Imation Corporation

Minnesota Mining and Manufacturing Company

Sony Corporation

Imation Ccorp.

Richard W Molstad

Douglas W Johnson

Yung Yip

Robert J Youngquist

Theodore A Schwarz

Denis J Langlois

Tim T Ngo

James S Anderson

Robert W Tapani

Durkee B Richards

Alan Olson

Richard E Jewett

Alan R Olson

Christopher L Hill

Bennett G Dy

Michael J Kelly

William Joseph Vanderheyden

Michael E Hamerly

Hung Thien Tran

Takanori Sato

Larold L Olson

Mark P Weber

Steven R Seeman

John Eric Heinz

Gary D Moeller

C Thomas Jennings

Brian D Findlay

Stacy A Henneberger

Tim Ngo

In an embodiment, a data storage tape includes a first side including recorded data and a second side including recorded error correcting code data for the recorded data on the first side. In another embodiment, a data storage tape comprises a first side including recorded data and a second side including a copy of the recorded data. Embodiments of the invention may distribute related data across both sides of a data storage tape and as a result may reduce the probability that a location-dependent error in the data storage tape will result in irretrievable data loss. Embodiments of the invention may be particularly useful for systems that can simultaneously retrieve or record data on both sides of a dual-sided data storage tape.

Robust data storage techniques for two-sided data storage tape

In general, the invention is directed to servo techniques that utilize servo patterns to facilitate head positioning relative to the data tracks. For example, the servo techniques may include a first series of servo patterns configured to allow calculation of a position error signal that substantially mitigates error resulting from a variation in velocity of the data storage tape during detection of the at least one of the servo patterns in the first series. The servo techniques may also include a second series of servo patterns interleaved within the first series of servo patterns in order to encode data. The encoded data may include linear position information. Embodiments may allow a data storage tape meeting a currently accepted data storage tape specification, e.g., an LTO Ultrium specification, to record data in a higher density than currently implemented with the specification.

Interleaved servo pattern

The invention provides a system comprising a non-linear array of magnetoresistive (MR) heads arranged in a two-dimensional matrix for reading information stored on magnetic media. The non-linear array of MR heads may comprise a planar array formed by a plurality of linear arrays of MR heads stacked to define a plurality of layers. Each of the linear arrays may share at least one shield element with another linear array of the non-linear array. In general, each layer is offset by one written track pitch and the number of layers of the invention is equal to the number of written track pitches in a channel pitch. The invention can also be used in a system for reading and writing information to magnetic media at improved track pitches relative to conventional read/write systems.

System with matrix array of write heads and matrix array of magnetoresistive (MR) read heads

The invention is directed to arrangements of tapered data storage tape guides which can improve the guiding of data storage tape. Tapered data storage tape guides having specific sizes relative to the data storage tape are also disclosed. The tapered data storage tape guides and arrangements of tapered guides can improve the ability to properly guide the data storage tape, e.g., during media fabrication, servo recording or readout, data recording or data readout. In one embodiment, a data storage tape guiding system may include a first tapered guide and a second tapered guide. The taper in the first guide can be opposite the taper in the second guide such that the data storage tape is forced against an upper flange of the first guide and forced against a lower flange of the second guide, or vice versa.

Data storage tape guiding systems using tapered guides

The invention provides a tape drive comprising a head mounted on a turntable. The turntable rotates to allow the head to access first and second sides of a data storage tape. Techniques for accessing the first and second sides may include rotating the turntable to position the head in first and second positions. In addition, the techniques may further include raising and lowering the turntable relative to the data storage tape in order to facilitate access to both sides of the data storage tape without requiring the data storage tape to be unspooled and re-spooled.

Accessing both sides of data storage tape

The invention is directed to patterns of amplitude-based servo windows that eliminate the need for conventional track identification marks, and various servo writing devices and head configurations that facilitate creation of such servo patterns. The patterns of servo windows may also eliminate the need for conventional synchronization marks. In accordance with the invention, the patterns of servo windows, themselves, can distinguish one track from another track in one or more servo bands and inherently provide synchronization without the need for synchronization marks between servo frames. In other words, the same amplitude-based servo windows that define the centerlines of the tracks can be arranged to provide track identification information and possibly inherent synchronization information.

Servo writing devices for creating servo patterns with inherent track ID

A servo pattern is described that facilitates high resolution and wide dynamic range to accurately pinpoint servo track centerlines on a magnetic tape. The servo pattern provides both absolute positioning information over an entire servo band and absolute positioning information relative to the centerline of each servo track included in the servo band. Therefore, the servo pattern includes implicit servo track identification in a single servo band, eliminating the need for conventional track identification marks. In other words, the servo pattern, itself, can distinguish one servo track from another servo track in the single servo band as well as provide highly accurate positioning information relative to each of the servo track centerlines.

Dual mode servo pattern

The invention combines the benefits of sectored servo data with the benefits of time-based servo data. Recording media such as magnetic tape, magnetic disks, optical tape and optical disks can store servo data in a time-based sectored servo format.

Time-based sectored servo data format

The invention provides a linear data storage medium, such as magnetic tape, in which data tracks that extend in one direction are recorded at a different density than data tracks recorded in the opposite direction. Various techniques are also described to facilitate such dual density recording. The invention is particularly advantageous for direction-dependent linear data storage media, by allowing similar error rates to be achieved in both directions on the media.

Dual density recording for direction-dependent linear media

Multi-band servo patterns with inherent track ID

Servo patterns with inherent track ID

The invention is directed to servo techniques that make use of sequences of servo marks, rather than individual marks for generation of position error signals. In particular, random or pseudo-random sequences of servo marks may be recorded on the medium in an overlapping fashion. For example, a first sequence of marks and a second sequence of marks may overlap in the servo track. The second sequence may be substantially non-correlated with the first sequence, and may be recorded in an offset location along the track relative to the first sequence. Different correlators can be used to detect the different sequences, and position error signals can be generated based on timings associated with the detection of the first sequence relative to the second sequence.

Sequenced time-based servo techniques

Servopositioning data is written onto a linear recording medium such that a position error signal (PES) is intentionally created. The signal substantially resembles a conventional time based servo pattern, but is insensitive to transverse position. In a preferred embodiment, the signal at a zero-azimuth, i.e., an angle sufficiently small in value such that there is no significant PES signal associated with the transverse motion.

Systems and methods for using noise measurement tracks with servopositioning signals

Servo positioning systems, methods, formats, and data recording media used in association with the same, employing additional timing reference information to improve immunity to time-based errors caused by instantaneous speed variations.

Time-based servopositioning systems

In general, the invention relates to a data storage tape including servo information on both sides of the tape. Techniques for writing servo information to both sides of the data storage tape are also described. For example, a mechanical arrangement of two servo write heads positioned with respect to the data storage tape can enable two-sided servo recording. In addition, a single servo write head may be used to write servo information to both sides of the data storage tape with the aid of a flux conductor. In that case, the magnetic field of the servo write head passes through the data storage tape to record servo information on both sides of the tape.

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Saint Paul, MN, United States of America

Richard W Molstad