| 摘要 |
PURPOSE:To increase magnetic recording density by laminating a nonmangetic plate on the surface of a soft magnetic material disc, spirally etching off a part of this nonmagnetic disc, and burying a magnetic paint therein to provide a magnetic body. CONSTITUTION:The surface of a soft magnetic material disc 1 of mild iron or the like is closely adhered with a nonmagnetic plate 7 of copper, rigid plastics, etc. and is stuck with a photoresist film 11 for etching on the resulted surface is prepared. Next, a spiral light pattern is projected onto the film 11 by an optical means, after which part of the plate 7 is removed down to the surface of the disc 1 by an etchant, whereby spiral grooves 12 are formed. Next, the film 11 is removed, and a magnetic paint is filled in the grooves 12. Thereby, magnetic films suifted for vertical magnetization are perpendicuarly disposed in contact with the disc 1, the impression of magnetic field to the magnetic body is made efficient and the density of magnetic recording is increased. |
