| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 428848000 | Circular shape (e.g., disk, etc.) | 27 |
| 20090029191 | METHOD FOR MAKING A MASTER DISK FOR NANOIMPRINTING PATTERNED MAGNETIC RECORDING DISKS, MASTER DISK MADE BY THE METHOD, AND DISK IMPRINTED BY THE MASTER DISK - A method for making a master disk to be used for nanoimprinting patterned-media magnetic recording disks uses sidewall lithography. In one implementation, the master disk substrate has a first pattern of concentric rings formed on it by sidewall lithography, followed by a second pattern of generally radially-directed pairs of parallel lines, also formed by sidewall lithography, with the pairs of parallel lines intersecting the rings. An etching process is then performed, using the upper pattern as an etch mask, to remove unprotected portions of the underlying concentric rings. This leaves a pattern of pillars on the substrate, which then serve as an etch mask for an etching process that etches unprotected portions of the master disk substrate. The resulting master disk then has pillars of substrate material arranged in a pattern of concentric rings and generally radially-directed pairs of parallel lines. | 01-29-2009 |
| 20090148725 | SUBSTRATE FOR PERPENDICULAR MAGNETIC RECORDING MEDIA AND PERPENDICULAR MAGNETIC RECORDING MEDIA USING SAME - Substrates for perpendicular magnetic recording media, and perpendicular magnetic recording media using such substrates, are disclosed. By setting the substrate inclination angle, or a parameter related to substrate shape relating to this angle, within an appropriate range, magnetic recording media can be obtained with excellent read signal quality and signal quality stability, regardless of the final substrate machining method. In a substrate for donut-shape magnetic recording media, comprising a main surface, an inner circumferential surface extending along the inside of the main surface, and an outer circumferential surface extending along the outside of the main surface, when the shape of the main surface is defined by a function Z(x,y) of x-y coordinates, the root mean square inclination angle (θsΔq), defined as the inverse tangent (tan−1 (sΔq)) of the root means square inclination (sΔq) which is the root mean square over the entire main surface of the micro-region surface inclination (Δρ) of the main surface, expressed by the following equation, is 5° or less | 06-11-2009 |
| 20090280358 | PATTERNED MEDIUM AND METHOD OF PRODUCING PATTERNED MEDIUM - A patterned medium is produced by forming a cover layer on a provisional substrate which has a flat surface, forming a patterned recording layer on the cover layer, forming a reinforcing layer on the recording layer in order to form a recording part which is formed by the cover layer, the recording layer and the reinforcing layer, bonding one surface of a main substrate on the reinforcing layer of the recording part, and removing the provisional substrate after bonding the main substrate on the reinforcing layer. | 11-12-2009 |
| 20090297889 | MASTER RECORDING MEDIUM FOR MAGNETICALLY TRANSFERRING SERVO PATTERN TO THE MAGNETIC RECORDING MEDIUM AND METHOD OF MANUFACTURING THE SAME - Provided are a master recording medium and a method of manufacturing the master recording medium. The master recording medium includes: a plate; and a magnetic layer which is formed on the plate for magnetically transferring of a servo pattern that is to be formed on a magnetic recording medium. The method of manufacturing a master recording medium includes: engraving a polymer layer by nano imprinting to form an engraved pattern corresponding to a servo pattern to be formed on a magnetic recording medium; forming a magnetic layer which fills in the engraved pattern of the polymer layer; forming a back plate layer on the magnetic layer; and performing processing to expose the servo pattern on a surface of the magnetic layer that is opposite a surface of the magnetic layer on which the back plate layer is formed. | 12-03-2009 |
| 20100021773 | HEAD MEDIA SPACING REDUCTION THROUGH DATA ZONE LUBE REMOVAL - The present invention is a manufacturing method of improving the signal-to-medium noise ratio of a magnetic media disk through closer head-to-media spacing, and the resulting disk, by evenly lubricating a magnetic media disk, increasing the viscosity of a selected region of the disk, and removing at least a portion of the lower viscosity region of the lubrication layer, thereby decreasing the thickness of the lubrication layer in the portion of the lower viscosity region, producing a magnetic media disk capable of closer head-to-media spacing in the portion of the lower viscosity region of the lubrication layer. | 01-28-2010 |
