Abstract: The present invention provides a magneto-optical recording medium including a recording layer, an intermediate layer and a reproducing layer stacked in this order. Information recorded in the recording layer is transferred to the reproducing layer through the intermediate layer so that the information is reproduced. The reproducing layer includes an upper reproducing layer, a coupling layer, and a lower reproducing layer formed in this order on the intermediate layer. Magnetic information in the upper reproducing layer in an area whose temperature is increased to a predetermined temperature is transferred to the lower reproducing layer through the coupling layer.

Abstract: A magneto-optical recording medium includes at least a first magnetic layer, a second magnetic layer and a third magnetic layer which are layered in this order, the first magnetic layer being formed of a perpendicularly magnetized film having a relatively small wall coercivity and a relatively large wall mobility compared with the third magnetic layer in the vicinity of a predetermined temperature, and the magneto-optical recording medium satisfies conditions Tc2<Tcomp1<Tc1 and Tc2<Tcomp1<Tc3 where Tcomp1 is a compensation temperature of the first magnetic layer, Tc1, Tc2 and Tc3 are Curie temperatures of the first, second and third magnetic layers, respectively.

Abstract: There is provided an optical reproduction apparatus and an optical recording and reproduction apparatus which can improve a CNR and can read at high speed. The center portion of a laser light emitted from a semiconductor laser is shaded by a light shading portion of a first light shade, and its peripheral portion is condensed and irradiates a super-resolution film of an optical disk. The center portion of a reflected light from the optical disk is mainly made of a signal component, and a noise component almost disappears. Thus, the reflected light from the optical disk is separated into the center portion and its peripheral portion, and the reflected light made of the signal component of the center portion is used for signal reproduction, so that the CNR can be increased.

Abstract: A magneto-optical recording medium has a domain wall displacement layer, a recording layer for accumulating information and a switching layer arranged between said domain wall displacement layer and said recording layer and having a Curie temperature lower than those of the latter two layers. The domain wall displacement layer, the switching layer and the recording layer are coupled by exchange coupling at temperature not higher than the Curie temperature of the switching layer. The saturation magnetization of the domain wall displacement layer and the recording layer are in opposite directions to each other when the layers are coupled by exchange coupling at a temperature close to the Curie temperature of the switching layer.

Abstract: A magneto-optical recording medium includes a substrate and a reproducing layer and a recording layer provided on the substrate. A recording magnetic domain is provided in the recording layer by heating the recording layer by irradiation with light and applying a recording magnetic field to the recording layer so that information is recorded in the recording layer. The recording layer is a magnetic film having magnetic anisotropy in a direction perpendicular to the film surface, and the magnetic film holds the recording magnetic domain formed therein.

Abstract: A multilayer film including a first magnetic layer, a second magnetic layer, and a third magnetic layer in the stated order is formed so that a Curie temperature TC2 of the second magnetic layer is set to be lower than a Curie temperature TC1 of the first magnetic layer and a Curie temperature TC3 of the third magnetic layer and that the third magnetic layer is a perpendicular magnetization film. In at least a part of a region at a temperature lower than TC2, the first magnetic layer is perpendicularly magnetized by exchange coupling with the second magnetic layer, and the magnetization of the third magnetic layer is transferred to the first magnetic layer via the second magnetic layer because of the exchange coupling. The second magnetic layer is made of a magnetic layer that remains in an in-plane magnetization state at room temperature and is perpendicularly magnetized in a temperature range from a critical temperature TCR higher than room temperature to the Curie temperature TC2 of the same.

Abstract: A magneto-optical recording medium including a magnetic recording layer for recording information and a magnetic reproducing layer provided on the magnetic recording layer for reading information. The magnetic reproducing layer is separated into a first reproducing layer having a first composition and a second reproducing layer having a second composition slightly different from the first composition. The first and second reproducing layers have the same principal components. By changing a ratio in film thickness between the first and second reproducing layers, variations in composition of the first and second reproducing layers can be corrected.

