Patents by Inventor Douglas W. Johnson

Douglas W. Johnson 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).

  • Publication number: 20120314318
    Abstract: Magnetic storage tape and techniques for erasing and writing to magnetic storage tape having a perpendicular squareness greater than 50 percent and a longitudinal squareness less than 50 percent are described. In general, the magnetic tape may be biased with a remanence magnetization, or magnetic orientation, in any direction. One or two head systems may use various magnetic field patterns to create the desired remanence magnetization. Servo marks may have a remanence magnetization in an opposite magnetic orientation than that of the remaining bias on the servo track, e.g., substantially perpendicular to the magnetic tape. In some examples, a write head may alternate the direction of the magnetic field to continuously bias and write servo patterns to the magnetic tape. In addition, a symmetrical servo mark may be created in the magnetic tape with a write head having a gap width approximately equal to the length of the servo mark.
    Type: Application
    Filed: June 13, 2011
    Publication date: December 13, 2012
    Applicant: Imation Corp.
    Inventors: Larold L. Olson, Douglas W. Johnson, Michael P. Sharrock
  • Publication number: 20120314322
    Abstract: Magnetic storage tape and techniques for erasing and writing to magnetic storage tape having a perpendicular squareness greater than 50 percent and a longitudinal squareness less than 50 percent are described. In general, the magnetic tape may be biased with a remanence magnetization, or magnetic orientation, in any direction. One or two head systems may use various magnetic field patterns to create the desired remanence magnetization. Servo marks may have a remanence magnetization in an opposite magnetic orientation than that of the remaining bias on the servo track, e.g., substantially perpendicular to the magnetic tape. In some examples, a write head may alternate the direction of the magnetic field to continuously bias and write servo patterns to the magnetic tape. In addition, a symmetrical servo mark may be created in the magnetic tape with a write head having a gap width approximately equal to the length of the servo mark.
    Type: Application
    Filed: June 13, 2011
    Publication date: December 13, 2012
    Applicant: Imation Corp.
    Inventors: Larold L. Olson, Douglas W. Johnson, Michael P. Sharrock
  • Patent number: 7889454
    Abstract: The invention is directed to a data storage medium that includes a plurality of servo bands distributed across the data storage medium and a plurality of data tracks positioned between each of the plurality of distributed servo bands. The data storage medium comprises a servo band pitch of less than 200 micrometers. The large number of servo bands distributed across the data storage medium with a relatively small servo band pitch reduces the influence of media dimensional instability. In this way, the invention may substantially increase data read head positioning accuracy, especially in the case of narrow track widths. A read head array arranged in a two-dimensional matrix that includes a first servo read head, a second servo read head, and a plurality of data read heads positioned between the first and second servo read heads may be applied to a data storage medium as described herein.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: February 15, 2011
    Assignee: Imation Corp.
    Inventors: Douglas W. Johnson, James S. Anderson, David A. Gobran, Denis J. Langlois
  • Patent number: 7878745
    Abstract: A stackable U-nut fastener includes first and second spaced arms and a folded edge portion interconnecting the arms. A plurality of U-nut fasteners can be engaged one with another to form a collated strip of fasteners. A collating tab from one arm of one U-nut fasteners engages an opening in an arm of an adjacent U-nut fastener.
    Type: Grant
    Filed: April 16, 2009
    Date of Patent: February 1, 2011
    Assignee: Illinois Tool Works Inc.
    Inventors: Anthony A. Allen, Don Hinson, John M. Kosidlo, Douglas W. Johnson, Troy D. Carman
  • Patent number: 7835108
    Abstract: The invention is directed to techniques for erasing data storage tape for reuse. In an embodiment, an erase head module for erasing data storage tape comprises a set of erase gaps and one or more servo read elements. The set of erase gaps is configured to coincide with data bands of the data storage tape to allow erasure of only the data bands of the data storage tape while not erasing servo bands of the data storage tape. The one or more servo read elements detect one of the servo bands of the data storage tape when the set of erase gaps are proximate the data bands of the data storage tape to allow the erase head module to accurately track the data bands with the set of erase gaps.
    Type: Grant
    Filed: June 28, 2007
    Date of Patent: November 16, 2010
    Assignee: Imation Corp.
