Abstract: A thermally assisted magnetic head has a medium-facing surface facing a magnetic recording medium; a near-field light generator disposed on a light exit face in the medium-facing surface; a magnetic recording element located adjacent to the near-field light generator; and a light emitting element disposed so that emitted light thereof reaches the near-field light generator; the near-field light generator is comprised of a cusp portion and a base portion; when ?in represents a wavelength of the emitted light from the light emitting element immediately before the emitted light reaches the near-field light generator, an intensity of near-field light generated when the material forming the cusp portion is irradiated with the light of the wavelength ?in is stronger than an intensity of near-field light generated when the material forming the base portion is irradiated with the light of the wavelength ?in.

Abstract: In an optical disk recording method adapted to record information on an optical disk by a light beam incident to the disk in one direction, the disk has a plurality of rewritable recording layers including a first layer nearest to a plane of incidence and a second layer distant from the plane of incidence. A target layer where user data is to be recorded is specified from the first and second layers. Prior to recording the user data to a requested address in the second layer when the target layer is the second layer, a partial region of the first layer corresponding to a same radial position as the requested address in the second layer is set to either a non-recorded state or a recorded state depending on a characteristic of the disk. The user data is recorded to the requested address in the target layer.

Abstract: At least a first recording layer (L0 layer) and a second recording layer (L1 layer) are provided. The first recording layer is disc-shaped, and has a first recording track path formed for recording recording information. The second recording layer is disc-shaped, arranged on the first recording layer and has a second recording track path formed in an opposite direction to the first recording track path for recording recording information. On edge parts on the outer circumference sides of the first recording layer and the second recording layer, first buffer areas (104-0 and 104-1) are further provided for preventing a recording or reproducing position from deviating from the first recording layer or the second recording layer and for interlayer jump. At least a part of the first buffer area is previously formed as a pre-recording area by an embossed pit (in the case of DVD-RW) or by a pit formed by recording laser irradiation (in the case of DVD-R).

Abstract: An optical transducer includes an optical element for directing an electromagnetic wave to a focal region and a metallic nano-structure having a longitudinal axis non-parallel to an electric field of the electromagnetic wave. The optical element for directing an electromagnetic wave may comprise one of a solid immersion lens, a solid immersion mirror, or a planar waveguide. The metallic nano-structure may comprise a metallic pin. The metallic nano-structure may be structured and arranged for resonant coupling of energy into a recording medium.

Abstract: The invention relates to a record carrier (1) comprising an area for storing data, the record carrier adhering to a pre-defined, standardized condition with respect to a physical parameter. The record carrier comprises parameter information on the physical parameter, which parameter information is of a higher precision than the precision of the physical parameter mentioned in the pre-defined, standardized condition. Using this high precision parameter information, it is possible to derive the exact position of a visible image pixel data making up a label. This parameter information thus enables a recorder to write a visible label on the record carrier according to the invention.

Abstract: First data representing user data and third data use the same error correction codes. The first data has a first error correction block structure and the third data has a second error correction block structure. That is to say, the first data and the third data have their respective error correction block structures proper for them. In particular, the recording density of the third data is made less dense than the recording density of the first data, and the number of correction codes in the first error-correction block is set at a multiple of m whereas the number of correction codes in the second error-correction block is set at n/m times the number of correction codes in the first error-correction block so that a data-piece count in the second error-correction block is also n/m times a data-piece count in the first error-correction block. As a result, it is possible to provide a good technique of recording shipping-time information onto a high-recording-density disc.

Abstract: A method for writing information on a highly coercive recording medium stably with an electric field applied through a metal probe and with a magnetic field applied from external and an information recording system that employs the method. The recording medium includes a substrate, a first ferromagnetic layer formed on the substrate, a nonmagnetic layer formed on the first ferromagnetic layer, and a second ferromagnetic layer formed on the nonmagnetic layer. The coercivity Hc2 of the second ferromagnetic layer is larger than that Hc1 of the first ferromagnetic layer. A magnetic field H is applied to the magnetic recording medium from a magnetic pole to change the magnetizing direction of the first ferromagnetic layer to a direction of the applied magnetic field, then a positive or negative voltage V is applied between the metal probe and the magnetic recording medium to change the quantum well level energy between the first and second ferromagnetic layers, thereby inducing an exchange magnetic field HE.