Abstract: A magneto-optical storage medium includes an interference layer, a magnetic domain expansion layer, an intermediate layer, a magnetic masking layer, a recording layer, and a protection layer which are sequentially formed on a substrate. The magnetic domain expansion layer produces a smaller frictional force due to wall coercivity than do the other magnetic layers. The intermediate layer has the Curie temperature TC2 which is lower than those of the other magnetic layers. The magnetic masking layer is in a perpendicular magnetization state at temperatures that are in a proximity of TC2, and changes into an in-plane magnetization state at temperatures that are higher than the proximity of TC2. The recording layer produces a higher coercive force than those produced by the magnetic domain expansion layer at room temperature.

Abstract: A magneto-optical recording medium is provided with at least: a recording layer, made of a perpendicular magnetization film, in which magnetized information is recorded in the form of a perpendicular direction of magnetization; a magnetic flux generating layer, made of a perpendicular magnetization film, which is exchange-coupled with the recording layer; and a read-out layer, having a perpendicular magnetization at a predetermined temperature or higher temperatures than the predetermined temperature, which copies the magnetized information of the recording layer by magneto-static coupling with the magnetic flux generating layer and the recording layer, wherein the magnetic flux generating layer is a magnetic film having a lower Curie temperature than that of the recording layer and having a larger total magnetization than that of the recording layer at a temperature at which the read-out layer has a perpendicular magnetization.

Abstract: A magnetooptical recording medium comprising at least a reproduction layer, an intermediate layer, a connection layer and a recording layer, wherein the reproduction layer and intermediate layer have a slant magnetic direction in a non-magnetic field, and the connection layer is composed of a layer non-magnetic at room temperature by itself which is induced to exhibit magnetism by contact with a magnetic layer.

Abstract: An MO disk includes a readout layer, an intermediate layer and a recording layer each of which is made of a rare earth-transition metal amorphous material. The MO disk also includes a fourth magnetic layer formed on the recording layer and made of a rare earth-transition metal amorphous magnetic material containing Gd. The fourth magnetic layer has a rare earth metal magnetization-dominant composition and an axis of easy magnetization oriented longitudinally at room temperature. The axis of easy magnetization is changed to be oriented perpendicularly to the fourth magnetic layer as the temperature of the fourth magnetic layer rises to the Curie temperature of the fourth magnetic layer.

Abstract: A magneto-optical recording medium 11 is irradiated with a reproducing light beam 13 so that only a minute magnetic domain 313b, which is subjected to recording in a recording layer 18 and which is smaller than ½ of a spot radius of the recording light beam 13, is selected by a gate layer 17 and transferred to a magnetic domain-magnifying and reproducing layer 3. The magnetic domain transferred to the magnetic domain-magnifying and reproducing layer 3 is magnified by using a magnifying and reproducing magnetic field 411 of an alternating magnetic field. A large reproduction signal is obtained from the magnified magnetic domain 419, and the minute magnetic domain can be subjected to reproduction at a high resolving power and at a high S/N ratio. The magnified magnetic domain 419 is reduced by using a reducing reproducing magnetic field 415 of the alternating magnetic field. The gate layer 17 has a thickness which is not less than a thickness of a magnetic wall of the magnetic domain.

Abstract: A magneto-optical recording medium has:

Abstract: A magneto-optical recording medium including a recording layer for recording information and a substrate for supporting the recording layer is disclosed. The recording layer includes: a recording magnetic film for recording the information, the recording magnetic film being formed of a perpendicular magnetic anisotropy film; a readout magnetic film for optically reading out the information, the readout magnetic film being capable of being magnetically coupled with the recording magnetic film by an exchange-coupling force; and a controlling magnetic film, provided between the recording magnetic film and the readout magnetic film, for controlling the exchange-coupling force. The controlling magnetic film has in-plane magnetic anisotropy at room temperature.

