Abstract: The present invention provides a method of magnetic transfer comprising: an initial magnetization step of performing an initial magnetization by applying a DC magnetic field perpendicular to a disk shaped perpendicular magnetic recording medium which is formed by laminating a soft magnetic layer and a magnetic layer on a substrate; an initial magnetization cleaning step of applying an in-plane magnetic field having an intensity larger than 100 [Oe] and less than an intensity of Hn, to the perpendicular magnetic recording medium after passed through the initial magnetization step in radial direction which directed from a center to an outer of the perpendicular magnetic recording medium. After or in a time of the magnetic transfer, a magnetic cleaning may be performed by applying an in-plane magnetic field having the same intensity as the initial magnetization cleaning step in radial direction instead of the initial magnetization cleaning or in combination.

Abstract: A master information carrier for magnetic transfer bears uneven signal patterns on its surface. When the minimum bit length in the uneven signal patterns is Bmin, dummy uneven patterns are provided in a depression of the uneven signal patterns, which has a length of 4Bmin or longer in the direction along a track. When magnetic transfer is performed, magnetized patterns corresponding to the dummy uneven patterns are transferred onto a slave medium. The magnetized patterns are patterns which will not be recognized as reproduction signals at a drive, into which the slave medium after magnetic transfer will be loaded.

Abstract: When signals are read out by a magnetic head from a magnetic recording medium on which magnetic bits corresponding to information are recorded along the tracks thereof by a magnetic transfer method, if a space which is longer than or equal to a length corresponding to three bits is present between consecutive magnetic bits, readout of signals from a sub-pulse generation area in the space is cancelled in readout of the magnetic bits by the magnetic head along the tracks. The signals are not read out at all, or even if the signals are read out, they are not processed as valid signals.

Abstract: The present invention provides a magnetic transfer method comprising: a magnetic transfer step of applying a magnetic field for transfer parallel to the plane of a disk shaped substrate having formed on the surface thereof a pattern composed of magnetic layer arrangement corresponding to information to be transferred to a perpendicular magnetic recording medium while a master recording medium for perpendicular magnetic transfer being the substrate is brought into close contact with the perpendicular magnetic recording medium, and thereby transferring the magnetic pattern of the master recording medium for perpendicular magnetic transfer to the perpendicular magnetic recording medium; and a servo correction information writing step of writing by use of a magnetic head, servo correction signal information into a section adjacent to the information transferred to the perpendicular magnetic recording medium by the magnetic transfer step.

Abstract: A magnetic transfer method comprises the processes of: adhering a side having a perpendicular magnetic recording layer of a perpendicular magnetic recording medium in which a perpendicular magnetic recording layer is formed on a surface of a disk shaped substrate, to a surface of a master recording medium in which a magnetic layer is formed corresponding to information to be recorded for transferring information to the perpendicular magnetic recording medium and of the side having the magnetic layer formed; and performing magnetic transfer by relatively rotating a magnetic field application device about the center of the perpendicular magnetic recording medium as an axis with respect to the perpendicular magnetic recording medium and the master recording medium, while applying a magnetic field to the perpendicular magnetic recording medium and the master recording medium by the magnetic field application device, wherein the magnetic field application device is rotated two or more times.

Abstract: The present invention provides a method of initializing a perpendicular magnetic recording medium in which a magnetic field having a magnetic field strength Hex is applied to a perpendicular magnetic recording medium having a magnetic layer having a coercive force Hc to initialize the magnetic layer, the method comprising the steps of: controlling a magnetic field strength HexP in a direction parallel to the medium surface of the magnetic field so that HexP>1.3×Hc; and controlling a magnetic field strength HexV in a direction perpendicular to the medium surface of the magnetic field so that HexV<Hc.

Abstract: According to the present invention, since the applied magnetic field strength is controlled so as to fall between maximum magnetic field strength×0.7 and the maximum magnetic field strength over almost an entire surface of the magnetic recording medium, there is not much variation in the strength of the applied magnetic field relative to media coercivity during DC demagnetization, which makes it possible to obtain uniform magnetization over almost the entire surface.

Abstract: The present invention provides a master disk for magnetic transfer which has a disk-like outer shape and in the surface of which a large number of fine magnetic layer patterns are formed, wherein the relationship between the outside diameter size d (mm) of the extreme outer circumference of the magnetic layer pattern and the master disk thickness t (mm) is given by 2.04×10?3×d+0.006?t?8.15×10?3×d+0.024, in order to exclude the effects of bows, strains and thickness deviations of a master disk in performing magnetic transfer and ensure that accurate transfer of magnetization patterns can be performed.

Abstract: Magnetic field absorbing regions, composed of protrusions or magnetic layers, are provided in an amplitude servo transfer pattern of a patterned master carrier for magnetic transfer. The magnetic field absorbing regions are provided in intermediate tracks between burst bit elements that constitute burst bit strings, which are provided adjacent to each other in a track width direction. The amplitude servo transfer pattern in magnetically transferred onto a magnetic recording medium. Portions of the magnetic recording medium corresponding to the magnetic field absorbing regions become magnetically non-inverted regions. Therefore, noise is not recorded, and servo tracking can be favorably performed.

