Patent ID: 8922785
Filing Date: 2014-12-30
Classification: B60L,B60T,B62K,B62M,G01B

Abstract:
1. A method for measuring a displacement, the method comprising: generating a first reflected beam and a transmitted beam from an incidence of a parallel beam upon a first diffraction grating and a semi-reflective mirror in sequence, the first diffraction grating and the semi-reflective mirror being disposed along an optical axis, wherein the first reflected beam is generated by a reflection of the parallel beam by the semi-reflective mirror and the transmitted beam is generated by a transmission of the parallel beam by the semi-reflective mirror; generating a second reflected beam by a reflection of the transmitted beam by a total reflection mirror movable along the optical axis; dividing the first reflected beam into a first 0 dividing the second reflected beam into a second 0 measuring a first displacement in a direction of the optical axis from a first light intensity obtained by receiving an interference beam of the first ±n