Abstract: The invention concerns a optical data memory, said memory comprising at least one layer of supporting material, said supporting material including molecules having, in a local zone, a collective state of molecules from at least one first collective state of molecules, and a second collective state of molecules. The invention is characterized in that only molecules having the first collective state of molecules in said local zone are capable of generating a second-harmonic signal when they are excited in said local zone by a reading electromagnetic radiation.

Abstract: An apparatus comprises a waveguide, an optical transducer for coupling electromagnetic radiation from the waveguide to a point adjacent to an air bearing surface to heat a portion of a storage medium, and a first wire positioned adjacent to the air bearing surface, wherein current in the wire produces a magnetic field in the heated portion of the storage medium.

Abstract: A data storage device comprises: a light waveguide element; a protective element; and a plurality of data storage elements interposed between the light waveguide element and the protective element. The light waveguide element irradiates light at a critical angle or more on the data storage elements. Each of the data storage elements comprises a transparent ferromagnetic element, which has been magnetized, disposed therein, and the magnetized transparent ferromagnetic element is movable by a magnetic field. When the magnetized transparent ferromagnetic element is moved close to the light waveguide element to allow light from the light guiding element to pass the data storage element, a first data is recorded, and when the magnetized transparent ferromagnetic element is moved away from the light waveguide element to prohibit light from the light guiding element to pass the data storage element, a second data is recorded.

Abstract: A magnetic write head arranged to maximize efficiency of an optical device used to locally heat a magnetic medium during use, also to maximize efficiency of a heater element for thermal fly height control. The magnetic head is constructed with a read head, a write head and a slider body. The write head is located between the read head and the slider body. A heater element can be located between the read head and the write head and an optical device such as an optical waveguide can be located between the write head and the slider body. The write head can be constructed to have a write pole that is closer to the slider body than the return pole is, thereby allowing the write pole to be adjacent to the optical device.

Abstract: Provided is a method for manufacturing a heat-assisted magnetic recording head, capable of joining a light source unit and a slider with a sufficiently high alignment accuracy. In the method, the unit including a light source is joined to the slider including a head part. First, at least one marker provided on the head-part end surface is set so that the distance from the waveguide incident center to the marker end is substantially equal to the distance from the light-emission center of the light source to the end surface of the light source. After that, the unit and slider are relatively moved while keeping the unit in surface contact with the slider, and the relative positions are set so that the end of the marker coincides with, or is at a distance within an acceptable range from, the edge of the surface of the light source.

Abstract: Provided is a magnetic recording medium that generates near-field light within itself and enables favorable heat-assisted magnetic recording with this near-field light. The medium comprises: a magnetic recording layer; and an optically changeable layer formed on the opposite side to a substrate relative to the magnetic recording layer, the optically changeable layer being made transparent or a refractive index of the layer being changed when irradiated by light with an intensity not less than a predetermined intensity. By the irradiation, a minute opening or a refractive-index-changed area is formed within the irradiated portion on the optically changeable layer. The light irradiation onto the minute opening or the refractive-index-changed area enables near-field light to be generated, which heats a portion of the magnetic recording layer. Thus, the anisotropic field of the portion is lowered to a writable value, which enables heat-assisted magnetic recording by applying write field.

Abstract: A magnetic recording medium (1a) includes: a plurality of magnetic dots (13), provided on a substrate (11), in each of which information is stored by heating of the magnetic body; and separator layers (50). Each of the separator layers (50) is structured such that a metallic body layer (52) and two dielectric body layers (51) are alternately stacked in an in-plane direction of the substrate (11). Each of the separator layers (50) separates two magnetic dots from each other in the in-plane direction. Both sides of each of the magnetic dots (13) in the in-plane direction of the substrate (11) have contact with two dielectric body layers (52), respectively. This provides a magnetic recording medium (1a) whose magnetic dots (13) can be entirely heated with a reduction in the amount of power that is consumed by a recording head.

