Patent Publication Number: US-2023149587-A1

Title: Scent retaining structure, method of manufacturing the scent retaining structure, and scent providing device

Description:
TECHNICAL FIELD 
     The present disclosure relates to a perfume retaining structure, a method of manufacturing the perfume retaining structure, and a scent providing device. 
     BACKGROUND ART 
     Technologies relating to scent providing devices that provide scents have conventionally been proposed. For example, Patent Document 1 proposes a technology for providing a scent by supplying air to a housing device that houses a perfume retainer and releasing vaporized perfume by a flow of air. Specifically, Patent Document 1 discloses a scent providing device that includes a containment portion that contains a perfume retainer, and a releasing portion that releases the scent from the perfume retainer contained in the containment portion. The scent providing device supplies air to the containment portion via a communication hole and vaporize liquid perfume retained by the perfume retainer while releasing the perfume with the air from the releasing portion. 
     CITATION LIST 
     Patent Document 
     
         
         Patent Document 1: Japanese Patent Application Laid-Open No. 2014-67293 
       
    
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, in the scent providing device disclosed in Patent Document 1, an area through which air flows from the communication hole to the releasing portion and an area in which the perfume retainer is retained are not separated in the containment portion. Thus, an increase in ventilation resistance of air that passes through the containment portion is caused. Thus, there is a possibility that the flow velocity of the air that passes through the containment portion decreases and the flow rate of the released scent decreases. 
     Thus, the present disclosure provides a new and improved perfume retaining structure, a method of manufacturing the perfume retaining structure, and a scent providing device that can reduce the ventilation resistance of air that passes through a space in which a perfume retainer is arranged. 
     Solutions to Problems 
     The present disclosure provides a perfume retaining structure that includes a perfume retainer, a retaining space in which the perfume retainer is arranged, and a first opening and a second opening that allow the retaining space to be opened to the outside. The retaining space has a ventilation area that faces the first opening and the second opening, and a retaining area that is arranged adjacent to the ventilation area and communicates with the ventilation area, and the perfume retainer is arranged in the retaining area. 
     Furthermore, the present disclosure provides a method of manufacturing the perfume retaining structure, including: producing a first case body provided with the retaining space that has the ventilation area provided with the first opening, and the retaining area that is divided from the ventilation area by a first rib, arranged adjacent to the ventilation area, and communicates with the ventilation area; storing the perfume retainer or a base material of the perfume retainer in the retaining area in the first case body; producing a case by attaching, to the first case body, a second case body that has a communication hole that communicates with the retaining space in the first case body and a second rib that is erected in the retaining space in the first case body, the first rib and the second rib limiting movement of the perfume retainer toward the ventilation area; and attaching, to the case, a case cover that has the second opening. 
     Furthermore, the present disclosure provides a scent providing device including: the perfume retaining structure that has the perfume retainer, the retaining space in which the perfume retainer is arranged, and the first opening and the second opening that allow the retaining space to be opened to the outside; and an air blowing source that supplies air to the retaining space, in which the retaining space has the ventilation area faced by the first opening and the second opening, and the retaining area that is arranged adjacent to the ventilation area and communicates with the ventilation area, the perfume retainer being arranged in the retaining area. 
     Effects of the Invention 
     As described above, according to the present disclosure, it is possible to reduce the ventilation resistance of air that passes through a space in which a perfume retainer is arranged. 
     Note that the effects described above are not necessarily restrictive. In addition to or in place of the effects described above, any of the effects described in the present specification or other effects that can be grasped from the present specification may be exerted. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view illustrating an appearance of a scent providing device according to an embodiment of the present disclosure. 
         FIG.  2    is a perspective view of an axial cross section of the scent providing device according to the same embodiment. 
         FIG.  3    is a perspective view illustrating an appearance of a perfume retaining structure according to the same embodiment. 
         FIG.  4    is a front view of the perfume retaining structure according to the same embodiment as viewed in the axial direction. 
         FIG.  5    is a rear view of the perfume retaining structure according to the same embodiment as viewed in the axial direction. 
         FIG.  6    is an axial sectional view of the perfume retaining structure according to the same embodiment. 
         FIG.  7    is an exploded perspective view of the perfume retaining structure according to the same embodiment. 
         FIG.  8    is a front view of a first case body of the perfume retaining structure according to the same embodiment as viewed in the axial direction. 
         FIG.  9    is an axial sectional view of the first case body of the perfume retaining structure according to the same embodiment. 
         FIG.  10    is a circumferential sectional view of the first case body of the perfume retaining structure according to the same embodiment. 
         FIG.  11    is a front view of a second case body of the perfume retaining structure according to the same embodiment as viewed in the axial direction. 
         FIG.  12    is a side view of the second case body of the perfume retaining structure according to the same embodiment. 
         FIG.  13    is a rear view of the second case body of the perfume retaining structure according to the same embodiment as viewed in the axial direction. 
         FIG.  14    is an axial sectional view of the second case body of the perfume retaining structure according to the same embodiment. 
         FIG.  15    is a front view of a case cover of the perfume retaining structure according to the same embodiment as viewed in the axial direction. 
         FIG.  16    is a side view of the case cover of the perfume retaining structure according to the same embodiment. 
         FIG.  17    is a rear view of the case cover of the perfume retaining structure according to the same embodiment as viewed in the axial direction. 
         FIG.  18    is an axial sectional view of the case cover of the perfume retaining structure according to the same embodiment. 
         FIG.  19    illustrates the first case body containing a perfume retainer as viewed in the axial direction. 
         FIG.  20    is a sectional view illustrating a configuration example of a retaining space. 
         FIG.  21    is a front view of a prism body of the perfume retaining structure according to the same embodiment as viewed in the axial direction. 
         FIG.  22    is an axial sectional view of the prism body of the perfume retaining structure according to the same embodiment. 
         FIG.  23    is a block diagram illustrating an example of a system configuration of the scent providing device. 
         FIG.  24    is a block diagram illustrating another example of the system configuration of the scent providing device. 
         FIG.  25    is a perspective view of an axial cross section of the scent providing device according to the same embodiment. 
         FIG.  26    is an explanatory view illustrating a rotation lock mechanism of the scent providing device according to the same embodiment. 
         FIG.  27    is an explanatory view illustrating operation of the rotation lock mechanism of the scent providing device according to the same embodiment. 
         FIG.  28    is an explanatory view illustrating the operation of the rotation lock mechanism of the scent providing device according to the same embodiment. 
         FIG.  29    is an explanatory view illustrating the operation of the rotation lock mechanism of the scent providing device according to the same embodiment. 
         FIG.  30    is an explanatory view illustrating operation of a rotation restricting mechanism of the perfume retaining structure according to the same embodiment. 
         FIG.  31    is an explanatory view illustrating a second step of a perfume cartridge manufacturing method according to the same embodiment. 
         FIG.  32    is an explanatory view illustrating a third step of the perfume cartridge manufacturing method according to the same embodiment. 
         FIG.  33    is an explanatory view illustrating a fourth step of the perfume cartridge manufacturing method according to the same embodiment. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     A preferred embodiment of the present disclosure will be described below in detail with reference to the accompanying drawings. Note that, in the present specification and drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and the description thereof will thus not be repeated. 
     Note that the description will be given in the following order. 
     1. Outline of scent providing device 
     2. Configuration example of perfume cartridge (perfume retaining structure) 
     3. Configuration example of scent providing device 
     4. Method of manufacturing perfume cartridge (perfume retaining structure) 
     In the following description, a direction to which a scent is blown may be referred to as the front side or the front end side, and the opposite direction may be referred to as the rear side or the rear end side. 
