摘要:
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.
摘要:
A reproduction layer, a magnetic domain extending layer, an intermediate layer, and a recording layer are formed in this order. The magnetic domain extending layer, the intermediate layer, and the recording layer are exchange-coupled. The intermediate layer has a Curie temperature lower than that of any other magnetic layer. A non-magnetic intermediate layer is formed between the reproduction layer and the magnetic domain extending layer. Upon reproduction, magnetization information in the recording layer is transferred to and extended in the magnetic domain extending layer, where an extended magnetic domain is formed. The reproduction layer is magnetostatically coupled with the magnetic domain extending layer, so that the extended magnetic domain is transferred to the reproduction layer. This makes it possible to provide a magneto-optical recording medium characterized in moving of magnetic domain walls and extension of magnetic domains in good conditions, and increased signal intensity with a simpler structure.
摘要:
An optical disk of the present invention includes a transparent dielectric film formed on a light incident side of the disk on an opposite side of an optical recording film so as to sandwich the transparent substrate therebetween, for suppressing bimetallic effects caused by a difference in thermal expansion between an optical recording film formed on an optical recording surface and the transparent substrate, whereby changes in tilt against temperature changes can be suppressed. Further, by an optimal selection of a reflectance of the transparent dielectric film, unwanted reflection due to multi-interference can be reduced at the same time.
摘要:
A magneto-optical recording medium with a reproducing layer that exhibits in-plane magnetization at room temperature and that comes to exhibit perpendicular magnetization as temperature rises. The second shielding layer is used to block the magnetization of record bits other than a record bit to be reproduced from being copied on a signal reproducing area in the reproducing layer. Consequently, even in the case of high-density record bits in the recording layer, only the magnetization of the record bit to be reproduced is copied on the reproducing layer. Therefore, the application of the magneto-optical recording medium makes it possible to produce superior reproducing signals even in the case where the records bits with high density are formed on the recording layer.
摘要:
In order to provide a magneto-optical recording medium which can select a single recording magnetic domain in the recording layer accurately and expand and transfer the same to the reproducing layer, the magneto-optical recording medium is arranged in the following manner. That is, the magnetization direction of the reproducing layer is in-plane at room temperature and shifts to perpendicular at or above a predetermined temperature Ttrans.. The recording layer is a magnetic layer which is magneto-statically coupled to the reproducing layer and shows the perpendicular magnetization up to its Curie temperature. The magnetic mask layer is provided between the recording layer and reproducing layer, and the magnetization thereof is reduced to 0 (zero) at or above a predetermined temperature (Tm) which is at or above Ttrans.. The magnetization of the magnetic mask layer is larger than that of the recording layer at least in a range between room temperature and Ttrans..
摘要:
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.
摘要:
In an optical disk, grooves and lands serving as recording tracks are provided, the grooves are shaped so as to have virtually the same width, and in a first region, the two side walls of each groove wind in accordance with address information. The first region of the groove is formed with its leading portion located at the same angular position as the leading portion of at least one of the first regions of the adjacent grooves. Moreover, the winding portions corresponding to respective bits of the address information are formed in a manner so as to synchronize to the adjacent grooves. With this arrangement, it becomes possible to easily detect address information from the grooves and lands, and consequently to obtain an information reproducing signal with high quality.
摘要:
A magneto-optical memory medium according to the present invention comprises a reproducing layer, which has in-plane magnetization at room temperature and perpendicular magnetization when heated to above a predetermined temperature by a reproducing light beam; a recording layer, which is magnetostatically coupled to the reproducing layer; and an in-plane magnetized layer, provided adjacent to the recording layer, which has a Curie temperature at the above-mentioned predetermined temperature. In this medium, at temperatures below the predetermined temperature, signals recorded at high density in the recording layer are masked, and the above-mentioned magnetostatic coupling is suppressed, by magnetic masking by the in-plane magnetized layer. At temperatures above the predetermined temperature, however, within a domain forming part of the in-plane magnetized layer, the recording layer and the reproducing layer are magnetostatically coupled, and a recording bit of the recording layer is copied and expanded to a magnetic domain in the reproducing layer. Accordingly, with this medium, by reproducing from an expanded magnetic domain of the reproducing layer, even information from recording bits recorded at high density can be reproduced with high signal quality.
摘要:
A magneto-optical memory medium according to the present invention comprises a reproducing layer, which has in-plane magnetization at room temperature and perpendicular magnetization when heated to above a predetermined temperature by a reproducing light beam; a recording layer, which is magnetostatically coupled to the reproducing layer; and an in-plane magnetized layer, provided adjacent to the recording layer, which has a Curie temperature at the above-mentioned predetermined temperature. In this medium, at temperatures below the predetermined temperature, signals recorded at high density in the recording layer are masked, and the above-mentioned magnetostatic coupling is suppressed, by magnetic masking by the in-plane magnetized layer. At temperatures above the predetermined temperature, however, within a domain forming part of the in-plane magnetized layer, the recording layer and the reproducing layer are magnetostatically coupled, and a recording bit of the recording layer is copied and expanded to a magnetic domain in the reproducing layer. Accordingly, with this medium, by reproducing from an expanded magnetic domain of the reproducing layer, even information from recording bits recorded at high density can be reproduced with high signal quality.
摘要:
A magneto-optical memory medium is provided, on a substrate, with a first magnetic layer, which shows in-plane magnetization at room temperature and perpendicular magnetization above a certain temperature, and a second magnetic layer, which shows perpendicular magnetization within a range from room temperature up to its Curie temperature. The first magnetic layer is made up of alternating films of rare earth metals and transition metals. As a result, a magneto-optical memory medium can be provided which has a wide reproducing power margin, and which is able to prevent deterioration of characteristics due to repeated laser projection.