Patent Publication Number: US-2022227270-A1

Title: Seat

Description:
TECHNICAL FIELD 
     The present invention relates to a seat with a seat cushion, a seat back, and a headrest. 
     BACKGROUND ART 
     An air-conditioning seat having a seat back formed with projecting portions which can cover the left and right sides of the head of a seated person as if the head of the seated person is lapped therebetween, such that the left and right projecting portions have slit-shaped air outlets configured to allow air supplied from a blower to blow leftward and rightward on the head of the seated person is hitherto known in the art (Patent document 1). In this technical scheme, ducts leading to the air outlets are connected to tubes in which air passing through the ducts can be made fragrant with a scent supplied from a scenting device, so that fragrantly scented air having an effect of increasing the comfort such as a relaxing effect, etc. can be blown toward the face and its vicinities of the seated person who can thereby get exposed to comfortable air. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Document 1: JP 2018-93921 A 
       
    
     SUMMARY OF INVENTION 
     The hitherto-known seat, however, would allow air let out through the air outlets to diffuse, and could not efficiently deliver a scent to the seated person. Moreover, the hitherto-known seat would also have a disadvantage of unnecessarily allowing the scent to reach any other person nearby. 
     Therefore, it is an object of the present invention to provide a seat which can efficiently deliver a scent to a seated person. 
     It is another object to restrain a scent from being delivered unnecessarily. 
     It is yet another object to provide a variety of scents exchangeable according to preferences. 
     It is yet another object to deliver a scent appropriate to the state of a seated person. 
     It is yet another object to improve an advantageous effect of a scent. 
     A seat, contrived to achieve any of the objects mentioned above, is a seat with a seat cushion and a seat upper portion provided above the seat cushion, the seat upper portion including a seat back and a headrest, the seat comprising: an air outlet located in the seat upper portion to let out air therethrough; an air inlet located in the seat upper portion to draw in air therethrough; at least one fan configured to produce a current of air flowing at a front side of the seat upper portion from the air outlet toward the air inlet; and a scenting device configured to scent air to be forced out through the air outlet, wherein the air outlet and the air inlet are located in such positions that at least part of the headrest is positioned between the air outlet and the air inlet in a direction of the current of air flowing from the air outlet toward the air inlet as viewed from a front side. 
     With this configuration, the air made fragrant with a scent and forced out through the air outlet is drawn in through the air inlet, whereby a current of fragrant air is formed so that the scent is restrained from diffusing; therefore, the scent can be delivered efficiently to the seated person. 
     The seat as described above may be configured such that the air outlet and the air inlet are located in such positions that a straight line connecting the air outlet and the air inlet intersects the headrest as viewed from the front side. 
     With this configuration, as viewed from the front side, the fragrant scent flowing from the air outlet toward the air inlet blows on the head of a seated person positioned at the front side of the headrest, so that the scent can be delivered more efficiently to the seated person. 
     The seat as described above may be configured such that the air outlet is located at one of left and right sides of the seat upper portion, and the air inlet is located at another of the left and right sides of the seat upper portion. 
     With this configuration, a current of fragrant air can be caused to flow from one of the left and right sides toward the other of the left and right sides as if it brushes past a seated person; therefore, the scent can be delivered more efficiently to the seated person. 
     The seat as described above may be a seat installed in a vehicle and configured such that the air outlet is located at a laterally inner side in the vehicle, and the air inlet is located at a laterally outer side in the vehicle. 
     With this configuration, a current of fragrant air is caused to flow from the laterally inner side toward the laterally outer side in the vehicle; therefore, the fragrant air with a scent as let out through the air outlet can be restrained from being delivered unnecessarily to the laterally opposite side that is upstream in the direction of the current. 
     The seat as described above may be configured such that the air outlet and the air inlet are located in the headrest. 
     With this configuration, a current of fragrant air can be caused to flow near the head of a seated person; therefore, the scent can be delivered more efficiently to the seated person. 
     The seat as described above may be configured such that the headrest includes a headrest body located at a rear side of a head of a seated person, and a pair of left and right protrusions protruding from the headrest body frontward, the pair of left and right protrusions being located at left and right sides of the head of the seated person such that the head of the seated person is be positioned therebetween, wherein the air outlet is located at one of the pair of left and right to protrusions, and the air inlet is located at another of the pair of left and right protrusions. 