Abstract: A dual-stack recordable optical data storage medium wherein a focused radiation beam having a wavelength ? enters through an entrance face of the medium during recording. The medium includes a substrate, a first recording stack L0, including a recording layer, the first recording stack L0 having an optical reflection value RL0 and an optical absorption value AL0 at the wavelength ?, and a second recording stack L1 including a recording layer, the second recording stack L1 having an optical reflection value RL1 and an optical absorption value AL1 at the wavelength ?, and a transparent spacer layer between the recording stacks. The second stack is closer to the entrance face than the first stack. By fulfilling the formula AL1?1?Rmin??(Rmin/RL0), where Rmin is the minimum effective optical reflection value for each recording stack, full compatibility is achieved with a read only version of the medium.

Abstract: According to the invention, an optical disc reproducing apparatus includes a housing for: a reading section which reads data recorded on an optical disc, a data storing section and a reproducing section which reproduces the stored data. A reference discal unit outside the housing rotates at a pre-determined reference rotational speed and direction. An operation discal unit mounted on the reference discal unit, may rotate at a desired speed and direction. A detection discal unit is coupled with the operation discal unit, to rotate in sync with the operation discal unit. First and second detecting sections detect a rotational speed and direction of the detection discal unit and the reference discal unit, respectively. A control section determines the rotational speed and direction of the detection discal unit based on detected results and controls the reading section, the storing section and the reproducing section, thereby performing a desired data reproduction.

Abstract: If regeneration is not performed normally when data is regenerated from a medium, a read retry processing unit changes the intensities of the laser beam and of the regeneration magnetic field respectively to prearranged stages to perform the regeneration again. A regeneration condition change unit remembers the regeneration sector number for one read command from the higher order. When retry occurs, the regeneration condition change unit counts the number of the sectors for each stage which can be regenerated at each stage, and by providing a coefficient for each stage in advance, changes the default regeneration condition using the sum of products of the coefficients and the number of the counted regenerable sectors.

Abstract: A device for storing optical discs is disclosed. The device includes a housing, a carousel arranged in the housing for movement relative to the housing, the carousel having a plurality of storage compartments each for storing a disc, an opening in the housing through which a disc can pass, drive means for driving the carousel relative to the housing to align each of the storage compartments and a disc stored in that storage compartment in registry with the opening, and an ejection system to eject a disc from a storage compartment and through the opening in said housing. The ejection system is powered by a motor and a clutch system, and control means is provided to cause said carousel to rotate and to cause the ejection system to operate as instructed by a user.

Abstract: A method for reproducing contents of an information recording medium, having at least one data zone, is disclosed, wherein a determination is made as to whether the entirety of a requested reproduction zone included in the data zone of the information recording medium contains data, or at least a part thereof belongs to a non-recorded zone at a predetermined timing on or after a point in time when the reproduction request is made. Then, when a reproduction request is made for a reproduction zone including such non-recorded zone, it is subsequently determined at the predetermined timing that the non-recorded zone is present in the reproduction zone, and an error process starts.

Abstract: A record mark is formed on a master disc DS. The record mark is formed substantially along a spiral standard locus, but a record mark position is displaced in a direction crossing the spiral standard locus according to record data. A wobble is formed such that the average value of the displacement of the record mark position is zero for each predetermined data unit with the standard locus as a reference.

Abstract: In order to stably carry out reproduction of information in an optical disc medium (10) using a PRML (partial-response maximum-likelihood) method for reproducing the signal, the optical disc medium (10) has not only a data recording area (14) where data is recorded at high density but also a system information recording area (16) where information is recorded at low density and binary equalizing/reproducing can be easily made. Information required to circuit setting is recorded in the system information recording area.

Abstract: A magnetism test method for a tray-type optical drive is disclosed. A preliminary input voltage is provided to a DC motor of the tray-type optical drive for performing a preliminary ejection on a tray and a magnetic clamper of the tray-type optical drive. Then, a test voltage smaller than the preliminary input voltage is provided to the DC motor to partially eject the tray, in which the tray is ejected to a point short of the complete distance of ejection. When the incomplete distance is longer than a predetermined distance, the magnetic force of the magnetic clamper is determined to abnormal.