Occupant protection apparatus

1. An occupant protection apparatus comprising:

an airbag configured to be stored in a head rest or a seat back of a vehicle seat and being inflated and deployed by a supply of gas, the airbag being formed as a single bag that is configured to cover a head of an occupant and including a front inflating part, which is inflated at a seat front side of the head, and a right and left pair of lateral inflating parts, which are connected to the front inflating part and are inflated at seat lateral sides of the head;

a three-point seat belt device including webbing equipped with a lap belt and a shoulder belt, and a belt take-up mechanism, the lap belt being adapted to restrain a pelvic region of the occupant, the shoulder belt being adapted to restrain an upper body of the occupant, and the belt take-up mechanism applying tension to the webbing;

a control unit that, in the event that an impact to the vehicle has been predicted or detected, activates the belt take-up mechanism before inflating and deploying the airbag; and

a build detection sensor configured to detect a build of the occupant seated in the vehicle seat,

wherein, in a case in which the build of the occupant detected by the build detection sensor is larger than a predetermined value, the control unit activates the belt take-up mechanism at an earlier stage than in a case in which the build of the occupant is not larger than the predetermined value.

2. An occupant protection apparatus comprising:

an airbag configured to be stored in a head rest or a seat back of a vehicle seat and being inflated and deployed by a supply of gas, the airbag being formed as a single bag that is configured to cover a head of an occupant and including a front inflating part, which is inflated at a seat front side of the head, and a right and left pair of lateral inflating parts, which are connected to the front inflating part and are inflated at seat lateral sides of the head;

a three-point seat belt device including webbing equipped with a lap belt and a shoulder belt, and a belt take-up mechanism, the lap belt being adapted to restrain a pelvic region of the occupant, the shoulder belt being adapted to restrain an upper body of the occupant, and the belt take-up mechanism applying tension to the webbing; and

a control unit that, in the event that an impact to the vehicle has been predicted or detected, activates the belt take-up mechanism before inflating and deploying the airbag,

wherein the front inflating part is equipped with portions that inflate at the seat front side of shoulders of the occupant, with one portion being positioned at one side in a seat width direction where the occupant is restrained by the shoulder belt and with another portion being positioned at the other side in the seat width direction, and the other portion at the other side is inflated and deployed to a position closer to a shoulder of the occupant than the one portion at the one side, and

wherein, among the portions of the front inflating part, the other portion at the other side in the seat width direction has a larger capacity than the one portion at the one side in the seat width direction.

3. An occupant protection apparatus comprising:

an airbag configured to be stored in a head rest or a seat back of a vehicle seat and being inflated and deployed by a supply of gas, the airbag being formed as a single bag that is configured to cover a head of an occupant and including a front inflating part, which is inflated at a seat front side of the head, and a right and left pair of lateral inflating parts, which are connected to the front inflating part and are inflated at seat lateral sides of the head;

a three-point seat belt device including webbing equipped with a lap belt and a shoulder belt, and a belt take-up mechanism, the lap belt being adapted to restrain a pelvic region of the occupant, the shoulder belt being adapted to restrain an upper body of the occupant, and the belt take-up mechanism applying tension to the webbing; and

a control unit that, in the event that an impact to the vehicle has been predicted or detected, activates the belt take-up mechanism before inflating and deploying the airbag,

wherein the front inflating part is equipped with portions that inflate at the seat front side of shoulders of the occupant, with one portion being positioned at one side in a seat width direction where the occupant is restrained by the shoulder belt and with another portion being positioned at the other side in the seat width direction, and the other portion at the other side is inflated and deployed to a position closer to a shoulder of the occupant than the one portion at the one side, and

wherein, among the right and left pair of lateral inflating parts, a lateral inflating part positioned at the other side in the seat width direction is inflated and deployed at an earlier stage than a lateral inflating part positioned at the one side in the seat width direction where the occupant is restrained by the shoulder belt.

4. An occupant protection apparatus comprising:

an airbag configured to be stored in a head rest or a seat back of a vehicle seat and being inflated and deployed by a supply of gas, the airbag being formed as a single bag that is configured to cover a head of an occupant and including a front inflating part, which is inflated at a seat front side of the head, and a right and left pair of lateral inflating parts, which are connected to the front inflating part and are inflated at seat lateral sides of the head;

a three-point seat belt device including webbing equipped with a lap belt and a shoulder belt, and a belt take-up mechanism, the lap belt being adapted to restrain a pelvic region of the occupant, the shoulder belt being adapted to restrain an upper body of the occupant, and the belt take-up mechanism applying tension to the webbing; and

a control unit that, in the event that an impact to the vehicle has been predicted or detected, activates the belt take-up mechanism before inflating and deploying the airbag,

wherein the front inflating part is equipped with portions that inflate at the seat front side of shoulders of the occupant, with one portion being positioned at one side in a seat width direction where the occupant is restrained by the shoulder belt and with another portion being positioned at the other side in the seat width direction, and the other portion at the other side is inflated and deployed to a position closer to a shoulder of the occupant than the one portion at the one side,

wherein, among the right and left pair of lateral inflating parts, a lateral inflating part positioned at the other side in the seat width direction is inflated and deployed at an earlier stage than a lateral inflating part positioned at the one side in the seat width direction where the occupant is restrained by the shoulder belt, and

wherein a cross-sectional area of a gas flow path, through which the gas flows into the lateral inflating part positioned at the other side in the seat width direction, is larger than a cross-sectional area of another gas flow path, through which the gas flows into the lateral inflating part positioned at the one side in the seat width direction.

5. An occupant protection apparatus comprising:

an airbag configured to be stored in a head rest or a seat back of a vehicle seat and being inflated and deployed by a supply of gas, the airbag being formed as a single bag that is configured to cover a head of an occupant and including a front inflating part, which is inflated at a seat front side of the head, and a right and left pair of lateral inflating parts, which are connected to the front inflating part and are inflated at seat lateral sides of the head;

a three-point seat belt device including webbing equipped with a lap belt and a shoulder belt, and a belt take-up mechanism, the lap belt being adapted to restrain a pelvic region of the occupant, the shoulder belt being adapted to restrain an upper body of the occupant, and the belt take-up mechanism applying tension to the webbing; and

a control unit that, in the event that an impact to the vehicle has been predicted or detected, activates the belt take-up mechanism before inflating and deploying the airbag,

wherein the lateral inflating parts are inflated as a result of the gas being supplied thereto via the front inflating portion.