| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heterodyne laser interferometric measuring machine which accurately eliminates the influence of a dead path from the measurement results. <P>SOLUTION: The heterodyne laser interferometric measuring machine includes a splitter 80, which splits a beam from a heterodyne laser source 10 into two physically separated parallel laser beams to generate a measurement beam B1 and a reference beam B2; a polarized beam splitter 30, which divides the measurement beam B1 and the reference beam B2 toward measurement optical paths LP1, LP2; a quarter-wave plates 31, 32 which are provided in the measurement optical paths LP1, LP2; measurement mirrors 341, 342 of which respective reflection surfaces are fixed toward the different directions on the virtual straight line of a movable measurement object 50 and to which the measurement beams B11, B12 are emitted; reflection mirrors 411, 412 to which reference beams B21, B22 are emitted; reflection mirrors 411, 412 which are arranged in the vicinity of the measurement mirrors 341, 342 and to which the reference beams B21, B22 are emitted; and an operation circuit 70, which calculates the placement from two beat signals, based on the light obtained by interfering reflection light of the measurement mirrors 341, 342 and light obtained, by interfering the reflection light of the reflection mirrors 411, 412. <P>COPYRIGHT: (C)2011,JPO&INPIT |
