Abstract: An apparatus for forming a magnetic transition pattern in a magnetic material by contact printing, comprising: (a) a stamper having an imprinting surface comprising a plurality of projections and depressions arranged according to the magnetic transition pattern, the stamper being formed of at least one high saturation magnetization, high permeability magnetic material; (b) means for supporting a workpiece such that a surface thereof comprised of the magnetic material is in contact with the imprinting surface; (c) magnet means for applying a unidirectional re-alignment magnetic field to the stamper and workpiece to effect selective re-alignment of magnetic domains of portions of the magnetic material facing the depressions of the imprinting surface, such that the pattern of selectively re-aligned magnetic domains forms a pattern replicating the pattern of projections and depressions; and (d) means for applying sufficient pressure to the stamper and workpiece to overcome magnetic attraction between the stamp

Abstract: A high field contrast magnetic stamper/imprinter for use in patterning of magnetic and magneto-optical (MO) recording media by contact printing, comprises: (a) a layer of a magnetic material having a high saturation magnetization Bsat?˜1.2 and high permeability ??˜5, including a first, topographically patterned surface and a second surface opposite the first surface, the first, topographically patterned surface comprising a patterned plurality of spaced-apart recesses with a plurality of non-recessed areas therebetween, the topographical pattern corresponding to a magnetic pattern to be formed in a magnetic or MO recording medium; and (b) a layer of Ni on the second surface. A corrosion-resistant protective overcoat layer may be present on the topographically patterned surface. A method for manufacturing the stamper/imprinter is also disclosed.

Abstract: A method and apparatus for using a dual-beam interferometer to test surface flatness is provided. The interferometer directs two beams focused at distinct points on a testing surface, such as the surface of a magnetic recording disc. An offset distance “d” between the two beams is provided on the target surface. In the present invention, the separation distance “d” is adjustable. The feature of adjustable separation distance in the interferometer allows the interferometer to meet the different spatial frequency requirements of various applications. In operation, first and second reflected beams are returned to an intensity beam splitter, where they are split and then recombined into two new beams of substantially equal intensity. The second of the two new light beams is constructed by the interference of half intensity of the first and half intensity of second beams, and is sent to a photodiode.

Abstract: A method of forming a magnetic transition pattern in a magnetic material by contact printing comprises steps of providing a stacked assembly including a workpiece including a surface comprised of the magnetic material including a plurality of initialized, unidirectionally aligned magnetic domains, and a high saturation magnetization stamper having an imprinting surface in intimate contact with the workpiece surface, the imprinting surface comprising a plurality of projections and depressions arranged in a pattern corresponding to the magnetic transition pattern to be formed in the magnetic material, and selectively magnetically re-aligning the initialized, unidirectionally aligned magnetic domains by placing the assembly in a fixed gap contact printing apparatus including a magnet means having a pair of spaced-apart, stationary magnetic poles providing an oppositely directed, uniform intensity, unidirectional re-alignment magnetic field.

Abstract: A method of forming a magnetic transition pattern in a longitudinal magnetic recording medium, comprising steps of: (a) providing a magnetic recording medium including a layer of a magnetic material having a surface comprised of a plurality of longitudinally extending magnetic domains; (b) contacting the surface of the layer of magnetic material with a topographically patterned imprinting surface of a stamper/imprinter formed of at least one high saturation magnetization, high permeability magnetic material; and (c) applying a unidirectional magnetic field perpendicular to the imprinting surface of the stamper/imprinter, the perpendicular magnetic field creating a longitudinal magnetic field component of sufficient strength to effect selective alignment of the magnetic domains of those portions of the layer of magnetic material which face the depressions of the imprinting surface while retaining the alignment of the magnetic domains of those portions of the layer of magnetic material which face the project

Abstract: A magnetic printing apparatus includes a dipole magnet that supplies a magnetic field to a magnetic media, a holder for holding the magnetic media, a set of stampers with servo patterns and a press for pressing the magnetic media firmly against the stampers while the magnetic media and stampers are being exposed to a magnetic field and a set of elastomer pads to distribute and equalize the force of the press on the magnetic media. Servo formatting, using the contact magnetic printing apparatus, is done by positioning the magnetic media against the stampers. A force is then applied to the magnetic media and stamper so that the two are in firm contact with each other. A sequence of magnetic fields is then applied to the stampers and magnetic media which duplicates the servo patterns of the stamper onto the magnetic media.

Abstract: Disclosed is a method of increasing the efficiency of ultra-violet (UV) curing of a lubricant thin film utilized as a topcoat layer of a data/information storage medium, comprising irradiating the lubricant thin film with UV radiation of a wavelength corresponding to a wavelength of maximum absorption of UV radiation by the lubricant thin film. Also disclosed are data/information storage media, e.g., magnetic or MO disks, comprising the UV-cured lubricant thin films as topcoat layers.

Abstract: A system and method for corrosion problems in magnetic media resulting from moisture penetrating through the carbon layer into the magnetic layer by diffusion or other methods are overcome by processing the carbon overcoat to stop and/or inhibit the moisture penetration. The process involves removing moisture channels from protective overcoats of thin film magnetic media by irradiating the protective overcoat with ultraviolet (UV) radiation in an inert hydrophobic chemical environment. Afterwards, the thin film magnetic media can be removed into ambient atmosphere where it is coated with a lubricant.

Abstract: High areal recording density, magnetic hard disk recording media including CSS landing zones with laser-textured surfaces having shallow bump heights of from about 40 to about 80 ?, bump spacing in the circumferential and radial directions of from about 10 to about 30 ?m, and bump diameter of from about 4 to about 8 ?m, are provided for use in disk drive systems utilizing padded head sliders operating at very low head slider flying heights of about 0.7 ?inch or below.

