Abstract: The magnetic recording medium is a particulate magnetic recording medium for heat-assisted recording, as well as includes a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic organic material support and a heat-diffusing layer of higher thermal conductivity than the magnetic layer between the nonmagnetic organic material support and the magnetic layer.

Abstract: The magnetic recording medium comprises a backing layer including a first magnetic layer, a second magnetic layer which is formed over the first magnetic layer, is ferrimagnetic and is magnetized in a direction opposite to the first magnetic layer, and a third magnetic layer formed over the second magnetic layer and magnetized in a direction opposite to the second magnetic layer; and a perpendicular magnetic recording layer for recording magnetic information formed over the backing layer. Antiferromagnetic exchange interconnection is formed between the first magnetic layer and the second magnetic layer and between the second magnetic layer and the third magnetic layer.

Abstract: A method for recording to and reproducing from a magnetic recording medium is disclosed in which an information signal is recorded and reproduced under thermal assist, and which allows one to stably record tiny recording magnetic domains and stably detect a reproduction output signal during reproduction when recording at high density. In this method, the temperature distribution in the information recording and reproduction region of the magnetic recording medium is controlled to be different during recording and during reproduction. This allows recording magnetic domains to be stabilized even when recording fine marks, and greatly increases the recording density because stable detection is possible without reducing the reproduction signal amplitude.

Abstract: A method for manufacturing a magneto-optical recording medium in which reading of recorded information is performed through domain wall displacement in a reproduction layer is provided, in which magnetic separation of groove side-wall portions is performed more reliably; as a result a magneto-optical recording medium with satisfactory recording and reproduction characteristics can be provided.

Abstract: A magneto-optic recording medium has a stacked structure composed of a memory layer, a domain wall displacement layer having domain wall-resistant magnetism smaller than the memory layer, and a switching layer having a lower Curie temperature than these layers interposed between these layers. A recording surface of the magneto-optic recording medium is divided into a plurality of tracks of a predetermined track pitch. A domain wall displacement layer has a recording track region limited in a track width direction in a central portion of each track. A magnetized state of a vertically magnetized memory layer is only transferred in the recording track region. A buffer region is magnetically oriented in an in-plane direction at a predetermined temperature or lower and is vertically magnetized at the predetermined temperature or higher.

Abstract: A first dielectric layer 3, a multilayer magnetic film 10 in which a first magnetic layer 4 having perpendicular magnetic anisotropy at room temperature, a second magnetic layer 5 having inplane magnetic anisotropy at room temperature, and a third magnetic layer 6 having perpendicular magnetic anisotropy at room temperature are sequentially laminated, a second dielectric layer 7, a reflective layer 8, and a protective layer 9 are sequentially laminated onto one principal plane of a disk substrate 2 on which a land and a groove exist, thereby forming a magnetooptic disk 1. Saturation magnetization of the second magnetic layer 5 is set to a range from 8.80×10?2 to 1.76×10?1 Wb/m2. A gas pressure upon film creation of the second magnetic layer is set to a range from 0.6 to 3.0 Pa. A content ratio of Co in the third magnetic layer 6 is set to a range from 15 to 17 atom %.

Abstract: A magneto-optical recording medium, including a recording layer, a transfer control layer magnetically coupled to the recording layer, and a reproduction layer. The recording layer includes a recording magnetic domain in which information is recorded by a magnetization direction vertical to the surface of the film. The reproduction layer includes a reproduction magnetic domain in which information in the recording layer is transferred and formed as a magnetization direction by magnetic coupling. The direction of magnetization of the recording magnetic domain of the recording layer and the direction of magnetization of the transfer control layer corresponding to the recording magnetic domain are in opposite directions in at least part of the range of temperatures less than a transfer temperature where the reproduction magnetic domain is transferred to the reproduction layer. The Curie point temperature of the transfer control layer is higher than this transfer temperature.

Abstract: A magnetic recording medium includes a positioning magnetic layer having magnetism and is used for positioning the optical head. The magnetic recording medium recording method includes a first step of moving the magnetic head to a predetermined position on the magnetic recording medium, a second step of supplying a positioning magnetic field Hr from the magnetic head to the positioning magnetic layer for positioning the optical head, and a third step of outputting positioning light Pr from the optical head for positioning the optical head, producing a magnetic optical effect with respect to the positioning magnetic layer magnetized by the positioning magnetic field Hr, and controlling the optical head so as to face a position of the magnetic head based on a detection result of the magnetic optical effect.

