PRODUCTION OF OPTICAL DRUM

摘要

PURPOSE:To provide the optical drum having precise shape accuracy by executing an inside surface ironing in a container having a desired inside surface characteristic and shape and transferring the inside surface characteristic and shape of the container to the outside surface of a cylindrical stock simultaneously with the thickness reduction working of the stock. CONSTITUTION:A cylindrical ironing device is used and the inside surface 4 of the cylindrical container 2 is finished to the surface characteristic and shape and size corresponding to the outside surface characteristic of the optical drum to be produced. The prescribed metallic cylindrical stock 6 is inserted into the container 2 and the inside surface of this metallic cylindrical stock 6 is subjected to the ironing. the metallic cylindrical stock 6 is subjected to a fairly large plastic deformation and internal pressure in the thickness direction thereof by this ironing and is press fitted to the inside surface of the container 2, by which the surface characteristic and shape of the inside surface 4 of the container 2 are exactly transferred to the outside surface of the metallic cylindrical stock 6. The outside surface characteristic and shape of the cylindrical optical drum are exactly obtd. in this way and the quality thereof is stabilized.