     With this configuration, a current of fragrant air can be caused to flow as if it brushes past the nose of a seated person; therefore, the scent can be delivered much more efficiently to the seated person. 
     The seat as described above may be configured such that the air outlet is located in one of the seat back and the headrest, and the air inlet is located in another of the seat back and the headrest. 
     With this configuration, a current of fragrant air can be caused to flow near the head of a seated person; therefore, the scent can be delivered more efficiently to the seated person. 
     The seat as described above may be configured such that the air outlet and the air inlet are located in an upper portion of the seat back. 
     With this configuration, a current of fragrant air can be caused to flow near the head of a seated person; therefore, the scent can be delivered more efficiently to the seated person. 
     The seat as described above may be configured such that the scenting device is detachable and attachable. 
     With this configuration, the type of scent can be changed according to preferences. 
     The seat as described above may be configured to comprise: a state detection sensor located at at least one of the seat cushion and the seat upper portion to acquire a measurement value for determining a state of a seated person; and a controller, wherein the scenting device includes fragrance emitters of a plurality of kinds, and the controller is configured to determine the state of the seated person based on the measurement value, and to switch from one fragrance emitter to another of the fragrance emitters depending on the state of the seated person. 
     This configuration makes it possible to deliver a scent appropriate to the state of a seated person. 
     The seat as described above may be configured to comprise: an odor sensor located downstream of the air inlet in the direction of the current of air; and a controller, wherein the scenting device includes fragrance emitters of a plurality of kinds, and the controller is configured to determine a state of a seated person based on a detection result of the odor sensor, and to switch from one fragrance emitter to another of the fragrance emitters depending on the state of the seated person. 
     This configuration makes it possible to deliver a scent appropriate to the state of a seated person. 
     The seat as described above may be configured to comprise a deodorizing filter located upstream of the scenting device in the direction of the current of air. 
     With this configuration, any smell which air could carry before getting scented can be reduced, so that such original smell of the air can be restrained from being mixed with the scent with which to make the air fragrant; therefore, the advantageous effect of the scent provided by the scenting device can be improved. 
     The seat as described above may be configured such that the fan includes a blower fan for forcing air out through the air outlet, and a suction fan for forcing air in through the air inlet. 
     The seat as described above may be configured to comprise an air passage provided in the seat upper portion and connecting the air inlet and the air outlet, wherein the fan is located in the air passage and configured to force air from the air inlet toward the air outlet. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       [ FIG. 1 ] is a perspective view of a car seat according to a first embodiment. 
       [ FIG. 2 ] is a diagram showing an automobile in which car seats are installed. 
       [ FIG. 3 ] is a diagram showing a structure of a headrest. 
       [ FIG. 4 ] includes (a) a perspective view showing a deodorizing filter, a blower fan and a scenting device, and (b) a side view of the scenting device as seen from a laterally outer side. 
       [ FIG. 5 ] is a schematic diagram for explaining attachment and detachment of the scenting device. 
       [ FIG. 6 ] is a block diagram of control implemented in the car seat. 
       [ FIG. 7 ] is a flowchart showing an example of a process to be executed by a controller. 
       [ FIG. 8 ] is a perspective view of a car seat according to a second embodiment. 
       [ FIG. 9 ] is a front elevation of the car seat according to the second embodiment. 
       [ FIG. 10 ] is a perspective view of a car seat according to a third embodiment. 
       [ FIG. 11 ] is a front elevation of the car seat according to the third embodiment. 
       [ FIG. 12 ] is a section X-X of  FIG. 11 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Next, a description will be given of a first embodiment of the invention. In this description, the front/rear (frontward/rearward), left/right (leftward/rightward; lateral), and upper/lower (upward/downward) are designated with reference to the front/rear, left/right and upward/downward directions for a person seated on a seat (i.e., seated person or occupant). 
     As shown in  FIG. 1 , a seat according to this embodiment is configured as a vehicle seat to be installed in a vehicle, specifically, a car seat S 1  to be installed in an automobile C (see  FIG. 2 ). 
     Referring now to  FIG. 2 , in the automobile C, a car seat S 1  and a car seat S 2  are installed. The car seat S 2  is arranged side by side with the car seat S 1 , particularly, at the right side of the car seat S 1 . The car seat S 2  is configured to be approximately symmetric (left-right reversed) to the car seat S 1 . 
