1. Field of the Invention
The present invention relates to a vehicle seat in which a child seat is built into an occupant seat formed by a seat cushion and a seat back which is reclinable with respect to the seat cushion.
2. Description of the Related Art
There are various types of conventional child seats. For example, there is a type in which the child seat is fixed to an ordinary occupant seat as a single unit. There is another type in which a child seat mounting/fixing member is built in an occupant seat so that the child seat is fixed to the occupant seat as a single unit. In yet another type, which will be referred to hereinafter as a "built-in type", a child seat is built in an occupant seat so that the vehicle seat can be changed between a state of use as an occupant seat and a state of use as a child seat as occasion demands.
With built-in type vehicle seats, there is no need to remove the child seat. Built-in type vehicle seats are therefore superior in that the only work involved therein is changing the seat from one state of use to the other (as an example, see Japanese Utility Model Application Laid-Open No. 2-23229).
The structure disclosed in the above-mentioned reference is as follows: in an ordinary occupant seat, a seat back and a connecting rod are swingable a predetermined amount with respect to a seat cushion. Vertical grooves are formed in a reverse surface of the seat back. A child restraining belt and a waist portion pad are accommodated in the vertical grooves. Accordingly, when the occupant seat is to be used, the vehicle seat is placed in its normal state. When the child seat is to be used, the seat back of the occupant seat is swung so that by using the seat cushion of the occupant seat as the seat cushion of the child seat as well, a child can sit facing the rear.
However, in such a structure, the seat cushion of the occupant seat is used also as the child seat. Therefore, a drawback arises in that the angles of the seat surface are not structured so as to allow an optimal seat surface for a child. Further, in order to protect the sides of the child's body, it is necessary to form side wall portions. However, such side wall portions are unnecessary in an occupant seat. Namely, separate, independent cushion capabilities for an occupant seat and a child seat cannot be ensured.