MEASUREMENT OF ECCENTRICITY FOR LIGHT TRANSMITTING LONG-SIZED BODY

摘要

PURPOSE:To achieve accurate measurement, by projecting X- and Y-axis side scatting patterns of a light transmitting object to be measured different in the refractive index between the axis center and the circumference thereof on a screen to compute a natural logarithm value pertaining to the scattering patterns. CONSTITUTION:A long-sized body 30 to be measured comprising an optical fiber 31 and a transparent cover layer 32 is irradiated with X- and Y-axis light beams to project scattering patterns on screens 55 and 56 by light transmitted through the fiber 31 and the layer 32 and distances from the center to both ends of the scattering patterns are represented by XL, XR, YL and YR and distance-ratio natural logarithm ln(XR/XL) and ln(YR/YL). Here, information of the scattering patterns captured by optical systems 57 and 58 and an outer diameter value of the layer 32 captured by a measuring section 61 are inputted into a processing system 59. The system 59 into which a known refractive index pertaining to the layer 32 is inputted through a setter 60 performs a computation based on formulas I and II to determine a relative eccentricity between the fiber 31 and the layer 32.