Straightness measuring apparatus for moving stage

摘要

[Problem]An apparatus for measuring rectilinear motion and rotation angle errors of a rectilinearly moving body such as a rectilinear motion table in a non-contact manner and at the same time by utilizing linearity of a laser beam. [Solving Means]The apparatus has a horizontal, parallel two-surface mirror positioned in a horizontal plane and including two reflection mirrors whose reflection surfaces face each other and are spaced by a distance ({square root}2)d and a vertical, parallel two-surface mirror positioned in a vertical plane and including two reflection mirrors whose reflection surfaces face each other and are spaced by a distance ({square root}2)d, and also has a light source for generating a laser beam, semi-transparent mirrors for splitting the laser beam into two laser beams, optical path changing reflection mirrors for changing a direction of each laser beam, and position sensors for detecting positions of the laser beam reflected from the horizontal, parallel two-surface mirror and the vertical, parallel two-surface mirror, respectively fixed to positions outside of the rectilinearly moving body, [Selected Drawing] FIG. 1 are fixed to positions outside of the rectilinearly moving body.