Abstract: The present invention provides a magnetooptic device, a magnetooptic head, and a magnetic disk drive each capable of performing optically assisted magnetic recording and each having a small size, improved recording density, and a higher transfer rate. In a magnetooptic device, a magnetic circuit including a magnetic gap and a thin film magnetic transducer having a coil portion are stacked on the surface of a semiconductor laser. By the arrangement, optically assisted magnetic recording can be performed, small size and light weight are achieved, and higher transfer rate can be implemented.

Abstract: An apparatus, comprising a slider. The slider includes a substrate with an air bearing surface and a trailing substrate side. The slider includes an optoelectronic heater and a magnetic head being mounted on the trailing substrate side. Thermal insulation is interposed between the optoelectronic heater and the magnetic head. The optoelectronic heater is thermally coupled to the trailing substrate side.

Abstract: An electromagnetic field generating element includes a conductor that generates near-field light when irradiated with light and generates a magnetic field when a current flows through the conductor. The electromagnetic field generating element further includes a soft magnetic body provided at a position along a dimension of the conductor, the dimension being perpendicular to (i) a direction in which the conductor faces a magnetic recording medium to which the near-field light and the magnetic field are applied and to (ii) a direction in which the current flows. The present invention thus allows for provision of an electromagnetic field generating element that allows for reduction in its power consumption in optically assisted magnetic read/write using near-field light.

Abstract: The invention is a near-field optical head that generates near-field light to heat a predetermined area of a medium and applies a magnetic field to the predetermined area to record information, the head including an optical waveguide 103 having a path for propagating a pencil of light, and a tip 117 having an optical minute opening 118 at the position facing against the predetermined area and collecting the pencil of light emitted from the optical waveguide 103 and simultaneously propagating the collected pencil of light to the optical minute opening 118 to generate the near-field light. The optical minute opening 118 is formed by a magnetic pole that applies a magnetic field to the predetermined area.

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 method for patterning a recording medium selectively thermally couples a recording medium and a heat source to alter a chemical composition of the recording medium. An apparatus for patterning a recording medium has a heat source for generating and directing an incident thermal wave to a recording medium so as to alter a chemical composition of the recording medium, and a controller for coordinating a mutual position of the incident thermal wave and the recording medium for inducing a direct thermal coupling between the recording medium and the heat source.

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 method and apparatus for controlling read-out and/or synchronization between an external magnetic field and written data during a reading operation from a magneto-optical recording medium includes generating a pulse in a reading signal in a read-out layer by copying a mark region from a storage layer to the read-out layer upon heating by a radiation power and with the aid of the external magnetic field. The waveform of the reading signal is analyzed, and the analysis result is used for correcting a phase deviation and/or for controlling a copy window size of the mark copying. Phase errors may thus be corrected for any size of the copy window. Even small changes in the copy window can be detected and corrected.

Abstract: A magneto-optical recording medium device of the present invention optimizes a magnetic field forming the front mask and a magnetic field forming the rear mask by use of a single bias magnetic field generator, by shifting the peak position of the bias magnetic field in the magneto-optical recording medium device so as to deviate from the center of the laser beam spot in a tangential direction of the magneto-optical recording medium, enabling extended recording and reproduction margins.

Abstract: A magneto-optical recording or reproducing device having an information erasing means for erasing information or data recorded on a magneto-optical recording medium. According to the invention, the information erasing means comprises an erasing magnet having a field strength sufficient to initialize the magneto-optical recording medium without the assistance of a laser and/or an optical scanning device.

Abstract: The invention provides a method for recording information in the form of a pattern of magnetic domains in a recording layer. The recording layer includes a material having a Curie temperature and grains, the grains having boundaries over which the exchange coupling is small. The method includes a first step of applying heat to the material, thereby heating an area of the recording layer to a temperature above the Curie temperature during a first interval. In a second step a magnetic field is applied to the area during a second interval, the second interval ending after the first interval.