     &lt;1. Outline of Scent Providing Device&gt; 
     First, a brief description will be given on an outline of a scent providing device according to the embodiment of the present disclosure.  FIG.  1    is a perspective view illustrating an appearance of a scent providing device  1  according to the present embodiment.  FIG.  2    is an axial sectional view of the scent providing device  1 . 
     The scent providing device  1  according to the present embodiment includes a perfume cartridge  200  and a device main body  700 . The device main body  700  has a housing  710 , and the housing  710  includes a battery  810 , an air pump  840 , and a circuit board  820  that controls power supply from the battery  810  to the air pump  840 . The perfume cartridge  200  can be attached to or detached from the front side of the device main body  700 . In the present embodiment, the perfume cartridge  200  corresponds to a perfume retaining structure. 
     The scent providing device  1  causes air to flow into a desired retaining space  231  selected from a plurality of retaining spaces  231  (only one retaining space  231   c  is illustrated in  FIG.  2   ) disposed in the perfume cartridge  200  to vaporize and release perfume retained by a perfume retainer (not illustrated) arranged in each retaining space  231 . For example, the scent providing device  1  causes air supplied from the air pump  840  to pass through the retaining space  231  in the perfume cartridge  200 , thereby vaporizing liquid perfume or moist perfume (hereinafter collectively referred to as “liquid perfume”) and releasing the perfume, together with air, from the retaining space  231 . 
     The scent providing device  1  according to the present embodiment is used as, for example, a device for releasing a scent into a limited range of space. For example, a user releases the scent from the scent providing device  1  once or a plurality of times near the user&#39;s face to get relaxed. In this case, the scent providing device  1  releases the scent in a straight direction to prevent the scent from spreading widely, and this prevents the scent to be perceived by people nearby. The scent providing device  1  may be a portable device that can be carried by a user or may be a stationary device. 
     &lt;2. Perfume Cartridge (Perfume Retaining Structure)&gt; 
     Next, the perfume cartridge  200  as the perfume retaining structure according to the present embodiment will be described in detail. 
       FIGS.  3  to  7    are views for describing a configuration example of the perfume cartridge  200 .  FIG.  3    is a perspective view illustrating an appearance of the perfume cartridge  200 .  FIG.  4    is a front view of the perfume cartridge  200  as viewed in the axial direction from the front side.  FIG.  5    is a rear view of the perfume cartridge  200  as viewed in the axial direction from the rear side.  FIG.  6    is an axial sectional view of the perfume cartridge  200 , and is an arrow view of a cross section taken along line I-I illustrated in  FIGS.  4  and  5   .  FIG.  7    is an exploded perspective view of the perfume cartridge  200 . 
     The perfume cartridge  200  has a cylindrical appearance as a whole. The perfume cartridge  200  has a plurality of (five in the present embodiment) retaining spaces  231   a  to  231   e  (hereinafter collectively referred to as the retaining spaces  231 , in a case where it is not particularly necessary to distinguish between them) for air supplied from the air pump  840 , which is an example of an air blowing source, to pass through. Perfume retainers  251  that retain liquid perfume are arranged in the retaining spaces  231 . The perfume may be, for example, an essential oil or an essential oil diluted with ethanol. One retaining space  231  may be included, or a plurality of the retaining spaces  231  may be included. 
     The perfume cartridge  200  according to the present embodiment includes a case  210 , a case cover  150 , and the perfume retainers  251 . The case  210  includes a first case body  211  and a second case body  100  fixed to the front side of the first case body  211 . The case cover  150  is attached to the front surface of the case  210  so as to be axially rotatable. The perfume retainers  251  retain liquid perfume and are arranged in the corresponding plurality of retaining spaces  231  disposed in the case  210 . 
     The perfume cartridge  200  has, on the rear end surface, first openings  221   a  to  221   e  (hereinafter collectively referred to as the first openings  221  in a case where it is not particularly necessary to distinguish between them) of the same number as the retaining spaces  231 . The first openings  221  allow the corresponding retaining spaces  231  to be opened to the outside. In the present embodiment, the five first openings  221   a  to  221   e , together with one pseudo hole  223 , are arranged at regular intervals of 60 degrees around the axis. Furthermore, the perfume cartridge  200  has a second opening  151  in the front end surface. The second opening  151  is disposed in the case cover  150 . The case cover  150  and the case  210  rotate relative to each other, and this allows the second opening  151  to selectively communicate with one of the plurality of retaining spaces  231 . 
     Therefore, the case  210  of the perfume cartridge  200  can be axially rotated by a certain rotation angle to switch which retaining space  231  air should pass through. Perfumes retained in the retaining spaces  231  may be all the same, or some or all of the perfumes may be different from each other. In a case where all the retaining spaces  231  retain the same perfume, a user can enjoy a favorite scent for a long period of time. Furthermore, in a case where each retaining space  231  retains a different perfume, which scent to release can be switched by switching which retaining space  231  air can be supplied into. Thus, for example, the scent can be switched depending on mood. 
     In the perfume cartridge  200  according to the present embodiment, the five retaining spaces  231  are arranged at regular intervals of 60 degrees, and one space serves as a pseudo space  232 . The pseudo space  232  is aligned with the second opening  151  of the case cover  150  in a case where the scent providing device  1  is not in use, so as not to let the scent escape from each retaining space  231  in the perfume cartridge  200 . Note that the number of the retaining spaces  231  is not limited to five. Furthermore, the retaining spaces  231  may not be positioned at regular intervals. 
     The perfume cartridge  200  has, on the outer peripheral surface, a protrusion  212  that serves as a positioning element for fitting the perfume cartridge  200 . The protrusion  212  is formed by a protrusion  113  of the second case body  100  and a protrusion  213  of the first case body  211  that are continuously disposed, and has a predetermined length along the axial direction. 
     The perfume cartridge  200  includes, on the outer peripheral surface on the rear end side, recesses  217  of the same number as the plurality of retaining spaces  231  and the pseudo space  232  combined. In the present embodiment, the plurality of recesses  217  is disposed at regular intervals of 60 degrees in the circumferential direction. The plurality of recesses  217  is disposed at positions corresponding to positions of the first openings  221  and the pseudo hole  223  disposed in the rear end surface. The recesses  217 , which engage with an engagement element included in the device main body  700 , have a function of fixing the case  210  at a predetermined rotation position and giving a user a rotational operation feeling. Note that the plurality of recesses  217  is only required to be disposed in the circumferential direction at the same phase intervals as the first openings  221  and the pseudo hole  223 . The recesses  217  may not be disposed at regular intervals, or may not be aligned with the positions of the first openings  221  and the pseudo hole  223 . 
     A label  255  is affixed to, excluding the protrusion  213 , the outer peripheral surface of the first case body  211  positioned in a central portion in the axial direction of the perfume cartridge  200 . The label  255  shows, for example, information regarding the scent of each of the perfume retainers  251  arranged in the corresponding retaining spaces  231 . Note that the label  255  may not be included. 
     The perfume cartridge  200  will be described below in detail on a component-by-component basis. 
