Abstract:
A vehicle seat includes: plural airbags for massaging that are provided at least at an interior of a seatback, and that inflate to push against portions of a body of a seated vehicle occupant; an air supplying/discharging device that has a forced-air source that feeds air under pressure, and a control valve that supplies and discharges the air, that has been fed under pressure from the forced-air source, to the plural airbags respectively, so that the air supplying/discharging device inflates and contracts the plural airbags individually; and an electronic control unit that, in a state in which the forced-air source is operated, repeats, at a uniform cycle, supplying and discharging of the air by switching of the control valve, to generate awakening vibrations at least at one airbag among the plural airbags.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2015-150924 filed on Jul. 30, 2015, the entire contents of which is incorporated by reference herein. 
       BACKGROUND 
       [0002]    Technical Field 
         [0003]    The present disclosure relates to a vehicle seat that can impart an awakening effect to a seated vehicle occupant. 
         [0004]    Related Art 
         [0005]    Vehicle seats that are equipped with a vibration generating device for imparting a massaging effect or an awakening effect to a seated vehicle occupant are known (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2014-212976 (Patent Document 1)). 
         [0006]    However, in a case in which a vibration generating device that imparts an awakening effect to a seated vehicle occupant is provided at a vehicle seat that has plural airbags that impart a relaxing effect (a refreshing effect) to the seated vehicle occupant by inflating and pressing portions of the body of the seated vehicle occupant, the problem arises that the space for the setting of the vibration generating device is insufficient. 
       SUMMARY 
       [0007]    Thus, an object of the present disclosure is to provide a vehicle seat that can impart a relaxing effect and can also impart an awakening effect to a seated vehicle occupant. 
         [0008]    In order to achieve the above-described object, a vehicle seat relating to a first aspect of the present disclosure includes: plural airbags for massaging that are provided at least at an interior of a seatback, and that inflate to push portions of a body of a seated vehicle occupant; an air supplying/discharging device that has a forced-air source that feeds air under pressure, and a control valve that supplies and discharges the air, that has been fed under pressure from the forced-air source, to the plural airbags respectively, so that the air supplying/discharging device inflates and contracts the plural airbags individually; and an electronic control unit that, in a state in which the forced-air source is operated, repeats, at a uniform cycle, supplying and discharging of the air by switching of the control valve, to generate awakening vibrations at least at one airbag among the plural airbags. 
         [0009]    In accordance with the first aspect, a seated vehicle occupant is made to relax due to the plural airbags for massaging, that are provided at least at the interior of the seatback, individually inflating to push against portions of the body of the seated vehicle occupant. Further, in a state in which the forced-air source is operated, the supplying and discharging of air due to switching of the control valve is repeated at a uniform cycle by the control of the electronic control unit, and awakening vibrations are generated at least at one airbag among the plural airbags. 
         [0010]    Namely, vibrations that awaken the seated vehicle occupant are imparted by the airbags that are used to relax the seated vehicle occupant. Accordingly, setting space for the provision of a vibration generating device that imparts an awakening effect to the seated vehicle occupant is unnecessary, and not only a relaxing effect, but also an awakening effect can be imparted to the seated vehicle occupant. 
         [0011]    Further, in a vehicle seat relating to a second aspect, which includes the vehicle seat relating to the first aspect, the electronic control unit generates the awakening vibrations at the at least one airbag when it is detected that the seated vehicle occupant is tending toward falling asleep. 
         [0012]    In accordance with the second aspect, when a seated vehicle occupant is tending toward falling asleep, an awakening effect can be imparted to that seated vehicle occupant who is tending toward falling asleep. 
         [0013]    In a vehicle seat relating to a third aspect, which includes the vehicle seat relating to the first aspect, the electronic control unit generates the awakening vibrations at the at least one airbag at a time of an automatic driving mode of a self-driving vehicle, when it is detected that the seated vehicle occupant is tending toward falling asleep or is in a state of falling asleep. 
         [0014]    In accordance with the third aspect, at the time of an automatic driving mode of a self-driving vehicle, when there is the need to awaken the seated vehicle occupant such as at a time when the seated vehicle occupant is tending toward falling asleep or is in a state of falling asleep and switching to a manual driving mode is to be carried out, or the like, an awakening effect can be imparted to the seated vehicle occupant who is tending toward falling asleep or is in a state of falling asleep. 
