Abstract: A clock and data recovery device of a memory system receives a multiplexed data signal obtained by multiplexing a plurality of data units, each of which is to be transmitted to one of a plurality of memories for storage therein, in an area corresponding to each memory in an amplitude direction and a time direction. The clock and data recovery device includes a clock generation circuit configured to generate a clock, and a data recovery circuit configured to execute phase synchronization with respect to a synchronization signal included in the multiplexed data signal using the generated clock and to recover one of the data units from the area corresponding to one of the memories, from the multiplexed data signal.

Abstract: A data storage device is disclosed comprising a disk surface comprising a magnetic recording layer comprising a first magnetic material having a first coercivity intermixed with a second magnet material having a second coercivity higher than the first coercivity, and a head comprising a write coil configured to magnetize the magnetic recording layer in order to write data to the disk surface. The data is written to the disk surface by configuring the magnetic recording layer into one of at least three recording states, and the data is read from the disk surface by reading the magnetic recording layer using the head to generate a multi-level read signal, where each level of the read signal corresponds to one of the recording states.

Abstract: According to one embodiment, a heat assisted magnetic recording system includes a magnetic recording medium comprising a magnetic recording layer, where the magnetic recording layer includes a plurality of physical bits. Each physical bit has a perpendicular magnetic anisotropy and one of at least three magnetic states, where the at least three magnetic states include a +1 magnetic state, a 0 magnetic state, and a ?1 magnetic state.

Abstract: A three-dimensional magnetic recording media can consist of a single recording layer configured with three or more separate magnetization levels. A first magnetization level can be written to a selected region of said recording layer by applying a first write field to the grains of said region to form a “spin-up” magnetization in the grains of said region. A second magnetization level can be written by applying a second opposite write field to selected grains of said region to form a “spin-down” magnetization. At least a third intermediate magnetization level can be written by applying a weaker or alternating write field to grains of said region to form an intermediate magnetization comprising a mixture of spin-up and spin-down grains. By such method, said region may comprise a data bit capable of storing 3 or more units of information corresponding to the number of separate magnetization levels employed.

Abstract: A magnetic microstructure comprising (i) a magnetic storage layer having a magnetic easy axis perpendicular to a film plane of the storage magnetic layer; (ii) a magnetic assist layer having a magnetic easy axis in the film plane; and (iii) a phase transition interlayer between the magnetic storage layer and the magnetic assist layer. The phase transition layer comprises a material, such as FeRh, that switches from antiferromagnetic at ambient to ferromagnetic at a transition temperature that is greater than ambient, but below the Curie temperature. When the phase transition interlayer is in antiferromagnetic phase, there exists little magnetic coupling between the storage and assist layers. When the interlayer changes to ferromagnetic phase, the interlayer couples the magnetic moments of the storage and assist layer ferromagnetically.

Abstract: An information recording apparatus includes an information obtaining unit, a sign arrangement generating unit, a sign arrangement recording unit. The information obtaining unit obtains information to be recorded on a recording medium. The sign arrangement generating unit, based on information to be obtained by the information obtaining unit, generates an arrangement having three or more kinds of signs for expressing the obtained information. The sign arrangement recording unit, while shifting recording positions of a recording area included in the recording medium, records physical features sequentially into the respective recording positions of the recording area included in the recording medium. And each physical feature corresponds to one kind of the signs.

Abstract: An apparatus includes a moveable arm for positioning an optical transducer adjacent to a storage medium, a light source, and an elliptical or ellipsoid shaped mirror mounted for reflecting light from the light source to the optical transducer. The elliptical mirror can be positioned on an ellipse, the moveable arm can pivot about an axis passing through a first focus of the ellipse, and the light source can direct light from a point on a second axis passing through a second focus of the ellipse to the elliptical minor. The light source can include a fixed laser and a moveable mirror mounted to pivot about the second axis or a moveable laser mounted to pivot about the second axis. A method performed by the apparatus is also provided.

Abstract: A recording medium, method and apparatus for managing data are discussed. According to an embodiment, the present invention provides a method of reproducing main data and additional data. The method includes receiving the additional data associated with the main data, the additional data being divided into a plurality of segment units; and reproducing the additional data in a synchronous manner with the main data using time information if indication information indicates a presence of the time information. The time information indicates a presentation time of the additional data with respect to the main data. The main data and the additional data are reproduced according to management data, the management data including link information for linking the main data and the additional data.

Abstract: A rapid data recording/reproducing method, a data recording system adopting the same, media for the system, and a tracking method, wherein the recording/reproducing method includes preparing media having a data recording layer in which a phase change is generated through electron absorption, generating electrons using an electron generating source at a position separated from the data recording layer by a predetermined interval, forming a magnetic field on the path of the electrons and cyclotron moving the electrons, recording data through local melting and cooling due to absorption of the electrons by the data recording layer. A micro-tip does not contact the data recording layer during electron collisions therewith, hence no damage is caused by or to the micro-tip. The present invention allows the region where the electron beam reaches the data recording layer to be minimized thereby maximizing the data recording density.

Abstract: A magneto-optical recording medium and a method for recording and reproduction thereon are provided in order to reproduce information recorded by multi-valued recording at a high S/N ratio. Disclosed is a magneto-optical recording medium including two magnetic layers capable of four-valued recording based on four combined magnetization states. Magnitudes of reproduction signals concerning the four magnetization states, obtained upon reproduction at a wavelength ?1, are different from those obtained upon reproduction at a wavelength ?2. The two magnetic layers, on which a signal (a) is recorded, are irradiated with light beams having the wavelengths ?1 and ?2 respectively. Signals (d), (e) reproduced from respective reflected light beams are sliced by using at least one slice level to obtain two-valued or higher multi-valued reproduction signals respectively.

Abstract: A magneto-optical recording medium has magneto-optical recording layers (11, 12, 13) and reproducing layers (21, 22, 23). The information recorded in the reproducing layers are reproduced by means of reproducing light beams (31, 32, 33) of different wavelengths, respectively. In reproduction, magnetic domains (4) recorded in the recording layers are transferred in the reproducing layers formed on the respective recording layers, the transferred magnetic domains (5) are enlarged with an external magnetic field, and the information is reproduced. Since information is recorded and reproduced for each recording layer, the recording density is improved. Further since the reproduction signals are amplified by the magnetic domain enlargement, the C/N is improved.

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 a recording layer and a reproducing layer respectively formed by magnetic layers on a substrate. A record magnetic domain is formed within the recording layer by using a magnetic head, which is transferred into a reproducing layer by irradiating a laser beam upon reproduction. The physical length in recording a unit bit is taken as a unit domain length. Where the unit domain length is 1T and “1” is recorded in 1T, “1” is recorded in a former half 1T/2 and “0” is in a latter half 1T/2 by applying one period of an alternating magnetic field to the unit domain length.

Abstract: A magneto-optical recording medium includes a recording layer and a reproducing layer respectively formed by magnetic layers on a substrate. A record magnetic domain is formed within the recording layer by using a magnetic head, which is transferred into a reproducing layer by irradiating a laser beam upon reproduction. The physical length in recording a unit bit is taken as a unit domain length. Where the unit domain length is 1T and “1” is recorded in 1T, “1” is recorded in a former half 1T/2 and “0” is in a latter half 1T/2 by applying one period of an alternating magnetic field to the unit domain length.