when the regulating unit  300  and the third conveying member  148  are viewed from above or below in the vertical direction, a configuration for causing developer that has dropped due to the regulating unit  300  to move toward the third conveying member  148  is additionally required. 
     In contrast, this configuration for causing the developer to move can be omitted if a configuration is adopted in which the regulating unit  300  and the third conveying member  148  overlap when the regulating unit  300  and the third conveying member  148  are viewed from above or below in the vertical direction. 
     Furthermore, in the present embodiment, as depicted in  FIG. 2 , downstream of the regulating unit  300  in the rotation direction of the movement sleeve  210 , there is provided a guide surface  90  that guides the moved developer to the developing roller  145 . 
     That is to say, downstream of the regulating unit  300 , there is provided a guide surface  90  that guides developer that has moved through the gap G 1  between the movement sleeve  210  and the regulating unit  300 , to the developing roller  145 . 
     This guide surface  90  is arranged between the developing roller  145  and the movement roller  200 . 
     Furthermore, the guide surface  90  is arranged in an inclined state with respect to the horizontal direction. More specifically, the guide surface  90  is arranged so as to descend toward the developing roller  145 . 
     Furthermore, the guide surface  90  is provided at the opposite side of the movement roller  200  to the side where the regulating unit  300  is installed. 
     In addition, in the present embodiment, a configuration is adopted in which the developer that has moved while being guided by the guide surface  90  accumulates in a region located between the outer peripheral surface  145 X of the developing sleeve  145 A and the guide surface  90  (in the drawing, in a region located more in the direction indicated by the arrow  2 Y than the straight line indicated by the reference characters  2 X) (in the space located between the outer peripheral surface  145 X and the guide surface  90 ). 
     With a configuration in which developer is accumulated in this way, the developer is more stably supplied to the outer peripheral surface  145 X of the developing sleeve  145 A and unevenness in the developer that adheres to the outer peripheral surface  145 X of the developing sleeve  145 A is reduced, compared to a configuration in which developer is not accumulated. 
     In addition, the developing device  14  is provided with a layer regulating unit  151  above the developing roller  145 . This layer regulating unit  151  is arranged with there being a gap G 2  between the layer regulating unit  151  and the developing roller  145 . Furthermore, the layer regulating unit  151  is arranged downstream of the guide surface  90  in the rotation direction of the developing sleeve  145 A. 
     The layer regulating unit  151  regulates the movement of some of the developer that has adhered to the outer peripheral surface  145 X of the developing sleeve  145 A, so that the thickness of the developer that has adhered to the surface of the developing sleeve  145 A is a predetermined thickness. 
     Furthermore, in the present embodiment, developer is caused to accumulate between the layer regulating unit  151  and the guide surface  90 . Thus, developer is more stably supplied to the outer peripheral surface  145 X of the developing sleeve  145 A and unevenness in the developer that adheres to this outer peripheral surface  145 X is reduced. 
     That is to say, in the present embodiment, the layer regulating unit  151  is provided in a position opposing the guide surface  90 , and an accumulation space  2 Z in which the developer accumulates is present between the guide surface  90  and the layer regulating unit  151 . 
     Thus, developer is more stably supplied to the outer peripheral surface  145 X of the developing sleeve  145 A and unevenness in the developer that adheres to the outer peripheral surface  145 X of the developing sleeve  145 A is reduced. 
     In addition, in the present embodiment, a space G 3  is provided between the guide surface  90  and the movement sleeve  210 . 
     In the present embodiment, when a lot of developer has accumulated in the accumulation space  2 Z, the developer in the accumulation space  2 Z and developer newly supplied from upstream to this accumulation space  2 Z drop downward through this space G 3 . 
     Thus, developer is less likely to be excessively supplied to the accumulation space  2 Z, and, for example, developer is less likely to become clogged due to being compressed and so forth. 
     Furthermore, in the developing device  14  of the present embodiment, a downward opposing unit  152  that opposes the developing roller  145  is provided below the developing roller  145 . 
     In the present embodiment, the opening  143  is provided between the layer regulating unit  151  and the downward opposing unit  152 , and the developing roller  145  is installed in this opening  143 . 
     It should be noted that, hereinabove, an example case has been described in which there is a regulating unit  300  that protrudes above the movement path R of the developer, and a side surface of this regulating unit  300  serves as a regulating surface  310  that regulates the movement of the developer. That is to say, hereinabove, an example case has been described in which there is a protrusion that protrudes above the movement path R, and the movement of the developer is regulated by a surface of this protrusion. 
     Incidentally, a regulating surface  310  can be set up even if this kind of protrusion is not provided, as depicted in  FIG. 3  (a drawing depicting another exemplary configuration of the developing device  14 ). 
     In the exemplary configuration depicted in  FIG. 3 , a section of the inner surface of the housing unit  141  extends in a direction intersecting the movement direction of the developer, and this section of the inner surface serves as the regulating surface  310  that regulates the movement of the developer. 
     The foregoing description of the exemplary embodiment of the present disclosure has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiment was chosen and described in order to best explain the principles of the disclosure and its practical applications, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the following claims and their equivalents.