Patent application number | Description | Published |
20090034115 | MAGNETIC RECORDING MEDIUM, RECORDING /REPRODUCING APPARATUS, AND STAMPER - A servo pattern is formed in a servo pattern region on at least one surface of a substrate of a magnetic recording medium by a concave/convex pattern including a plurality of convex parts, at least protruding end parts of which are formed of magnetic material, and at least one concave part. The servo pattern region includes an address pattern region and a burst pattern region. The at least one concave part is formed in the servo pattern region so that a larger of an inscribed circle with a largest diameter out of inscribed circles on protruding end surfaces of the convex parts formed in the address pattern region and an inscribed circle with a largest diameter out of inscribed circles on protruding end surfaces of the convex parts formed in the burst pattern region is an inscribed circle with a largest diameter out of inscribed circles on protruding end surfaces of the convex parts formed in the servo pattern region. | 02-05-2009 |
20090059409 | Magnetic recording reproducing apparatus - The magnetic recording and reproducing apparatus includes: a perpendicular recording magnetic recording medium including a track pattern including track portions and gap portions arranged so as to be alternately adjacent to each other in a cross-track direction, at least part of portions corresponding to the track portions being recording areas having the width substantially the same as the width of the track portions, portions between the recording areas being non-recording areas; and a magnetic head of a perpendicular recording type for applying a recording magnetic field to the recording areas. The anisotropic magnetic field Hk (T) of the recording areas of the magnetic recording medium and the recording magnetic field intensity Fw (t) of the recording magnetic field at the upper surface of the recording areas satisfy the following inequality (I): | 03-05-2009 |
20090168245 | INFORMATION RECORDING MEDIUM, RECORDING/REPRODUCING APPARATUS, AND STAMPER - Data track patterns and servo patterns are formed on an information recording medium by concave/convex patterns divided into ring-shaped regions that are concentric with the data track patterns. In the servo patterns, a unit convex length and a unit concave length along the direction of rotation increase in each ring-shaped region from an inside to an outside of the ring-shaped region in proportion to the distance from the center of the data track patterns and a value produced by dividing an average unit convex (or concave) length inside each ring-shaped region by a distance from the center to the ring-shaped region decreases toward the outer periphery of the medium. The ring-shaped regions include plural first regions between an innermost region and an outermost region. Respective lengths along a radial direction of the first regions increase toward an outer periphery of the medium. | 07-02-2009 |
20090185308 | MAGNETIC RECORDING MEDIUM, RECORDING REPRODUCING APPARATUS, AND STAMPER - On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region, where M is a natural number of two or higher. Each burst pattern is formed so as to include two types of burst signal units that are positioned at different distances from a center of data track patterns and have an equal length along a radial direction of the substrate. The length along the radial direction is (2·M/N) times the track pitch, where N is a natural number of two or higher. In a predetermined range where both ends in the radial direction do not match a center in the radial direction of a burst pattern, (2·M) centers in the radial direction of the burst patterns are present at intervals of (1/N) times the track pitch in the radial direction, the two types of burst signal units are formed of recording regions and do not overlap each other in the direction of rotation, centers of the burst signal units in the radial direction are separated by (M/N) times the track pitch, and facing end parts in the radial direction of the burst signal units are separated via non-recording regions. | 07-23-2009 |
20090207522 | MAGNETIC RECORDING MEDIUM, RECORDING/REPRODUCING APPARATUS, AND STAMPER - On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region, where M is a natural number of two or higher. Each burst pattern is formed so as to include two types of burst signal units that are positioned at different distances from a center of data track patterns and have an equal length along a radial direction of the substrate. The length along the radial direction is (2·M/N) times the track pitch, where N is a natural number of two or higher. In a predetermined range where both ends in the radial direction do not match a center in the radial direction of a burst pattern, (2·M) centers in the radial direction of the burst patterns are present at intervals of (1/N) times the track pitch in the radial direction, the two types of burst signal units are formed of non-recording regions and do not overlap each other in the direction of rotation, centers of the burst signal units in the radial direction are separated by (M/N) times the track pitch, and facing end parts in the radial direction of the burst signal units are separated via recording regions. | 08-20-2009 |