     (First Case Body) 
       FIGS.  8  to  10    are views illustrated for description of the first case body  211 .  FIG.  8    is a front view of the first case body  211  as viewed in the axial direction from the front side.  FIG.  9    is an axial sectional view of the first case body  211 , and is an arrow view of a cross section taken along line II-II in  FIG.  8   .  FIG.  10    is a circumferential sectional view of the first case body  211 , and corresponds to a sectional view at line illustrated in  FIG.  9   . Note that a rear view of the first case body  211  as viewed in the axial direction from the rear side coincides with a rear view of the perfume cartridge  200  illustrated in  FIG.  11   . 
     The first case body  211  has a cylindrical outer shape in which the length in the axial direction is longer than the diameter. An axial hole  215  that has openings on both end sides in the axial direction is disposed in a central portion of the first case body  211 . Around the axial hole  215 , the plurality of (five in the present embodiment) retaining spaces  231  and the pseudo space  232  are disposed around the axis at predetermined intervals (at regular intervals of 60 degrees in the present embodiment). The plurality of retaining spaces  231  and the pseudo space  232  each has a fan-like circumferential cross-sectional shape. 
     The plurality of retaining spaces  231  and the pseudo space  232  each has an opening on the front side of the first case body  211 . Furthermore, the rear sides of the plurality of retaining spaces  231  are opened to the outside via the corresponding first openings  221 , while the rear side of the pseudo space  232  is closed. The plurality of retaining spaces  231  has first ribs  235   a  to  235   e  (hereinafter collectively referred to as the first ribs  235  in a case where it is not particularly necessary to distinguish between them) that are formed to divide a rear end portion of each retaining space  231  in the circumferential direction. In each retaining space  231 , the first opening  221  is arranged on one side of areas divided in the circumferential direction by the first rib  235 . Thus, the plurality of first openings  221  is also arranged at regular intervals of 60 degrees around the axis so as to correspond to the positions of the retaining spaces  231 . 
     The protrusion  213  having a predetermined length along the axial direction is disposed on the outer peripheral surface of the first case body  211 , at a position corresponding to an outer peripheral portion of the pseudo space  232 . A hole  227  that communicates between the outer peripheral surface of the first case body  211  and the pseudo space  232  is disposed adjacent to the front side of the protrusion  213 . The hole  227  like this, together with an engagement projection ( 117 ) of the second case body  100 , has a function of fixing the first case body  211  and the second case body  100 . The hole  227  may be a recess that does not reach the pseudo space  232 . A plurality of the holes  227  may be disposed at different phase positions. 
     A recess  229  is disposed on the outer peripheral surface of a front side end portion of the first case body  211 , in a portion positioned at a boundary between the pseudo space  232  and the retaining space  231   e . The recess  229  like this, together with a ridge  119  of the second case body  100 , has a function as a positioning element for assembling the first case body  211  and the second case body  100 . The ridge may be disposed on the first case body  211 , and the recess may be disposed on the second case body  100 . 
     (Second Case Body) 
       FIGS.  11  to  14    are views illustrated for description of the second case body  100 .  FIG.  11    is a front view of the second case body  100  as viewed in the axial direction from the front side.  FIG.  12    is a side view of the second case body  100 .  FIG.  13    is a rear view of the second case body  100  as viewed in the axial direction from the rear side.  FIG.  14    is an axial sectional view of the second case body  100 , and is an arrow view of a cross section taken along line Iv-Iv in  FIGS.  11  and  13   . 
     The second case body  100  has a cylindrical outer shape in which the length in the axial direction is shorter than the diameter. The outer peripheral surface of the second case body  100  is knurled, and is provided with a plurality of fine grooves formed along the circumferential direction. 
     An axial hole  111  that has openings on both end sides in the axial direction is disposed in a central portion of the second case body  100 . The axial hole  111  has a small-diameter portion  111   a  on the front side and a large-diameter portion  111   b  on the rear side. In a state where the second case body  100  is attached to the first case body  211 , the axial hole  111  in the second case body  100  can be integrated with the axial hole  215  in the first case body  211  to form one axial hole. Around the axial hole  111 , a plurality of (five in the present embodiment) communication holes  101   a  to  101   e  (hereinafter collectively referred to as the communication holes  101  in a case where it is not particularly necessary to distinguish between them) each having openings on both ends in the axial direction is disposed. The plurality of communication holes  101 , together with one pseudo hole  103 , is disposed around the axial hole  111  at regular intervals (at regular intervals of 60 degrees in the present embodiment). However, the communication holes  101  may not be positioned at regular intervals. 
     In a state where the second case body  100  is attached to the first case body  211 , the plurality of communication holes  101   a  to  101   e  communicates with the retaining spaces  231   a  to  231   e , respectively, and allows the retaining spaces  231   a  to  231   e  to be opened to the outside. The first openings  221   a  to  221   e  respectively disposed in the retaining spaces  231   a  to  231   e  and the corresponding communication holes  101   a  to  101   e  in the second case body  100  are positioned in the same phase around the axis. That is, the first opening  221  disposed in each retaining space  231  is linearly connected with the corresponding communication hole  101  along the axial direction. 
     On the rear end surface of the second case body  100 , second ribs  121   a  to  121   e  (hereinafter collectively referred to as the second ribs  121  in a case where it is not particularly necessary to distinguish between them) are disposed adjacent to the corresponding communication holes  101   a  to  101   e . The second ribs  121  are erected so as to extend rearward, and are arranged in the retaining spaces  231  in the second case body  100  in a state where the second case body  100  is attached to the first case body  211 . Furthermore, when the state where the second case body  100  is attached to the first case body  211  is viewed in the axial direction, the second ribs  121  of the second case body  100  are arranged to overlap the first ribs  235  of the first case body  211 . The second ribs  121  of the second case body  100  and the first ribs  235  of the first case body  211  divide each retaining space  231  into an area facing the communication hole  101  and the first opening  221  (ventilation area A), and the remaining area in which the perfume retainer  251  is arranged (retaining area F) (see  FIGS.  8  and  10   ). 
     The second case body  100  has, on the front side, a front-side recess  108  that contains the case cover  150 . Furthermore, the second case body  100  has, on the rear side, a rear-side recess  109  that contains a front end portion of the first case body  211 . The engagement projection  117  that engages with the hole  227  in the first case body  211  is disposed on the inner peripheral surface of the rear-side recess  109 . In the present embodiment, two engagement projections  117  are disposed (see  FIGS.  13  and  14   ). Furthermore, the ridge  119  that is inserted into a recess  219  of the first case body  211  is disposed on the inner peripheral surface of the rear-side recess  109 . 
     When the second case body  100  and the first case body  211  are assembled, the second case body  100  and the first case body  211  are aligned using the ridge  119  and the recess  219  and are fixed using the engagement projections  117  and the holes  227 . At that time, in a state where the front end portion of the first case body  211  is fitted in the rear-side recess  109  of the second case body  100 , the front end surface of the first case body  211  abuts against the bottom surface of the rear-side recess  109  of the second case body  100 , and the retaining spaces  231   a  to  231   e  are isolated from one another. 
     The protrusion  113  having a predetermined length along the axial direction is disposed on the outer peripheral surface of the second case body  100 , at a position corresponding to an outer peripheral portion in which the pseudo hole  103  is arranged. In a state where the second case body  100  is attached to the first case body  211 , the protrusion  113  of the second case body  100  and the protrusion  213  of the first case body  211  are continuously arranged and integrated to form the protrusion  212 . 
