Patents by Inventor Theodore A. Schwarz

Theodore A. Schwarz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6947247
    Abstract: 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.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: September 20, 2005
    Assignee: Advanced Research Corporation
    Inventors: Theodore A. Schwarz, Matthew P. Dugas
  • Publication number: 20050195525
    Abstract: 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.
    Type: Application
    Filed: February 17, 2005
    Publication date: September 8, 2005
    Inventors: Matthew Dugas, Theodore Schwarz
  • Publication number: 20050180040
    Abstract: 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.
    Type: Application
    Filed: March 2, 2004
    Publication date: August 18, 2005
    Inventors: Matthew Dugas, Theodore Schwarz
  • Publication number: 20050168869
    Abstract: 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.
    Type: Application
    Filed: January 30, 2004
    Publication date: August 4, 2005
    Inventors: Matthew Dugas, Theodore Schwarz
  • Publication number: 20040223248
    Abstract: 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.
    Type: Application
    Filed: May 7, 2004
    Publication date: November 11, 2004
    Applicant: ADVANCED RESEARCH CORPORATION
    Inventors: Matthew P. Dugas, Theodore A. Schwarz, Gregory L. Wagner
  • Publication number: 20040174628
    Abstract: 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.
    Type: Application
    Filed: March 4, 2004
    Publication date: September 9, 2004
    Inventors: Theodore A. Schwarz, Matthew P. Dugas
  • Patent number: 6330123
    Abstract: 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≧2. The system may further include a head assembly having a single magnetoresistive read element tapped to provide at least (K+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.
    Type: Grant
    Filed: May 19, 2000
    Date of Patent: December 11, 2001
    Assignee: Imation Corp.
    Inventors: Theodore A. Schwarz, Robert J. Youngquist, Hung T. Tran
  • Patent number: 6134070
    Abstract: 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.
    Type: Grant
    Filed: May 22, 1997
    Date of Patent: October 17, 2000
    Assignee: Imation Corp.
    Inventors: Hung T. Tran, Theodore A. Schwarz, Robert J. Youngquist, Alan R. Olson, Richard W. Molstad, Gary D. Moeller, Richard E. Jewett, Christopher L. Hill
  • Patent number: 6122147
    Abstract: 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.
    Type: Grant
    Filed: January 5, 1999
    Date of Patent: September 19, 2000
    Assignee: Imation Corp.
    Inventors: A. Saeed Fahimi, Theodore A. Schwarz
  • Patent number: 6091565
    Abstract: 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 .gtoreq.2. The system may further include a head assembly having a single magnetoresistive read element tapped to provide at least (K+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.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: July 18, 2000
    Assignee: Imation Corp.
    Inventors: Theodore A. Schwarz, Robert J. Youngquist, Hung T. Tran
  • Patent number: 5946156
    Abstract: 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 .gtoreq.2. The system may further include a head assembly having a single magnetoresistive read element tapped to provide at least (K+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.
    Type: Grant
    Filed: March 4, 1997
    Date of Patent: August 31, 1999
    Assignee: Imation Corp.
    Inventors: Theodore A. Schwarz, Robert J. Youngquist, Hung T. Tran
  • Patent number: 5786967
    Abstract: Improved data protection features for a magnetic recording tape cartridge comprise a recess in the cartridge shell and a movable "file protect" device, which may be a rotatable plug or slidable member. The features enable tape drives to distinguish between two types of cartridges with otherwise identical form factors, allowing one of the cartridges to contain a recording tape with different characteristics that require the tape drive to identify the characteristics of the tape prior to use.
    Type: Grant
    Filed: December 3, 1993
    Date of Patent: July 28, 1998
    Assignee: Imation Corp.
