Abstract: Fabrication of an MO disc, the formation of a master pattern of servo and track information, and the subsequent transfer of that pattern to a series of pits and grooves on a substrate. On top of that substrate, at least one sacrificial layer is provided atop a relatively hard layer. The recording stack may be provided with both silicon nitride and silicon dioxide top layers, with the silicon dioxide layer acting as a sacrificial layer to ensure that the hard layer, of silicon nitride, remains at the end of the process. A layer of aluminum or aluminum alloy may be deposited, with the aluminum plugs filling the grooves and pits (created by the embossed servo information) to a level higher than any of the adjacent layers of silicon dioxide, silicon nitride, or similar dielectric layer.

Abstract: A storage medium stores information on a plurality of tracks formed thereon, each of the tracks being divided into a plurality of sectors. The storage medium includes a physically formed sector beginning identifier provided at a leading portion of each sector, and an information storing portion. The information storing portion, another sector address portion at the trailing end of the information storing portion, includes at least one sector address portion at a leading end of the information storing portion, another sector address portion at the trailing end of the information storing portion, and a data portion provided between the two sector address portions.

Abstract: A reconfigurable and stationary element for the engineering of the wavefront of electromagnetic radiation. The element includes a phase change material that may be reversibly transformed between its crystalline and amorphous states. By forming a gradient in crystallinity, a phase taper may be stored in the phase change material of the instant element. The phase taper provides control of the phase angle of reflected or reradiated electromagnetic radiation. An incident wavefront of electromagnetic radiation interacts with the instant element and is reradiated with controlled propagation characteristics imposed by the stored phase taper. The instant element may provide non-specular reflection, beam steering, focusing, defocusing, symmetrical and asymmetrical cross section effects, and wavefront correction. In a preferred embodiment, a pattern of amorphous marks is formed within a crystalline matrix of phase change material.

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 magneto-optical recording medium includes at least a reflective layer and a recording layer formed in this order on a substrate, in which record and reproduction of information are carried out by irradiating the medium with laser beam from a recording layer side. The reflective layer includes two or more thin film layers different in surface roughness, of which one near the substrate has a surface tension smaller than a surface tension of one near the recording layer. The medium exhibits a coercive force and CNR of a recording layer of a magneto-optical recording medium to realize high density recording by contriving the constitution of the recording layer.

Abstract: Structures of storage media for optical storage systems, especially for systems in the near-field configuration to couple radiation between the optical head and the media at least in part by evanescent fields.

Abstract: It is an object of the present invention to provide a method for recording information in an optical recording medium with a good direct overwriting characteristic. The method for recording information in an optical recording medium according to the present invention forms record marks in a recording layer containing a phase change material by modulating the power of a laser beam between a plurality of power levels including a recording power Pw, an erasing power Pe and ground power Pb. The erasing power Pe is set to a level within a region where a reflection coefficient of a region between neighboring record marks approaches a reflection coefficient of the record mark as the erasing power Pe increases. As a result, a good overwriting characteristic can be obtained when data are recorded at a high linear velocity.

Abstract: A magneto-optical recording medium includes a magnetic reproducing layer having an axis of easy magnetization in a direction perpendicular to its layer surface, a magnetic intermediate layer formed on the magnetic reproducing layer and having an axis of easy magnetization in a plane at a room temperature, and a magnetic recording layer formed on the magnetic intermediate layer and having an axis of easy magnetization in a direction perpendicular to its layer surface. The magnetic reproducing layer has a composition of GdxFeCoy where 22 at %≦x≦25 at % and 16 at %≦y≦23 at %.

Abstract: An optical recording medium is capable of linear recording in a photon mode. An organic material changed in molecular orientation on light illumination to exhibit birefringence is used as a recording material. For example, a recording layer having, as a recording material, an organic material changed in molecular orientation caused by trans-cis rearrangement, is changed in birefringence with changes in the molecular orientation of the organic material. The recording system which utilizes the changes in the molecular orientation of the organic material has linear characteristics and gives outputs different depending on e.g., the degree or the angle of orientation, thus enabling multi-valued recording.

Abstract: A magneto-optical recording medium which is capable of improving the floating stability and the travelling stability of an optical head of a slider type, by forming a lubricating protective layer having a transparent/translucent property on a surface on which the optical head is placed.

Abstract: Tracking control is carried out by a push-pull method or by mechanical feed at the time of recording signals, and tracking control is carried out by a phase difference tracking method at the time of reproduction. Thus, a phase change type optical disk which enables phase difference reproduction and is erasable may be realized. In a phase change type optical disk having a phase difference reproduction structure, servo mechanism at the time of reproducing signals may be stably controlled by causing the reflectance of a blank portion to be higher than the reflectance of a recording mark portion.

Abstract: A magneto-optical recording medium in a near-field optical storage system is provided. A flying optical head is suspended over the medium by a cushion of gas. The medium includes a magneto-optical recording layer including at least one recording track for magneto-optical recording of information. A tracking feature is associated with the recording track. An upper transparent dielectric layer is provided having an upper surface which is substantially planar over a recordable area of the medium above the recording track and the tracking feature. A reflector layer is positioned below the magneto-optical layer above a base substrate.

