PHOTOTHERMOMAGNETIC DISK DEVICE

摘要

PURPOSE:To improve mass productivity, recording preservation characteristic and repetitive recording and erasing characteristic and to improve reliability by forming successively a thin photomagnetic oxide film and thin dielectric film on a metallic substrate and irradiating laser light from the thin dielectric film side toward the thin photomagnetic film. CONSTITUTION:The thin photomagnetic oxide film 2 having >=200 deg.C Curie temp. and the thin high-refractive index dielectric film 3 are successively formed on the metallic substrate 1 which is formed with guide track grooves and has high reflectivity. The recording sensitivity is decreased by heat radiation if the film 2 is directly formed on the substrate 1 and therefore the heat radiation is prevented by the heat insulating layer 4. The scratch resistance and magnetooptic contrast are improved by the thin film 3. Recording, reproducing and erasing are executed by irradiating the laser light 5 on the film 2 from the film 3 side without through the substrate 1 and therefore the high-temp. and high-humidity resting characteristic, recording preservability, repetitive recording and erasing characteristic are improved and the reliability is improved.