     (Case Cover) 
       FIGS.  15  to  18    are views illustrated for description of the case cover  150 .  FIG.  15    is a front view of the case cover  150  as viewed in the axial direction from the front side.  FIG.  16    is a side view of the case cover  150  as viewed laterally, and corresponds to a view of the case cover  150  illustrated in  FIG.  15    as viewed from above.  FIG.  17    is a rear view of the case cover  150  as viewed in the axial direction from the rear side.  FIG.  18    is an axial sectional view of the case cover  150 , and is an arrow view of a cross section taken along line V-V in  FIGS.  15  and  17   . 
     The case cover  150  has a disk portion  153  and a cylindrical portion  155  erected so as to extend rearward from the disk portion  153 . The cylindrical portion  155  has a hollow cylindrical shape having an opening on the rear end side. The cylindrical portion  155  is inserted into the axial hole  111  in the second case body  100  and the axial hole  215  in the first case body  211 . The disk portion  153  has a disk shape of an appropriate thickness. The disk portion  153  is contained in the front-side recess  108  of the second case body  100 . The case cover  150  is attached to the case  210  so as to allow relative rotation with respect to the case  210 . 
     The case cover  150  has the second opening  151  that penetrates the disk portion  153  in the axial direction. In accordance with the relative rotation position of the case cover  150  with respect to the case  210 , the second opening  151  can communicate with one of the plurality of communication holes  101  formed in the second case body  100 . That is, the second opening  151  allows one of the retaining spaces  231  to be opened to the outside in accordance with the relative rotation position of the case cover  150  with respect to the case  210 . An engagement protrusion  159  that protrudes rearward is formed on the rear end surface of the disk portion  153 . The engagement protrusion  159  is a minute protrusion having a height of, for example, 0.15 to 0.3 mm, and is disposed at a position where the engagement protrusion  159  can engage with the communication hole  101  in the second case body  100  (see  FIG.  6   ). 
     The cylindrical portion  155  has a slit  155   a  that extends in the axial direction. A protrusion (a portion indicated by reference numeral  768  in  FIG.  26   ) disposed on a fixed axle of a platform portion of the device main body  700  described later is inserted into the slit  155   a . The cylindrical portion  155  has, at a bottom portion of a hollow internal space, an engagement recess  157  formed by bulging on both sides of the inner peripheral surface of the cylindrical portion  155 . An engagement portion (a portion indicated by reference numeral  769  in  FIGS.  26  and  27   ) disposed at a front end portion of the fixed axle of the platform portion of the device main body  700  is inserted into the engagement recess  157 . The cylindrical portion  155  has two locking claws  156  formed in a rotationally symmetrical manner on the outer peripheral surface on the front side. In a state where the cylindrical portion  155  of the case cover  150  is inserted into the axial holes  111  and  125  in the case  210 , the locking claws  156  are arranged at the large-diameter portion  111   b  of the axial hole  111  in the second case body  100  and are locked to a step portion between the small-diameter portion  111   a  and the large-diameter portion  111   b  (see  FIG.  30   ). Therefore, the case cover  150  does not easily come off the case  210 . 
     (Perfume Retainer) 
     The perfume retainers  251  arranged in the corresponding plurality of retaining spaces  231  each includes a base material, and the base material retains liquid perfume. For example, the perfume retainers  251  may be retainers obtained by impregnating an impregnation material as a base material with liquid perfume. In this case, for example, a porous body or a fiber body that includes polyester, nylon, felt, polyacetal, or the like may be used as the impregnation material. Furthermore, it is preferable that the impregnation material has resistance to liquid perfume. The liquid perfume may be, for example, an essential oil or an essential oil diluted with ethanol. The perfume retainers  251  may retain the same liquid perfume or different liquid perfumes for each retaining space  231 . 
     Each perfume retainer  251  is arranged in the retaining area F in the retaining space  231  in the case  210  (see  FIG.  6   ). The dimension in the longitudinal direction (the axial direction of the perfume cartridge  200 ) of the perfume retainer  251  may, for example, coincide with the length in the axial direction of the retaining area F. Furthermore, in this case, a cross-sectional shape of the perfume retainer  251  perpendicular to the longitudinal direction may approximate a circumferential cross-sectional shape of the retaining area F. That is, in a case where the perfume retainer  251  has a shape that coincides with or approximates the spatial shape of the retaining area F, the perfume retainer  251  becomes relatively large in volume, and may accordingly retain a relatively large amount of liquid perfume. 
     However, the shape of the perfume retainer  251  is not limited to such an example. For example, the perfume retainer  251  may have a stick shape in the form of a round bar or a square bar, or may have a trapezoidal shape formed by die-cutting a plate-like base material. The perfume retainer  251  exemplified in  FIG.  7    has the same length as the length in the axial direction of the retaining area F in the retaining space  231 , and is constituted by a polygonal plate material having a central portion that can be arranged close to the ventilation area A side. 
     (Ventilation Area and Retaining Area) 
     As described above, each retaining space  231  has the ventilation area A and the retaining area F. The ventilation area A has both end portions in the axial direction that can face the first opening  221  and the second opening  151 . In the present embodiment, the ventilation area A of each retaining space  231  can face the second opening  151  of the case cover  150  via the corresponding communication hole  101  in the second case body  100 . The retaining area F is arranged adjacent to the ventilation area A and communicates with the ventilation area A, and is an area in which the perfume retainer  251  is arranged. 
     The ventilation area A and the retaining area F are arranged adjacent to each other, and are divided by the first rib  235  formed on the first case body  211  on the rear side of the retaining space  231  and by the second rib  121  formed on the second case body  100  on the front side of the retaining space  231 . The ventilation area A and the retaining area F communicate with each other via a space between the two ribs  121  and  235 . 
       FIGS.  19  and  20    are views for describing the ventilation area A and the retaining area F in the retaining space  231 .  FIG.  19    illustrates the first case body  211  with the perfume retainer  251  arranged in the retaining space  231  as viewed from the front side.  FIG.  20    is an axial sectional view schematically illustrating the retaining space  231  in which the perfume retainer  251  is arranged. 
     When the perfume cartridge  200  is viewed in the axial direction, the second rib  121  of the second case body  100  and the first rib  235  of the first case body  211  are arranged at a position so as to overlap each other. In  FIG.  20   , a space above an imaginary line L connecting the two ribs  121  and  235  is the retaining area F in which the perfume retainer  251  is arranged, and a space below the imaginary line L is the ventilation area A that can face the first opening  221  and the second opening  151  of the case cover  150 . The ventilation area A linearly connects the first opening  221  and the second opening  151  along the axial direction. Thus, the ventilation resistance of air that is supplied from the first opening  221  into the retaining space  231  and flows via the communication hole  101  to the second opening  151  is lowered. 
     The retaining area F is arranged adjacent to the ventilation area A in a direction intersecting the axial direction. The retaining area F and the ventilation area A communicate with each other via the space between the two ribs  121  and  235 . A central portion in the axial direction of the perfume retainer  251  arranged in the retaining area F is arranged in the space between the two ribs  121  and  235  and arranged close to the ventilation area A. This arrangement facilitates vaporization of liquid perfume retained by the perfume retainer  251  by a flow of air that passes through the ventilation area A. At this time, in a case where the perfume retainer  251  is in the form of an impregnation material impregnated with liquid perfume, the liquid perfume penetrates to a portion positioned on the ventilation area A side of the impregnation material, and this facilitates continuous vaporization of the perfume. 
     The two ribs  121  and  235  have a function as a restricting portion that limits movement of the perfume retainer  251  toward the ventilation area A. Furthermore, in the present embodiment, it can also be said that a recess  237  that is formed by the first rib  235  in the retaining space  231  in the first case body  211  and contains an end portion of the perfume retainer  251  has a function as the restricting portion. 
