摘要:
Fabrication of an MO disc, the formation of a master pattern of servo and track information, and the subsequent transfer of that pattern to a series of pits and grooves on a substrate. On top of that substrate, at least one sacrificial layer is provided atop a relatively hard layer. The recording stack may be provided with both silicon nitride and silicon dioxide top layers, with the silicon dioxide layer acting as a sacrificial layer to ensure that the hard layer, of silicon nitride, remains at the end of the process. A layer of aluminum or aluminum alloy may be deposited, with the aluminum plugs filling the grooves and pits (created by the embossed servo information) to a level higher than any of the adjacent layers of silicon dioxide, silicon nitride, or similar dielectric layer. Since the polishing rate of aluminum can be far faster than that of the silicon dioxide, then the aluminum can be etched or otherwise removed down to a level equal to or slightly below a planar surface with the silicon dioxide, with the silicon dioxide layer allowing for some small level of over polishing. The silicon nitride layer is protected completely; the silicon dioxide layer partially remains and is partially removed; and the aluminum metal which fills the grooves and pits would rise only to a level substantially equal the very flat top surface of the silicon dioxide.
摘要:
A data storage system including a source of heat, a substrate, a storage layer, a lubricant layer, a flying head, and a dielectric layer is disclosed. The dielectric layer is disposed between the lubricant layer and the storage layer. The flying head is disposed above the lubricant layer. The dielectric layer has a heat capacity that is sufficient to generate a temperature gradient between the storage layer and the lubricant layer so as to reduce lubricant evaporation onto the flying head.
摘要:
Fabrication of an MO disc, the formation of a master pattern of servo and track information, and the subsequent transfer of that pattern to a series of pits and grooves on a substrate. On top of that substrate, at least one sacrificial layer is provided atop a relatively hard layer. The recording stack may be provided with both silicon nitride and silicon dioxide top layers, with the silicon dioxide layer acting as a sacrificial layer to ensure that the hard layer, of silicon nitride, remains at the end of the process. A layer of aluminum or aluminum alloy may be deposited, with the aluminum plugs filling the grooves and pits (created by the embossed servo information) to a level higher than any of the adjacent layers of silicon dioxide, silicon nitride, or similar dielectric layer. Since the polishing rate of aluminum can be far faster than that of the silicon dioxide, then the aluminum can be etched or otherwise removed down to a level equal to or slightly below a planar surface with the silicon dioxide, with the silicon dioxide layer allowing for some small level of over polishing. The silicon nitride layer is protected completely; the silicon dioxide layer partially remains and is partially removed; and the aluminum metal which fills the grooves and pits would rise only to a level substantially equal the very flat top surface of the silicon dioxide.
摘要:
A positioning system for selectively directing a first beam of light towards a destination and a second beam of light towards a first diffractive optic. The first beam of light and the second beam of light traverse a substantially co-linear optical path. The first diffractive optic diffracts the second beam of light into a plurality of optical spots. The second beam of light comprising the plurality of optical spots is directed onto a second diffractive optic. A change in position of the plurality of optical spots relative to the second diffractive optic is sensed in a reflection of the second beam of light by a detection element and representative signals are derived thereof. The signals are coupled to a directing assembly, which directs the first beam of light towards the destination.
摘要:
Embodiments of a data storage system having thermally activated readout are provided, in one embodiment, a data storage system includes a source of heat, a substrate, a write layer disposed above the substrate, a copy layer disposed above the write layer, a flying head disposed above the layers and carrying the source of heat for heating a selected spot on the copy and write layers, wherein the write layer comprises a ferromagnetic material selected to have an extremely high coercivity at room temperature and a very high write temperature Twrite, and the copy layer comprises a ferromagnetic material selected to have a coercivity always less than coercivity of the write layer at the same temperature and a copy temperature Tcopy substantially less than the write temperature of the write layer.
摘要:
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.
摘要:
A method for self-servo writing begins by calibrating at least one ruler formed on at least one storage disk. A ruler is a position-sensing pattern that defines the radial position of a recording head. The calibration process determines at least one correction factor for the at least one ruler on the disk. A servo system is then activated and the correction factors are used when writing the final servo pattern. During the process of writing the final servo patterns, the correction factors are modified to account for variations in any repeatable disturbances and for errors caused by any non-repeatable disturbances.
摘要:
A system and method for encoding read-only information comprises a storage medium, a plurality of position marks disposed on the storage medium, and a light beam directed towards the position marks to produce a reflection of the light beam from the position marks. The position marks are configured such that the reflection of the light beam is not responsive to a plane of polarization of the light beam. In one embodiment, the position marks comprise rows of substantially circular pits. The dimensions of the substantially circular pits depend on a wavelength of the light beam and a numerical aperture of a lens that directs the light beam towards the position marks.
摘要:
An optical disk has groups of features (such as depressed areas) arranged in a preselected position sensing servo pattern, and a flat, non-grooved surface between a plurality of circumferentially spaced sectors. A single photodetector senses the change in amplitude of reflected light as a spot from a laser passes over one of the features and generates position sensing signals corresponding to the pattern. At least three phases of the position sensing signal are generated for each sector. Each phase is determined by edges on the disk offset circumferentially with respect to each other and separated radially from each other by a preselected critical distance that is independent of the pitch of the recording tracks on the disk to provide a track error signal that is substantially linear within a desired range to either side of a zero-crossing point.Each even sector includes a plurality of features formed in an arrangement which is the complement and/or reversal in order circumferentially of their arrangement in the intervening odd sectors to cancel simultaneously, by averaging the position sensing signals from adjacent sectors, errors caused by variations in pattern size and/or radial velocity of an optical head as it moves generally radially of the disk.