     Referring back to  FIG. 1 , the car seat S 1  includes a seat cushion S 10  and a seat upper portion S 20  that is a portion provided above the seat cushion S 10 . The seat upper portion S 20  includes a seat back S 21  and a headrest S 22 . To be more specific, the seat upper portion S 20  includes a seat back S 21 , a headrest S 22 , and left and right armrests S 23 . 
     The seat cushion S 10 , and the seat back S 21  of the seat upper portion S 20  has a plurality of state detection sensors  50  located thereat. Each state detection sensor  50  is a sensor configured to acquire a measurement value for determining a state of a seated person seated on the car seat S 1 . Herein, the state of a seated person refers to a state including a frame of mind of the seated person, such as a state of his/her emotion being excited or not, a state of his/her nerve being irritated or not, a state of being drowsy or not, etc. 
     The state detection sensor  50  is a sensor capable of sensing the state of a seated person, and examples thereof include a heartbeat sensor, a respiration sensor, etc. For example, when a heart rate as measured by the heartbeat sensor or the like is higher than usual, a state of excitement or a state of irritation may be presumed to have arisen; when the heart rate is lower than usual, a drowsy state may be presumed to have arisen. Further, for example, when a respiration rate as measured by the respiration sensor or the like is lower than usual, a drowsy state may be presumed to have arisen. For the heartbeat sensor and the respiration sensor, pressure sensors may be used, for example. Thus, the heartbeat or respiration can be determined from variation in the measurement value (pressure value) acquired by the pressure sensors. 
     The plurality of state detection sensors  50  may all be sensors of the same type, or consist of a mix of sensors of different types. To be more specific, for example, the plurality of state detection sensors  50  may all be heartbeat sensors, or may all be respiration sensors, or may consist of heartbeat sensors and respiration sensors as mixedly arranged. 
     The headrest S 22  has a blower unit  100  and a suction unit  200  located therein. Specifically, the headrest S 22  includes a headrest body  31  located at a rear side of a head of a seated person, and a pair of left and right protrusions  32  protruding from left and right ends of the headrest body  31  frontward. The pair of left and right protrusions  32  are located in such to positions that the head of the seated person is to be positioned between the pair of left and right protrusions  32  located at left and right sides of the head of the seated person. In other words, the head of a person when seated will lie between the pair of left and right protrusions  32 . The blower unit  100  is located at the right protrusion  32 , and the suction unit  200  is located at the left protrusion  32 . 
     As shown in  FIG. 3  and  FIG. 4( a ) , the blower unit  100  is a device configured to force air made fragrant with a scent to come out, and includes a case  110 , a deodorizing filter  130 , a blower fan  140 , and a scenting device  150 . 
     The case  110  is a member that contains the deodorizing filter  130 , the blower fan  140  and the scenting device  150 , and has an intake port  111  through which to take in air, and an air outlet  112  through which to let out air. 
     The deodorizing filter  130  is a filter for removing odor from air taken in through the intake port  111 , and is located upstream of the scenting device  150  in a direction of a current of air as indicated by arrows in the drawings. 
     The blower fan  140  is a fan for forcing air out through the air outlet  112 , and is located downstream of the deodorizing filter  130  and upstream of the scenting device  150 . In other words, the blower fan  140  is located between the deodorizing filter  130  and the scenting device  150 . 
     As shown in  FIG. 4( a ), ( b ) , the scenting device  150  is a device configured to scent air to be forced out through the air outlet  112  by the air blower  140 . The scenting device  150  includes fragrance emitters  151  of a plurality of kinds, and a frame  152  that supports the fragrance emitters  151 . 
     Each of the fragrance emitters  151  is a member made of an air-permeable material impregnated with one of fragrant scents different from each other, such as fragrant olive, jasmine, mint, and grapefruit aromas, etc. In this embodiment, the scenting device  150  includes six fragrance emitters  151  as a plurality of fragrance emitters  151 ; it is, however, to be understood that any number of fragrance emitters  151  may be provided. 
     The frame  152  is supported rotatably about a shaft  152 A relative to the case  110 . 
     The scenting device  150  is located in the case  110 , such that one of the plurality of fragrance emitters  151  is positioned between the blower fan  140  and the air outlet  112 . The scenting device  150  is provided such that a fragrance emitter  151  positioned between the blower fan  140  and the air outlet  112  can be changed to another by a controller  300 , as will be described later, controlling the phase of the frame  152 . The blower unit  100  is configured such that when the blower fan  140  is actuated, air thereby caused to pass through the fragrance emitter  151  positioned between the blower fan  140  and the air outlet  112  is made fragrant with a scent with which that fragrance emitter  151  is impregnated, and let out through the air outlet  112 . 
