Minnesota Mining and Manufacturing Company

Advanced Research Corporation

Imation Corporation

Theodore A Schwarz

Matthew P Dugas

Robert J Youngquist

Hung Thien Tran

Gregory Lawrence Wagner

Richard W Molstad

Chak M Leung

Peter G Bischoff

Robert W Tapani

Durkee B Richards

Gary D Moeller

Johnny C Chen

Pradeep Thayamballi

Moses Mekala David

Sten R Gerfast

Michael E Hamerly

James S Anderson

Richard E Jewett

Steven R Seeman

John Eric Heinz

Alan R Olson

Christopher L Hill

Robert E Wolff

Eddie T Morioka

A Saeed Fahimi

Noel L Allen

Tim Ngo

Eugene S Johnson

A method of formatting magnetic media includes providing an integrated thin film magnetic recording head having a recording element. The recording element includes first and second magnetically permeable thin film subpole members separated by a substantially low permeability subgap member. An integrated electrically conductive coil structure is embedded in part within the subgap member and in part in-between the first and second subpole members. The recording element also includes a magnetically permeable thin film layer spanning from at least the first subpole member to the second subpole member and including one or more arbitrary recording gap patterns. The direction of film growth of the magnetically permeable thin film layer is substantially orthogonal to the direction of thin film growth of the first and second magnetically permeable thin film subpole members. The method includes passing magnetic media over the magnetic recording head to format the magnetic media.

Magnetic media formatted with an intergrated thin film subgap subpole structure for arbitrary gap pattern magnetic recording head

A method of recording servo information includes writing servo information in a data storage medium using a compound magnetic recording head. The compound magnetic recording head has a substrate including first and second magnetically permeable substrate portions and a substantially non-magnetic member interposed between the first and second magnetically permeable substrate portions. A magnetically permeable layer is provided over the first and second magnetically permeable substrate portions of the substrate and includes first and second writing gap features associated with the first and second substrate portions. The writing gap features are formed using a patterned mask layer over the magnetically permeable layer, wherein the patterned mask layer comprises first and second patterned gap features corresponding to the first and second writing gap features.

Methods for recording servo information

The present invention relates to direct current ('DC') pre-erasing servo channels of a magnetic tape prior to writing servo data in a servo channel. The present invention particularly relates to those servo recordings which were written with a uni-polar current waveform. The DC pre-erase is performed using a uni-polar direct current of a polarity that is opposite to the polarity of the direct current used to write the servo data. This pre-erase may be done with one or more heads. Also, as will be described, the pre-erase of a servo channel and writing to a servo channel may be done by making two passes over a single head or by using two or more heads to perform both steps. Also, it is within the scope of the present invention to have the heads mounted on a single mount or have the heads on separate mounts and on separate tape decks.

Apparatuses and methods for pre-erasing during manufacture of magnetic tape

Servo track magnetic recording head for pre-erasing magnetic tape

The present invention relates to apparatuses and methods used in manufacturing magnetic tape. More specifically, the present invention relates to a method of writing a servo pattern on magnetic tape so as to minimize errors in the servo pattern, the heads used to write such servo data, and the magnetic tape manufactured with such heads. Errors in the servo pattern may be minimized by synthesizing the slanted transitions in a time based servo pattern using servo write gaps that are perpendicular to the tape motion. In so minimizing errors, distortion in the reading and/or writing of the data tracks can be prevented.

Stepped time based servo pattern and head

An arbitrary gap thin film magnetic recording head is fabricated by forming a substrate based on traditional vertical planar thin film head wafer technology which is designed to produce an integrated subgap and subpole substrate structure. The recording head includes a pair of magnetically permeable thin film subpoles, separated by a low permeability subgap structure. An electrically conductive coil may be embedded, in part, within the subgap structure. Thus, the subpoles and subgap structure form part of a magnetic circuit. A highly permeable magnetic surface film spans from one subpole to the other having one or more arbitrary gap patterns. That is, a surface thin film is deposited and patterned on the tape bearing surface of the head to optimize various element configurations, gap patterns and head-to-tape medium contact.