         [0015]    Further, in a vehicle seat relating to a fourth aspect, which includes the vehicle seat relating to any one of the first through third aspects, the electronic control unit vibrates the plural airbags with the awakening vibrations at a predetermined timing and in a predetermined order. 
         [0016]    In accordance with the fourth aspect, the plural airbags are vibrated with the awakening vibrations at a predetermined timing and in a predetermined order, by control of the electronic control unit. Accordingly, an awakening effect can be effectively imparted to the seated vehicle occupant (the seated vehicle occupant who is tending toward falling asleep). Further, at the time of an automatic driving mode of a self-driving vehicle, when the seated vehicle occupant is tending toward falling asleep or is in a state of falling asleep and there is the need to awaken the seated vehicle occupant, an awakening effect can be effectively imparted to that seated vehicle occupant who is tending toward falling asleep or is in a state of falling asleep. 
         [0017]    Further, in a vehicle seat relating to a fifth aspect, which includes the vehicle seat relating to any one of the first through third aspects, the electronic control unit vibrates the plural airbags with the awakening vibrations at a predetermined timing and in a random order. 
         [0018]    In accordance with the fifth aspect, the plural airbags are vibrated with the awakening vibrations at a predetermined timing and in a random order, by control of the electronic control unit. Accordingly, an awakening effect can be more effectively imparted to the seated vehicle occupant (the seated vehicle occupant who is tending toward falling asleep). Further, at the time of an automatic driving mode of a self-driving vehicle, when the seated vehicle occupant is tending toward falling asleep or is in a state of falling asleep and there is the need to awaken the seated vehicle occupant, an awakening effect can be more effectively imparted to that seated vehicle occupant who is tending toward falling asleep or is in a state of falling asleep. 
         [0019]    In accordance with the first aspect, a relaxing effect can be imparted and an awakening effect can also be imparted to a seated vehicle occupant. 
         [0020]    In accordance with the second aspect, when a seated vehicle occupant is tending toward falling asleep, an awakening effect can be imparted to that seated vehicle occupant who is tending toward falling asleep. 
         [0021]    In accordance with the third aspect, at the time of an automatic driving mode of a self-driving vehicle, when a seated vehicle occupant is tending toward falling asleep or is in a state of falling asleep and there is the need to awaken the seated vehicle occupant, an awakening effect can be imparted to the seated vehicle occupant who is tending toward falling asleep or is in a state of falling asleep. 
         [0022]    In accordance with the fourth aspect, an awakening effect can be effectively imparted to a seated vehicle occupant (a seated vehicle occupant who is tending toward falling asleep), and further, at the time of an automatic driving mode of a self-driving vehicle, when the seated vehicle occupant is tending toward falling asleep or is in a state of falling asleep and there is the need to awaken the seated vehicle occupant, an awakening effect can be effectively imparted to the seated vehicle occupant who is tending toward falling asleep or is in a state of falling asleep. 
         [0023]    In accordance with the fifth aspect, an awakening effect can be more effectively imparted to a seated vehicle occupant (a seated vehicle occupant who is tending toward falling asleep), and further, at the time of an automatic driving mode of a self-driving vehicle, when the seated vehicle occupant is tending toward falling asleep or is in a state of falling asleep and there is the need to awaken the seated vehicle occupant, an awakening effect can be more effectively imparted to the seated vehicle occupant who is tending toward falling asleep or is in a state of falling asleep. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is a perspective view showing a vehicle seat relating to a present embodiment. 
           [0025]      FIG. 2  is a cross-sectional view showing a state in which an airbag, that is provided at the vehicle seat relating to the present embodiment, is contracted. 
           [0026]      FIG. 3  is a cross-sectional view showing a state in which the airbag, that is provided at the vehicle seat relating to the present embodiment, is inflated. 
           [0027]      FIG. 4  is a block diagram showing an airbag driving device that is provided at the vehicle seat relating to the present embodiment. 
           [0028]      FIG. 5  is an explanatory drawing that shows timing charts for vibrating the airbag that is provided at the vehicle seat relating to the present embodiment, and the strength of pressure within the airbag. 
           [0029]      FIG. 6  is an explanatory drawing that shows conditions for vibrating the airbag that is provided at the vehicle seat relating to the present embodiment. 