Abstract: A method for thermally writing a magnetic servo pattern on a magnetic disc medium prior to assembling the medium in a disc drive is provided in which the medium is first magnetized in a uniform magnetization direction. A plurality of magnetic domains are then thermally written on the medium, one magnetic domain at a time, by individually heating each magnetic domain with a light beam while exposing the magnetic domain to a magnetic field. The magnetic field has an orientation that is opposite to the uniform magnetization direction. The light beam forms an illumination pattern on the medium having a shape that at least partially defines a boundary of each magnetic domain.

Abstract: A method and apparatus for using a dual-beam interferometer to test surface flatness is provided. The interferometer directs two beams focused at distinct points on a testing surface, such as the surface of a magnetic recording disc. An offset distance “d” between the two beams is provided on the target surface. In the present invention, the separation distance “d” is adjustable. The feature of adjustable separation distance in the interferometer allows the interferometer to meet the different spatial frequency requirements of various applications. In operation, first and second reflected beams are returned to an intensity beam splitter, where they are split and then recombined into two new beams of substantially equal intensity. The second of the two new light beams is constructed by the interference of half intensity of the first and half intensity of second beams, and is sent to a photodiode.

Abstract: A magnetic recording medium is formed with a distribution of servo-marks in the form of pits or indentations with an attendant reduction in potential corrosion and increased tribology. Embodiments providing a protective overcoat, e.g. containing carbon, over a magnetic recording medium having a servo-patterned substrate; applying a fluoropolyether comprising one or more acrylate groups on the protective overcoat by dip coating the magnetic recording medium in a solution of the fluoropolyether and polymerizing the fluoropolyether by ultraviolet radiation.

Abstract: A method of forming a magnetic transition pattern in a longitudinal magnetic recording medium, comprising steps of:

Abstract: An automatic testing system. A sampling and converting device obtains a plurality of electronic parameters from a tested device and transforms them into a plurality of digital signals. A microprocessor receives the digital signals and performs various short-circuit tests, over-current tests and over-voltage tests in a specific sequence.

Abstract: Marks with curved edges are used in data patterns and sensed with proximity recording. Circular, elliptical, and oval marks are examples of marks with curved edges that can be used in the present invention. The marks with curved edges are used to define data patterns (e.g. position error signal patterns) as a function of radius. If the marks with curved edges have been recorded longitudinally, an amplitude of a read back signal, such as a peak amplitude, is determined in order to generate a position error signal. If the marks with curved edges have been recorded vertically, an area under the curve of the read back signal is determined in order to generate a position error signal.

Abstract: A method for patterning a carbon-containing substrate utilizing a patterned layer of a resist material as a mask and then safely removing the mask from the substrate without adversely affecting the substrate, comprising sequential steps of: (a) providing a substrate including a surface comprising carbon; (b) forming a thin metal layer on the substrate surface; (c) forming a layer of a resist material on the thin metal layer; (d) patterning the layer of resist material; (e) patterning the substrate utilizing the patterned layer of resist material as a pattern-defining mask; and (f) removing the mask utilizing the thin metal layer as a wet strippable layer or a plasma etch/ash stop layer.

Abstract: High areal storage density, patterned magnetic media comprising a patterned plurality of at least partially crystalline, ferromagnetic particles or grains are provided by means of a simple, economical process wherein a non-magnetic substrate is provided with a layer of an amorphous, paramagnetic or anti-paramagnetic material comprising at least one component, e.g., a metal element, which is ferromagnetic when in at least partially crystalline form, and at least partially crystallizing the at least one component at selected areas of the amorphous layer to form a spaced-apart pattern of at least partially crystallized, ferromagnetic particles or grains of the at least one component, the particles or grains being spaced apart and surrounded by a matrix of the amorphous material. Embodiments include utilizing a focussed or scanned laser source and an amorphous Ni—P layer for forming ferromagnetic Ni particles or grains.

Abstract: A magnetic recording medium is formed with a distribution of servo-marks in the form of pits or indentations with an attendant reduction in potential corrosion and increased tribology. Embodiments providing a protective overcoat, e.g. containing carbon, over a magnetic recording medium having a servo-patterned substrate; applying a fluoropolyether comprising one or more acrylate groups on the protective overcoat by dip coating the magnetic recording medium in a solution of the fluoropolyether and polymerizing the fluoropolyether by ultraviolet radiation.

Abstract: A magnetic recording medium is formed with a distribution of servo-marks in the form of pits or indentations with an attendant reduction in potential corrosion and increased tribology. Embodiments providing a protective overcoat, e.g. containing carbon, over a magnetic recording medium having a servo-patterned substrate; applying a fluoropolyether comprising one or more acrylate groups on the protective overcoat by dip coating the magnetic recording medium in a solution of the fluoropolyether and polymerizing the fluoropolyether by ultraviolet radiation.

Abstract: A magnetic data recording medium substrate has a contact zone and a data zone. The contact zone is textured by forming multiple texturing features, each having a bell-shaped profile resembling a Gaussian curve. The features preferably are formed by pulsed laser energy applied to a glass substrate, or to an aluminum nickel-phosphorous substrate coated with a glass layer. As compared to previous laser texturing approaches, the laser beam is less narrowly focused to provide a beam impingement area with a diameter of at least three microns, forming texturing features with diameters of at least three microns. The texturing features preferably are uniform in height and diameter, and may be symmetrical or have asymmetrical aspects, so long as bell-shaped profiles are present in the direction of travel of the recording medium, relative to transducing heads.