Abstract: A magneto-optical disk which reproduces information with an optical pickup head which uses an electromagnetic force as the driving force is provided. Other areas than at least the recording track are magnetized uniformly in a direction of canceling the influence of external magnetic field applied by the optical pickup head or a recording pattern having a frequency higher than modulation transfer function (MTF) of the optical pickup head is recorded to the other areas than at least the recording track. Read signals SP12 and SP14 from the magneto-optical disk are low in bit error rate.

Abstract: Certain embodiments of the present invention are directed at data storage devices capable of storing, reading and writing data to storage areas of nanometer dimensions. Certain embodiments are directed at devices wherein a fluid medium and particles are provided between a storage medium and an energy-emitting tip to channel energy from the tip to the storage medium. Certain embodiments are directed at devices wherein conductor molecules are attached to the surface of the storage medium and channel energy to the storage medium from an energy-emitting tip. Certain embodiments of the present invention are directed at methods of reading and writing to a storage medium by making use of intermediate particles and/or molecules to channel beams from a tip to a storage medium where data is stored.

Abstract: A method for patterning a recording medium selectively thermally couples a recording medium and a heat source to alter a chemical composition of the recording medium. An apparatus for patterning a recording medium has a heat source for generating and directing an incident thermal wave to a recording medium so as to alter a chemical composition of the recording medium, and a controller for coordinating a mutual position of the incident thermal wave and the recording medium for inducing a direct thermal coupling between the recording medium and the heat source.

Abstract: A magnetic recording medium comprises, on a substrate, a recording auxiliary layer, a recording holding layer, recording control layer, and a recording layer. The recording layer is constructed by using a ferri-magnetic material having perpendicular magnetization. The data can be recorded at a super high density by using the recording and reproducing head of the present invention, because the recording layer has the perpendicular magnetization. The disappearance of data, which would be otherwise caused by the thermomagnetic relaxation phenomenon, is suppressed after recording the data, because the recording layer has large coercive force at the room temperature. The data, which is recorded at the super high density on the magnetic recording medium, can be reproduced by using a magnetic resistance element carried on the recording and reproducing head.

Abstract: A thermally assisted magnetic recording method is implemented for a storage disk with a magnetic recording layer which includes recording areas and non-recording areas. In this method, a heating laser is moved relative to the disk in facing relation to the magnetic recording layer for locally heating the recording areas. As the laser spot transitions from a recording area to the subsequent non-recording area, the heating is stopped. In cooperation with the heating laser, a magnetic field applier locally magnetizes the recording areas of the magnetic recording layer for recording signals. As the magnetic field applier transitions from a recording area to the subsequent non-recording area, the application of the magnetic field is stopped after the heating by the heating laser is stopped.

Abstract: A magneto-optical storage medium that protects against the effects of cross-talk, making it possible to further reduce the level of track density, and which also makes it possible to conduct high-density recording/playback with a reduced magnetic field for erasure and a favorable level of playback signal quality. More specifically, a magneto-optical storage medium, which includes at least the following laminated layers, in the following order: a playback layer, a non-magnetic layer, a transfer layer, a cut-off layer, and a recording layer. The playback layer preferably displays easy in-plane magnetization characteristics within the monolayer at room temperature, and the transfer layer and the recording layer each have easy magnetization characteristics in the vertical direction of the monolayers at room temperature when each layer is considered as a monolayer.

Abstract: In an information recording method of the present invention by carrying out recording data while carrying out tracking servo accurately, high density recording of signals at a good S/N can be carried out, and high density recording by a vertical magnetic recording system can be carried out. A magnetic disk comprises a magnetic recording layer, and the magnetic recording layer is magnetized in advance such that magnetized regions A and B having different magnetization directions are formed. At a time of recording data, vertical magnetic recording is carried out by a magnetic head while carrying out accurate tracking servo by optically tracking by a magneto-optical effect utilizing a difference in the magnetization directions of the magnetized regions A and B. Therefore, high-density recording at a good S/N is possible.

