MAGNETO-OPTICAL RECORDING MEDIUM AND MAGNETO-OPTICAL RECORDING METHOD FOR SAID MEDIUM

摘要

PURPOSE:To control the magnetic field direction of a recording layer to execute overwriting by providing the magnetic layer having a high magnetic permeability on a magneto-optical recording medium, applying magnetic fields in the direction reverse from each other to the magnetic layer from both sides of the magneto-optical recording medium and controlling the power of the laser to be projected to the recording medium. CONSTITUTION:An underlying layer 12, buffer layer 14 and protective layer 16 on a transparent glass substrate 11 provided with guide grooves are made of SiO2, etc. The recording layer 13 is a thin amorphous magnetic film consisting of TbFe, etc., and the high-permeability magnetic layer 15 consists of 'Permalloy(R)', etc. These layers are successively deposited. Permanent magnets 20 (20a, 20b) and 21 are installed on both sides of the recording medium 10 and the magnetic fields H1H2 are applied to the recording medium in the directions reverse from each other. The laser light is condensed by a lens 2 and H2 does not leak to the recording layer 13 and the layer 13 is magnetized downward when the power of the laser to be projected is low. H2 is applied to both the layers 13, 15 and therefore, H2 leaks to the layer 13 side as well and the layer 13 is magnetized upward regardless of the recording of the light when the power is high. The overwriting is, therefore, executed by modulating the laser power between the low and high levels by 1, 0 of information.