Abstract: Embodiments of the invention generally provide a method for optimizing the performance of a hydrodynamic bearing used with a disc drive. In one embodiment, the invention provides a method to determine a range of dimension values associated with at least one hydrodynamic groove disposed on the hydrodynamic bearing to improve at least one or more hydrodynamic bearing performance factors. In another embodiment, the invention provides a hydrodynamic bearing having at least one cross-section dimension associated with an optimum radial stiffness for at least one hydrodynamic groove shape. In another embodiment, the invention provides a hydrodynamic bearing having at least one groove pitch ratio associated with an optimum radial stiffness for at least one hydrodynamic groove shape.

Abstract: A storage medium stores information on a plurality of tracks formed thereon, each of the tracks being divided into a plurality of sectors. The storage medium includes a physically formed sector beginning identifier provided at a leading portion of each sector, and an information storing portion. The information storing portion, another sector address portion at the trailing end of the information storing portion, includes at least one sector address portion at a leading end of the information storing portion, another sector address portion at the trailing end of the information storing portion, and a data portion provided between the two sector address portions.

Abstract: A magneto-optic recording medium, which has a multilayered magnetic layer including a recording layer and a reproducing layer, is capable of reproducing a micro mark by utilizing a temperature distribution generated by laser beam irradiation for transferring a domain wall from the recording layer to the reproducing layer and by utilizing the movement of the domain wall. Each of the recording areas is arranged so that the recording area is adjacent to a magnetic partition area of a neighboring track. The recording areas and the magnetic partition areas are arranged alternately in one track, and an edge of a record mark is positioned in the recording area. Preferably, when reproducing information recorded on this magneto-optic recording medium, two neighboring tracks are irradiated with one laser beam for reproduction so that high speed transmission can be performed.

Abstract: A laminated structure which has a substrate formed of a synthetic resin or glass and a silicon carbide coating layer formed by sputtering, wherein the light transmittance of the silicon carbide coating layer is 80% or less. Preferably, the silicon carbide coating layer has a light reflectance of 10 to 50%, the synthetic resin is polycarbonate, the impurity ratio on the surface of the silicon carbide coating layer is 1.0×1012 atoms/cm2 or less, and the silicon carbide layer has a thickness of 15 to 100 nm. The laminated structure is suitable for a recording medium such as a CD-ROM and a DVD-ROM since it has a silicon carbide layer excellent in oxidation resistance, chlorine resistance, moisture resistance, and the like.

Abstract: Magneto-optical storage media designed for optical storage systems such as disk drives with optical flying heads. Dielectric layers are designed and implemented to maximize optical coupling between the flying optical head and the media and to reduce variations of signals with flight height of the flying optical head.

Abstract: There are provided a magneto-optical disk, a super-resolution magneto-optical disk and a domain wall moving magneto-optical disk whose cross-talk, cross-write and cross-erasure are suppressed and whose recording density is improved. A recording magnetic layer formed on a land is shut off magnetically from the recording magnetic layer formed on a groove and thermal diffusion in the track direction is suppressed, by selectively oxidizing a magnetic layer formed on a side wall between the land and the groove.

Abstract: A laser beam is directed from an optical head (40) while an alternating magnetic field is applied from a magnetic head (52). A reproduced signal from the optical head (40) is input to a reproduced signal detecting circuit (45) through a reproduced signal amplifying circuit (41). The detected signal (CK) of discontinuous regions provided at prescribed intervals in the groove of a magneto-optical recording medium (1) is input to an external synchronous signal generating circuit (46) and, in response, an external synchronous signal (SYN) is generated. In synchronization with the external synchronous signal (SYN), the reproduced signal detecting circuit (45) calculates a difference between the reproduced signal generated when a magnetic field for magnetic domain magnification is applied and the reproduced signal generated when a magnetic field for magnetic domain erasure is applied. The difference is detected as a reproduced signal (RF).

Abstract: A magneto-optic recording medium includes a second auxiliary magnetic film, a first auxiliary magnetic film and a magneto-optic recording film on a substrate. The auxiliary magnetic films change from in-plane magnetization to vertical magnetization at critical temperatures TCR1 and TCR2. Since they have the relation TCR1>TCR2, the magnetic domain transferred from the magneto-optic recording film to the first auxiliary magnetic film at the time of reproduction is expanded in diameter and is transferred to the second auxiliary magnetic film when the temperature profiles of the auxiliary magnetic films inside an optical spot are utilized. The magnetic domain of the magneto-optic recording film can be expanded and transferred, too, by means of magnetostatic coupling by using a non-magnetic film in place of the first auxiliary magnetic film. Pulse reproduction light subjected to power modulation in synchronism with a reproduction clock can be used at the time of reproduction.

Abstract: A magneto-optical recording medium comprises a protective layer having a self-lubricating property formed at an uppermost layer on a side opposite to a substrate wherein a recording or reproducing light beam comes into a side of the protective layer. The thickness and the refractive index of the protective layer are selected under predetermined conditions depending on whether or not evanescent light is transmitted through the protective layer. It is possible to perform high density recording and reproduction thereof by utilizing the evanescent light. A protective layer having a self-lubricating property may be also formed on a bottom surface of an optical head opposing to the optical recording medium. Even when the optical head contacts with the surface of the optical recording medium, the sliding scratch scarcely occurs, because the optical head smoothly glides on the recording medium surface.