     The perfume cartridge  200  according to the present embodiment has, on a side surface of the perfume retainer  251  arranged in the retaining area F, the ventilation area A through which air passes. When air passes through the ventilation area A, the liquid perfume is vaporized, mixed with the air, and released. At this time, movement of the perfume retainer  251  toward the ventilation area A is limited. Consequently, an increase in ventilation resistance of air that passes through the ventilation area A is prevented. Furthermore, a space from the first opening  221 , which is an air supply port, to the second opening  151 , which is a release port, is a closed space without any other open ports. With this arrangement, the perfume vaporized by ventilation can be efficiently released from the release port. 
     &lt;3. Configuration Example of Scent Providing Device&gt; 
     So far, the configuration example of the perfume cartridge  200  as the perfume retaining structure according to the present embodiment has been described. Next, a configuration example of the scent providing device  1  that is used with the perfume cartridge  200  fitted will be described. 
     (3.1 Example of Overall Configuration) 
     As illustrated in  FIGS.  1  and  2   , the scent providing device  1  includes the perfume cartridge  200  and the device main body  700 . In addition to the battery  810 , the circuit board  820 , and the air pump  840  included in the housing  710 , the device main body  700  includes, on the front end side of the housing  710 , a prism portion  500 , a rotation operation portion  600 , and a base portion  740 . 
     The prism portion  500  includes a transparent material, and is arranged in the rotation operation portion  600 . The prism portion  500  may be press-fitted into the rotation operation portion  600 , or may be joined or fixed by appropriate means.  FIGS.  21  and  22    are explanatory views illustrating a configuration example of the prism portion  500 .  FIG.  21    is a front view of the prism portion  500  as viewed in the axial direction.  FIG.  22    is an axial sectional view of the prism portion  500 . 
     The prism portion  500  has an axial hole  530  in which the perfume cartridge  200  is arranged. A positioning groove  531  that serves as a positioning element for fitting the perfume cartridge  200  is formed on a part of the outer peripheral surface of the axial hole  530 . The prism portion  500  has, on the rear side, a tapered shape having a diameter that gradually decreases toward a rear end portion. The outer surface of the tapered shape portion is mirror-finished to serve as a mirror surface portion  510 . Thus, a user can visually identify, from the front side of the scent providing device  1  via the prism portion  500 , characters, designs, and the like on the outer peripheral surface of the perfume cartridge  200  reflected on the mirror surface portion  510 . A constituent material of the prism portion  500  is not particularly limited, as long as it has transparency after formation. For example, the prism portion  500  may be constituted by glass, crystal, or transparent resin. 
     Returning to  FIGS.  1  and  2   , the rotation operation portion  600  is arranged on the outer periphery of the prism portion  500  and the perfume cartridge  200 . The rotation operation portion  600  has an integrated outer cylinder portion  610  and a retaining portion  620 . The outer cylinder portion  610  has an axial hole  611  in which the prism portion  500  is fitted, and is arranged on the outer periphery of the prism portion  500 . The retaining portion  620  has a spindle-shaped portion  630  that has a tapered shape having a diameter that gradually increases toward the front side, and an inner cylinder portion  640  disposed continuously with a rear end portion of the spindle-shaped portion  630 . The spindle-shaped portion  630  is arranged on the outer periphery of the mirror surface portion  510  of the prism portion  500 , and the inner cylinder portion  640  retains the perfume cartridge  200  in an inner peripheral portion. On the inner peripheral portion of the inner cylinder portion  640 , a positioning groove  641  is formed and arranged continuously with the positioning groove  531  of the prism portion  500 . 
     The case  210  of the perfume cartridge  200  is provided with the protrusion  212  that serves as a positioning element for fitting the perfume cartridge  200 . The protrusion  212  is fitted in the positioning groove  531  on the prism portion  500  and the positioning groove  641  on the inner cylinder portion  640 . Therefore, the perfume cartridge  200  can be positioned with respect to the rotation operation portion  600 , and the rotation operation portion  600  and the case  210  of the perfume cartridge  200  can be rotated together. 
     The base portion  740  has a support portion  750  and a platform portion  760 . The support portion  750  has a tubular shape. The platform portion  760  is supported in an inner peripheral portion of the support portion  750  so as to be movable in the axial direction. The platform portion  760  and the support portion  750  are coupled by a heart cam mechanism  763 . The platform portion  760  can be retained at an advanced position as well as at a retracted position with respect to the support portion  750 . Furthermore, a rear end portion of the perfume cartridge  200  is rotatably supported in the inner peripheral portion of the support portion  750 . Moreover, the inner cylinder portion  640  of the retaining portion  620  of the rotation operation portion  600  is rotatably supported on the front side of the inner peripheral portion of the support portion  750 . 
     The support portion  750  is provided with a piston  855  as an engagement element that can enter a recess  217  disposed on the outer peripheral surface of the rear end portion of the perfume cartridge  200 . The piston  855  is biased toward the outer peripheral surface of the perfume cartridge  200  by a piston spring  853 . Therefore, while the perfume cartridge  200  is being rotated, the piston spring  853  contracts and the piston  855  retracts. When one of the recesses  217  coincides with the position of the piston  855 , the piston  855  enters the recess  217 . Therefore, it is possible to fix the perfume cartridge  200  to a predetermined rotation position, and give a user a rotational operation feeling. 
     The platform portion  760  has a fixed axle  761  that extends toward the front side. The fixed axle  761  is inserted into the cylindrical portion  155  of the case cover  150  of the perfume cartridge  200 . The engagement portion (not illustrated) (the portion indicated by reference numeral  769  in  FIGS.  26  and  27   ) is disposed at a front end of the fixed axle  761 . In the cylindrical portion  155  of the case cover  150  of the perfume cartridge  200 , the engagement portion engages with an engagement portion (not illustrated) formed in the cylindrical portion  155  to restrict relative rotation between the case cover  150  and the base portion  740 . Therefore, the rotation operation portion  600  and the case  210  of the perfume cartridge  200 , which can rotate together, can rotate relative to the base portion  740 . 
     The platform portion  760  has an air supply port  765  that penetrates the platform portion  760  in the axial direction. The air pump  840  is driven by power supplied from the battery  810  to introduce air into the air supply port  765 . The air introduced into the air supply port  765  is supplied to one of the plurality of retaining spaces  231  disposed in the perfume cartridge  200 . 
     Furthermore, the platform portion  760  has a protrusion  764  for positioning. The protrusion  764  can be engaged with a locking groove (not illustrated) (a portion indicated by reference numeral  643  in  FIG.  27   ) formed on the inner cylinder portion  640  of the rotation operation portion  600 . Specifically, the protrusion  764  of the platform portion  760  engages with the locking groove on the inner cylinder portion  640  of the rotation operation portion  600  in a state where the platform portion  760  is retained by the support portion  750  at the advanced position. Furthermore, in a state where the platform portion  760  is retained by the support portion  750  at the retracted position, the protrusion  764  of the platform portion  760  is disengaged from the locking groove on the inner cylinder portion  640 . Such a mechanism functions as a rotation lock mechanism that limits relative rotation between the rotation operation portion  600  and the base portion  740  in a state where the perfume cartridge  200  has been removed from the scent providing device  1 . The rotation lock mechanism will be described later in detail. 
