LENGTH CALIBRATION APPARATUS FOR MEASURING ECCENTRICITY OF MULTIPLE CONCENTRIC BODY HAVING LIGHT PERMEABILITY

摘要

PURPOSE:To perform calibration imparting a reference length simply and rapidly and to miniaturize the titled apparatus, by providing a plurality of light emitting bodies to a light receiving screen so as to provide a relative interval. CONSTITUTION:When the axial line of a multiple concentric body is set to a Y-axis, light irradiation systems 2, 3 and light receiving screens 8, 9 are respectively arranged on an X-axis and a Z-axis crossing the Y-axis at a right angle and image pickup systems 4, 5 are arranged in opposed relation to the screens 8, 9. Slits 10, 11 are formed to the screens 8, 9 so as to provide a relative back surfaces of the screens 8, 9 so as to correspond to the positions of the slits 10, 11. The lights having strong directionality emitted from the light irradiation systems 2, 3 impinge against the concentric body 1 to scatter while the scattered lights are projected on the screens 8, 9 and the scattering pattern thereof is caught through the image pickup systems 4, 5. When the absolute length of the scattering pattern is calculated, said absolute length is calibrated but, at that time, the lights emitted from the light emitters 12, 13 and transmitted through the slits 10, 11 are caught by the image pickup systems 4, 5 to impart a predetermined reference length.