    Inventors: Douglas W. Johnson, Yung Yip
  • Publication number: 20090311071
    Abstract: A stackable U-nut fastener includes first and second spaced arms and a folded edge portion interconnecting the arms. A plurality of U-nut fasteners can be engaged one with another to form a collated strip of fasteners. A collating tab from one arm of one U-nut fasteners engages an opening in an arm of an adjacent U-nut fastener.
    Type: Application
    Filed: April 16, 2009
    Publication date: December 17, 2009
    Inventors: Anthony A. Allen, Don Hinson, John M. Kosidlo, Douglas W. Johnson, Troy D. Carman
  • Patent number: 7595950
    Abstract: 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.
    Type: Grant
    Filed: March 27, 2006
    Date of Patent: September 29, 2009
    Assignee: Imation Corp.
    Inventors: Larold L. Olson, Brian D. Findlay, C. Thomas Jennings, Douglas W. Johnson, Denis J. Langlois, Richard W. Molstad
  • Publication number: 20090122446
    Abstract: A data storage tape guiding system is configured to guide a data storage tape along a tape path crossing a read/write head. The data storage tape guiding system includes data storage tape supply components and data storage tape take-up components. An entirety of the supply components is disposed on a common first plane on a first side of the read/write head. An entirety of the take-up components is disposed on a common second plane on a second side of the read/write head. The common first plane is different than the common second plane.
    Type: Application
    Filed: November 12, 2007
    Publication date: May 14, 2009
    Inventors: Douglas W. Johnson, James L. Albrecht, Geoffrey A. Lauinger, Gregory W. Visich
  • Publication number: 20090073604
    Abstract: The invention is directed to a data storage medium that includes a plurality of servo bands distributed across the data storage medium and a plurality of data tracks positioned between each of the plurality of distributed servo bands. The data storage medium comprises a servo band pitch of less than 200 micrometers. The large number of servo bands distributed across the data storage medium with a relatively small servo band pitch reduces the influence of media dimensional instability. In this way, the invention may substantially increase data read head positioning accuracy, especially in the case of narrow track widths. A read head array arranged in a two-dimensional matrix that includes a first servo read head, a second servo read head, and a plurality of data read heads positioned between the first and second servo read heads may be applied to a data storage medium as described herein.
    Type: Application
    Filed: November 13, 2008
    Publication date: March 19, 2009
    Inventors: Douglas W. Johnson, James S. Anderson, David A. Gobran, Denis J. Langlois
  • Patent number: 7495859
    Abstract: 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.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: February 24, 2009
    Assignee: Imation Corp.
    Inventors: Mark P. Weber, Richard E. Jewett, Douglas W. Johnson, Richard W. Molstad, Alan R. Olson
  • Publication number: 20090002859
    Abstract: The invention is directed to techniques for erasing data storage tape for reuse. In an embodiment, an erase head module for erasing data storage tape comprises a set of erase gaps and one or more servo read elements. The set of erase gaps is configured to coincide with data bands of the data storage tape to allow erasure of only the data bands of the data storage tape while not erasing servo bands of the data storage tape. The one or more servo read elements detect one of the servo bands of the data storage tape when the set of erase gaps are proximate the data bands of the data storage tape to allow the erase head module to accurately track the data bands with the set of erase gaps.
    Type: Application
    Filed: June 28, 2007
    Publication date: January 1, 2009
    Inventors: Douglas W. Johnson, Yung Yip
  • Patent number: 7466510
    Abstract: The invention is directed to a data storage medium that includes a plurality of servo bands distributed across the data storage medium and a plurality of data tracks positioned between each of the plurality of distributed servo bands. The data storage medium comprises a servo band pitch of less than 200 micrometers. The large number of servo bands distributed across the data storage medium with a relatively small servo band pitch reduces the influence of media dimensional instability. In this way, the invention may substantially increase data read head positioning accuracy, especially in the case of narrow track widths. A read head array arranged in a two-dimensional matrix that includes a first servo read head, a second servo read head, and a plurality of data read heads positioned between the first and second servo read heads may be applied to a data storage medium as described herein.
    Type: Grant
    Filed: June 3, 2005
    Date of Patent: December 16, 2008
    Assignee: Imation Corp.
