| 摘要 |
An optical encoder includes a cylindrical reflective scale (20), a point light source (10) for irradiating the reflective scale, and light-receiving elements (32a, 32b, 32c, 32d) for receiving the light beams reflected by the reflective scale. The pitch of the reflective scale is set to an appropriate value such that the pitch of interference fringes formed by light beams that are reflected by the reflective scale is matched to the pitch of the light-receiving elements at a position with a desired gap. |