20090231746 | Magnetic recording apparatus and magnetic recording medium - In the magnetic recording apparatus, a recording layer is formed in a concavo-convex pattern, and recording elements are formed of convex portions of the concavo-convex pattern. Furthermore, the following equation (I) | 09-17-2009 |
20120230167 | MICROWAVE ASSISTED MAGNETIC HEAD AND MAGNETIC DISK DEVICE - A microwave assisted magnetic head of the present invention includes: at least two or more auxiliary coils that are arranged in a periphery of a writing main pole; and microwave current supply means that applies microwave currents to the at least two or more auxiliary coils. The at least two or more auxiliary coils respectively include linear body parts linearly arranged on an ABS side, two of the linear body parts of the at least two or more auxiliary coils are arranged in a substantially orthogonal positional relationship, and the microwave current supply means is configured such that the microwave current supply means changes phase differences of the microwave currents applied respectively to the at least two or more auxiliary coils. Therefore, the microwave current can be easily controlled, and thus, a circularly polarized magnetic field with high magnetization inversion efficiency can be generated as an assistance magnetic field. | 09-13-2012 |
20120250472 | MAGNETIC HEAD FOR MICROWAVE ASSISTED MAGNETIC RECORDING - A magnetic head that writes information to a recording medium includes a magnetic pole layer that generates a writing magnetic field to the recording medium, a microstripline that is disposed in proximity to the magnetic pole layer and to which high frequency current is applied, and a ferromagnetic thin film that is disposed on a portion of the microstripline that faces the recording medium, and that generates a high frequency alternate-current (AC) magnetic field to be applied to the recording medium, using a current magnetic field generated on the microstripline due to the high frequency current. | 10-04-2012 |
20120320474 | MICROWAVE ASSISTED MAGNETIC RECORDING HEAD AND MAGNETIC RECORDING METHOD THEREWITH - A microwave assisted magnetic head includes a main magnetic pole; a trailing shield, a main coil for causing the main magnetic pole to generate a perpendicular recording field, at least one secondary coil for generating an in-plane alternate-current (AC) magnetic field with a frequency in a microwave band from a magnetic recording gap between the main magnetic pole and the trailing shield, nonmagnetic films formed on magnetic recording gap facing surfaces that are defined by the main magnetic pole and the trailing shield, the main magnetic pole and the trailing shield being configured with first soil magnetic films, and second soft magnetic films formed further on the surfaces of the nonmagnetic films. The second soft magnetic films have larger anisotropy fields than the first soft magnetic films have. | 12-20-2012 |
20130083428 | MAGNETIC RECORDING APPARATUS - A magnetic recording apparatus includes a magnetic recording medium that is provided with a first magnetic layer with magneto crystalline anisotropy energy, a second magnetic layer with magneto crystalline anisotropy energy that is smaller than the magneto crystalline anisotropy energy of the first magnetic layer, and a nonmagnetic metal layer that is positioned between the first magnetic layer and the second magnetic layer and that provides coupling force between the first magnetic layer and the second magnetic layer; and a magnetic head that includes a main pole that applies a recording magnetic field in a direction perpendicular to a film surface of the magnetic recording medium to the magnetic recording medium, and an alternate current (AC) magnetic field generator that applies an AC magnetic field with a frequency of 1-40 GHz to the magnetic recording medium. | 04-04-2013 |
20130128382 | SUSPENSION WITH HIGH CONDUCTIVITY GROUND LAYER - A suspension is configured to support a magnetic head slider having a recording head element for recording to a magnetic recording medium and a microwave generating element that applies a high-frequency magnetic field to the magnetic recording medium when recording to the magnetic recording medium is conducted by the recording head element. The suspension includes a flexure that supports the magnetic head slider, and a microwave signal transmission line and a recording signal transmission line that are supported by the flexure. The microwave signal transmission line is connected to the microwave generating element and configured to transmit microwave signals for generating the high-frequency magnetic field, the recording signal transmission line being connected to the recording head element and configured to transmit recording signals. The flexure has a main body part, a support part for the magnetic head slider, and a pair of arm parts that links the main body part and the support part. The recording signal transmission line is supported between the main body part and the support part by a separate support part separated from the flexure, the microwave signal transmission line is supported between the main body part and the support part by at least one of the pair of arm parts, and a portion of the one of the arm parts that supports the microwave signal transmission line has a lamination structure in which an insulating layer that supports the microwave signal transmission line on one surface and a substrate whose portion opposing the other surface of the insulating layer has conductivity are laminated. | 05-23-2013 |