    Inventors: Sten R. Gerfast, Eugene S. Johnson, Eddie T. Morioka, Theodore A. Schwarz, Robert W. Tapani
  • Patent number: 5609948
    Abstract: A wear-resistant thin-film magnetic head assembly and method of making same. The head assembly includes a wear-resistant layer of diamond-like carbon and a substrate of titanium carbide particles dispersed in an alumina matrix. Adhesion of the diamond-like carbon to the substrate is improved by depositing an adhesion promoting layer on the substrate. A second adhesion promoting layer can be deposited onto the diamond-like carbon layer to facilitate the deposition of electromagnetic circuitry on the diamond-like carbon layer. Diamond-like carbon can be used as an insulator anywhere inside the head assembly. The present invention simplifies the construction of a head assembly and increases its resistance to wear by moving magnetic media.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: March 11, 1997
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Moses M. David, Theodore A. Schwarz
  • Patent number: 5572378
    Abstract: A direct file access system for a magnetic tape where all data files begin at a designated location on the tape. The direct file access system may be used with a reduced rewind data configuration to decrease data access time. The reduced rewind data configuration divides data files into generally equal portions so that data files begin and end at the designated location on the tape, eliminating rewind sequences. A method and system for reducing the number of tape retensioning passes is included to further decrease access time.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: November 5, 1996
    Assignee: Imation Corp.
    Inventors: Theodore A. Schwarz, Robert E. Wolff, Robert J. Youngquist
  • Patent number: 5541793
    Abstract: A bidirectional thin-film magnetoresistive tape head assembly. The invention minimizes wear on the head assembly by: (1) minimizing the distance between the read elements and their respective write elements, (2) forming the head assembly from hard materials, and (3) placing a hard block between the read and write elements. The head assembly uses only a single pair of read and write elements per data track, but the pairs are reversed with respect to each other so that the head assembly is capable of reading-while-writing on the tape in both directions.
    Type: Grant
    Filed: April 4, 1994
    Date of Patent: July 30, 1996
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Theodore A. Schwarz
  • Patent number: 5434732
    Abstract: A mechanism for accurately positioning a recording/playback head on the center of a track including a stepper motor and coil assembly in combination controlling coarse and fine transverse head position. The coil is attached to a pivoting actuator arm which provides a mounting member for a recording/playback head. A torsion spring is attached to the actuator arm and to a stage which is driven by a stepper motor lead screw to incrementally position the actuator arm. The coil assembly operates to pivot the recording/playback head transversely, thereby providing fine position control, and is mounted together with other members at either sides of a pivot axis to provide a dynamically balanced structure.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: July 18, 1995
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Theodore A. Schwarz, Durkee B. Richards, Robert J. Youngquist
  • Patent number: 5390054
    Abstract: A digital recording system utilizing a magnetoresistive transducer in a magnetic recording head. The system measures the amplitude of an output signal, E.sub.o, from the transducer for various bias currents as a recorded magnetic media passes by the head. The system then determines the bias current for which the output signal, E.sub.o, is maximized and multiplies that bias current by a suitable factor. The system then operates at the calculated bias current level, thereby minimizing the error rate of the system.
    Type: Grant
    Filed: March 12, 1993
    Date of Patent: February 14, 1995
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Robert Youngquist, Theodore Schwarz, Richard Molstad, Tim Ngo
  • Patent number: 5379170
    Abstract: A mechanism for accurately positioning a recording/playback head on the center of a track including a stepper motor and coil assembly in combination controlling coarse and fine transverse head position. The coil is attached to a pivoting actuator arm which provides a mounting member for a recording/playback head. A torsion spring is attached to the actuator arm and to a stage which is driven by a stepper motor lead screw to incrementally position the actuator arm. The coil assembly includes a coil bundle juxtaposed between at least two sets of split magnets. The coil assembly operates to pivot the recording/playback head transversely, thereby providing fine position control.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: January 3, 1995
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Theodore A. Schwarz
  • Patent number: 5339202
    Abstract: An adjustable write-equalized recording circuit for recording data onto a magnetic tape. The circuit variably adjusts the amplitude of write-equalization pulses relative to the data waveform by an amount that can be either preset or determined during operation.
    Type: Grant
    Filed: March 26, 1993
    Date of Patent: August 16, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: John E. Heinz, Michael E. Hamerly, Richard W. Molstad, Theodore A. Schwarz, Robert J. Youngquist
  • Patent number: 5331493
    Abstract: A bidirectional thin-film magnetoresistive tape head assembly. The invention minimizes wear on the head assembly by: (1) minimizing the distance between the read elements and their respective write elements, (2) forming the head assembly from hard materials, and (3) placing a hard block between the read and write elements. The head assembly uses only a single pair of read and write elements per data track, but the pairs are reversed with respect to each other so that the head assembly is capable of reading-while-writing on the tape in both directions.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: July 19, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Theodore A. Schwarz