| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical encoder that has a passive optical fiber scanning head enabling a position measurement with a high resolving power.SOLUTION: In an optical encoder for generating a plurality of phase difference scanning signals relating to a relative position of a reflection type linear scale 10 movable in at least one measurement direction with respect to an optical fiber scanning head 20, within the optical fiber scanning head 20, a scan plate 21 is arranged in front of an end of a reflection type linear scale 10 side of an optical fiber 30. The phase difference scanning signal is encoded according to a wavelength. One beam flux incident onto the scan plate 21 is divided into at least two partial beam fluxes, and the reflection type linear scale 10 is irradiated with these partial beam fluxes. Then, these partial beam fluxes are converged once again for generating the phase difference scanning signal, and interfere with each other. These partial beam fluxes travel on a different optical path length during the division and the re-convergence. |