     As shown in  FIG. 5 , the scenting device  150  is detachable from and installable in the headrest S 22  of the seat upper portion S 20 . To be more specific, the blower unit  100  is detachable from and installable in the headrest S 22 , and the scenting device  150  is detachable from and installable in the case  110  of the blower unit  100 . Although not illustrated in the drawings, the suction unit  200  is also detachable from and installable in the headrest S 22 . In the present embodiment, the blower unit  100  is configured to be detachable from the right protrusion  32  rightward, i.e., on a right side opposite to a side on which a person is to come when seated; the suction unit  200  is configured to be detachable from the left protrusion  32  leftward, i.e., on a left side opposite to the side on which a person is to come when seated. 
     The scenting device  150  may be configured such that each of the fragrance emitters  151  (see  FIG. 4 ) is detachable from and installable in the frame  152  so that the fragrance emitters  151  can be changed individually to a new one or to one having a different scent. 
     As shown in  FIG. 3 , the suction unit  200  is a device configured to suck air, and includes a case  210 , an odor sensor  220 , a second deodorizing filter  230 , and a suction fan  240 . 
     The case  210  is a member that contains the odor sensor  220 , the second deodorizing filter  230 , and the suction fan  240 , and has an air inlet  211  through which to suck in air, and an exhaust port  212  through which to discharge air. 
     The odor sensor  220  is a sensor that detects an odor of air taken in through the air inlet  211 , and is located downstream of the air inlet  211  in the direction of the current of air. In this embodiment, the odor sensor  220  acquires a measurement value for checking a state of health, a state of mind, or the like of a seated person from the properties, such as the types and/or intensities, of the components of body odor of the seated person as contained in air taken in through the air inlet  211 . 
     The second deodorizing filter  230  is a filter for removing odor from air taken in through the air inlet  211  and having flowed across the odor sensor  220 , and is located downstream of the odor sensor  220  in the direction of the current of air. 
     The suction fan  240  is a fan for drawing in air through the air inlet  211 , and is located downstream of the second deodorizing filter  230  in the direction of the current of air. The suction fan  240  and the blower fan  140  of the blower unit  100  are fans configured to produce a current of air flowing at a front side of the seat upper portion S 20  from the air outlet  112  toward the air inlet  211 . That is, in the present embodiment, the car seat S 1  comprises two fans, to be more specific, the blower fan  140  and the suction fan  240 , as “(at least one) fan” according to the invention. 
     Next, a description will be given of arrangement of the air outlet  112  and the air inlet  211  in the car seat S 1  of the present embodiment. 
     As shown in  FIG. 1 , the air outlet  112  and the air inlet  211  are both located in the seat upper portion S 20 . To be more specific, the air outlet  112  is located at one of left and right sides, specifically, at the right side, of the seat upper portion S 20 , whereas the air inlet  211  is located at the other of the left and right sides, specifically, at the left side, of the seat upper portion S 20 . In other words, for the car seat S 1 , the air outlet  112  is located at a laterally inner side in the automobile C, that is, located on a side on which the adjacent car seat S 2  (see  FIG. 2 ) is located, and the air inlet  211  is located at a laterally outer side in the automobile C, that is, located on a side opposite to the side on which the car seat S 2  is located. 
     More specifically, the air outlet  112  and the air inlet  211  are both located in the headrest S 22  that is a constituent part of the seat upper portion S 20 . To elaborate, the air outlet  112  is located at one of the pair of left and right protrusions  32 , specifically, at the right protrusion  32 , whereas the air inlet  211  is located at the other of the pair of left and right protrusions  32 , specifically, at the left protrusion  32 . For that matter, the air outlet  112  is located in a laterally outer side surface of the right protrusion  32 , and the air inlet  211  is located in a laterally inner side surface of the left protrusion  32 , so that the air outlet  112  and the air inlet  211  face each other in laterally opposite directions. 
