| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical encoder with high resolution by enhancing the S/N ratio (maximum intensity/minimum intensity) of a signal acquired with the movement of a scale. SOLUTION: An optical pattern of the movable scale 102 and that of a fixed scale 103 are disposed at a prescribed interval, the optical patterns each having transmitting parts and screening parts alternately disposed at prescribed pitches, thereby removing the effect of diffracted light owing to the optical patterns and of filtering light. Preferably, the movable scale 102 is in contact with the fixed scale 103. Further, the percentage of the transmitting part is made larger than that of the screening part on at least one of the scales 102 and 103. This makes it possible to further remove the effect of filtering light. COPYRIGHT: (C)2005,JPO&NCIPI
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