Abstract: 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 41-44 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 45-47 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.

Abstract: A magneto-optical disk which reproduces information with an optical pickup head which uses an electromagnetic force as the driving force is provided. Other areas than at least the recording track are magnetized uniformly in a direction of canceling the influence of external magnetic field applied by the optical pickup head or a recording pattern having a frequency higher than modulation transfer function (MTF) of the optical pickup head is recorded to the other areas than at least the recording track. Read signals SP12 and SP14 from the magneto-optical disk are low in bit error rate.

Abstract: There is disclosed a magneto-optical information reproducing apparatus which can perform information reproducing with a low crosstalk level, and the apparatus comprises a biasing electromagnet 19 for generating a reproducing magnetic field, and an MPU 26 for adjusting an intensity of the magnetic field generated by the biasing electromagnet 19 with respect to a land and a groove so that with respect to one of the land and the groove in which reproducing object information is recorded, a level of a crosstalk attributed to the information recorded in the other one of the land and the groove is lowered.

Abstract: A method for writing data to and/or reading data from locations on a surface via a tip comprises moving the tip between the locations on the surface. At each location, energy is selectively applied to the surface via the tip and the tip and the surface are selectively forced together in synchronization with the application of energy.

Abstract: A magneto-optical recording medium device of the present invention optimizes a magnetic field forming the front mask and a magnetic field forming the rear mask by use of a single bias magnetic field generator, by shifting the peak position of the bias magnetic field in the magneto-optical recording medium device so as to deviate from the center of the laser beam spot in a tangential direction of the magneto-optical recording medium, enabling extended recording and reproduction margins.

Abstract: The present invention relates to a method and an apparatus for reading information from a domain expansion magneto-optical recording medium, wherein the duration of the expansion direction of an external magnetic field is determined according to the upper limiting frequency of the reading system. The reading density and power margin can thus be improved.

Abstract: External magnetic fields H(x) or reproducing light beams L(x) having different intensity patterns are applied to an identical recording position on a magneto-optical recording medium so that different pieces of information corresponding to the patterns are reproduced from the identical recording position. A function H(x) or L(x) is a password for obtaining the information. Only a person, who knows the function, can access specified information recorded on the magneto-optical recording medium. The function H(x) or L(x) is a function in which the magnetic field intensity or the light intensity is modulated with respect to the recording position x so that magnetic domains may be thinned out to perform reproduction at a specified cycle from continuous magnetic domains in a recording area.

Abstract: A magnetic recording device is provided according to the present invention for magnetic recording on a recording medium. The magnetic recording device includes a magnetic pole and a C-aperture structure disposed adjacent the magnetic pole. A focusing element receives light from a light source and focuses the received light onto the C-aperture structure, such that the light incident upon the C-aperture structure and a magnetic flux flowing through the magnetic pole are co-locatable on a recording medium disposed adjacent to the magnetic recording device. The focusing element may include a planar waveguide receiving and focusing the light onto the C-aperture structure.

Abstract: While a magneto-optical recording medium is irradiated with a laser beam, the medium is rotated relative to the beam at a controlled speed in such a manner that a high temperature region of a heat spot produced on the basis of the light intensity distribution of the beam is formed outside the associated light spot. A magnetic field source includes a magnetic field generator which is narrow in the direction along the track of the medium. The field source is positioned with the field generator at the heat center outside the light spot to apply a narrow recording magnetic field to the high temperature region. This forms a recording magnetic domain in the high temperature region. The magnetic domain is rectangular and narrow in the direction along the track. Rectangular recording magnetic domains adjoining in the direction along the track hardly interfere with each other even if they are closely spaced. This results in high density recording.

