DISPLACEMENT DETECTION DEVICE, AND ERROR CORRECTION METHOD FOR SCALE FOR DISPLACEMENT DETECTION DEVICE

摘要

Provided is a displacement detection device wherein the cumulative displacement amount error of a scale for the displacement detection device is reduced. The displacement detection device comprises a scale (115) provided with a plurality of marks, a first position detection sensor (111) and a second position detection sensor (112) which detect the positions of the marks (110), and a processing unit (409) which performs calculation processing on output signals from the first position detection sensor (111) and the second position detection sensor (112). The first position detection sensor (111) and the second position detection sensor (112) are disposed at a distance (L) from each other in a relative movement direction so as to be relatively movable with respect to the scale (115). The processing unit (409) calculates a correction value (P') of a mark pitch (P) between the marks (110) using the distance (L), a first time (TPK) required for K marks among the plurality of marks to pass the detection position of the first position detection sensor (111), and a second time (TL) required for a specific mark among the plurality of marks (110) to move the distance (L), the second time being measured simultaneously with the first time.