Fujitsu Corporation

Texas Instruments Japan Limited

Fujitsu Limited & Texas Instruments Japan

Michio Matsuura

Masakazu Taguchi

Akira Minami

Shigeyoshi Tanaka

Hiromichi Kuwano

Kazuyuki Tamanoi

Akihiro Itakura

Akiyoshi Uchida

Yoshihide Fujita

Haruhiko Izumi

Mineo Moribe

A method is provided for storing data by distributing the data into plural storage units that are accessible independently of one another. The method includes the steps of dividing data to be stored into plural data blocks, generating parity data corresponding to the data blocks, distributing the plural data blocks and the parity data into the storage units to let the storage units store the same, responding to a situation where any of the storage units becomes inaccessible, reconstructing data stored in the storage unit that has become inaccessible before the situation occurs based on data stored in the remaining storage units, dividing the reconstructed data into plural reconstructed data blocks, generating parity data corresponding to the reconstructed data blocks, and distributing the plural reconstructed data blocks and the parity data corresponding thereto into accessible storage units to let the accessible storage units store the same.

Method and device for storing data

Stable recording and reproduction of data onto and from a recording medium that requires precise tracking is provided by using a simple head tracking mechanism. In a hard disk drive (), a piece of sector data to be written or read is pre-associated with a sector number of a sector where the piece of sector data is to be written or read. A seek control unit () corrects first-order run-out relative to a revolution axis of a DTM magnetic disk () and permits second-and-higher order run-out relative to the revolution axis, and moves a read/write head () gradually in one radial direction of the DTM magnetic disk at a shift pitch smaller than the track pitch for each revolution in accordance with the sector numbers of the sectors where pieces of sector data are to be written or read, within a range of tracks containing the sector numbers of the sectors where the pieces of sector data are to be written or read. A recording/reproducing unit () writes or reads, in accordance with a present sector number of a sector where the write/read head is located, a corresponding piece of sector data onto or from the DTM magnetic disk, independently of the order of the sector numbers.

Hard disk drive

A data storage device is provided that is suitable for use under the environment where mechanical shock is frequently applied. The data storage device includes plural storage units as closed structures each of which houses a storage medium therein, the storage medium being capable of moving relative to a head for access, an external force detection portion for outputting signals corresponding to external forces applied to the storage units in plural directions, and a controller for controlling the storage units. The storage units are arranged in such a manner that the storage units are different from one another in a direction of relative movement between the storage medium and the head, and the controller selectively makes one or more of the storage units perform an access operation in accordance with the signal outputted from the external force detection portion.

Data storage device

An optical disk recording method of recording data on an optical disk by applying laser light to a track of the optical disk, includes the steps of a) driving a plurality of laser light sources in sequence in a time division manner, and applying a light flux to one track of the optical disk successively, and b) producing a plurality of rows of record marks in the one track.

Magneto-optical storage medium capable of recording plural rows of marks on each track

A storage medium library retains polygonal data storage plates. The library includes a box for accommodating the plates, a drive unit for recording or retrieving data with respect to each storage plate, and a plate changer for transferring the storage plates between the changer and the drive unit. Each storage plate includes a recording section and a handling section surrounding the recording section. The handling section is formed with engagement recesses. The accommodation box is internally provided with support ledges which the handling sections of the storage plates contact. The plate changer includes two extendable arms for supporting the storage plates. Each extendable arm is provided with claws to be inserted into the recesses of the handling section of the transferred storage plate.

Storage medium library and storage medium magazine

An optical recording medium (D) includes tracks (T) extending along a spiral. The tracks (T) include a plurality of first sections (Ta) and a plurality of second sections (Tb) differing from the first sections with respect to at least one of width and depth. Each of the first sections (Ta) includes a first overlapping portion () in which the trailing end and other portion of the first section overlap each other in the tracking direction, the trailing end and the other portion of the first section being located in adjacent tracks. Each of the second sections (Tb) includes a similar configured second overlapping portion (). Due to such a structure, the beam spot can be easily caused to circulate on the same track of the optical recording medium (D) during idling.

Optical recording medium and optical information processor

In a method and an apparatus for aberration correction according to the invention, aberration occurring in recording/reproducing information derived from causes such as thickness variation of a substrate, a tilt, a focus error and a tracking error is detected, and the aberration is corrected by correcting these causes.

Method and apparatus for aberration correction

An optical storage medium includes a plurality of tracks and a plurality of information pits arranged in the tracks. The information pits are designed to produce reflection light upon irradiation of light. The information pits are disposed in a matrix layout so that the reflection light includes at least four diffracted rays. An information pit is offset from the predetermined reference point in the track direction and the tracking direction. Thus, the particular information pit carries information indicated by the offset position relative to the reference point.

Optical recording medium having pits disposed in a matrix layout and apparatus for processing thereof

A driving circuit for a magnetic head that is used for modulating magnetic field in a magneto-optical disk drive is provided, which reduces power consumption even if the magnetic head has large inductance. The driving circuit comprises a switching circuit for generating pulse-like drive current in synchronization with a timing for applying a pulse of light in accordance with a space between pits to be recorded on a magneto-optical disk, and a conversion circuit for converting the pulse-like drive current into sine-wave current to be supplied to the magnetic head such that the maximum magnetic field can be obtained at the timing for applying a pulse of light.

Method for driving magnetic head and driving circuit of magneto-optical disk drive

A method and apparatus for magnet-optical recording are provided that can reduce heat in pulse driving of a magnetic head coil of a magnet-optical recording apparatus. Data inversion detection means generates a signal TRDET that becomes the high level when a magnetic inversion of data occurs and becomes the low level when no magnetic inversion of data occurs. Means for reducing an exciting energy use this signal TRDET so as to generate a strobe signal STRB that has a short period of the high level when a magnetic inversion of data occurs and a normal period of the high level when no magnetic inversion of data occurs. The magnetic head coil is excited during a period in which the strobe signal STRB is the high level, so that the pulsed magnetic field is generated, which is applied to a magnet-optical recording medium.

Method and apparatus for recording magnetized mark utilizing magnetic field generated by adjacent magnetized mark to reduce energy level for generating pulsed magnetic field

Method for recording plural rows of record marks in one track in magneto-optical recording device

A method is provided for performing data-writing or data-reading with an optical data storage medium including a substrate. The method includes the following steps. The storage medium is irradiated with light from a light source via an objective lens, so that a light spot is formed on the storage medium. Then, the lens is moved from the focus point to a predetermined defocus point where the light spot has a maximum peak intensity. The defocus point is detected as a minimum depletion point regarding the aberration caused by a thickness error of the substrate.

Method of performing data-recording or data-reading with optical storage medium

Method for recording a plural rows of record marks in one track in magneto-optical recording device

The magnetizing control signal MAGCH becomes the high level if there is no magnetic reversal during a period of a predetermined number of clocks and becomes the low level if there is a magnetic reversal. If the magnetizing control signal MAGCH is the low level, the high voltage VH is applied to the center tap of the bifilar winding of the magnetic head via the transistor . The transistors or the transistors are turned on in accordance with the write data signal DATA, *DATA. Therefore, the magnetizing current flows through one of the winding elements and . If the magnetizing control signal MAGCH is the high level, the transistors or the transistors are turned on in accordance with the write data signal DATA, *DATA. Therefore, the magnetizing current flows from the low voltage VL to both the winding elements and

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Kawasaki, Japan

Michio Matsuura