Abstract: A motor-kinetic identification apparatus includes a pliant material, a source of a magnetic field embedded in the pliant material and a magneto metric element embedded in the material. The pliant is adapted to be gripped by a user. The pliant material has a normally biased rest shape and the shape becomes deformed upon the material being gripped. The magnetic field has a field contour dependent on said shape of said material. The magneto metric element is disposed within the field and has a detectable state commensurate with the magnetic field contour.

Abstract: A method of, and apparatus for, defining disk tracks in magnetic recording media. The track-writing apparatus (20) is capable of forming tracks (340) with a track width (TW) and track spaces (350) with a space width (SW) on a magnetic media disk (70) having an upper surface (70S), wherein the disk comprises a magnetic medium with a thermal diffusion length (X). The apparatus comprises, in order along an optical axis (A1), a laser light source (30) capable of providing a pulsed laser light beam (B1), a light pipe (32), and illumination shaping optical system (40) that provides substantially uniform illumination over an exposure region (ER), and a phase plate (60) having a phase grating (210) with a grating period (p), arranged proximate and substantially parallel to the upper surface of the disk so as to form an periodic irradiance distribution (380) at the surface of the disk when the phase plate is illuminated with the exposure region.

Abstract: In a thermally-assisted magnetic recorder configured to heat a medium with a heat source like a light beam and thereby decrease the coercive force of a recording portion so as to magnetically record information on the recording portion decreased in coercive force by applying a recording magnetic field from a recording magnetic pole thereto, relative timing between heating of the medium and magnetic recording is optimized by locating a reversing point of magnetization, in which the coercive force of the recording portion equals the intensity of the recording magnetic field, in the leading side of the trailing edge of the recording magnetic pole.

Abstract: The present invention provides an information storage apparatus which at least records information by applying a magnetic field to a recording medium with a smaller power consumption. A default value of a recording magnetic field is set to a minimum value of the apparatus. Through a learning process, the default value of the recording magnetic field is changed to a value in the vicinity of the minimum value.

Abstract: Using MSR (magnetically induced super-resolution) technology, a read-head field is applied to a magneto-optical recording medium when reading an information signal from a recording layer of a magneto-optical recording medium, in order to magnetize the read light-irradiated magnetic layer in one direction in a part of an area within the read light spot. The magneto-optical recording medium using MSR technology adopts the on-land recording method in which an information signal is written to the land, which enables read of an information signal by the MSR technology with a smaller read-head field.

Abstract: An magneto-optical disk device (100) includes a magnetic head (11), a DC magnetic field applying device (12), an optical head (13) and a magnetic field control circuit (16). The DC magnetic field applying device (12) applies a DC magnetic field to a magneto-optical recording medium (10) through a core of the magnetic head (11). The magnetic field control circuit (16) applies the DC magnetic field of a variable intensity to the magneto-optical recording medium (10) to determine the appropriate intensity of the DC magnetic field providing an error rate not exceeding a predetermined reference value in a reproduced signal of a predetermined recording pattern detected by the optical head (13). Consequently, the signal can be accurately reproduced from the magneto-optical recording medium (10) by domain-enlarging reproduction using the DC magnetic field.

Abstract: A recording method for recording information on a recording layer of a magneto optical recording medium by radiating a recording light beam onto the medium while applying a magnetic field in a recording direction to the medium. The method includes applying a magnetic field having a magnetic field strength H1 in the recording direction when recording a record mark having a mark length A on the recording layer, and applying a magnetic field have a magnetic field strength H2 in the recording direction when recording a record mark having a mark length B (B≠A) on the recording layer. Independent of the lengths of the magnetic domains recorded on the recording layer, the record information can be transferred to a reproducing layer making it possible to reproduce high density record information.

Abstract: The present invention relates to a head arrangement for reading a magneto-optical recording medium (10) comprising a storage layer and a read-out layer. The head arrangement comprises an improved field generating means for generating a magnetic field used for copying a written mark from said storage layer to said read-out layer upon laser heating, the field generating means being arranged to generate a predetermined field gradient and/or a predetermined local maximum in a field component perpendicular to the surface of the recording medium (10). The width of the spatial overlap can thus be reduced such that an improved resolution and/or power marginis obtained.