Abstract: A magnetic-transfer method comprising the steps of: initially DC-magnetizing a transfer-recipient disc in a circumferential direction, by applying a magnetic field to the transfer-recipient disc in the circumferential direction thereof; bringing initially DC-magnetized transfer-recipient disc and a master disc into close contact with each other, on the top side of the master disc a magnetic layer including a great number of protrusions that configure a magnetic pattern being formed, ratio t/b of thickness t of the magnetic layer to circumferential length b of the protrusion being from 0.5 to 4.

Abstract: When signals are read out by a magnetic head from a magnetic recording medium on which magnetic bits corresponding to information are recorded along the tracks thereof by a magnetic transfer method, if a space which is longer than or equal to a length corresponding to three bits is present between consecutive magnetic bits, readout of signals from a sub-pulse generation area in the space is cancelled in readout of the magnetic bits by the magnetic head along the tracks. The signals are not read out at all, or even if the signals are read out, they are not processed as valid signals.

Abstract: An amplitude servo pattern capable of providing accurate servo control through reproduced amplitude with reduced noise is provided. The amplitude servo pattern has servo burst signals composed of burst bit strings adjacently disposed in a track width direction. The burst bit strings are disposed such that the servo burst signals adjacently disposed in the track width direction have a phase difference with each other in a track direction.

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 magnetic recording medium containing a magnetic recording layer with a coercivity squareness ratio of 0.4 to 0.9 is produced by magnetic transfer, for which a magnetic field is applied to an unrecorded magnetic recording medium while maintaining a patterned side of the patterned master medium in close contact with the magnetic recording layer for magnetic transfer. At least portions of the patterned side are made of a soft-magnetic material, and the pattern formed on the patterned side has a bit length of 60 nm or smaller. It is possible to arrange the magnetic recording layer to have a coercive force of 398 kA/m or greater, reduce the bit length to 55 nm or smaller, and heat the magnetic recording layer to 100° C. or higher during application of the magnetic field.

Abstract: A master information carrier for magnetic transfer bears uneven signal patterns on its surface. When the minimum bit length in the uneven signal patterns is Bmin, dummy uneven patterns are provided in a depression of the uneven signal patterns, which has a length of 4Bmin or longer in the direction along a track. When magnetic transfer is performed, magnetized patterns corresponding to the dummy uneven patterns are transferred onto a slave medium. The magnetized patterns are patterns which will not be recognized as reproduction signals at a drive, into which the slave medium after magnetic transfer will be loaded.

Abstract: A magnetic transfer device for bringing a master carrier with information and a slave medium into intimate contact with each other and then applying a transfer field to transfer the information to the slave medium. The master carrier has an inclined face on its radially outer end. After the magnetic transfer of the information, claws are inserted in the gas formed by the inclined face of the master carrier and the slave medium. The slave medium held in intimate contact with the master carrier is separated from the master carrier by lifting the slave medium with the claws.

Abstract: In the magnetic transferring method for magnetically transferring an information signal such as a servo signal from the master medium to the slave medium, when magnetic transfer is performed by bringing a master medium and a slave medium into close contact with each other, the master medium bearing an information signal and the slave medium having a lubricating layer formed on the surface of its recording plane during use, and applying a transfer magnetic field, the magnetic transfer is performed by bringing the slave medium before the formation of the lubricating layer and the master medium into close contact with each other. Thus, the separation of the slave medium from the master medium after the magnetic transfer is facilitated, and the adsorption of dust on the slave medium is prevented.

Abstract: A magnetic recording medium, which contains a chromium-containing primer layer and a magnetic layer at least on one surface of a nonmagnetic support member, the chromium-containing primer layer contains chromium and at least one type of element selected from a group of cobalt, beryllium, osmium, rhenium, titanium, zinc, tantalum, aluminum, molybdenum, tungsten, vanadium, iron, antimony, iridium, ruthenium, rhodium, platinum, palladium, silicon, and zirconium, and the magnetic layer contains a ferromagnetic metal alloy containing at least cobalt, platinum and chromium, and a nonmagnetic material.

Abstract: A magnetic recording medium, which comprises a flattening layer with a thickness of 0.1-5.0 &mgr;m, a seed layer, a nonmagnetic primer layer containing chromium with a chromium concentration of 77-100 atom %, a Co—Cr type alloy magnetic layer, a protective layer, and a lubricating layer coated sequentially on at least one of the surfaces of a flexible nonmagnetic support member, whereby the seed layer is designed in such a manner that the linear expansion coefficient (ESE) of the seed layer and the linear expansion coefficient (EUL) of the nonmagnetic primer layer satisfy the relation: |ESE−EUL|/EUL<0.3, and the tensile strength (SSE) of the seed layer and the tensile strength (SUL) of the nonmagnetic primer layer satisfy the relation: SSE/SUL>1.

Abstract: There are provided an information recording medium which permits accurate tracking servo, and a method for recording and reproducing for an information recording medium which allows recording and reproducing of a signal at a favorable S/N by carrying out at least one of information recording and information reproduction while accurately performing tracking servo. A magneto-optic disk includes a magnetic recording layer for magnetically recording information. The magnetic recording layer is in advance magnetized for concentrically or spirally around the center of the disk in such a manner that magnetized regions are disposed such that adjacent regions are magnetized in different directions and alternately arranged in the radial direction of the disk. Accordingly, tracking can be continuously performed and accurate tracking servo can also be performed.