PRODUCTION OF POLYGON MIRROR

摘要

PURPOSE:To provide the method for stable production of the polygon mirror having high reflectivity without variation in cutting and burnishing performance and without scattering of light. CONSTITUTION:A diamond tip 50 to be used in the process for production of the polygon mirror which finishes a reflection surface to a mirror finished surface by moving a cutting tool holding the diamond tip 50 to feed while pressing this bit to a metallic blank material has a main cutting edge 50A of a straight shape and an auxiliary cutting edge 50B of a straight shape. Its front face 51 is so inclined that the main cutting edge side is lower from the position apart by 0.1 to 0.4mm to the auxiliary cutting edge side from a cutting edge corner 54. The cutting edge corner viewed from the rake surface side is retreated in a range of over 0.1mum and below 0.6mum by the angle theta of the inclination and the angle of relief 8 of a front relief face 53 and a microcutting edge 50C connecting the retreated cutting edge corner 54 and the one end of the auxiliary cutting edge 50B is formed. The cutting by the main cutting edge 50A, the microcutting by the microcutting edge 50C and the burnishing by the auxiliary cutting edge 50B are continuously executed in accordance with the feed motion of the cutting tool.