Optische Translationsmessung

摘要

A method for determining the relative motion of a surface with respect to a measurement device comprising: illuminating the surface with illumination, through a partially transmitting object, such that illumination is reflected from the surface to illuminate a detector with illumination which is not an image of a point on or a portion of the surface; simultaneously illuminating the detector with reference illumination derived from said incident illumination; coherently detecting the reflected illumination of the detector utilizing said reference illumination such that the detector generates a signal; determining the relative motion of the surface parallel to the surface, based on variations of the signal with motion.