     The air pump  840  may be, for example, a diaphragm pump that sucks and pumps air by deforming the diaphragm by supply of an alternating current to a piezoelectric element. The battery  810  may be a replaceable cell that only discharges, or may be a secondary cell that can charge and discharge. Driving of the air pump  840  is controlled by operating an operation switch  730 . For example, the operation switch  730  is pressed to turn on or off a switching element of the circuit board  820 , and power is supplied from the battery  810  to the air pump  840 . Therefore, air is supplied to the perfume cartridge  200  via the air supply port  765 . 
     For example, energization may be switched between on and off every time the operation switch  730  is repeatedly pressed, or the energization may remain on while the operation switch  730  is being pressed. Another electronic component as exemplified by a light source such as a light emitting diode (LED) that indicates an actuation state of the scent providing device  1  may be installed on the circuit board  820 . Furthermore, a communication interface may be installed on the circuit board  820  so that the scent providing device  1  can be operated by using a remote controller, a smart phone, or the like. 
     Note that the air blowing source that supplies air toward the perfume cartridge  200  is not limited to the air pump  840 , and may be, for example, a blower of a type having a rotating fan. Furthermore, the air blowing source that supplies air toward the perfume cartridge  200  may not be of an electrically-driven type but of a manually-operated type. In a case of where the air blowing source is of a manually-operated type, the battery, the operation switch, and the circuit board may be omitted. 
       FIGS.  23  and  24    are block diagrams illustrating examples of a system configuration of the scent providing device  1 . In the examples of  FIGS.  23  and  24   , the battery  810  is electrically connected to the air pump  840  via the circuit board  820  and a switching element  830 . In response to an operation on the operation switch  730 , power of the battery  810  is supplied to the air pump  840 . When the air pump  840  is driven and air is supplied to the retaining space  231  in the perfume cartridge  200 , liquid perfume retained by the perfume retainer arranged in the retaining space  231  vaporizes, and a scent is released together with the air. In the example of  FIG.  23   , the rotation operation portion  600  can be manually rotated to switch which retaining space  231  in the perfume cartridge  200  should be the retaining space  231  into which air supplied from the air pump  840  is to be introduced. 
     Furthermore, in the example of  FIG.  24   , the battery  810  is electrically connected, via the circuit board  820  and a switching element  835 , to a motor  850  that drives the rotation operation portion  600  to rotate. For example, in response to an operation on a rotation changeover switch by a user, power of the battery  810  is supplied to the motor  850 , and the rotation operation portion  600  is driven to rotate. It may thus be possible to switch which retaining space  231  in the perfume cartridge  200  should be the retaining space  231  into which air supplied from the air pump  840  is to be introduced. 
     (3.2. Rotation Operation) 
     Next, rotation operation of the perfume cartridge  200  in the scent providing device  1  will be described with reference to  FIGS.  2  and  25   .  FIG.  2    illustrates a state in which the scent providing device  1  is not in use, and  FIG.  25    illustrates a state in which the scent providing device  1  is in use. 
     As illustrated in  FIG.  2   , when the scent providing device  1  is not in use, the retaining spaces  231  in the perfume cartridge  200  do not communicate with the air supply port  765 , and the pseudo space  232  is aligned with an outlet of the air supply port  765 . Since the second opening  151  of the case cover  150  is positioned in the same phase with the air supply port  765 , the pseudo space  232  is aligned with the second opening  151 . Therefore, none of the retaining spaces  231  in which the perfume retainers  251  are arranged communicate with the air supply port  765  and the second opening  151 , and this state prevents releasing of the scent. 
     As illustrated in  FIG.  25   , when the scent providing device  1  is in use, the rotation operation portion  600  is rotated to cause the perfume cartridge  200  to rotate together and allow the desired retaining space  231   e  to communicate with the air supply port  765  via the first opening  221   e . At this time, the retaining space  231   e  that communicates with the air supply port  765  communicates with the second opening  151  via the communication hole  101   e . A user can operate the operation switch  730  to supply air from the air pump  840  to the retaining space  231   e  so that the liquid perfume retained by the perfume retainer  251  (not illustrated) arranged in the retaining space  231   e  may be vaporized and released together with the air. 
     (3.3. Rotation Lock Mechanism) 
     Next, the rotation lock mechanism of the scent providing device  1  will be described with reference to  FIGS.  26  and  27   .  FIGS.  26  and  27    are perspective views illustrating only the retaining portion  620  of the rotation operation portion  600  and the platform portion  760  of the base portion  740 .  FIG.  27    illustrates a state of the retaining portion  620  and the platform portion  760  relatively rotated by 90 degrees from the state in  FIG.  26   . 
     As described above, the positioning groove  641  is formed on the inner peripheral portion of the inner cylinder portion  640  of the retaining portion  620 . An engagement groove  643  is formed on an outer peripheral portion of the inner cylinder portion  640 , at a position rotated 180 degrees from the position where the positioning groove  641  is disposed. The engagement groove  643  can be engaged with the protrusion  764  disposed on the platform portion  760  of the base portion  740 . As described above, the platform portion  760  of the base portion  740  is supported by the heart cam mechanism  763  so as to allow the platform portion  760  to move in the axial direction in the inner peripheral portion of the support portion  750 . In a state where the platform portion  760  has moved toward the front side, the protrusion  764  of the platform portion  760  enters and engages with the engagement groove  643  on the retaining portion  620 . In a state where the platform portion  760  has moved toward the rear side, the protrusion  764  and the engagement groove  643  are disengaged from each other.  FIGS.  26  and  27    illustrate a state where the platform portion  760  has moved toward the rear side and the protrusion  764  and the engagement groove  643  are disengaged from each other. 
     Operation of the rotation lock mechanism will be specifically described with reference to  FIGS.  28  and  29   .  FIG.  28    is an axial sectional view of a front end portion of the scent providing device  1 .  FIG.  29    is a perspective view illustrating only the retaining portion  620  of the rotation operation portion  600  and the platform portion  760  of the base portion  740 , and illustrates a perspective view of the retaining portion  620  and the platform portion  760  illustrated in  FIG.  28    as viewed from below. In each of  FIGS.  28  and  29   , a state where the perfume cartridge  200  is fitted in the device main body  700  is illustrated in an upper part, and a state where the perfume cartridge  200  is being removed from the device main body  700  is illustrated in a lower part. 
     As illustrated in the upper parts of  FIGS.  28  and  29   , in a state where the perfume cartridge  200  is fitted in the device main body  700 , the heart cam mechanism  763  retains the platform portion  760  at the retracted position. At this time, the protrusion  764  of the platform portion  760  and the engagement groove  643  on the inner cylinder portion  640  of the retaining portion  620  are disengaged from each other. Thus, the retaining portion  620  can now rotate relative to the platform portion  760 , and the perfume cartridge  200  that rotates together with the rotation operation portion  600  can now rotate with respect to the device main body  700 . 
     On the other hand, as illustrated in the lower parts of  FIGS.  28  and  29   , when the perfume cartridge  200  is removed from the device main body  700 , the heart cam mechanism  763  retains the platform portion  760  at the advanced position. At this time, the protrusion  764  of the platform portion  760  is engaged with the engagement groove  643  on the inner cylinder portion  640  of the retaining portion  620 . Thus, the retaining portion  620  and the platform portion  760  are now unable to rotate relative to each other, and the retaining portion  620  is retained at a prearranged rotation position when the perfume cartridge  200  is attached or detached. Therefore, the perfume cartridge  200  can be easily attached to or detached from the device main body  700  by aligning the perfume cartridge  200  with the predetermined rotation position. 