Abstract: An optical recording medium is provided which has a reflective film, a lower dielectric film, a recording film and an upper dielectric film stacked in this order on a substrate, and is adapted to receive light from the side of the upper dielectric film and reproduce a signal by utilizing at least reflected light from the recording film. The optical recording medium is characterized in that a surface of the recording film at an interface with the upper dielectric film has a surface roughness of not greater than 4 Å.

Abstract: A magneto-optical storage medium includes an interference layer, a magnetic domain expansion layer, an intermediate layer, a magnetic masking layer, a recording layer, and a protection layer which are sequentially formed on a substrate. The magnetic domain expansion layer produces a smaller frictional force due to wall coercivity than do the other magnetic layers. The intermediate layer has the Curie temperature TC2 which is lower than those of the other magnetic layers. The magnetic masking layer is in a perpendicular magnetization state at temperatures that are in a proximity of TC2, and changes into an in-plane magnetization state at temperatures that are higher than the proximity of TC2. The recording layer produces a higher coercive force than those produced by the magnetic domain expansion layer at room temperature.

Abstract: A magneto-optical recording medium having a writing layer, a switching layer and a readout layer on a substrate, wherein a magnetization direction corresponding to information is written in the writing layer, and the magnetization direction of the writing layer is transferred to the readout layer by a magnet static coupling force from the writing layer at a temperature of at least room temperature, and wherein the writing layer is composed of a plurality of layers which are made of alloys of a rare earth metal and a transition metal and which are exchange-coupled one another, including a layer having rare earth metal dominant magnetization at room temperature and a layer having transition metal dominant magnetization at room temperature.

Abstract: A reproducing layer having perpendicular magnetization in a single layer, an in-plane magnetic layer, and a recording layer having perpendicular magnetization are formed in this order. When the reproducing layer, the in-plane magnetic layer, and the recording layer have the Curie temperatures of Tc1, Tc2, and Tc3, these values satisfy conditions of Tc2<Tc1 and Tc2<Tc3. The reproducing layer has in-plane magnetization due to an exchange coupling with the in-plane magnetic layer at lower than Tc2. At Tc2 or higher, magnetization information is expanded and transferred from the recording layer to the reproducing layer, so that the reproducing layer has single-domain perpendicular magnetization.

Abstract: A magneto-optical storage medium includes an interference layer, a magnetic domain expansion layer, an intermediate layer, a magnetic masking layer, a recording layer, and a protection layer which are sequentially formed on a substrate. The magnetic domain expansion layer produces a smaller frictional force due to wall coercivity than do the other magnetic layers. The intermediate layer has the Curie temperature TC2 which is lower than those of the other magnetic layers. The magnetic masking layer is in a perpendicular magnetization state at temperatures that are in a proximity of TC2, and changes into an in-plane magnetization state at temperatures that are higher than the proximity of TC2. The recording layer produces a higher coercive force than those produced by the magnetic domain expansion layer at room temperature.

Abstract: In a magneto-optical recording medium comprising a recording layer and a reproducing layer, a transfer layer and a magnetic shielding layer are successively formed between the recording layer and the reproducing layer respectively. The reproducing layer is prepared from Gd33(Fe70Co30)67 changing from an in-plane magnetization film to a perpendicular magnetization film at 150° C., for example. The transfer layer is prepared from Gd28(Fe90Co10)72 changing from an in-plane magnetization film to a perpendicular magnetization film at 50° C., for example. The magnetic shielding layer is prepared from SiN, for example. The recording layer is prepared from Tb20(Fe90Co10)80 whose saturation magnetization is maximized around the transition temperature of 50° C. of the transfer layer. A signal can be directly recorded in the recording layer with no magnetic influence from the reproducing layer.

Abstract: A magnetooptical recording medium has a first magnetic layer which is an in-plane magnetization film at both room temperature and high temperatures and changed to a perpendicular magnetization film at intermediate temperatures, and a second magnetic layer which is composed of a perpendicular magnetization film. The recording medium enables realization of high S/N reproduction of information recorded at a pitch below the diffraction limit of light with a simple structure, and further improvement in linear recording density and track density.