DISPLACEMENT DETECTION APPARATUS, DISPLACEMENT GAUGING APPARATUS AND FIXED POINT DETECTION APPARATUS

摘要

A displacement detection apparatus, a displacement measurement apparatus and a fixed point detection apparatus can highly accurately detect a fixed point or a displacement by minimizing the influence of the disturbances of polarization due to the bend and/or the stress of the optical fiber for transmitting light emitted from a light source to a detector. The present invention provides a displacement detection apparatus including a light source that emits light, a condenser lens that gathers light emitted from the light source, an optical fiber that transmits light gathered by the condenser lens, a depolarization element that dissolves polarization of light gathered by the condenser lens, a diffraction grating fitted to an object of measurement to receive and diffract light transmitted by the optical fiber, and a light receiving section that receives light diffracted by the diffraction grating, the displacement of the object of measurement being detected by the quantity of diffracted light received by the light receiving section.