           [0030]      FIG. 7  is a perspective view showing a self-driving vehicle that has the vehicle seat relating to the present embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    An embodiment is described in detail hereinafter on the basis of the drawings. Note that, for convenience of explanation, arrow UP that is shown appropriately in the respective drawings is the upward direction of a vehicle seat  10  (of a self-driving vehicle  60 ), arrow FR is the frontward direction of the vehicle seat  10  (of the self-driving vehicle  60 ), and arrow RH is the rightward direction of the vehicle seat  10  (of the self-driving vehicle  60 ). Accordingly, in the following description, when vertical, longitudinal and left-right directions are used without being specified, they refer to the vertical of the vertical direction (of the vehicle), the longitudinal of the longitudinal direction (of the vehicle) and the left and right of the left-right direction at the vehicle seat  10  (of the self-driving vehicle  60 ). 
         [0032]    First, the overall structure of the vehicle seat  10  relating to the present embodiment is described. As shown in  FIG. 1 , the vehicle seat  10  has a scat cushion  12  that supports the buttocks and femoral region of a seated vehicle occupant (hereinafter called “the driver” as an example), and a seatback  14  that is provided so as to extend upward from the rear end portion of the seat cushion  12  and that supports the lumbar region and the back portion of the driver. Further, a headrest  16  that supports the head portion of the driver is provided at the upper end portion of the seatback  14 . 
         [0033]    Plural airbags  30  that are respectively for massaging (refreshing) are provided at the interiors of the seat cushion  12  and the seatback  14  of the vehicle seat  10 . Due to the respective airbags  30  inflating and pushing portions of the driver&#39;s body, the airbags  30  massage the lumbar region or the back portion and the femoral region or the like of the driver, and relax (refresh) the driver. 
         [0034]    Note that the airbags  30  within the seatback  14  are, for example, disposed in the vertical direction in two rows, and the airbags  30  within the seat cushion  12  are, for example, disposed in the longitudinal direction in two rows (see  FIG. 1 ). Because the respective airbags  30  have the same structures, here, description is given by using the airbag  30  within the seatback  14  as an example. 
         [0035]    As shown in  FIG. 2  and  FIG. 3 , the seatback  14  has a seat frame  20 , a seat pad  22  that is disposed at the driver&#39;s side (hereinafter also called “obverse side” upon occasion) of the seat frame  20 , a slab  24  that is shaped as a sheet and is disposed at the obverse side of the seat pad  22 , and a skin  18  that covers the obverse side of the slab  24 . 
         [0036]    The seat pad  22  is formed from a cushion body, and is structured by a foamed resin such as foamed urethane or the like for example. The slab  24  is softer than the seat pad  22 , and is structured from a material that can elastically (flexurally) deform, e.g., a foamed resin such as foamed urethane or the like whose void ratio is different than that of the seat pad  22 . 
         [0037]    Note that the slab  24  is provided in order to make the seating comfort of the vehicle seat  10  better. Further, the skin  18  also structures the design surface of the vehicle seat  10 . The respective airbags  30  are provided between the seat pad  22  and the slab  24  due to the back surfaces (the surfaces that are at the obverse-reverse opposite sides of the obverses thereof) being fixed by double-sided tape or an adhesive to the obverse side of the seat pad  22 . 
         [0038]    Each of the airbags  30  is structured from an expandable/contractible material such as a resin material such as polyurethane or the like, or a rubber material, or the like. As shown in  FIG. 1  through  FIG. 3 , each of the airbags  30  is structured to include a large diameter portion  26  that is substantially circular in a front view seen from the front direction, and a small diameter portion  28  that communicates with the large diameter portion  26 . Note that the large diameter portion  26  is fixed to the obverse side of the seat pad  22 , and the small diameter portion  28  is disposed at the slab  24  side. 
         [0039]    Here, an airbag driving device  40 , that has an air supplying/discharging device  50  that carries out the supplying and discharging of air to and from the respective airbags  30  and that inflates and contracts the respective airbags  30  individually, is described on the basis of  FIG. 4 . 
         [0040]    As shown in  FIG. 4 , the airbag driving device  40  is structured to include the air supplying/discharging device  50  to which the respective airbags  30  are connected, and a control device (an Electronic Control Unit (ECU))  58  that controls the air supplying/discharging device  50 . The ECU (control device  58 ) is a microcomputer having a Central Processing Unit (CPU) and memory including RAM and ROM. The air supplying/discharging device  50  is structured to include an intake opening  52 , an exhaust opening  54 , a pump  56  that serves as an air force-feeding means, and plural electromagnetic valves  32  that serve as control valves. 