Abstract: A magnetooptic recording medium has at least a recording layer for recording data and a reproducing layer for reproducing the data recorded in the recording layer onto a substrate and reproduces the data by setting a proper reproducing laser power upon reproduction. According to the magnetooptic recording medium, magnetizing directions of a buffer area, a sector address area, and a gap area which are sandwiched between data areas in which the data is recorded are uniformly magnetized in the recording direction.

Abstract: In a magneto-optical recording medium, a first magnetic layer is made of a material using a Gd—Fe film or a Gd—Fe—Co film as a base so that a magnetic field normalized based on saturation magnetization of a magnetic domain wall driving field can be larger than 1, and an element concentration ratio (at. % ratio) of Gd to Fe or Fe—Co is set in a range of 28.0?Gd?29.0. A second magnetic layer is made of a material using a Tb—Fe film or a Dy—Fe film as a base, to which a nonmagnetic element such as Al or Cr, and Co are added. A third magnetic layer is made of a material using a Tb—Fe—Co film or a Dy—Fe—Co film as a base, and an element concentration ratio (at. % ratio) of Tb or Dy to Fe—Co is set in a range of 23.5?Tb?25.5 or 25.5?Dy?28.5.

Abstract: A magneto optical recording medium capable of stable recording and readout using a DWDD system is provided. The magneto optical recording medium of the present invention comprises an optical disk substrate and a multilayer recording film comprising essentially a readout layer, an intermediate layer, and a recording layer successively formed on top of the substrate. The readout layer has a smaller magnetic domain wall coercivity than the recording layer. The intermediate layer comprises a magnetic layer whose Curie temperature is lower than the readout layer and the recording layer. A recorded/readout magnetic domain corresponding to recorded/readout information is formed only in a groove area of the optical disk substrate. The thickness of the recording film at the boundary between mutually adjacent recording track areas is smaller than the thickness of the recording film in the center portions of the recording track areas.

Abstract: There is provided a domain wall displacement type magneto-optical recording medium and a recording method that allow signals recorded with a high density over the limit of resolution of optical systems to be regenerated without increasing complexity of a recording and regenerating apparatus or narrowing an operation margin even if a substrate having address information or the like incorporated therein is used. An information track has portions used for recording and regenerating information in the form of a magneto-optical signal and portions having irregularities to provide address information or servo information formed therein alternately arranged, and directions of magnetization of the third magnetic layer are polarized in one direction above the portions having the irregularities.

Abstract: An optical disk is made of tracks that are magnetically separated from one another by scanning a focused light beam over lands between tracks at a predetermined power and annealing to lower the magnetic anisotropy of a magnetic layer on the lands, and is provided with a power testing region comprising one or more tracks for finding the predetermined annealing power at the location of at least one of the group consisting of a specific region within the data region, a region more to the inner side than the innermost track of the data region, and a region more to the outer side than the outermost track of the data region. Thus, an optical disk and a manufacturing method for the same can be provided that have a high recording density and with which annealing can be implemented in a short time and at the correct annealing width.

Abstract: A magnetooptic recording medium has at least a recording layer for recording data and a reproducing layer for reproducing the data recorded in the recording layer onto a substrate and reproduces the data by setting a proper reproducing laser power upon reproduction. According to the magnetooptic recording medium, magnetizing directions of a buffer area, a sector address area, and a gap area which are sandwiched between data areas in which the data is recorded are uniformly magnetized in the recording direction.

Abstract: A magneto-optical disk having a small-sized diameter and a large capacity and able to record and reproduce disk discrimination information, and a recording method and a reproducing method of the same, wherein a recording layer including a main recording region in which a first information is recorded, a sub recording region in which a second information including the disk discrimination information is recorded, and a buffer region formed between the main recording region and the sub recording region and in which a third information is recorded is provided on a substrate, the second information is recorded by a mark array formed in stripe shapes in the sub recording region and the buffer region, a plurality of marks constituting the mark array are obtained by changing the magnetization state of the recording layer, and the third information is reproduced by a modulation signal of a reflection ratio along a circumferential direction of the disk.

Abstract: A magnetic recording medium for thermally-assisted recording is a bilayer of a high-coercivity, high-anisotropy ferromagnetic material like FePt and a switching material like FeRh or Fe(RhM) (where M is Ir, Pt, Ru, Re or Os) that exhibits a switch from antiferromagnetic to ferromagnetic at a transition temperature less than the Curie temperature of the high-coercivity material. The high-coercivity recording layer and the switching layer are exchange coupled ferromagnetically when the switching layer is in its ferromagnetic state. To write data the bilayer medium is heated above the transition temperature of the switching layer. When the switching layer becomes ferromagnetic, the total magnetization of the bilayer is increased, and consequently the switching field required to reverse a magnetized bit is decreased without lowering the anisotropy of the recording layer. The magnetic bit pattern is recorded in both the recording layer and the switching layer.

