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).
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Patent number: 7173794Abstract: 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.Type: GrantFiled: September 17, 2003Date of Patent: February 6, 2007Assignee: Imation Corp.Inventors: Richard W. Molstad, Douglas W. Johnson, Robert W. Tapani
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Patent number: 7139151Abstract: Time-based servopositioning systems, methods, formats, and data recording media used in association with the same, employing bands of signals that differ from each other in the polarity of the servo signal, or the orientation of the servo signal, or the pattern width of the servo signal.Type: GrantFiled: March 3, 2003Date of Patent: November 21, 2006Assignee: Imation Corp.Inventors: Douglas W. Johnson, Yung Yip
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Patent number: 7095583Abstract: 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.Type: GrantFiled: June 2, 2004Date of Patent: August 22, 2006Assignee: Imation Corp.Inventors: Douglas W. Johnson, Denis J. Langlois, Richard W. Molstad, Yung Yip
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Patent number: 7079343Abstract: 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.Type: GrantFiled: July 19, 2004Date of Patent: July 18, 2006Assignee: Imation Corp.Inventors: Richard W. Molstad, Douglas W. Johnson, Durkee B. Richards
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Patent number: 7054097Abstract: The invention provides a read-while-write recording system for a linear data storage medium, such as magnetic tape or other data storage medium in which data is stored on parallel data tracks that extend along a length of the medium. The invention makes use of separate sliders for the read and write elements, and separate actuators to control the positioning of the sliders. Each of the sliders may also include servo elements to read servo marks. In order to limit the effect of movement of the first slider on the positioning of the second slider, a tape guide is implemented between the different sliders.Type: GrantFiled: March 18, 2005Date of Patent: May 30, 2006Assignee: Imation Corp.Inventors: Yung Yip, Douglas W. Johnson
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Patent number: 7031097Abstract: 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.Type: GrantFiled: February 10, 2004Date of Patent: April 18, 2006Assignee: Imation Corp.Inventors: Richard W. Molstad, Douglas W. Johnson, Yung Yip
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Patent number: 7006329Abstract: A magnetic head assembly in a linear tape system. The magnetic head assembly includes a magnetic head having a central section, a first outrigger, and a second outrigger. The central section maintains at least one read/write element. The first outrigger is positioned adjacent the central section and forms at least one air bleed slot. The second outrigger is positioned adjacent the central section opposite the first outrigger and also forms at least one air bleed slot. Finally, the central section is laterally moveable relative to the outriggers. With this configuration, the moveable, central section, otherwise used for lateral positioning of the read/write element relative to a magnetic tape, is separated from the outriggers that otherwise minimize a fly height between the magnetic tape and the outriggers.Type: GrantFiled: June 2, 2003Date of Patent: February 28, 2006Assignee: Imation Corp.Inventors: Douglas W. Johnson, Christopher J. Zwettler, Saeed A. Fahimi
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Patent number: 6999269Abstract: 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.Type: GrantFiled: September 17, 2003Date of Patent: February 14, 2006Assignee: Imation Corp.Inventors: Douglas W. Johnson, Richard W. Molstad, Yung Yip
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Patent number: 6950269Abstract: Servopositioning data is written onto a linear recording medium such that a position error signal is intentionally created. Precise control over the distance between servo signals simulates position error signals at any frequency or magnitude. Drives that normally assume that such distance is constant perceive the simulated position error signals as vertical tape motion. Thus, a servo writer can create such signals at pre-determined levels within the servo pattern.Type: GrantFiled: January 18, 2002Date of Patent: September 27, 2005Assignee: Imation Corp.Inventor: Douglas W. Johnson
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Patent number: 6918553Abstract: In general, the invention is directed to techniques for reducing deformation of tape in data tape cartridges during storage to promote dimensional stability and increased tape longevity. The techniques involve controlling the winding tension applied to a tape during a final winding pass prior to unloading a data tape cartridge containing the tape from a drive. Excessive winding tensions can produce strain and compression on a tape pack, causing the tape to deform over time. Applications of reduced winding tension during the final pass provide reduced tape pack tension during periods in which the data tape cartridge is not used.Type: GrantFiled: February 5, 2003Date of Patent: July 19, 2005Assignee: Imation Corp.Inventors: Christopher J. Zwettler, Douglas W. Johnson
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Patent number: 6874720Abstract: A subambient pressure feature for assisting in guidance of storage tape within a tape transport system such as a data storage tape cartridge and/or a tape drive. The storage tape is extended between two tape reels along a tape path defined, in part, by a tape guide. The tape guide includes a curved tape-receiving surface defined by an entrance side and an exit side. The subambient pressure feature is located along the tape path and is adapted to induce frictional engagement between the tape and at least a portion of the tape-receiving surface at speeds of not less than 1 meter/second to suppress lateral tape motion.Type: GrantFiled: June 2, 2003Date of Patent: April 5, 2005Assignee: Imation Corp.Inventors: Christopher J. Zwettler, Saeed A. Fahimi, Michael A. Mewes, Douglas W. Johnson
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Patent number: 6842305Abstract: A servo track configuration includes at least one servo track having a width. A servo pattern is repeatedly recorded in the at least one servo track. Repeatedly recording the servo pattern includes repeating the simultaneous recording of first and second reference pattern lines and a track pattern line in the at least one servo track. Each of the first and second reference pattern lines has an identical predetermined geometry and extends across the width of the at least one servo track. Further, the track pattern line has a predetermined geometry that is different than the predetermined geometry of the first and second reference pattern lines and extends across the width of the at least one servo track.Type: GrantFiled: February 17, 2003Date of Patent: January 11, 2005Assignee: Imation Corp.Inventors: Richard W. Molstad, Michael J. Kelly, Douglas W. Johnson
