| 摘要 |
PURPOSE:To obtain a writing magnetic field and an erasing magnetic field of sufficient intensity by providing an electromagnet opposite to a condenser lens and a magnetic body, which focuses a magnetic field generated by the electromagnet on a beam-irradiation point on a recording medium, at the condenser lens side. CONSTITUTION:A laser beam LB from a laser device 3 is scanned through a condenser lens 4 to raise the temperature of a magnetic thin film 1 on a recording medium 2 above the Curie temperature or the temperature where its coercive force decreases extremely. When a digital data signal DS is sent during the beam scanning, an AC current generator 5 supplies a positive or negative current to an electromagnet 8 when data is a ''1'' or ''0'', and a magnetic field generated by the electromagnet 8 corresponding to the current is converged by a magnetic body 9 at the side of a condenser lens 4 to be applied to the beam irradiation point of the thin film 1. Then, the direction of the magnetization of the thin film 1 is inverted to record the input data successively on the surface of the thin film 1 as the combination of positive and negative magnetization directions. |