| 20100028721 | LUBRICANT FOR MAGNETIC DISK, PROCESS FOR PRODUCING THE SAME, AND MAGNETIC DISK - A lubricant for magnetic disks which can form a lubricating layer having a reduced thickness while attaining a high coverage and is excellent in heat resistance and adhesion to a protective layer. The lubricant for magnetic disks comprises a perfluoropolyether compound in which the relationship between the number-average molecular weight and the standardized value of the number of hydroxy groups contained in the molecule satisfies the following: the number-average molecular weight is in the range of 1,000-6,000; the standardized value of the number of hydroxy groups contained in the molecule is 180 or higher; and the compound is in a region located below the line connecting the point where the number-average molecular weight is 1,000 and the standardized value of the number of hydroxy groups in the molecule is 400 to the point where the number-average molecular weight is 6,000 and the standardized value of the number of hydroxy groups in the molecule is 1,600. The compound has at least one hydroxy group around the center of the molecular chain. | 02-04-2010 |
| 20100247978 | METHOD OF MANUFACTURING A SUBSTRATE FOR A MAGNETIC DISK - A magnetic disk substrate manufacturing method of this invention includes a main surface polishing process that polishes disk-shaped glass substrates by the use of a polishing machine having a carrier pressed between a pair of polishing surface plates and adapted to make an orbital motion while rotating on its axis in a state of holding the disk-shaped glass substrates. In the polishing machine, the carrier is placed in a state where a plate-like member is disposed on one side of main surfaces of the disk-shaped glass substrate, so that only the other side of the main surfaces of the disk-shaped glass substrate is polished while allowing the one side of the main surfaces of the disk-shaped glass substrates to be a non-polishing main surface. | 09-30-2010 |
| 20100273030 | GLASS SUBSTRATE FOR A MAGNETIC DISK, MAGNETIC DISK AND METHOD OF MANUFACTURING A MAGNETIC DISK - A glass substrate for a magnetic disk, wherein, in regions with respect to two places arbitrarily selected on a surface of the glass substrate on its central portion side relative to its outer peripheral end, a surface shape with a shape wavelength in a band of 60 to 500 μm is extracted from surface shapes in each of the regions and, assuming that a root mean square roughness Rq of the surface shape is given as a microwaviness Rq, the difference between the microwavinesses Rq of the regions is 0.02 nm or less or the difference between standard deviations of the microwavinesses Rq of the regions is 0.04 nm or less. | 10-28-2010 |
| 20120077060 | EVALUATION METHOD OF MAGNETIC DISK, MANUFACTURING METHOD OF MAGNETIC DISK, AND MAGNETIC DISK - An evaluation method that can easily evaluate properties of a carbon protective film and a lubricant on a magnetic-disk surface or particularly, an evaluation method of a magnetic disk in which the properties of the magnetic-disk surface can be evaluated accurately so that a strict demand for interactions between the magnetic-disk surface and a head can be met is provided. In a state in which an element portion of the magnetic head provided with the head element portion that projects by thermal expansion is projected, after being brought into contact with a predetermined radial position on the surface of the rotating magnetic disk, the head is further made to perform seeking in a state in which the element portion is projected by a specified amount, whereby the properties of the carbon film or the lubricant formed on the magnetic-disk surface is evaluated. | 03-29-2012 |
| 20120129009 | Perpendicular Magnetic Recording Disc | 05-24-2012 |
| 20120276417 | LUBRICANT FOR MAGNETIC DISK AND MAGNETIC DISK - A lubricant for a magnetic disk that is excellent in heat resistance and is suitably used in a magnetic disk to be mounted on a magnetic recording device of a thermally assisted magnetic recording system and a magnetic disk provided with a lubricant layer containing this lubricant. The lubricant for a magnetic disk contains a compound where perfluoropolyether groups each having a perfluoropolyether main chain in its structure and a phosphazene ring at an end are linked to each other through a linking group. The linking group is an aliphatic group or a phosphazene ring. In a magnetic disk having at least a magnetic recording layer, a protective layer, and a lubricant layer on a substrate, the lubricant layer contains the lubricant for a magnetic disk. | 11-01-2012 |
| 20130034749 | CYCLOPHOSPHAZENE COMPOUND, LUBRICANT COMPRISING SAME, AND MAGNETIC DISK - A cyclophosphazene compound of the formula (I), and lubricants and magnetic disks using the compound | 02-07-2013 |
| 20140127534 | MEDIA HAVING GRAPHENE WEAR PROTECTION LAYERS - An optical or magnetic storage medium is disclosed that includes a disc having layers of graphene on one or both sides of the disc to provide wear protection against scratches and mechanical abrasion. | 05-08-2014 |
| 428848100 | Having zones (e.g., landing zone or contact stop/start (CSS) zone, etc.) | 3 |
| 20090305082 | MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING AND REPRODUCING DEVICE WITH MAGNETIC RECORDING MEDIUM, AND MAGNETIC-RECORDING-MEDIUM MANUFACTURING METHOD - Although dots and servo patterns are made of the same magnetic material, the dots have a relatively low coercive force so as to allow data deletion and rewrite by a magnetic head, whilst the servo patterns have a high coercive force compared with the coercive force of the dots. The coercive force of the servo patterns is strong enough so as to eliminate the influence of shape magnetic anisotropy. | 12-10-2009 |