Intergrated thin film subgap subpole structure for arbitrary gap pattern magnetic recording heads and method of making the same

Methods and systems for data recording and reading for increasing overall tape data storage density, especially for data written in azimuth style. The principles of the invention provide servo formats and systems that allow accurate on track guidance for higher density applications and that are less sensitive to off track error. Preferred embodiments of the invention offer servo formats and systems of the invention that allows positive track and group identification at the beginning, end, and optionally periodically along the length of a tape.

Servo systems, servo heads, servo patterns for data storage especially for reading, writing, and recording in magnetic recording tape

The present invention relates to a method of synthesizing the slanted transitions in a time based servo pattern using servo write gaps that are perpendicular to the tape motion. The present invention particularly relates to a method of writing a servo pattern on magnetic tape so as to minimize errors in the servo pattern. The slanted transitions in a time-based servo pattern are synthesized using servo write gaps that are perpendicular to the tape motion. The slanted portions of the write gaps are synthesized by a series of short segmented vertical and horizontal segments. In so minimizing errors, distortion in the reading and/or writing of the data tracks can be prevented.

Large angle azimuth recording methods and devices. In one aspect of the invention methods of recording one or data tracks having data transitions oriented at a large azimuth angle are provided. In another aspect of the invention methods of reading a data track having data transitions oriented at a large azimuth angle are provided. Such methods include steps of suppressing a side track signal. In other aspects of the invention, head modules and devices for writing and/or reading large azimuth angle data tracks are provided.

Large angle azimuth recording and head configurations

A tape servo system includes tape having bands of tracks including at least one data band having a plurality of data tracks of track pitch P and a servo band dedicated for servo information. The servo band includes two or more noncontiguous servo tracks with each pair of adjacent servo tracks of the two or more noncontiguous servo tracks having a center to center separation equal to M*P, wherein M for each pair of adjacent servo tracks may be any integer&gE;2. The system may further include a head assembly having a single magnetoresistive read element tapped to provide at least (K&plus;1) tapped servo read elements for use in reading servo information written to the servo band; wherein K is equal to the integer M for the pair of adjacent servo tracks having the greatest center to center separation and a repositioning assembly for repositioning the head assembly as a function of the servo information. Further, the center to center separation between pairs of adjacent servo tracks of the two or more noncontiguous servo tracks may be different for at least two pairs of adjacent servo tracks. A servo tracking data recording tape with two or more noncontiguous servo tracks having center to center separation between pairs of adjacent servo tracks being different for at least two pairs of adjacent servo tracks is also provided along with a method for servo track identification for use therewith. Further, track read/write head assemblies wherein the servo read and write elements are along the same gap lines as the data read and write assemblies, respectively, are provided.

Head assembly having a single pass servo writer

A servo track recording tape includes a plurality of data tracks and a servo band dedicated for servo information. The servo band includes substantially uniformly written servo carrier information across a predetermined servo carrier width along the length of the tape with at least one encoded track pitch defined therein. Each encoded track pitch has alternating erased and non-erased portions along the length of the tape for defining servo tracks. The alternating erased and non-erased portions of the at least one encoded track pitch include encoded information provided by varying the length of one or more of the erased portions. The encoded information may be representative of tape locations along the length of the tape. The servo band may include two or more encoded track pitches defined in the substantially uniformly written servo carrier information with each encoded track pitch defining corresponding servo tracks. The alternating erased and non-erased portions of each of the two or more encoded track pitches may include encoded information uniquely identifying the corresponding servo tracks. Another servo tracking data recording tape includes a servo band including at least one single frequency servo track written in an erased width of the servo band along the length of the tape. The single frequency servo track includes encoded blocks of information along the length of the tape representative of at least one characteristic of the tape. Systems, head assemblies and encoding methods for use in providing such encoded servo track recording tape configurations are also described.

Encoded servo track configurations, servo writer and systems/method

A magnetic head assembly in a linear tape system having an interface region having a substantially flat region with a substantially square leading edge and at least one cavity in the flat region. The cavity has a depth of about 0.5 micrometers to about 20 micrometers. At least one read-write element is located on the flat region adjacent to the cavity. As a magnetic tape traversing the interface region, a sub-ambient condition is generated. The magnetic tape is bent or otherwise deformed as it passes over the cavity, thereby increase tape stability at the interface with the read-write elements. A magnetic tape system for recording, reproducing and/or erasing magnetic information in a linear tape system or for servo-writing magnetic tapes is also disclosed.

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Woodbury, MN, United States of America

Theodore A Schwarz