Abstract: A magneto-optical recording medium includes at least three magnetic layers of a first magnetic layer, a second magnetic layer and a third magnetic layer, in which a recording mark recorded in the third magnetic layer by irradiation of a light beam is transferred through the second magnetic layer formed above the third magnetic layer to the first magnetic layer formed above the second magnetic layer for reproduction, wherein the first magnetic layer is provided with a high temperature mask having no spontaneous magnetization in a region where its temperature becomes a predetermined temperature or higher.

Abstract: An optical recording medium has spirally or concentrically formed tracks and is capable of an optical recording. The optical recording medium includes a data recording and reproducing area divided into a plurality of zones in the radial direction. One zone is divided into a plurality of sectors respectively having an address part including pits having address information and a data part only composed of grooves. The number of sectors forming each zone is different. An optical disc is formed so that an average reflectance Iadd of the address part and an average reflectance Idata of the data part satisfy a relation expressed by 0.7≦(Iadd/Idata)≦1.3 or 0.8≦(Iadd/Idata)≦1.2.

Abstract: A magneto-optical recording medium wherein a magnetic domain is transferred from a recording layer to a reproducing layer is expanded. When the reproducing layer is formed, the composition ratio of a transition metal at a surface of the reproducing layer on a reproducing light beam-incoming side is made to be higher than the composition ratio of the transition metal at a surface of the reproducing layer on a side opposite to the reproducing light beam-incoming side. Thus, the operation to expand the magnetic domain, transferred from the recording layer to the reproducing layer, is performed smoothly, and the jitter of the reproduced signal is reduced to improve signal-to-noise ratio (S/N) of the reproduced signal.

Abstract: A magneto-optical recording medium, including a recording layer, a transfer control layer magnetically coupled to the recording layer, and a reproduction layer. The recording layer includes a recording magnetic domain in which information is recorded by a magnetization direction vertical to the surface of the film. The reproduction layer includes a reproduction magnetic domain in which information in the recording layer is transferred and formed as a magnetization direction by magnetic coupling. The direction of magnetization of the recording magnetic domain of the recording layer and the direction of magnetization of the transfer control layer corresponding to the recording magnetic domain are in opposite directions in at least part of the range of temperatures less than a transfer temperature where the reproduction magnetic domain is transferred to the reproduction layer. The Curie point temperature of the transfer control layer is higher than this transfer temperature.

Abstract: A magneto-optical recording medium includes a substrate and a reproducing layer and a recording layer provided on the substrate. A method for reproducing information from the magneto-optical recording medium includes increasing the temperature of the magneto-optical recording medium irradiated by laser light and included in an inside part of a light spot to a temperature range including a temperature at which the saturated magnetization of at least the recording layer or the reproducing aid layer is maximized, and reproducing the information only from a temperature region within the light spot where the information can be transcribed from the recording layer by a magnetic coupling force between the recording layer and the reproducing layer, by transcribing the recording magnetic domain from the recording layer onto the reproducing layer.

Abstract: A magneto-optical recording medium comprising four magnetic layers including a mask layer, a reproduction layer, an intermediate layer and a recording layer, wherein the reproduction layer and the recording layer each have a direction of easy magnetization extending in a layer stacking direction at room temperature, the mask layer and the intermediate layer each have a direction of easy magnetization extending in an in-plane direction at room temperature, the mask layer, the reproduction layer, the intermediate layer and the recording layer have Curie temperatures Tc1, Tc2, Tc3 and Tc4, respectively, which satisfy relationships of Tc3<Tc2, Tc3<Tc4 and Tc3<Tc1, and the intermediate layer is a rare-earth-rich magnetic layer.

Abstract: A magnetic recording medium includes: a disk substrate; and a recording layer having magnetic anisotropy along a direction perpendicular to a surface of the disk substrate. The recording layer is formed so that a product of a coercive force Hc and saturated magnetization Ms of the recording layer (Ms·Hc) at room temperatures is increased sufficiently so that a shortest mark length of the recording layer can be decreased to a desired value.

