摘要 |
An optical encoder (100) according to the present invention includes a light source (110) that emits light; a scale (140) including scale gratings (141,142) each having a predetermined pitch; a light source grating (120) disposed between the light source (110) and the scale (140) and having a predetermined pitch; and interference fringe detection means (150) that detects an interference fringe generated by the light source grating (120) and the scale (140). The scale gratings (141,142) are disposed side by side, and the adjacent scale gratings (141,142) are displaced from each other by a 1/2 period. |