PHOTOELECTRIC RECORDING MEDIUM AND ITS RECORER AND REPRODUCER

摘要

PURPOSE:To realize an increase of capacity for a recording medium, by forming the vertical magnetic thin films on both surfaces of a substrate with the magnetization facilitating axes vertical to the surface of the substrate and then magnetizing previously these two vertical magnetic thin films in the same direction. CONSTITUTION:A region 1-a in a vertical magnetic thin film 1 having a magnetization facilitating axis in the direction vertical to the film surface is equal to a microregion where the magnetization is reversed after information is written by the heat magnetic effect which is caused by a coaction of a diamagnetic field 2 produced from an ambient region 1-b previously magnetized in a single direction or a write- in magnetic field 3 and a light beam 4. In the erasion mode, this magnetization reversing region is heated up higher than the Curie point, and at the same time a backward erasing magnetic field 5 is applied against the diamagnetic field given from an ambient magnetizing region. Then the magnetization is reversed and fixed in the cooling mode to obtain the same direction as the ambient region. Thus erasion is carried out.