| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical displacement detection device capable of reducing the cost without degrading performance, by improving a main scale, and to provide the main scale and a manufacturing method of the main scale. SOLUTION: In the optical displacement detection device 1, grooves 25 of V-shaped sections are repeatedly formed in a rear face of the main scale 2 at predetermined pitches, and reflection coating 50 is formed on a whole rear face of a transparent substrate 20 to cover the grooves 25. A reflective type diffraction grating 5 is constituted as a periodical grating in which units 55 formed of reflecting faces 51, 52, 53 are repeated. Further, by focusing attention on a fact that a fixing stage for mounting the main scale 2 is made of metal, material such as resin and glass is used for base material of the main scale 2, where difference between a linear expansion coefficient of the metal material used for forming the fixing stage and that of the material such as resin and glass is within a predetermined range. COPYRIGHT: (C)2005,JPO&NCIPI
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