     (3.4. Rotation Restricting Mechanism) 
     Next, a rotation restricting mechanism for the case  210  and the case cover  150  of the perfume cartridge  200  will be described. The perfume cartridge  200  according to the present embodiment has the rotation restricting mechanism that limits relative rotation between the case  210  and the case cover  150  in a state where the perfume cartridge  200  is not fitted in the device main body  700 . 
     In the axial sectional view of the perfume cartridge  200  illustrated in  FIG.  6   , the engagement protrusion  159  formed on the rear end surface of the disk portion  153  of the case cover  150  has entered the communication hole  101   c  in the second case body  100 . In this state, rotation of the case cover  150  with respect to the case  210  is limited. 
       FIG.  30    is a view for describing operation of the rotation restricting mechanism when the perfume cartridge  200  is fitted in the device main body  700 . As described above, in a state where the case cover  150  and the case  210  are assembled, the locking claws  156  disposed on an outer peripheral portion of the cylindrical portion  155  of the case cover  150  are locked to the step portion between the small-diameter portion  111   a  and the large-diameter portion  111   b  of the axial hole  111  disposed on the second case body  100 . At this time, a gap S that is at least equal to or larger than the height of the engagement protrusion  159  is formed between the locking claws  156  and the step portion (see the view illustrated in an upper part of  FIG.  30   ). 
     When the perfume cartridge  200  is fitted, the engagement portion  769  disposed at the front end of the fixed axle  761  of the platform portion  760  is inserted into the engagement recess  157  disposed in the bottom portion of the internal space in the cylindrical portion  155  of the case cover  150 . At this time, for example, the engagement portion  769  is lightly press-fitted into the engagement recess  157 , and the case cover  150  moves toward the front by the length of the gap S described above. As a result, the engagement protrusion  159  of the case cover  150  illustrated in  FIG.  6    moves to a position nearer to the front than the communication hole  101   c , and the case cover  150  can now rotate with respect to the case  210 . Therefore, the case  210  can rotate in a state where the perfume cartridge  200  is fitted in the device main body  700 . 
     With the rotation restricting mechanism like this, when the perfume cartridge  200  is not in use, the rotation position of the second opening  151  of the case cover  150  is aligned with the position where the pseudo space  232  is arranged in the case  210  to ensure that none of the retaining spaces  231  in which the perfume retainers  251  are arranged are opened to the outside via the second opening  151 . Thus, leakage of the perfume can be prevented when the perfume cartridge  200  is not in use. 
     Note that the engagement protrusion  159  and the communication hole  101  that constitute the rotation restricting mechanism are an example of an engagement portion and an engaged portion, and the engagement portion and the engaged portion are not limited to such an example. The engagement portion and the engaged portion are only required to be engaged before the perfume cartridge  200  is fitted in the device main body  700  and disengaged from each other after the perfume cartridge  200  has been fitted in the device main body  700 . 
     &lt;4. Method of Manufacturing Perfume Cartridge (Perfume Retaining Structure)&gt; 
     Next, an example of a method of manufacturing the perfume cartridge  200  according to the present embodiment illustrated in  FIGS.  3  to  6    will be described. The method of manufacturing the perfume cartridge  200  according to the present embodiment includes first to fourth steps. The method of manufacturing the perfume cartridge  200  will be described below in order of steps with reference to  FIGS.  31  to  33     FIGS.  31  to  33    are schematic views illustrating a vicinity of one of the plurality of retaining spaces  231  constituting the perfume cartridge  200 . 
     (4.1. First Step) 
     In the first step, the first case body  211  exemplified in  FIGS.  8  to  10    and the like is produced. In the first case body  211 , the plurality of retaining spaces  231  and the pseudo space  232  are formed. The first rib  235  is formed on the rear end side of each retaining space  231  to divide the retaining space  231  into the ventilation area A in which the first opening  221  is disposed, and the retaining area F that is arranged adjacent to the ventilation area A and communicates with the ventilation area A. The method of producing the first case body  211  is not particularly limited. For example, the first case body  211  may be molded by pouring a molten resin material into a mold and solidifying the resin material. The resin material used is not particularly limited, but is preferably a resin material having resistance to liquid perfume. 
     (4.2. Second Step) 
     In the second step, the perfume retainer  251  is stored in the retaining area F in the first case body  211 . For example, as illustrated in  FIG.  31   , each perfume retainer  251  that already retains liquid perfume is inserted into the retaining area F in the corresponding retaining space  231 . At this time, a rear end portion of the perfume retainer  251  is inserted into the recess  237  formed by the first rib  235 . Liquid perfumes retained by the perfume retainers  251  contained in the corresponding retaining spaces  231  may be all the same, or some or all of the liquid perfumes may be different from each other. 
     Note that, in the second step, it is also possible to insert, into the retaining area F, an impregnation material that does not retain liquid perfume, and then apply liquid perfume to impregnate the impregnation material with the liquid perfume. 
     (4.3. Third Step) 
     In the third step, the case  210  is produced by attaching the second case body  100  to the first case body  211  in which the perfume retainers  251  are arranged in all the retaining spaces  231 . For example, as illustrated in  FIG.  32   , the second case body  100  has the plurality of communication holes  101  that communicates with the corresponding retaining spaces  231  in the first case body  211 , and the second ribs  121  that are erected in the corresponding retaining spaces  231 . By attaching the second case body  100  to the first case body  211 , movement of each perfume retainer  251  toward the ventilation area A is restricted by the first rib  235  and the second rib  121 . 
     (4.4. Fourth Step) 
     In the fourth step, the case cover  150  having the second opening  151  is attached to the case  210 . As illustrated in  FIG.  33   , the case cover  150  is provided with the second opening  151 , and the case cover  150  is attached to the case  210  so as to allow relative rotation with respect to each other. Thus, the rotation position of the case cover  150  with respect to the case  210  is switched to allow the second opening  151  to communicate with one of the retaining spaces  231  via the corresponding communication hole  101 . Although not illustrated, at the time of manufacturing, the second opening  151  may be aligned with and attached to a position corresponding to the pseudo space  232  disposed in the first case body  211 . This arrangement prevents leakage of the scent from any one of the retaining spaces  231  when the perfume cartridge  200  is not in use. 
     As described above, in the perfume cartridge  200  according to the present embodiment, the retaining space  231  in the perfume cartridge  200 , in which the perfume retainer  251  is arranged, has the ventilation area A and the retaining area F. The ventilation area A can face the first opening  221  and the second opening  151 . The retaining area F is arranged adjacent to the ventilation area A and communicates with the ventilation area A, and the perfume retainer  251  is arranged in the retaining area F. The perfume cartridge  200  like this includes, as the restricting portion that limits movement of the perfume retainer  251  toward the ventilation area A, the first rib  235 , the recess  237  formed by the first rib  235 , and the second rib  121 . Thus, it is possible to reduce a possibility that the perfume retainer  251  enters the ventilation area A and hinders a flow of air that passes through the ventilation area A. Consequently, ventilation resistance of air that passes through the ventilation area A is reduced, and a decrease in flow rate of the scent released from the scent providing device  1  is prevented. 