20130128387 | SUSPENSION WITH HIGH CONDUCTIVITY GROUND LAYER - A suspension is configured to support a magnetic head slider having a recording head element for recording data signals to a magnetic recording medium and a microwave generating element that applies a high-frequency magnetic field to the magnetic recording medium when recording is conducted by the recording head element. The suspension includes a flexure that supports the magnetic head slider and a microwave signal transmission line. The microwave signal transmission line is connected to the microwave generating element and configured to transmit microwave signals for generating the high-frequency magnetic field. A portion that supports the microwave signal transmission line of the flexure includes a lamination structure, a ground layer with the thickness of 0.1 μm or greater and less than 2 μm and having higher conductivity than that of the flexure main plate, and an insulating layer that supports the microwave signal transmission line. | 05-23-2013 |
20130128388 | SUSPENSION WITH HIGH CONDUCTIVITY GROUND LAYER - A suspension is configured to support a magnetic head slider having a recording head element for recording to a magnetic recording medium and a microwave generating element that applies a high-frequency magnetic field to the magnetic recording medium when recording is conducted by the recording head element. The suspension has a flexure that supports the magnetic head slider, a microwave signal transmission line and a recording signal transmission line. The microwave signal transmission line is connected to the microwave generating element and configured to transmit microwave signals for generating the high-frequency magnetic field. The microwave signal transmission line and the recording signal transmission line are supported between the main body part and the support part, a portion of which has a first lamination structure where a first ground layer is conductive and a first insulating layer supports the microwave signal transmission. | 05-23-2013 |
20130242430 | MAGNETIC RECORDING MEDIUM, METHOD FOR MANUFACTURING MAGNETIC RECORDING MEDIUM, AND MAGNETIC RECORDING OR REPRODUCING APPARATUS - Ion irradiation is applied to the surface of a recording layer which has a granular structure containing ferromagnetic particles which are composed of an L10 ordered alloy and a non-magnetic intergranular layer, thereby the ferromagnetic particles in the side of the substrate are transformed into an L10 ordered alloy having a high magnetic anisotropy, and the ferromagnetic particles in the side of the surface of the medium are transformed into an A1 disordered alloy having a low magnetic anisotropy. | 09-19-2013 |
20130258514 | MICROWAVE-ASSISTED MAGNETIC RECORDING DEVICE AND METHOD USING NON-CONSTANT MICROWAVE - A magnetic recording device includes a magnetic disk and a magnetic head that performs magnetic recording to the magnetic disk. The magnetic head includes a main magnetic pole layer and a microwave generating element. The magnetic recording device further includes a microwave generating element driving current control circuit. The microwave generating element driving current control circuit, during the magnetic recording, applies a microwave generating element driving current at a first current level to the microwave generating element for a period that is from at the latest a polarity reversal of the recording current before a subsequent polarity reversal of the recording voltage, and thereafter applies another microwave generating element driving current at a second current level, which is smaller than the first current level, to the microwave generating element, or stops the application of the another microwave generating element driving current until the polarity reversal of the recording voltage. | 10-03-2013 |
20130258527 | MAGNETIC HEAD AND MAGNETIC RECORDING APPARATUS - A magnetic head includes a microwave-generating element connected to a ground line. The ground line is made shorter by connecting the ground line to a conductive slider substrate so that the microwave-generating element is in a short-circuited end condition. This allows a microwave excitation current to be efficiently supplied to the microwave-generating-element, thus enabling effective microwave-assisted recording. | 10-03-2013 |