Abstract: The present invention relates to an apparatus and a corresponding method for determining write strategy parameters for recording data on an optical record carrier (100) and to an apparatus and a corresponding method for determining read parameters for reading data from an optical record carrier (100).

Abstract: A holographic storage medium, and a method and an apparatus for recording/reproducing data on/from the holographic storage medium. The method including: dividing a datapage into a plurality of regions; modulating the data into codewords having different on-pixel rates; and arranging the codewords in the plurality of regions, based on the different on-pixel rates.

Abstract: An optical pickup includes a first objective lens, a second objective lens having a numerical aperture different from that of the first objective lens, and an objective lens holder that holds the objective lenses. The first objective lens is attached to the objective lens holder via a spacer. The objective lens holder has a first fixture hole that receives the spacer with the first objective lens and a second fixture hole that receives the second objective lens. The first fixture hole is provided with a spacer supporting portion in which the spacer is inserted in a rotatable manner.

Abstract: A recording-and-reproducing apparatus for managing content data recorded on a removable recording medium includes: a device configured to acquire reproduction information required for reproducing the content data; a device configured to generate a first management file for individually managing the content data; a device configured to register control information for the content data in a second management file collectively managing the content data. Further, the apparatus includes a device configured to read out the control information in the second management file recorded on the recording medium; a memory in which the control information of the second management file read out by the read-out device is expanded; a device configured to compare the control information in the second management file expanded in the memory and the content data recorded on the recording medium; and a device configured to update the control information in the second management file expanded in the memory.

Abstract: An optical pickup includes a diffraction grating partitioned into three areas, in which the phase of periodic grating groove structure in an area is successively shifted from that in the adjacent area by 90°. In the generation of a differential push-pull signal, an amplification factor K for sub push-pull signals is varied depending on the type of the optical disk. By such composition of the optical pickup, amplitude deterioration of the tracking error signal accompanying displacement of the object lens is reduced.

Abstract: A lens-side grating diffracts, in a direction of an emitter-side grating, two laser beams passed through the lens-side grating from an optical disk side. The emitter-side grating substantially passes the laser beam having a longer wavelength than the other laser beam, and directs it to a desired region of the light receiving element. The emitter-side grating diffracts the laser beam having a shorter wavelength than the other laser beam to direct a +1st diffracted beam of the laser beam thus diffracted to the same light receiving region as a 0th diffracted beam of the other laser beam. Such a structure may be employed that a ?1st diffracted beam of the laser beam of the longer wavelength is directed to the same light receiving region as the 0th diffracted beam (passed beam) of the laser beam of the short wavelength.

Abstract: A transmitting/reflecting member for transmitting a laser beam of a first wavelength emitted from a first light source includes a first surface on which the laser beam of the first wavelength emitted from the first light source is incident and a second surface which faces the first surface and from which the laser beam of the first wavelength emerges, an angle ? defined between the first and second surfaces satisfies a condition of ??0, and a third-order astigmatism and a third-order coma aberration occurring when the laser beam of the first wavelength passes through the transmitting/reflecting member are both 5 m? or smaller. In this way, good recording performance or reproduction performance for various optical discs can be realized by focusing laser beams having different wavelengths on information recording surfaces of optical discs whose protective substrates differ in thicknesses.

Abstract: A recording medium, a method of creating a file of the recording medium, and a method and apparatus for reproducing the same are disclosed. In the recording medium including a plurality of recording layers, the method of creating a file of the recording medium includes continuously recording a stream data file within a first recording layer and a second recording layer among the plurality of recording layers, which are adjacent to one another, and forming a PlayList file so as to enable seamless playback of the recorded stream data file, wherein the PlayList file includes a presentation start time (IN-Time), at which playback begins, positioned in the first recording layer, and a presentation end time (OUT-Time), at which playback is ended, positioned in the second recording layer.

Abstract: A method to provide data storage services using one or more holographic data storage media disposed in a holographic data storage system operated by a data storage services provider, wherein the holographic data storage system comprises a light source, a spatial light modulator, and a plurality of holographic data storage media, wherein the method receives information provided by the data storage services customer, allocates a first holographic data storage medium for exclusive storage of information provided by the data storage services customer, defines an outer storage portion of the first allocated holographic data storage medium, and stores the information as one or more holograms encoded in the outer storage portion of the first holographic data storage medium.

Abstract: According to one embodiment, a write-once information recording medium includes a transparent resin substrate having concentric or spiral grooves and lands, and a recording film formed on the grooves and lands of the transparent resin substrate, wherein the recording film includes an organic dye layer containing a metal complex monomer and a metal complex polymer, a recording mark is formed in the organic dye layer by emission of a short-wavelength laser beam, and a light reflectance of the recording mark formed by emission of the short-wavelength laser beam is higher than that before emission of the short-wavelength laser beam, and the grooves wobble within a predetermined amplitude range.