     As shown in  FIG. 2 , the air outlet  112  and the air inlet  211  are located in such positions that part of the headrest S 22 , specifically, a central portion (a portion except the left and right end portions) of the headrest body  31 , is positioned between the air outlet  112  and the air inlet  211  in a direction of the current of air flowing from the air outlet  112  toward the air inlet  211  as viewed from a front side (between chain lines shown in  FIG. 2 ). Moreover, the air outlet  112  and the air inlet  211  are located in such positions that a straight line connecting the air outlet  112  and the air inlet  211  (see the arrow) intersects the headrest S 22  (the central portion of the headrest body  31 ) as viewed from the front side. 
     As shown in  FIG. 6 , the car seat S 1  further includes a controller  300 . The controller  300  includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an input/output circuit, etc., and is connected to the state detection sensors  50  and the odor sensor  220  and thus allowed to acquire measurement values from the state detection to sensors  50  and the odor sensor  220  that is provided in the suction unit  200 . It is to be understood that the controller  300  may be located in the car seat S 1 , or outside of the car seat S 1 . 
     The controller  300  controls the operations of the fans  140 ,  240 , such as the on-off control over the fans  140 ,  240 . Further, the controller  300  determines the state of a seated person based on the measurement values of the state detection sensors  50  and/or the detection results of the odor sensor  220 , and switches from one fragrance emitter  151  to another (see  FIG. 4 ) depending on the state of the seated person. Specifically, the controller  300  causes the frame  152  of the scenting device  150  to rotate to regulate its phase, thereby switching the fragrance emitter  151  positioned between the blower fan  140  and the air outlet  112 , depending on the state of the seated person. 
     For example, if the controller  300  makes a determination based on the measurement values of the state detection sensors  50  and the odor sensor  220  that the state of a seated person is indicative of an irritated state, then the controller  300  causes the frame  152  of the scenting device  150  to rotate so that a fragrance emitter  151  impregnated with a fragrant scent of jasmine is positioned between the blower fan  140  and the air outlet  112 . In this way, the car seat S 1  can cause air made fragrant with a scent of jasmine having an emotionally relieving effect to be let out through the air outlet  112  by actuating the blower fan  140 . 
     Also, for example, if the controller  300  makes a determination based on the measurement values of the state detection sensors  50  and the odor sensor  220  that the state of a seated person is indicative of a drowsy state, then the controller  300  causes the frame  152  of the scenting device  150  to rotate so that a fragrance emitter  151  impregnated with a fragrant scent of mint is positioned between the blower fan  140  and the air outlet  112 . In this way, the car seat S 1  can cause air made fragrant with a scent of mint having an awakening effect to be let out through the air outlet  112  by actuating the blower fan  140 . 
     Next, a description will be given of one example of a process executed by the controller  300 . 
     As shown in  FIG. 7 , the controller  300 , first, actuates the blower fan  140  and the suction fan  240  (S 101 ). As a result, a current of air flowing at the front side of the seat upper portion S 20 , specifically, of the headrest body  31 , from the air outlet  112  toward the air inlet  211  is produced. 
     Next, the controller  300  executes a sensing step of acquiring measurement values from the state detection sensors  50  and/or the odor sensor  220  (S 102 ). Thereafter, the controller  300  determines the state of a seated person based on the acquired measurement values (S 103 ). Then, the controller  300  causes the frame  152  of the scenting device  150  to rotate to thereby switch the fragrance emitter  151  positioned between the blower fan  140  and the air outlet  112 , depending on the state of the seated person (S 104 ). Accordingly, the air caused to flow from the air outlet  112  toward the air inlet  211  can be made fragrant with a scent such as to settle an irritated nerve of the seated person or to shake off the drowsiness of the seated person. 
     According to the first embodiment described above, as shown in  FIG. 2 , the air made fragrant with a scent and forced out through the air outlet  112  (see the arrows) is drawn in through the air inlet  211 , and a current of fragrant air is produced accordingly, so that the scent can be restrained from diffusing. Therefore, the scent can be delivered efficiently to an occupant seated on the car seat S 1 . 
     Furthermore, the air outlet  112  and the air inlet  211  are located in such positions that a straight line connecting the air outlet  112  and the air inlet  211  intersects the headrest S 22  as viewed from the front side; thus, the fragrant scent flowing from the air outlet  112  toward the air inlet  211 , as viewed from the front side, blows on the head of a seated person positioned at the front side of the headrest S 22 . Accordingly, the scent can be delivered more efficiently to the seated person. 
