Magneto-optical recording medium, and information reproducing method using the medium
AssigneeCanon Kabushiki Kaisha
InventorNaoki Nishimura
Life of this patent
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Abstract
A magneto-optical recording medium includes a reproducing layer, a recording layer and an intermediate layer provided between the reproducing layer and the recording layer. The reproducing layer is an in-plane magnetization film at least at room temperature, and becomes a perpendicular magnetization film at a temperature between room temperature and the Curie temperature thereof. The recording layer is a perpendicular magnetization film in a temperature range from room temperature to the Curie temperature thereof. The intermediate layer has a larger in-plane magnetic anisotropy at room temperature than the in-plane magnetic anisotropy of the reproducing layer.
Claims4
An information reproducing method for reproducing information recorded on a recording layer of a magneto-optical recording medium, wherein said magnetooptical recording medium includes a transparent substrate, a reproducing layer on said transparent substrate said reproducing layer having in-plane magnetization at room temperature, and having perpendicular magnetization at a temperature between room temperature and the Curie temperature thereof;
- a recording layer having perpendicular magnetization in a temperature range from room temperature to the Curie temperature thereof;
- an intermediate layer which is between said reproducing layer and said recording layer has a larger in-plane magnetic anistropy that the in-plane magnetic anistropy of said reproducing layer at room temperature
- wherein the Curie temperatures of said respective layers are higher than room temperature, and said reproducing layer, said intermediate layer, and said recording layer are laminated on the substrate in this order and wherein the Curie temperature of said intermediate layer is lower than the Curie temperatures of said recording layer and said reproducing layer;
- said information reproducing method comprising the steps of:
- (a) irradiating a light beam spot from the reproducing layer side;
- (b) converting a magnetization in a partial region, in the light beam spot irradiated region, on said reproducing layer into a perpendicular magnetization;
- (c) transferring information recorded on said recording layer to the partial region, which has a perpendicular magnetization of said reproducing layer by magnetic coupling;
- and
- (d) reproducing the information by detecting light reflected by said medium.
Dependencies are inferred from the claim text.