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: The present invention provides an apparatus for manufacturing a magnetic recording medium including, a mold structure formed of a disc-shaped substrate having on a surface thereof a concavo-convex pattern having convex portions which correspond to a servo area and a data area of a magnetic recording medium; and an imprinting and magnetic field applying unit which transfers a concavo-convex pattern on the basis of the concavo-convex pattern of the mold structure into an imprint resist layer that is made of an imprint resist composition and that is formed on a magnetic layer of a magnetic recording medium base by pressing the mold structure against the imprint resist layer, and which transfers magnetism to the servo area by application of a magnetic field via the mold structure.

Abstract: A master information carrier has on its surface a signal area where an embossed pattern formed by protruding portions and recessed portions and representing a signal pattern to be transferred has been formed. The shortest bit length of the embossed patter is 300 nm or shorter, and the embossed pattern is formed so that the total of the areas of the upper surfaces of the protruding portions of the embossed pattern is smaller than the total of the areas of inter-protruding-portions in the signal area.

Abstract: The present invention provides a method for producing a magnetic recording medium having servo areas and data areas using a mold structure. The method includes at least forming an imprint resist layer on a substrate surface of a magnetic recording medium, forming a convexo-concave pattern in the imprint resist layer by pressing convex portions of the mold structure against the imprint resist layer, and transferring magnetism to the servo areas in the magnetic recording medium by applying a magnetic field via the mold structure, wherein the imprint resist layer is formed only on areas of the substrate surface corresponding to the data areas in the magnetic recording medium, and the magnetic field is applied to areas of the substrate surface corresponding to the servo areas, with the areas of the substrate surface corresponding to the servo areas being in contact with convex portions of the mold structure.

Abstract: The present invention provides a method for producing a magnetic recording medium having servo areas and data areas using a mold structure having a plurality of convex portions, the method, including: forming an imprint resist layer on a surface of a substrate for the magnetic recording medium, forming a convexo-concave resist pattern in the formed imprint resist layer by pressing the plurality of convex portions of the mold structure against the imprint resist layer, and transferring magnetism to the servo areas in the magnetic recording medium by applying a magnetic field to the servo areas via the mold structure.

Abstract: A master information carrier for magnetic transfer includes a master substrate made of metal, including an embossed pattern corresponding to information to be transferred. The master substrate is produced by laminating a metal disk with a predetermined thickness on an original disk, on which an embossed pattern is formed, by electroforming, peeling off the metal disk and die-cutting a disk in a desired size. An outer diameter of the metal disk is at least 1.7 times longer than an outer diameter of the die-cut master substrate. When the metal disk is peeled off from the original disk, deformation due to the forces acting from the side of the outer circumference is reduced. The flatness of the metal disk is ensured and the transfer qualities are improved. Further, a step of removing distortion of the metal disk, caused at the time of peeling off the metal disk, may also be provided.

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: 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: A flexible recording medium, which has a track width in the range of approximately 1-3 ?m, capable of facilitating good tracking control. A magnetic pattern bearing servo signals is provided on the guard bands formed on both sides of a data track of a magnetic recording medium. An improvement in tracking control is achieved by performing the servo tracking in a continuous manner.

Abstract: The present invention provides a master recording medium, a magnetic transfer method, a magnetic transfer apparatus, and a magnetic recording medium and a magnetic recording and reproducing apparatus thereby made, which are capable of obtaining a good regenerative signal with few even harmonic components such as the second-order harmonic components on reproducing the information transferred to the magnetic recording medium in the case of recording the information on the magnetic recording medium having a magnetic layer composed of the perpendicular magnetization film by the magnetic transfer.

Abstract: An aspect of the present invention provides a master medium for perpendicular magnetic transfer, comprising: a disk-like substrate on a surface of which a plurality of protruding magnetic-layer patterns corresponding to information to be transferred to a magnetic recording medium targeted for transfer are formed. In the master medium for perpendicular magnetic transfer, a ratio of a circumferential width L of the protruding magnetic-layer patterns to a circumferential gap S between the protruding magnetic-layer patterns is L/S<1. According to the aspect of the present invention, good magnetic transfer can be performed and, therefore, a perpendicular magnetic recording medium (a slave disk) that is free from defects and has a good C/N ratio can be obtained. In addition, it is possible to perform good magnetic transfer.

Abstract: A patterned master carrier for magnetic transfer is used to transfer a magnetization pattern, which does not cause a problem such as an error attributable to a subpulse upon signal reproduction, to a slave medium. A signal pattern on a surface of a patterned master carrier for the magnetic transfer includes signal areas and no-signal areas, and the signal area is provided with an actual signal pattern and a dummy signal pattern adjacent to the no-signal area. Therefore, the actual signal pattern is not adjacent to the no-signal area.

Abstract: A signal such as a servo tracking signal is recorded on a flexible slave medium by magnetic transfer. When forming the flexible slave medium of a magnetic strip in a continuous length, the signal is recorded on the magnetic strip by patterned master magnetic transfer prior to or simultaneously with shaping the magnetic strip into a desired shape.

Abstract: A master carrier for magnetic transfer is equipped with a substrate having a land/groove pattern. The land/groove pattern is formed from a magnetic material and corresponds to information that is transferred to a magnetic recording disk. Each land in the land/groove pattern has four round corners whose radius is from 1% through 47% of the width of a data track on the disk.

Abstract: A master information carrier for magnetic transfer to an in-plane magnetic recording medium includes a base sheet having an irregularity pattern representing information to be transferred to an in-plane magnetic recording medium and a magnetic layer formed along the irregularity pattern. The thickness da1 of the magnetic layer on the upper surface of a protruding portion of the irregularity pattern and the thickness da2 of the magnetic layer on each of the side surfaces of the protruding portion satisfy the following condition, 0.05<da2/da1?1.3.

Abstract: An accurate magnetic transfer to a high-density slave medium having two magnetic layers and utilizing antiferromagnetic coupling is performed. By applying a first magnetic field that causes both the first and second magnetic layers of the magnetic layer of a slave medium to reach saturation magnetization unidirectionally along the circumferential direction of the track, the first and second magnetic layers are magnetized uniformly in the same direction as the first magnetic field. Then, a second magnetic field that inverts the magnetization of the first magnetic layer and has no effect on the magnetization of the second magnetic layer is applied in the opposite direction, whereby only the magnetization direction of the first magnetic layer is inverted in the direction of the second magnetic field. Thereby, a favorable initial magnetization state in which the magnetization directions of the first and second magnetic layers are oriented antiparallel can be obtained.

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: 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: 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.