METHOD AND APPARATUS FOR MEASURING PERIOD OF PROMINENCE AND DEPRESSION STRUCTURE ON SURFACE OF LINE MATERIAL FOR MEASURING STRUCTURE IN REAL TIME BY USING CHANGE OF PATTERNS ACCORDING TO AMOUNT OF RECEIVED LIGHT

摘要

PURPOSE: A method and an apparatus for measuring a period of a prominence and depression structure on a surface of line material are provided to measure the structure in real time by using the change of patterns according to the amount of received light. CONSTITUTION: A method for measuring the period of a prominence and depression structure on a surface of line material(100) is provided. A light emitting part and a light receiving part are arranged at both sides of the line material. Light from the light emitting part is irradiated to the light receiving part while the line material(100) is forwarding with a predetermined speed. The period of the prominence and depression structure is calculated by using change patterns according to an amount of received light corresponding to the prominence and depression structure of the line material(100). A step wave is formed by using signals according to the change of the amount of the received light.