| 摘要 |
PROBLEM TO BE SOLVED: To provide a displacement detecting device superior in stability with the lapse of time while coping with an angle change in a diffraction grating, and while miniaturizing the device regardless of the kind of light source. SOLUTION: This displacement detecting device is characterized by having the light source 51 for emitting the light, a polarized light separating part 58 for emitting the light by separating the light emitted from the light source 51 into the two light mutually different in a polarized light component, a first lens 41a arranged between the light source 51 and the polarized light separating part 58, a reflection optical system 14 for respectively reflecting the two first diffracted light obtained by diffracting the two light emitted from the polarized light separating part 58 by the diffraction grating 11, a light branching part 44 for dividing the synthetic light into a plurality by generating the synthetic light by synthesizing the two second diffracted light obtained by diffracting the first diffracted light reflected by the reflection optical system 14 by the diffraction grating 11, a polarized light part 42 for respectively passing only a prescribed polarized light component on the divided synthetic light, a light receiving element 52 for generating an interference signal by respectively photoelectrically transducing the interference light passing through the polarized light part 42, and a second lens 41 arranged between the polarized light part 42 and the light receiving element 52. COPYRIGHT: (C)2004,JPO
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