| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical displacement measuring instrument that uses coherent parallel light with fewer optical components and achieves resolution being equal to or higher than the period of a diffraction lattice for optical displacement measurement. SOLUTION: The optical displacement measuring instrument comprises a light source optical system 1A that has a light source 11 for irradiating coherent light L11a, and a lens 12 for forming parallel coherent light L11b from the radiation light L11a of the light source 11, a transmission type diffraction grating 21 for displacement measurement that moves in parallel with grating vector to the parallel coherent light L11b being radiated from the light source optical system 1A and diffracts the coherent light L11b, a light reception means 3 for receiving interference light DL201 being formed by the interference of diffraction light DL100 where the coherent light L11b is diffracted by the diffraction grating 21 for position measurement, and a position detection means 4 for detecting the relative movement position of the diffraction grating 21 for displacement measurement from the output signal of the light reception means 3.
|
