Method of manufacturing a metal polygon mirror

摘要

It is an object of the present invention to provide a metal mirror manufacturing method which can effectively use the precision of a polygon mirror blank obtained by press working by omitting a peeling step, thereby improving the productivity. In order to achieve this object, there is provided a metal mirror manufacturing method of manufacturing a polygon mirror by finishing each surface (2a,2b) of a metal mirror blank (10) having undergone press working into a mirror surface (4a,4b) by a cutting process, including the first step of cutting intersecting portions (8) between the respective surfaces of the mirror blank by a cutting process by a predetermined amount (g), and the second step of flattening each of the surfaces (2a,2b) by causing a mirror-working cutting tool (7) to enter the mirror blank from a cut mark of each intersecting portion cut in the first step.