Abstract: On a disk-shaped substrate in which a predetermined region ranging in a radial direction is used as a data region for recording/reproduction, a first dielectric layer, a magnetic layer, and a second dielectric layer are provided. The data region includes recording/reproducing tracks composed of a plurality of discontinuous grooves or lands ranging from an innermost track to an outermost track. Magnetic anisotropy of each of magnetic layers positioned between the respective recording/reproducing tracks is reduced to a level lower than that of magnetic anisotropy of the magnetic layers positioned on the recording/reproducing tracks, so that the magnetic layers are magnetically separated only between the recording/reproducing tracks and not magnetically separated in flat portions without grooves. Thus, reflectance is even in the flat portions, thereby allowing tilt detection.

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: Using MSR (magnetically induced super-resolution) technology, a read-head field is applied to a magneto-optical recording medium when reading an information signal from a recording layer of a magneto-optical recording medium, in order to magnetize the read light-irradiated magnetic layer in one direction in a part of an area within the read light spot. The magneto-optical recording medium using MSR technology adopts the on-land recording method in which an information signal is written to the land, which enables read of an information signal by the MSR technology with a smaller read-head field.

Abstract: An optical disk is made of tracks that are magnetically separated from one another by scanning a focused light beam over lands between tracks at a predetermined power and annealing to lower the magnetic anisotropy of a magnetic layer on the lands, and is provided with a power testing region comprising one or more tracks for finding the predetermined annealing power at the location of at least one of the group consisting of a specific region within the data region, a region more to the inner side than the innermost track of the data region, and a region more to the outer side than the outermost track of the data region. Thus, an optical disk and a manufacturing method for the same can be provided that have a high recording density and with which annealing can be implemented in a short time and at the correct annealing width.

Abstract: A magnetooptic recording medium has at least a recording layer for recording data and a reproducing layer for reproducing the data recorded in the recording layer onto a substrate and reproduces the data by setting a proper reproducing laser power upon reproduction. According to the magnetooptic recording medium, magnetizing directions of a buffer area, a sector address area, and a gap area which are sandwiched between data areas in which the data is recorded are uniformly magnetized in the recording direction.

Abstract: A magneto-optical recording medium comprising a recording magnetic layer made of a perpendicularly magnetized film and a multilayer reproducing film, wherein the multilayer reproducing film has two reproducing magnetic layers which are in a in-plane magnetized state at room temperature and shift to a perpendicularly magnetized state with a rise in temperature and an in-panel magnetized layer disposed between the two reproducing magnetic layers, which is in an in-plane magnetized state from room temperature to a Curie temperature and has a lower Curie temperature than the recording magnetic layer and the reproducing magnetic layers.

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 magnetooptical recording medium includes a first magnetic layer, a second magnetic layer whose Curie temperature is lower than that of the first magnetic layer, and a third magnetic layer, comprising a vertically-magnetizing film, whose Curie temperature is higher than that of the second magnetic layer. The first magnetic layer, the second magnetic layer and the third magnetic layer are in a state of exchange coupling with each other at a portion of a vertically-magnetizing film. A domain walls formed in the first magnetic layer moves when the temperature of the medium has been raised to at least the Curie temperature of the second magnetic layer.

Abstract: Information is recorded on a light transmission material such as a light transmission substrate (1) or a light transmission protecting film as a change of refractive index or a change of extinction coefficient or a change of transmittance or a change of reflectance

Abstract: A magneto-optical recording medium including a substrate, a reproducing layer formed on the substrate, an intermediate layer formed on the reproducing layer, a recording layer formed on the intermediate layer and a high magnetization layer formed on the recording layer. The intermediate layer is made of a non-magnetic material, and set at a prescribed thickness so that a leakage magnetic field from the recording layer to the reproducing layer is so distributed that the intensity thereof is increased from an end to the center of its domain. The high magnetization layer is made of an alloy or a multilayer film of a noble metal and a transition metal having saturation magnetization stronger than that of the recording layer under a reproducing temperature. At room temperature, the coercive force of the recording layer is larger than that of the high magnetization layer. Consequently, transfer/enlargement from the recording layer to the reproducing layer is readily caused in this magneto-optical recording medium.

Abstract: A magneto-optical recording medium includes a reproducing layer. When a laser beam is irradiated to the magneto-optical recording medium, a magnetic domain in a recording layer is transferred, through enlargement, to a reproducing layer increased in temperature. The magneto-optical recording medium further includes a calibration area that has a calibration magnetic domain recorded in a predetermined pattern in the recording layer. In a reproducing apparatus, a laser beam of an optical head is adjusted in output depending upon a reproduced signal obtained by reproducing the calibration magnetic domain.

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.