Abstract: A recording medium on which data is recorded in units of clusters, a method and apparatus for reproducing data on the recording medium, and a method and apparatus for recording data on the recording medium, wherein each of the clusters includes a plurality of address fields, each address field includes 32-bit address unit number (AUN) address information, and the AUN address information includes a reserved area recorded on 4 bits, layer information, recorded on 3 bits, indicating a layer on which data corresponding to the AUN address information is recorded, and location information, recorded on 25 bits, indicating a location of the data corresponding to the AUN address information. In the recording medium of the present invention, a space in which addresses are recorded is expanded, thereby securing an address area in which addresses of data can be recorded in a data structure.

Abstract: A thermally assisted magnetic head comprises: a slider substrate, a first surface located opposite to a medium-facing surface, and side surfaces located between the medium-facing surface and the first surface; a magnetic head portion having a near-field light generator on the medium-facing surface side, and a magnetic recording element, the magnetic head portion being fixed to one of the side surfaces; and a laser diode element a relative position of which to the slider substrate is fixed so that emitted light thereof can reach the near-field light generator; a relation of ?in<?max is satisfied, where ?in is a wavelength of the emitted light from the laser diode element immediately before the emitted light reaches the near-field light generator, and ?max is a wavelength of irradiating light at which an efficiency of generation of near-field light generated from the near-field light generator is maximum.

Abstract: An optical information recording medium having a disk-shaped substrate formed with spiral grooves on one main surface, and having an optical reflection layer formed with grooves at the surface corresponding to the grooves of the substrate for reflecting a laser beam, an optical recording layer, a protective layer, and an optical transparency layer in this order on the main surface thereof. The optical information recording medium has a main information area and a sub-information area to the inner circumferential side thereof, in which the track pitch TrB of the grooves in the sub-information area is about 0.32 ?m or less, and the depth D of the grooves and the half-band width W of the grooves satisfy a relation represented by: W?2D+70, whereby the difference between the reflectivity at the land surface and the reflectivity at the groove surface in the sub-information area can be restricted to less than 30%, thereby preventing occurrence of mis-decipherment for BCA marks.

Abstract: A method for appropriately performing initialization of an optical information recording medium is provided, in which an initialization process is prevented from stopping so that yield from manufacturing the optical information recording medium is improved. In the initialization of an information layer with a burst cutting area (hereinafter referred to as “BCA”), at least one of the initialization conditions including a laser power, a linear speed, and a focal point of the laser beam for the information layer is changed between the BCA region and a data area that is an area for recording and reproducing information. In the initialization of an information layer without the BCA, at least one of the initialization conditions including a laser power, a linear speed, a focal point of the laser beam for the information layer and a feed pitch is changed between the area corresponding to the BCA and the area corresponding to the data area.

Abstract: Recording timing of a Data segment is set so as to avoid locating a wobble modulated portion as preformat information which indicates information on Physical segments of a recording type optical disc, and a recording start head position of the Data segment to be recorded in a track, in the same area of the track.

Abstract: An optical information recording medium which makes it possible to reduce the noise level, improve the C/N ratio and store record data for a long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Al as the main component and having Au added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer side.

Abstract: A turntable provided in the carousel changer has a plurality of trays provided around its rotating shaft. The turntable is provided with an annular rib including a plurality of recessed portions and a plurality of raised portions. A sensor is provided to have the rib passed therethrough and detects recessed portions and raised portions in the rib as the turntable is driven by a motor to rotate. The controller receives a detection result by the sensor and controls the motor based on the ratio of the widths of a raised portion and a recessed portion adjacent to each other in the rib. Therefore, this carousel changer can accurately stop a tray carrying an optical disk desired to be reproduced in a prescribed position.

Abstract: An optical information recording medium which is capable of performing high-density recording of record data, and storing the recorded data for a long time period such that the recorded data can be normally reproduced during the long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Cu as the main component and having Au added thereto, and disposed in the vicinity of the first recording film.

Abstract: The difference is detected between the outputs from first and second heads in a recording medium drive. The first head is positioned relative to the boundary between a first recording track and a separation track isolating the first recording track and a second recording track from each other. The second head is positioned relative to the boundary between the separation track and the second recording track. A position information specifying the positions of the first and second heads are generated based on the difference. The first and second heads follow the different boundaries, so that the outputs of the first and second heads reliably vary. The difference between the outputs thus reliably changes. An accurate position information can be generated based on the difference. The position information may be utilized in tracking servo control, for example. This enables establishment of the tracking servo control with a higher accuracy.

Abstract: An optical information recording medium which makes it possible to reduce the noise level and improve the C/N ratio. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Zn as the main component and having Cu added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer side.