     Since the air outlet  112  is located at one of the left and right sides of the seat upper portion S 20  and the air inlet  211  is located at the other of the left and right sides of the seat upper portion S 20 , a current of fragrant air can be caused to flow from one of the left and right sides toward the other of the left and right sides as if it brushes past a seated person. Therefore, the scent can be delivered more efficiently to the seated person. 
     Since the air outlet  112  is located at a laterally inner side in the automobile C, and the air inlet  211  is located at a laterally outer side in the automobile C, a current of fragrant air is caused to flow from the laterally inner side toward the laterally outer side in the automobile C, as a matter of course. Accordingly, the fragrant air with a scent as let out through the air outlet  112  can be restrained from being delivered unnecessarily to the laterally opposite side that is upstream in the direction of the current of the fragrant air. In addition, with this configuration, even if another car seat S 2  is located at the laterally opposite side, upstream of the car seat S 1  in the direction of the current of air as in the present embodiment, the scent can be restrained from being delivered to a person seated on this another car seat S 2 . The same may be said for the car seat S 2  configured to be approximately symmetric (left-right reversed) to the car seat S 1 . Consequently, the scent let out through the air outlet  112  of the car seat S 1  can be efficiently delivered only to an occupant seated on the car seat S 1 ; similarly, the scent let out through the air outlet  112  of the car seat S 2  can be efficiently delivered only to an occupant seated on the car seat S 2 . 
     Since the air outlet  112  and the air inlet  211  are located in the headrest S 22 , a current of fragrant air can be caused to flow near the head of a seated person. Accordingly, the scent can be delivered more efficiently to the seated person. 
     Since the air outlet  112  is located at one of the pair of left and right protrusions  32  and the air inlet  211  is located at the other of the pair of left and right protrusions  32 , a current of fragrant air can be caused to flow as if it brushes past the nose of a seated person. Accordingly, the scent can be delivered much more efficiently to the seated person. 
     Since the scenting device  150  is detachable and attachable, the type of scent can be changed according to preferences. Accordingly, in this embodiment, the type of scent can be changed individually for the respective car seats S 1 , S 2 . 
     Since the controller  300  is configured to determine the state of a seated person based on the measurement values of the state detection sensors  50  and to switch from one fragrance emitter  151  to another depending on the state of the seated person, a scent appropriate to the state of the seated person can be delivered. 
     Similarly, since the controller  300  is configured to determine the state of a seated person based on a detection result of the odor sensor  220  and to switch from one fragrance emitter  151  to another depending on the state of the seated person, a scent appropriate to the state of the seated person can be delivered. 
     Since the deodorizing filter  130  is located upstream of the scenting device  150  in the direction of a current of air, any smell which air could carry before getting scented can be reduced. Accordingly, such original smell of the air can be restrained from being mixed with the scent imparted by the scenting device  150 ; therefore, the advantageous effect of the scent provided by the scenting device  150  can be improved. 
     Next, a description will be given of a second embodiment. Hereinbelow, the same aspects/elements as in the above-described embodiment may be explained, for example, simply by the drawings with the same reference characters used therein, and thus, if deemed appropriate, will not be described in detail, while specific aspects/elements different from those as in the above-described embodiment will be described in detail. 
     As shown in  FIG. 8 , in a car seat S 1  according to the present embodiment, an air inlet  211  is located in the headrest S 22  of the seat upper portion S 20 , as in the first embodiment. On the other hand, an air outlet  115  through which to let out air is located in the seat back S 21  of the seat upper portion S 20 . 
     To be more specific, the seat back S 21  includes a seat-back central portion  21 , and a pair of left and right seat-back side portions  22  provided at the left and right sides of the seat-back central portion  21  and bulging at their front sides farther frontward than the seat-back central portion  21  does. The air outlet  115  is located at the front side of one of the pair of left and right seat-back side portions  22 , specifically, of the right seat-back side portion  22 . The air outlet  115  is located, as is the case with the air outlet  112  of the first embodiment, at the right side of the seat upper portion S 20 , that is, at one of the left and right sides of the seat upper portion S 20 . 
     As shown in  FIG. 9 , the air outlet  115  and the air inlet  211  are located in such positions that part of the headrest S 22 , specifically (part of the central portion of the headrest body  31  and the right protrusion  32 ) is positioned between the air outlet  115  and the air inlet  211  in a direction of the current of air flowing from the air outlet  115  toward the air inlet  211  as viewed from a front side. Moreover, the air outlet  115  and the air inlet  211  are located in such positions that a straight line connecting the air outlet  115  and the air inlet  211  (see the arrow) intersects the headrest S 22  (part of the central portion of the headrest body  31 ) as viewed from the front side. 
