Patent ID: 6919928

Claim:
A position determining device for determining a position of a subject movable within a predetermined movement range, the position determining device comprising: a relative position determiner for determining a relative movement amount of the subject with respect to a reference point; and an absolute position determiner for determining an absolute position of the subject within the movement range; wherein said position determining device determines the position of the subject in accordance with data outputted from the absolute position determiner and said position determining device operates until the absolute position determiner detects the subject reaching a limit of the movement range; and the reference point for determination of the relative position determiner is established at the limit of the movement range of the subject after the absolute position determiner detects the subject reaching the limit of the movement range, and the position determining device determines the position of the subject in accordance with data outputted from the relative position determiner, and upon activation of the positioning determining device, the position determining device obtains the absolute position of the subject within the movement range outputted from the absolute position determiner without performing an initialization process upon activation, wherein said initialization process includes moving the subject to a predetermined position upon activation.