         [0041]    One electromagnetic valve  32  is provided for each airbag  30 . Each of the electromagnetic valves  32  is a three-way valve, and has a common port  34 , an intake port  36  and an exhaust port  38 . Common tubes  48  are connected to the respective common ports  34 , and an intake tube  46  is connected to the respective intake ports  36 . Further, an exhaust tube  44  is connected to the respective exhaust ports  38 . 
         [0042]    The respective common tubes  48  are connected to the corresponding airbags  30 , and the intake tube  46  is connected to the pump  56 . Further, the exhaust tube  44  is connected to the exhaust opening  54 . An intake pipe  42  is connected between the pump  56  and the intake opening  52  so as to communicate therewith. Note that the intake tube  46  and the exhaust tube  44  are each structured by a single tube being branched-off and connected to the respective electromagnetic valves  32 . 
         [0043]    The control device  58  is electrically connected to the air supplying/discharging device  50 , and controls the operation of the pump  56 , and the opening/closing of the respective ports (the common ports  34 , the intake ports  36 , the exhaust ports  38 ) of the electromagnetic valves  32 . Note that the control device  58  is structured so as to be able to individually control the opening/closing of the respective ports (the common ports  34 , the intake ports  36 , the exhaust ports  38 ) of the respective electromagnetic valves  32 . 
         [0044]    Further, the control device  58  is electrically connected to an operation portion (not illustrated) that is operated by the driver who is seated in the vehicle seat  10 . Accordingly, due to the driver operating the operation portion, the inflation and contraction of the plural (some or all) of the airbags  30  are repeated individually and intermittently. 
         [0045]    Concretely, when, due to the control of the control device  58 , there is a supplying state in which the common port  34  and the intake port  36  of the electromagnetic valve  32  are open and the exhaust port  38  is closed and the common tube  48  and the intake tube  46  communicate with one another, air is supplied from the pump  56  to the airbag  30  interior, and, as shown in  FIG. 3 , the airbag  30  inflates. 
         [0046]    Further, when, due to the control of the control device  58 , there is an exhausting state in which the common port  34  and the exhaust port  38  of the electromagnetic valve  32  are open and the intake port  36  is closed and the common tube  48  and the exhaust tube  44  communicate with one another, air is discharged from the airbag  30  interior, and, as shown in  FIG. 2 , the airbag  30  contracts. 
         [0047]    Note that, because the slab  24  is softer than the seat pad  22  and is structured from a material that can elastically (flexurally) deform, when the airbag  30  inflates, the slab  24  and the skin  18  are made to bulge-out toward the vehicle body front side. Further, the airbag driving device  40  (the air supplying/discharging device  50  and the control device  58 ) are disposed within the seatback  14  or within the seat cushion  12 . 
         [0048]    Operation of the vehicle seat  10 , that relates to the present embodiment and is structured as described above, is described next. 
         [0049]    Due to the driver, who is seated in the vehicle seat  10  illustrated in  FIG. 1 , operating the operation portion, the airbag driving device  40  shown in  FIG. 4  is driven. Namely, a massaging operation (a massage mode) for the driver is started. Note that, at usual times (at times other than the massaging operation), the electromagnetic valves  32  are controlled by the control device  58  to be in exhausting states. Namely, the respective airbags  30  are in the contracted state shown in  FIG. 2 . 
         [0050]    When the massaging operation is started, the pump  56  operates due to control of the control device  58 . Further, at the airbag  30  that is in the supplying state in which the exhaust port  38  of the electromagnetic valve  32  is closed and the common port  34  and the intake port  36  are open, air that is taken-in from the intake opening  52  via the intake pipe  42  is supplied via the intake tube  46 , the electromagnetic valve  32  and the common tube  48 , and the airbag  30  inflates as shown in  FIG. 3 . Namely, the slab  24  and the skin  18  bulge-out and press the lumbar region or the back portion and the femoral region or the like of the seated driver. 
         [0051]    Thereafter, operation of the pump  56  stops, and, at the airbag  30  that is inflated, the intake port  36  of the electromagnetic valve  32  closes and common port  34  and the exhaust port  38  open such that the airbag  30  is set in an exhausting state, and the air within the airbag  30  is exhausted, via the common tube  48 , the electromagnetic valve  32  and the exhaust tube  44 , from the exhausting opening  54 , and the airbag  30  contracts as shown in  FIG. 2 . Namely, the slab  24  and the skin  18  return to their original states, and the pressing of the lumbar region or the back portion and the femoral region or the like of the seated driver is cancelled. 