     It is to be understood that in this embodiment, a blower unit (not shown) having the same configuration as that of the first embodiment to let out air made fragrant with a scent through the air outlet  115  is located in the seat back S 21 . The air outlet  115  may be, for example, an opening formed directly in the case of the blower unit, as is the case with the air outlet  112  of the first embodiment, or a port connected via a duct or the like to an air nozzle of the blower unit. 
     According to the second embodiment as described above, air made fragrant with a scent and forced out through the air outlet  115  is drawn in through the air inlet  211 , so that a current of fragrant air is produced accordingly; therefore, the scent can be restrained from diffusing, and the scent can be delivered efficiently to a seated person. 
     Furthermore, as the air outlet  115  is located in the seat back S 21 , and the air inlet  211  is located in the headrest S 22 , a current of fragrant air can be caused to flow near the head of a seated person. Accordingly, the scent can be delivered more efficiently to the seated person. 
     In the present embodiment, the air outlet  115  is located in the seat back S 21  and the air inlet  211  is located in the headrest S 22 ; however, an alternative arrangement may be implemented in which the air outlet is located in the headrest S 22 , and the air inlet is located in the seat back S 21 . 
     Next, a description will be given of a third embodiment. 
     As shown in  FIG. 10 , a car seat S 1  according to the present embodiment is configured such that an air outlet  115  and an air inlet  215  are located in an upper portion of the seat back S 21 , i.e., in a position above a center (equidistant from upper and lower extremities) of the seat back S 21 . 
     To elaborate, the air outlet  115  is located in one of a pair of left and right seat-back side portions  22 , specifically, at a front side of an upper portion of the right seat-back side portion  22 , whereas the air inlet  215  is located in the other one of the pair of left and right seat-back side portions  22 , specifically, at a front side of an upper portion of the left seat-back side portion  22 . The air outlet  115  is located at a right side (i.e., one of the left and right sides) of the seat upper portion S 20 , while the air inlet  215  is located at a left side (i.e., the other of the left and right sides) of the seat upper portion S 20 . 
     As shown in  FIG. 11 , the air outlet  115  and the air inlet  215  are located in such positions that the headrest S 22  in its entirety is positioned between the air outlet  115  and the air inlet  215  in a direction from the air outlet  115  toward the air inlet  215  as viewed from a front side (between chain lines shown in  FIG. 11 ). 
     As shown in  FIG. 12 , the car seat S 1  according to the present embodiment has an air passage  410  provided in the seat upper portion S 20 , specifically in the seat back S 21 . The air passage  410  is provided to connect the air inlet  215  and the air outlet  115 . In this air passage  410 , a deodorizing filter  430 , a fan  440 , and a scenting device  450  are arranged in this order from an upstream side toward a downstream end in a direction of a current of air flowing through the air passage  410  (see the arrows). 
     The deodorizing filter  430  is a filter for removing odor from air taken through the air inlet  215  into the air passage  410 . 
     The fan  440  is a fan that produces a current of air flowing at a front side of the seat upper portion S 20  (seat back S 21 ) from the air outlet  115  toward the air inlet  215 . To be more specific, the fan  440  forces air to flow in the air passage  410  from the air inlet  215  toward the air outlet  115 , so that air is let out through the air outlet  115 , while air is drawn in through the air inlet  215 . In the car seat S 1  of this embodiment, only one fan  440  is provided. 
     The scenting device  450  scents air to be forced out through the air outlet  115 . The scenting device  450  does not include any such fragrance emitters  151  as provided in the scenting device  150  of the first embodiment, and disclosed here by way of example is a member made of an air-permeable material impregnated with a fragrant scent. 
     According to the third embodiment as described above, air made fragrant with a scent and forced out through the air outlet  115  is drawn in through the air inlet  215 ; accordingly, a to current of fragrant air is formed and the scent is restrained from diffusing, whereby the scent can be delivered efficiently to a seated person. 
     Furthermore, as the air outlet  115  and the air inlet  215  are located in an upper portion of the seat back S 21 , a current of fragrant air can be caused to flow near the head of a seated person. Therefore, the scent can be delivered more efficiently to the seated person. 
