Seagate Technology Incorporated

Shih-Fu Lee

David S Kuo

Neil Deeman

Koichi R Wago

Dieter Klaus Weller

Edward Charles Gage

William Albert Challener

Jason L Pressesky

Duane Clifford Karns

Kim Yang Lee

Li-Ping Wang

Bing K Yen

Joseph Leigh

Yong Hu

Alexander Yulievich Dobin

Jianmin Wang

Hamid Ghazvini

Eric Kenneth Dahlin

Koichi Wage

Dave M Tung

Elias Ted Johnson, Jr

A method of imprint lithography includes imprinting a first pattern with a first template on a first substrate of a lithographic template. A second pattern is imprinted with a second template on the substrate of the lithographic template. The first pattern and the second pattern at least partially overlap, thus forming a third pattern. The third pattern is lithographically formed on a second substrate with the lithographic template. In an embodiment, the first pattern is a concentric line pattern formed by thin film deposition. In an embodiment, the second pattern is a radial line pattern. In an embodiment the first pattern and the second pattern may have line frequency increased.

Method for imprint lithography

A method of performing writable optical recording of a medium to form multilevel oriented nano-structures therein, comprises steps of providing a disc-shaped, writable recording medium having a planar surface; and encoding data/information in the medium by forming a plurality of multilevel nano-structured pits in the surface by scanning with a focused spot of optical energy to form at least one data track therein, including scanning the optical spot in a cross-track direction while rotating the disc about a central axis.

Multilevel data structure

Systems and methods are provided for correcting write synchronization of a magnetic storage device with respect to magnetic storage media and its corresponding writable magnetic bits, or dots. In particular, these systems and methods involve using time-shifting principles to calibrate the magnetic storage devices to correct slow drifts of reader-writer timing. It is to be appreciated that time-shifting techniques can be applied in a variety of manners. For example, the very dots on the media can be positioned in time-shifted fashion. In another example, the writing to the dots can be time-shifted.

Time-shifted bits for write synchronization correction

An optical profiler for an ultra-smooth surface, such as a magnetic recording disk, provides for a normally incident beam deflection against the target surface to be profiled. A linearly polarized laser light of a first polarization is focused on the target surface in a normally incident direction. The beam is reflected back along its original path from the focal point. Optics are provided that change the polarization of the reflected beam to a second polarization. A reflected beam, with a second polarization, is directed onto a position sensitive detector for evaluation.

Method and optical profiler

A polarization detection system structured for optical read-out of disc-shaped optical data/information storage and retrieval media with surfaces comprised of pits or marks configured as multilevel oriented nano-structures (ONS) with varying pit or mark orientations and widths. The polarization detection system comprises: an optical beam source; a stage for mounting and rotating an optical disc medium about a central axis; at least one photodetector; a beam splitter positioned in an optical path between the source and stage, for directing an incident beam from the source onto an optical disc mounted on the stage and a return beam from the disc onto the photodetector; and an optical polarizer positioned in an optical path between the beam splitter and the at least one photodetector, for detection and analysis of changes in polarization of the return beam effected by variation of the orientation of the walls and/or widths of the pits or marks of the disc.

Polarization state detector systems and methods for read-out of multilevel oriented nano-structure optical media

Writeable optical recording of multilevel oriented nano-structure discs

A stamper/imprinter for use in forming a magnetic transition pattern in a magnetic material by means of contact printing, comprising: (a) a non-magnetic substrate having a major surface comprising a patterned plurality of spaced-apart recesses with a plurality of non-recessed areas therebetween, the patterned plurality of recesses corresponding to the magnetic transition pattern to be formed in the magnetic material; and (b) unidirectionally permanently magnetized material filling each of the plurality of recesses and having exposed surfaces substantially coplanar with the plurality of non-recessed areas.

Magnetic media patterning via contact printing utilizing stamper having magnetic pattern formed in non-magnetic substrate

The present invention provides a method for detecting missing servo patterns on printed recording media. In general, the method first comprises the step of generating a map of anticipated servo burst patterns for a magnetic medium. The magnetic medium is typically a magnetic storage disc. Next, the magnetic medium is placed onto a disc reading assembly. Using the disc reading assembly, individual servo bursts on the magnetic medium are identified. In one embodiment, signals from the magnetic medium are processed through a frequency down conversion process, coupled with band pass filtering and rms-to-DC conversion. This enables higher throughput of signal processing. A map of identified servo bursts on the magnetic medium can then be generated. The map of identified servo bursts is then compared with the map of anticipated servo burst patterns. In this way, missing servo bursts can be detected.

High throughput missing pattern detector for servo printed recording media

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

Contact printing of longitudinal magnetic media with perpendicularly applied magnetic field

A system and a method for measuring micro-waviness of a magnetic recording disk using a high-speed glide test are disclosed. The HSG test is a viable production-level test methodology for high performance media that require well-controlled and low micro-waviness.

High speed glide test for screening magnetic disc micro-waviness and a system therefor

A plurality of redundant sets of servo data are recorded on a magnetic hard disk. The set meeting a predetermine criteria is employed when the hard disk is assembled into a hard disk drive. The determination of which set has the criteria may be conducted by the disk drive itself. The criteria may include a determination the set of servo data having meeting a minimum quality criteria or the fewest errors. The criteria may include a selection of a set of servo data having a specific pattern where the prerecorded sets may comprise a differing servo patterns that may be used by disk drives requiring specific servo patterns. The servo data are printed onto the hard disk by means of a stamper or mask having all the sets of servo data.

Redundant servo pattern stamper

The invention relates to a method for testing a magnetic disc having a plurality of tracks, and apparatus for such testing. The method includes scanning the magnetic disc along radial lines, storing a sequence of data points representing slopes of a plurality of tracks along the radial lines, operating on the stored set of points to determine a measured average slope for each track around an entire revolution of each track to establish a representative slope for each of the tracks of the plurality of tracks, taking a radial moving average to establish a sequence of data points, and comparing the curvature profile to a pre-established limit to determine suitability of the disc for use in a disc drive.

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Fremont, CA, United States of America

Shih-Fu Lee