POSITION DETECTION DEVICE

摘要

This position detection device (1) has: an optical sensor (2) for irradiating linear light onto a head part (Bt) of a reference bolt (B) having height in a direction that intersects a measurement surface, and for using the reflected light therefrom to measure the distance to the head part (Bt) of the reference bolt (B); a rotation support shaft (3) for moving the linear light in two directions that intersect the irradiation direction; a position sensor for detecting the movement position of the rotation support shaft (3) at a point in time in which the distance having a predetermined value has been measured by the optical sensor (2); and a computation unit for computing the coordinates of the center of a bolt hole (Pb) substantially at the center of the reference bolt (B) in the plane defined by the two movement directions, from a plurality of position data obtained from the position sensor.