     Moreover, as only one fan  440  is provided, a unit for producing a current of air flowing from the air outlet  115  toward the air inlet  215  can be made compact and smaller as compared with an alternative configuration in which a plurality of fans are provided. 
     In contrast, the configuration as in the above-described first embodiment includes the blower fan  140  and the suction fan  240  as “(at least one) fan”, and the blower unit  100  and the suction unit  200  are provided separately; accordingly, the need for providing an air passage connecting the air inlet and the air outlet in the seat upper portion S 20  can be saved. Therefore, the rigidity of the seat upper portion S 20  can be enhanced. 
     Although the embodiments of the invention have been described above, the present invention is not limited to the above-described embodiments, and can be modified where appropriate for practical applications. 
     For example, the arrangement of the air outlet and the air inlet may be reversed laterally from the arrangement in each of the embodiments. 
     In the setup constructed as in the first embodiment, the controller  300  may be configured to actuate first the suction fan  240  only, without actuating the blower fan  140 , to cause the suction unit  200  to take in air in the vehicle, measure its odor by using the odor sensor  220 , and if the measurement value of the odor sensor  220  is not lower than a predetermined level, then continue to actuate the suction fan  240  for a predetermined period of time to deodorize the air in the vehicle by using the second deodorizing filter  230 , and thereafter actuate the blower fan  140  to force air made fragrant with a scent to come out through the air outlet  112 . Herein, the controller  300  may be configured to skip the deodorizing step if the measurement value of the odor sensor  220  is lower than the predetermined value, and actuate the blower fan  140  to force air made fragrant with a scent to come out through the air outlet  112 . 
     Although the state detection sensors  50  are located at both of the seat cushion S 10  and the seat upper portion S 20  in the first embodiment, the state detection sensor may be located at only one of the seat cushion and the seat upper portion. Alternatively, the seat may be configured to comprise no state detection sensor. 
     Although the blower unit  100  including one blower fan  140  is provided in the first embodiment, an alternative configuration with a plurality of blower fans may be feasible. The same goes for the suction fan in the suction unit. Although the number of the blower fan(s)  140  and the number of the suction fan(s)  240  provided in the first embodiment are the same, the numbers may be different. In the setup configured as in the third embodiment, a plurality of fans  440  may be provided. 
     Although the scenting device  150  in the first embodiment is configured to be removable from the seat upper portion S 20  by first removing the blower unit  100  from the seat upper portion S 20  and then removing the scenting device  150  from the case  110  of the blower unit  100 , the scenting device may be configured to be directly attachable to and detachable from the seat upper portion such as the headrest, the seat back, etc. It is to be understood that if the scenting device  150  or at least part of the fragrance emitters  151 , for example, is not attached in the car seat S 1 , air to be forced out through the air outlet  112  is not made fragrant with a scent; however, in this case as well, a current of air flowing at a front side of the seat upper portion S 20  from the air outlet  112  toward the air inlet  211  is produced by actuating the fans  140 ,  240 , so that local or personal air-conditioning feature may be available. 
     Although the controller  300  in the first embodiment is configured to automatically change the scent depending on the state of a seated occupant, an alternative configuration may be feasible such that the scent can be changed by a seated person&#39;s own operation according to his/her preferences. Optionally, the modes of changing the scent may be provided in a manner switchable between a mode in which the scent is automatically changed and a mode in which the scent is changed by a seated person&#39;s manual operation. 
     The air outlet located in the headrest S 22  or the seat back S 21  of the seat upper portion S 20  in the above-described embodiments may alternatively be located in the armrest S 23  of the seat upper portion S 20 . The same goes for the air inlet. 
     In the above-described embodiments, the car seat S 1  comprising the seat back S 21  and the headrest S 22  provided separately is illustrated by way of example; however, a seat having a seat back and a headrest formed integrally in one piece, for example, like an air-conditioning seat as described in the Patent document 1, may be compatible. 
     In the above-described embodiments, the car seat S 1  installed in the automobile C is illustrated as an example of a seat according to the invention, but the seat may be a vehicle seat as installed in any vehicle other than an automobile, such as rail cars, ships or aircrafts, etc. Moreover, the seat is not limited to a vehicle seat, but may be a seat as used in amusement facilities, in relaxation facilities, or at home. 
     The elements explained in the above-described embodiments and modified examples may be implemented in combination where appropriate.