Device for detection of center of rotation of rotating object

摘要

A device for the detection of the center of rotation of a rotating object under test comprises means for illuminating a laser beam on at least one position on the surface of the object thereby generating an interference fringe, means for subjecting the resultant reflected scattered laser beams to spectral analysis by the laser Doppler effect thereby finding the velocity of rotation of the position at which the interference fringe is formed on the surface, and means for determining the center of rotation on the basis of the velocity so found. Protection of the spectral analysis from the adverse effect of the pedestal component is accomplished by causing interference fringes to be formed at a plurality of positions on the surface of the object under test or by placing in the optical path for one of the pair of laser beams a prism capable of continuously modulating the laser frequency.