| 摘要 |
PROBLEM TO BE SOLVED: To provide an encoder advantageous in terms of measurement resolution.SOLUTION: An encoder includes: a scale; a light emission part which emits light toward the scale; a light receiving part in which a plurality of light receiving elements to receive the light from the scale are arrayed; and an optical system placed between the light emission part and the scale, having an opening member with an opening through which the light from the light emission part passes, and increasing the volume of light made incident on each of the plurality of light receiving elements out of the light from the light emission part.SELECTED DRAWING: Figure 1 |
