| 摘要 |
PURPOSE:To make the magnitude of recording in the direction perpendicular to a writing direction as small as about mum and to increase the density of tracks by maintaining a heating temp. at the Curie temp. or compensation temp. of a thin magnetic film or below. CONSTITUTION:The intensity of the magnetic field required in the case of inverting the magnetization of part of a magnetic material by using a magnetic head depends on the magnitude of the magnetization of the magnetic material and is smaller as the temp. of the magnetic material is higher. Such a magnetic material which does not induce the magnetization inversion at the ordinary service temp. TB unless the magnetic field has the intensity HB is, therefore, considered here. HA<HB is obtd. and therefore, the magnetization inversion does not arise if the magnetic field HA is impressed to such magnetic material by the magnetic head. More specifically, the wiring of information is not executed. Whereas, the temp. is locally increased to TA or above, then the condition for the magnetization inversion is correspondingly satisfied and the magnetization inversion arises. The writing direction is thereby determined by the gap of the magnetic head (by assuming that the diameter of a heating beam is larger) and the size of the writing region in the direction perpendicular thereto is determined by the diameter of the heating beam. High-density recording is thus obtd. |