         [0052]    The above-described inflating and contracting operations are carried out repeatedly at a predetermined time difference (e.g., a difference of one to three seconds) at some of or all of the airbags  30 . Due to the above operations, the lumbar region or the back portion and the femoral region or the like of the driver who is seated in the vehicle seat  10  is massaged, and a relaxing effect and a refreshing effect can be imparted to the driver. 
         [0053]    Namely, a region suitable for driving that is shown in  FIG. 6  (a relaxed state that is detected from heartbeat fluctuations that are periodic fluctuations in the heartbeat interval) can be maintained for the driver. Note that the positions of the airbags  30  that are inflated and contracted, and the timing (the predetermined time difference) of causing the inflation and expansion of the airbags  30 , and the like can be changed by the driver operating the operation portion. 
         [0054]    Further, there may be a structure in which the state (the heartbeat fluctuations) of the driver who is in the midst of driving are sensed by a state detecting device (not illustrated) such as an in-vehicle camera (not illustrated) or a sensor or the like that senses biomedical signals (the respiratory rate or the heartbeat rate or the like) of the driver, and, as shown in  FIG. 6 , when it is detected that the driver is in a tense state (the heartbeat fluctuations are larger than in the region that is the relaxed state), the massaging operation is started automatically, rather than by the driver operating the operation portion. 
         [0055]    Further, the state (the heartbeat fluctuations) of the driver who is in the midst of driving may be sensed by a state detecting device such as an in-vehicle camera or a sensor that senses biomedical signals of the driver or the like, and, as shown in  FIG. 6 , when it is detected that the driver is tending toward falling asleep (the heartbeat fluctuations are smaller than in the region that is the relaxed state), an awakening effect can be imparted to the driver who is tending toward falling asleep (a light sleep of an extent of being overcome by drowsiness), by using the airbags  30 . 
         [0056]    Namely, due to the airbag driving device  40  being controlled by the control device  58  that is shown in  FIG. 4 , at least one predetermined airbag  30  is vibrated (hereinafter, this mode is called “awakening mode” upon occasion). Concretely, as shown in  FIG. 5 , the pump  56  and the common port  34  are set in an on (operated) state always, and the intake port  36  and the exhaust port  38  are alternately turned on (opened) and off (closed) at a predetermined timing (e.g., every 0.2 seconds). 
         [0057]    Due to the above operations, the predetermined airbag  30  is inflated and contracted at a uniform cycle (e.g., a 0.2 second interval), and therefore, vibrations can be imparted to the driver who is tending toward falling asleep, and an awakening effect can be imparted to that driver. Accordingly, the driver can be effectively prevented from falling asleep at the wheel, and a suitable driving region (a relaxed state) can be maintained for the driver. 
         [0058]    Note that the airbag  30  that is in the vicinity of the lumbar region, where it is easiest for the driver to fit closely to the seatback  14 , is desirably selected as the predetermined airbag  30  that imparts vibrations to the driver. Further, the state detecting device detecting in this way that a driver who is in the midst of driving is tending toward falling asleep is an example of a condition under which the awakening mode is executed at the vehicle seat  10  relating to the present embodiment. 
         [0059]    Further, in the self-driving vehicle  60  that is shown in  FIG. 7 , at times such as when the need arises to switch the driving mode from an automatic driving mode to a manual driving mode (including a driving support mode), or the like, the vehicle seat  10  relating to the present embodiment is effective also at times when an awakening effect is imparted to a driver who is in a state of falling asleep (who is in a deep sleep of the extent of a sound sleep) at the time of the automatic driving mode. 
         [0060]    Namely, at the time of the automatic driving mode, the state detecting device, such as an in-vehicle camera or a sensor that senses biomedical signals of the driver or the like, detects that the driver is in a state of falling asleep, and, when a peripheral information detecting device  62  that is described later, or the like, detects that there is the need to switch to the manual driving mode such as when the vehicle arrives at its destination or the like for example, an awakening effect can be imparted to the driver who is in a state of falling asleep by causing the airbag  30  to vibrate as described above. 