Abstract: 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.

Abstract: The present invention relates to magneto-optical recording technique whereby improved domain expansion reading is achieved. A mark region is recorded as a sub-mark portion and an adjacent sub-space portion, wherein the length of the sub-mark portion is set to be less than or equal to the length of the sub-space portion. Stray field variations due to different runlengths of the recording data can thus be equalized even for short channel bit lengths, while the resolution and/or power margin is improved.

Abstract: A signal recording/playback apparatus includes a recording data converter. The recording data converter converts on a data pattern having a large influence on adjacent tracks on an optical disk, and outputs the converted data to an optical pickup. Specifically, by performing a data converting process in which, for a data pattern having a predetermined length of at least consecutive bits having identical values, part of the bits is inverted based on a conversion table, the recording data converter compensates a recording operation. Alternatively, instead of inverting the bits, by controlling the output power and pulse width of a laser, the recording operation is compensated. The signal recording/playback apparatus includes a played-back data converter. In the data playback mode of the signal recording/playback apparatus, the data converted by the recording data converter is identified and decoded into the original data by the played-back data converter. The played-back data converter outputs the original data.

Abstract: A magnetic recording medium comprises, on a substrate, a recording auxiliary layer, a recording holding layer, recording control layer, and a recording layer. The recording layer is constructed by using a ferri-magnetic material having perpendicular magnetization. The data can be recorded at a super high density by using the recording and reproducing head of the present invention, because the recording layer has the perpendicular magnetization. The disappearance of data, which would be otherwise caused by the thermomagnetic relaxation phenomenon, is suppressed after recording the data, because the recording layer has large coercive force at the room temperature. The data, which is recorded at the super high density on the magnetic recording medium, can be reproduced by using a magnetic resistance element carried on the recording and reproducing head.

Abstract: Disclosed are a reproducing method and a reproducing apparatus capable of performing reproduction with a wide power margin, as well as a recording method and a recording apparatus preferably used for super high density recording. A recording and reproducing apparatus 101 principally comprises a magnetic field-applying unit, a laser beam-radiating section, and a signal processing system. A magnetic coil 29, which is provided for the magnetic field-applying unit, is arranged so that its axis of magnetic field generation 102 is oblique to a surface of an information-recording medium 100. A reproducing magnetic field is applied in an oblique direction to the surface of the information-recording medium 100 by using the magnetic coil 29 while radiating a reproducing light beam to the medium by using the laser beam-radiating section. Accordingly, the leak magnetic field in the in-plane direction from a recording magnetic domain in a recording layer is amplified.

Abstract: In an information storage apparatus for recording information in a recording medium by applying an external magnetic field to a position illuminated by the light beam, an external magnetic field control part controls an external magnetic field strength based on the illuminated position on the recording medium.

Abstract: A bit of binary information which is one of the “1” and “0” is assigned to a domain pattern which is a combination of a recorded magnetic domain and a magnetic domain magnetized in the direction opposite to the direction in which the recording domain is magnetized. A bit of binary information which is the other of “1” and “0” is assigned to a domain pattern consisting of two magnetic domains magnetized in the same direction as the foregoing magnetic domain is magnetized. Consequently, two or more consecutive bits of record information are formed, on a recording layer, as a series of domain patterns each of which is a combination, as a record information unit, of a recorded magnetic domain and a magnetic domain magnetized in the direction opposite to the direction in which the recording domain is magnetized. Independent of the lengths of the magnetic domains recorded on the recording layer, the record information can be transferred to a reproducing layer.

Abstract: A bias magnet (magnetic head) is driven when data is read from an MSR disk. When data reading is awaited in a condition in which “reproduction still” is turned on, the bias magnet is not driven.