ORIENTING METHOD OF MAGNETIC FIELD OF MAGNETIC DISC

PURPOSE:To improve surface roughness and internal defects by applying horizontal magnetic fields in a circumferential direction alternately upon a magnetic disc from the top surface side and bottom surface side thereof. CONSTITUTION:A set of magnets 5a, 5b is disposed on the top surface side of a magnetic disc 1 and a set of magnets 6a, 6b on the bottom surface side at such magnetisms at which the horizontal magnetic fields in the circumferential direction are generated respectively. Thereupon, when the disc 1 is rotated, the magnetic thin film 2 right after the formation by coating receives the horizontal magnetic field formed by the magnets 5a, 5b and the horizontal magnetic field formed by the magnets 6a, 6b alternately, and the magnetic powder is unified in the circumferential direction. At the same time, in the vertical direction, the magnetic powder is attracted alternately to the top side and the bottom side as well and is consequently moved. By such movement, the surface and inside of the film 2 are made uniform, whereby the surface roughness is improved and internal defects are reduced.