     Furthermore, in the perfume cartridge  200  according to the present embodiment, the restricting portion is constituted by the first rib  235  and the second rib  121  formed on the first case body  211  and the second case body  100 , respectively. With this arrangement, at the time of manufacturing of the perfume cartridge  200 , a structure that limits movement of the perfume retainer  251  can be easily formed by appropriately arranging the perfume retainer  251  in the retaining space  231  and appropriately assembling the first case body  211  and the second case body  100 . In particular, the perfume cartridge  200  according to the present embodiment includes the plurality of retaining spaces  231  in which the perfume retainers  251  are arranged. Thus, it is significant that the structure that limits movement of the perfume retainer  251  in each retaining space  231  can be easily formed by appropriately arranging the perfume retainer  251  in the retaining space  231  and appropriately assembling the first case body  211  and the second case body  100 . 
     Furthermore, in the perfume cartridge  200  according to the present embodiment, the case cover  150  has the engagement protrusion  159  that is engaged with the communication hole  101   c  in the second case body  100  while the perfume cartridge  200  is not fitted in the device main body  700  and that is disengaged from the communication hole  101   c  in the second case body  100  while the perfume cartridge  200  is fitted in the device main body  700 . With this arrangement, the retaining space  231  in which the perfume retainer  251  is arranged can be retained as a closed space when the perfume cartridge  200  is not in use, and leakage of the scent is prevented when the perfume cartridge  200  is not in use. 
     The preferred embodiment of the present disclosure has been described above in detail with reference to the accompanying drawings, but the technical scope of the present disclosure is not limited to such an example. It is obvious that a person having ordinary knowledge in the technical field of the present disclosure can come up with various changes and modifications within the scope of the technical idea described in the claims, and such various changes and modifications are naturally understood to belong to the technical scope of the present disclosure. 
     For example, in the embodiment described above, movement of the perfume retainer  251  toward the ventilation area A is limited by the first rib  235  and the second rib  121  that divide the retaining space  231  into the ventilation area A and the retaining area F. However, the technology of the present disclosure is not limited to such an example. For example, in a case where the perfume retainer  251  has adhesiveness, the perfume retainer  251  may be fixed to an inner wall of the retaining space  231 , more specifically, in an area that does not face the first opening  221  and the second opening  151 . Thus, movement of the perfume retainer  251  toward the ventilation area A may be limited. Even if the ventilation area A and the retaining area F are divided in this way, the ventilation resistance of air that passes through the ventilation area A is reduced, and it is possible to prevent a decrease in flow rate of the scent released from the scent providing device  1 . 
     Furthermore, in the embodiment described above, the ventilation area A linearly connects the first opening  221  and the second opening  151  along the axial direction, and the retaining area F is arranged adjacent to the ventilation area A in a direction intersecting the axial direction. However, the technology of the present disclosure is not limited to such an example. For example, the ventilation area A may be disposed spirally or tortuously from the first opening  221  toward the second opening  151 , and the retaining area F may be arranged partially or entirely adjacent to the ventilation area A so as not to hinder a flow of air in the ventilation area A. Even if the ventilation area A and the retaining area F are arranged in this way, the ventilation resistance of air that passes through the ventilation area A is reduced Thus, a decrease in flow rate of the scent released from the scent providing device  1  is prevented. 
     Note that the following configurations also belong to the technical scope of the present disclosure. 
     (1) A perfume retaining structure including: 
     a perfume retainer; 
     a retaining space in which the perfume retainer is arranged; and 
     a first opening and a second opening that allow the retaining space to be opened to the outside, 
     in which the retaining space has 
     a ventilation area that faces the first opening and the second opening, and 
     a retaining area that is arranged adjacent to the ventilation area and communicates with the ventilation area, the perfume retainer being arranged in the retaining area. 
     (2) The perfume retaining structure according to (1), in which the ventilation area linearly connects the first opening and the second opening along a predetermined direction, and the retaining area is arranged adjacent to the ventilation area in a direction intersecting the predetermined direction. 
     (3) The perfume retaining structure according to (1) or (2), further including a restricting portion that limits movement of the perfume retainer toward the ventilation area. 
     (4) The perfume retaining structure according to (3), in which the restricting portion is a recess that contains a part of the perfume retainer. 
     (5) The perfume retaining structure according to (3), in which the restricting portion is a rib that extends between the ventilation area and the retaining area. 
     (6) The perfume retaining structure according to any one of (1) to (5), in which the perfume retaining structure includes a plurality of the retaining spaces. 
     (7) The perfume retaining structure according to any one of (1) to (6), in which the perfume retaining structure includes a perfume cartridge to be fitted in a scent providing device. 
     (8) The perfume retaining structure according to any one of (1) to (7), further including: 
     a case that has the retaining space and the first opening; and 
     a case cover that is attached to the case and has the second opening. 
     (9) The perfume retaining structure according to (8), further including a restricting portion that limits movement of the perfume retainer toward the ventilation area. 
     (10) The perfume retaining structure according to (9), in which the restricting portion is a recess that is disposed on the case and contains a part of the perfume retainer. 
     (11) The perfume retaining structure according to (9), in which 
     the case includes a first case body that has the retaining space, and a second case body that is attached to the first case body and has a communication hole that communicates with the retaining space, and 
     the restricting portion is a rib that is formed on the second case body and extends into the retaining space in the first case body. 
     (12) The perfume retaining structure according to any one of (8) to (11), in which 
     the case has a plurality of the retaining spaces and the first openings, 
     the case cover has the second opening, 
     the case cover is rotatably attached to the case, and 
     the second opening faces one of the plurality of the retaining spaces. 
     (13) The perfume retaining structure according to (12), in which 
     the perfume retaining structure includes a perfume cartridge to be fitted in a scent providing device, and 
     the case cover has an engagement portion that is engaged with an engaged portion of the case while the perfume cartridge is not fitted in the scent providing device and that is disengaged from the engaged portion of the case while the perfume cartridge is fitted in the scent providing device. 
     (14) The perfume retaining structure according to (12) or (13), in which the retaining spaces are arranged at regular intervals around a central axis of the perfume retaining structure. 
     (15) A method of manufacturing a perfume retaining structure, including: 
     producing a first case body provided with a retaining space that has a ventilation area provided with a first opening, and a retaining area that is divided from the ventilation area by a first rib, arranged adjacent to the ventilation area, and communicates with the ventilation area; 
     storing a perfume retainer or a base material of the perfume retainer in the retaining area in the first case body; 
     producing a case by attaching, to the first case body, a second case body that has a communication hole that communicates with the retaining space in the first case body and a second rib that is erected in the retaining space in the first case body, the first rib and the second rib limiting movement of the perfume retainer toward the ventilation area; and 
     attaching, to the case, a case cover that has a second opening. 
     (16) A scent providing device including: 
     a perfume retaining structure that has a perfume retainer, a retaining space in which the perfume retainer is arranged, and a first opening and a second opening that allow the retaining space to be opened to the outside; and 
     an air blowing source that supplies air to the retaining space, 
     in which the retaining space has 
     a ventilation area that faces the first opening and the second opening, and 
     a retaining area that is arranged adjacent to the ventilation area and communicates with the ventilation area, the perfume retainer being arranged in the retaining area. 
     REFERENCE SIGNS LIST 
     
         
           1  Scent providing device 
           100  Second case body 
           101  Communication hole 
           121  Second rib (restricting portion) 
           150  Case cover 
           151  Second opening 
           153  Disk portion 
           155  Cylindrical portion 
           159  Engagement protrusion 
           200  Perfume cartridge 
           210  Case 
           211  First case body 
           221  First opening 
           231  Retaining space 
           235  First rib (restricting portion) 
           237  Recess (restricting portion) 
           251  Perfume retainer 
           700  Device main body 
         Ventilation area A 
         Retaining area F