| 20110143171 | DATA ZONE LUBE REMOVAL - In an embodiment, a magnetic disk comprising a substrate having a non-data zone region and a data zone region and a lubrication layer on the substrate, wherein a portion of the lubrication layer on the non-data zone region has a greater thickness of higher viscosity than a portion of the lubrication layer on the data zone region. | 06-16-2011 |
| 20110311841 | MAGNETIC DISK AND METHOD FOR MANUFACTURING SAME - Provided are a magnetic disk comprising a granular magnetic recording layer which causes less noise even with a recording capacity thereof of 250 G or more bits per square inch; and a method for manufacturing the same. The magnetic disk according to the present invention comprises: a granular magnetic recording layer ( | 12-22-2011 |
| 428848200 | Specified texture or roughness (e.g., average roughness (Ra), etc.) | 4 |
| 20100081013 | MAGNETIC DISK SUBSTRATE AND MAGNETIC DISK - In a magnetic disk substrate being annular and having a first and a second main surface, (1) surface roughness measured by an atomic force microscope having a resolution of 256×256 pixels per 2 μm square and/or (2) the number of foreign substances detected to have sizes of 0.1 μm or more and 1.0 μm or less upon detection of scattered light from the magnetic disk substrate when laser light with a wavelength of 405 nm is irradiated with a spot size of 5 μm at a laser power of 25 mW differ/differs between the first and the second main surfaces. Only the first main surface has a surface quality usable as a magnetic recording surface. The number of the foreign substances detected to have the sizes of 0.1 μm or more and 1.0 μm or less upon detection of the scattered light from the magnetic disk substrate when the laser light with the wavelength of 405 nm is irradiated with the spot size of 5 μm at the laser power of 25 mW is 400 or less per 30 cm | 04-01-2010 |
| 20100227202 | BIT-PATTERNED MEDIA WITH ANTIFERROMAGNETIC SHELL - A method of producing bit-patterned media is provided whereby a shell structure is added on a bit-patterned media dot. The shell may be an antiferromagnetic material that will help stabilize the magnetization configuration at the remanent state due to exchange coupling between the dot and its shell. Therefore, this approach also improves the thermal stability of the media dot and helps each individual media dot maintain a single domain state. | 09-09-2010 |
| 20130136952 | SUBSTRATE FOR MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING MEDIUM, METHOD OF MANUFACTURING MAGNETIC RECORDING MEDIUM, AND METHOD OF INSPECTING SURFACE - A substrate for a magnetic recording medium having a disc shape with a central hole is provided in which the surface roughness of the principal surface of the substrate is 1 angstrom or less in terms of root mean square roughness (Rq) when a space period (L) of an undulation in the circumferential direction is in the range 10 to 1,000 μm, and in which when a component in the vertical axis direction of a line segment Z connecting a point A with the space period (L) of 10 μm and a point B with the space period (L) of 1,000 μm in a curve S marked on a double logarithmic graph which is obtained by analyzing the surface roughness using a spectrum and in which the horizontal axis is set to the space period (L) (μm) and the vertical axis is set to the power spectrum density (PSD) (k·angstrom | 05-30-2013 |
| 428848300 | Uniform texture | 1 |
| 20090214897 | MAGNETIC STORAGE APPARATUS - A magnetic storage apparatus is provided with a perpendicular magnetic recording medium having a soft magnetic underlayer and a recording layer, and a magnetic head having a medium opposing surface. The soft magnetic underlayer has axes of easy magnetization oriented along a circumferential direction. A return yoke part of a recording element in the head includes return side yokes arranged in a radial direction of a main magnetic pole part on the medium opposing surface, whereby a magnetic flux of a recording magnetic field flows in the radial direction within the soft magnetic underlayer. | 08-27-2009 |
| 428848500 | Having specified pits, tracks, or indicia | 6 |
| 20090214898 | MAGNETIC RECORDING MEDIUM AND MANUFACTURING METHOD THEREOF - Embodiments of the present invention help to produce discrete track media and bit patterned media having both excellent recording and reproducing performance and reliability. According to one embodiment, a manufacturing method forms a nonmagnetic layer mainly composed of the same element as a nonmagnetic element contained in magnetic recording layers and on the magnetic recording layers and a mask layer having apertures for forming more concentrated parts of the nonmagnetic element in the magnetic recording layers on the nonmagnetic layer. The method implants ions of the nonmagnetic element through the nonmagnetic layer masked by the mask layer to form the more concentrated parts of the nonmagnetic element in the magnetic recording layer. | 08-27-2009 |
