Patent attributes
There is provided a chair that realizes a state preferably following a motion of a sitter in accordance with a posture of the relevant sitter, and a state preferably supporting the sitter. The chair includes a lower frame portion supported so as to be capable of rocking between a standing position and a rearward tilting position with respect to a base, and an upper frame portion supported so as to be capable of rocking between a normal position and a rear end position with respect to the relevant lower frame portion. Furthermore, upper frame portion biasing that elastically biases the upper frame portion from the rear end position to the normal position is provided. This upper frame portion biasing is adapted to change an elastically biasing force to the upper frame portion corresponding to a position in the rocking movement of the lower frame portion.