    Inventors: Douglas W. Johnson, James S. Anderson, David A. Gobran, Denis J. Langlois
  • Publication number: 20080278846
    Abstract: A magnetic tape system comprises a magnetic tape, a magnetic head, a set of guides arranged to guide the magnetic tape along a tape path over the magnetic head, a first resistance mechanism, and a second resistance mechanism. The set of guides comprises a first rotatable guide positioned before the magnetic head along the tape path and including a first flyable tape path surface, and a second rotatable guide positioned after the magnetic head along the tape path and including a second flyable tape path surface. The first and second resistance mechanisms resist rotation of the first and seconds guides, respectively.
    Type: Application
    Filed: May 10, 2007
    Publication date: November 13, 2008
    Inventors: James S. Anderson, Douglas W. Johnson
  • Patent number: 7436622
    Abstract: The invention is directed to techniques for storing information on a linear data storage medium, such as magnetic tape. According to the invention, a write head array concurrently writes a plurality of data tracks and at least one servo track onto the magnetic tape. In this way, the servo track is integrated between the data tracks. The servo track may, for instance, be located in the middle of a data band, and may span a distance corresponding to two data tracks. By concurrently writing the servo track with the data tracks, track misregistration (TMR) can be reduced or eliminated during the write operation.
    Type: Grant
    Filed: July 31, 2006
    Date of Patent: October 14, 2008
    Assignee: Imation Corp.
    Inventors: Douglas W. Johnson, Denis J. Langlois
  • Publication number: 20080198500
    Abstract: 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.
    Type: Application
    Filed: February 20, 2007
    Publication date: August 21, 2008
    Inventors: Mark P. Weber, Richard E. Jewett, Douglas W. Johnson, Richard W. Molstad, Alan R. Olson
  • Patent number: 7379254
    Abstract: The invention is directed to a servo frame that includes servo windows written with different frequencies to provide redundant positioning information. The servo frame includes a set of first servo windows recorded at a first frequency and a set of second servo windows recorded at a second frequency arranged in a checkerboard-like pattern. The different frequencies of the servo windows allow the servo frame to achieve improved positioning information redundancy. A servo track may include a plurality of the servo frames described herein to accurately position data read/write heads adjacent corresponding data tracks. The redundancy built into each of the servo frames substantially minimizes errors in the positioning information.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: May 27, 2008
    Assignee: Imation Corp.
    Inventors: Denis J. Langlois, Douglas W. Johnson
  • Patent number: 7342748
    Abstract: 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.
    Type: Grant
    Filed: December 14, 2004
    Date of Patent: March 11, 2008
    Assignee: Imation Corp.
    Inventors: Yung Yip, James S. Anderson, Douglas W. Johnson, Denis J. Langlois, Richard W. Molstad
  • Publication number: 20080024905
    Abstract: The invention is directed to techniques for storing information on a linear data storage medium, such as magnetic tape. According to the invention, a write head array concurrently writes a plurality of data tracks and at least one servo track onto the magnetic tape. In this way, the servo track is integrated between the data tracks. The servo track may, for instance, be located in the middle of a data band, and may span a distance corresponding to two data tracks. By concurrently writing the servo track with the data tracks, track misregistration (TMR) can be reduced or eliminated during the write operation.
    Type: Application
    Filed: July 31, 2006
    Publication date: January 31, 2008
    Inventors: Douglas W. Johnson, Denis J. Langlois
  • Patent number: 7204445
    Abstract: The invention is directed to arrangements of tape guides which can improve the guiding of data storage tape. Tape guides having specific sizes relative to the data storage tape are also disclosed. The disclosed tape guides and arrangements of tape 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. The invention is particularly useful for magnetic tape, but may also find application with optical tape, holographic tape, or other formats of data storage tape.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: April 17, 2007
    Assignee: Imation Corp.
    Inventors: Douglas W. Johnson, Allan R. Markert, Wayne P. Schaefer, Robert W. Tapani
  • Patent number: 7204446
    Abstract: 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.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: April 17, 2007
    Assignee: Imation Corp.
    Inventors: Douglas W. Johnson, James S. Anderson, Richard W. Molstad, Robert W. Tapani