| 20090311558 | MAGNETIC RECORDING MEDIUM AND MANUFACTURING METHOD - A magnetic recording medium that includes: a disc-shaped substrate; and plural magnetization retainers arranged on the disc-shaped substrate in plural circulations around a center of the substrate, each of the magnetization retainers having a length in a circumferential direction in such a manner that the length becomes longer as closer to outer circumference at least in a predetermined area, each retaining magnetization individually, each being formed of a magnetic material having axis of easy magnetization of magnetocrystalline anisotropy in a direction perpendicular to front and back surfaces of the substrate, each being filled with an ion that weakens the magnetocrystalline anisotropy of the magnetic material such that an amount of ion implantation becomes less as closer to the outer circumference in the predetermined area. | 12-17-2009 |
| 20100173177 | MOLD STRUCTURE USED TO PRODUCE DISCRETE TRACK MEDIUM, IMPRINTING METHOD, METHOD FOR PRODUCING DISCRETE TRACK MEDIUM, AND DISCRETE TRACK MEDIUM - To provide a mold structure used to produce a discrete track medium, including in a surface of the mold structure: a plurality of line pattern forming concave portions which are positioned so as to be adjacent and substantially parallel to each other; and a communicating concave portion which is positioned so as to intersect the line pattern forming concave portions and connects the line pattern forming concave portions. | 07-08-2010 |
| 20100233517 | METHOD FOR MAKING A MASTER DISK FOR NANOIMPRINTING PATTERNED MAGNETIC RECORDING DISKS AND MASTER DISK MADE BY THE METHOD - A method for making a master disk to be used for nanoimprinting patterned-media magnetic recording disks uses sidewall lithography. In one implementation, the master disk substrate has a first pattern of concentric rings formed on it by sidewall lithography, followed by a second pattern of generally radially-directed pairs of parallel lines, also formed by sidewall lithography, with the pairs of parallel lines intersecting the rings. An etching process is then performed, using the upper pattern as an etch mask, to remove unprotected portions of the underlying concentric rings. This leaves a pattern of pillars on the substrate, which then serve as an etch mask for an etching process that etches unprotected portions of the master disk substrate. The resulting master disk then has pillars of substrate material arranged in a pattern of concentric rings and generally radially-directed pairs of parallel lines. | 09-16-2010 |
| 20110200846 | METHOD OF MANUFACTURING A MAGNETIC RECORDING MEDIUM HAVING A DISCRETE TRACK STRUCTURE - A method of manufacturing a magnetic recording medium having a discrete track structure enables the discrete track structure to be fabricated in a simple method with good productivity while maintaining satisfactory accuracy of the discrete track structure and holding favorable magnetic separation performance between tracks. The method comprises steps of: forming an aluminum film on a nonmagnetic substrate; executing an anodizing process on the aluminum film to form an alumina layer including nano-holes in a self-organizing manner; forming a resist pattern exposing recording track regions; and depositing a magnetic material in the nano-holes in the recording track regions. The method can further comprise a step of forming recessed parts at positions of the nano-holes to be formed in the anodizing process. The method can further comprise a step of forming a first underlayer of titanium and a second underlayer of gold. | 08-18-2011 |
| 20110300410 | Bit-Patterned Magnetic Media Formed in Filler Layer Recesses - A recessed field is formed surrounding resist columns that are in a pattern of bit patterned magnetic media. A filler layer is formed in the recessed field. The resist columns are removed to leave recesses in the filler layer that replicate the pattern. Bit patterned magnetic media is formed in the recesses. | 12-08-2011 |
| 428848600 | Edge feature (e.g., chamfered edge, etc.) | 1 |
| 20150340054 | MAGNETIC DISK SUBSTRATE WITH OFFSET PORTION ON A MAIN SURFACE WITHIN A RANGE OF 92.0 to 97.0% IN A RADIAL DIRECTION FROM A CENTER, MAGNETIC DISK WITH SUBSTRATE AND MAGNETIC DISK DEVICE - A magnetic disk substrate having a flat main surface, an end face, and a chamfered face formed between the main surface and the end face. The substrate has an offset portion, present on the main surface within a range of 92.0 to 97.0% in a radial direction from a center of the substrate. A distance from the center of the substrate to the end face of the substrate in a radial direction is 100%, the offset portion being raised or lowered with respect to a virtual straight line connecting two points on the main surface, set at positions of 92.0% and 97.0%. A maximum distance from the virtual straight line to the offset portion in a direction perpendicular to the virtual straight line is a “maximum offset value.” | 11-26-2015 |