         [0061]    Note that “automatic driving mode” is a mode in which a controller  64  (see  FIG. 7 ) (which includes an ECU) that is provided at the self-driving vehicle  60  drives the self-driving vehicle  60  on the basis of peripheral information, that is detected by the peripheral information detecting device  62  (see  FIG. 7 ) that is provided at the self-driving vehicle  60 , or the like. Further, “manual driving mode” is a mode in which the driver himself operates the steering wheel and the like and drives the self-driving vehicle  60 . 
         [0062]    In this way, at the time of the automatic driving mode of the self-driving vehicle  60 , the state detecting device detecting that the driver is in a state of falling asleep (or is tending toward falling asleep), and the peripheral information detecting device  62  or the like detecting that there is the need to awaken the driver such as there is the need to switch to the manual driving mode or the like, is an example of a condition under which the awakening mode is executed. 
         [0063]    Further, the plural airbags  30  that are disposed within the seatback  14  and within the seat cushion  12  may be made to vibrate at a predetermined timing and in a predetermined order, by the control of the control device  58 . In accordance with such a structure, because the driver can, to a certain extent, predict which of the airbags  30  will vibrate, an awakening effect can be imparted effectively without imparting discomfort to a driver who is tending toward falling asleep (who is lightly sleeping) in particular. 
         [0064]    Further, the plural airbags  30  that are disposed within the seatback  14  and within the seat cushion  12  may be made to vibrate at a predetermined timing and in a random order, by the control of the control device  58 . In accordance with such a structure, because the driver cannot predict which of the airbags  30  will vibrate, the driver can be prevented from becoming used to the vibration of the airbag  30  at a fixed position. Accordingly, an awakening effect can be imparted more effectively to a driver who is in a state of falling asleep (who is in a deep sleep) in particular. 
         [0065]    As described above, in accordance with the vehicle seat  10  relating to the present embodiment, vibrations can be imparted to the driver by using the airbags  30  that are used for massaging (refreshing). Accordingly, in the vehicle seat  10  that is provided with the airbags  30  for massaging (refreshing), there is no need to provide a vibration generating device separately from the airbags  30 , and the occurrence of the problem of space for setting this vibration generating device being insufficient, and the problem of the manufacturing cost increasing due to this vibration generating device, can be prevented. 
         [0066]    Further, in accordance with the present embodiment, as described above, because there is no need to provide a vibration generating device within the seatback  14  or within the seat cushion  12  of the vehicle seat  10 , the thicknesses of the seat pads  22  within the seatback  14  and within the seat cushion  12  can be ensured. Accordingly, the problem of a deterioration in the seating comfort of the driver also does not arise. 
         [0067]    Although the vehicle seat  10  relating to the present embodiment has been described above on the basis of the drawings, the vehicle seat  10  relating to the present embodiment is not limited to the illustrated structure, and the design thereof can be changed appropriately within a scope that does not depart from the gist of the present disclosure. For example, there may be a structure in which the awakening mode is executed continuously for a constant time, rather than being executed at a predetermined timing. 
         [0068]    Further, although there is a structure in which the electromagnetic valve  32  is provided per airbag  30 , embodiments are not limited to this, and there may be a structure in which several airbags  30  are connected to one of the electromagnetic valves  32 . Namely, there may be a structure in which several of the airbags  30  among the plural airbags  30  vibrate simultaneously. 
         [0069]    Further, the driver may be massaged by the airbags  30  that vibrate in the awakening mode, and it suffices for the airbags  30  to be provided at least at the interior of the seatback  14 . Further, embodiments are not limited to the imparting of an awakening effect to the driver, and, for example, in the self-driving vehicle  60  shown in  FIG. 7 , an awakening effect may be imparted to a vehicle occupant who is seated in the rear seat or in the front passenger&#39;s seat who is scheduled to be driving next. 
         [0070]    Further, embodiments are not limited to a structure in which the awakening mode is executed automatically on the basis of state information of the driver that is detected by a state detecting device. For example, there may be a structure in which the awakening mode is executed (manually) by a vehicle occupant who is seated in a rear seat or the front passenger&#39;s seat turning a switch (not shown) on. 
         [0071]    Moreover, although the present embodiment is a structure in which the airbag driving device  40  is provided at the interior of the vehicle seat  10 , embodiments are not limited to this, and may be structured such that the airbag driving device  40  is provided at the exterior of the vehicle seat  10  (e.g., at the lower surface of the seat cushion  12  or the rear surface of the seatback  14  or the like). Further, there may be a structure in which only the pump  56  of the air supplying/discharging device  50 , or only the control device  58 , is provided at the exterior of the vehicle seat  10 .