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Publication number: 20040240113Abstract: A magnetic head assembly in a linear tape system. The magnetic head assembly includes a magnetic head having a central section, a first outrigger, and a second outrigger. The central section maintains at least one read/write element. The first outrigger is positioned adjacent the central section and forms at least one air bleed slot. The second outrigger is positioned adjacent the central section opposite the first outrigger and also forms at least one air bleed slot. Finally, the central section is laterally moveable relative to the outriggers. With this configuration, the moveable, central section, otherwise used for lateral positioning of the read/write element relative to a magnetic tape, is separated from the outriggers that otherwise minimize a fly height between the magnetic tape and the outriggers.Type: ApplicationFiled: June 2, 2003Publication date: December 2, 2004Applicant: Imation Corp.Inventors: Douglas W. Johnson, Christopher J. Zwettler, Saeed A. Fahimi
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Publication number: 20040238668Abstract: A subambient pressure feature for assisting in guidance of storage tape within a tape transport system such as a data storage tape cartridge and/or a tape drive. The storage tape is extended between two tape reels along a tape path defined, in part, by a tape guide. The tape guide includes a curved tape-receiving surface defined by an entrance side and an exit side. The subambient pressure feature is located along the tape path and is adapted to induce frictional engagement between the tape and at least a portion of the tape-receiving surface at speeds of not less than 1 meter/second to suppress lateral tape motion.Type: ApplicationFiled: June 2, 2003Publication date: December 2, 2004Applicant: Imation Corp.Inventors: Christopher J. Zwettler, Saeed A. Fahimi, Michael A. Mewes, Douglas W. Johnson
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Publication number: 20040174132Abstract: Time-based servopositioning systems, methods, formats, and data recording media used in association with the same, employing bands of signals that differ from each other in the polarity of the servo signal, or the orientation of the servo signal, or the pattern width of the servo signal.Type: ApplicationFiled: March 3, 2003Publication date: September 9, 2004Applicant: Imation CorpInventors: Douglas W. Johnson, Yung Yip
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Patent number: 6781778Abstract: 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.Type: GrantFiled: July 16, 2001Date of Patent: August 24, 2004Assignee: Imation Corp.Inventors: Richard W. Molstad, Douglas W. Johnson, Durkee B. Richards
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Publication number: 20040149846Abstract: In general, the invention is directed to techniques for reducing deformation of tape in data tape cartridges during storage to promote dimensional stability and increased tape longevity. The techniques involve controlling the winding tension applied to a tape during a final winding pass prior to unloading a data tape cartridge containing the tape from a drive. Excessive winding tensions can produce strain and compression on a tape pack, causing the tape to deform over time. Applications of reduced winding tension during the final pass provide reduced tape pack tension during periods in which the data tape cartridge is not used.Type: ApplicationFiled: February 5, 2003Publication date: August 5, 2004Applicant: Imation Corp.Inventors: Christopher J. Zwettler, Douglas W. Johnson
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Patent number: 6685074Abstract: A dispensing apparatus and method are disclosed for dispensing sheet material from at least one roll of the sheet material. Dispensing is transferred from a stub roll to a reserve roll automatically in response to sensing a predetermined quantity of the stub roll. An isolating element is provided to lift the reserve roll out of contact with dispensing rollers during dispensing of sheet material from the stub roll, and a nipping element is provided to nip sheet material of the reserve roll when dispensing is transferred from the stub roll to the reserve roll. A cam controls movement of both the isolating element and the nipping element. Structure is also provided for sensing the diameter of the reserve roll of sheet material and providing an indication when the reserve roll is a predetermined diameter. The dispenser is quiet and capacity efficient.Type: GrantFiled: February 21, 2002Date of Patent: February 3, 2004Assignee: Fort James CorporationInventors: Dale T. Gracyalny, David Carpenter, Kamala Grasso, Douglas W. Johnson, Peter D. Johnson, John E. Longan, John R. Moody, Hugh L. Smith, Ronald J. Vish
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Publication number: 20030123179Abstract: A servo track configuration includes at least one servo track having a width. A servo pattern is repeatedly recorded in the at least one servo track. Repeatedly recording the servo pattern includes repeating the simultaneous recording of first and second reference pattern lines and a track pattern line in the at least one servo track. Each of the first and second reference pattern lines has an identical predetermined geometry and extends across the width of the at least one servo track. Further, the track pattern line has a predetermined geometry that is different than the predetermined geometry of the first and second reference pattern lines and extends across the width of the at least one servo track.Type: ApplicationFiled: February 17, 2003Publication date: July 3, 2003Inventors: Richard W. Molstad, Michael J. Kelly, Douglas W. Johnson
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Publication number: 20030106656Abstract: A creping blade for creping a cellulosic web from a rotatable cylinder in a creping process includes first and second side faces. The first side face is at least substantially opposite to the second side face. The blade also includes an upper surface that is not orthogonal to at least one of the first and second side faces. Also included are a plurality of notches. Each of the notches has a bottom portion and an open end. The bottom portion is at least substantially parallel to the upper surface and the open end is defined by at least a portion of the upper surface. The notches are configured to increase the caliper of the cellulosic web when the creping blade crepes the cellulosic web from an outer surface of the rotatable cylinder. Also provided are systems and methods for creping a cellulosic web and creped paper.Type: ApplicationFiled: January 21, 2003Publication date: June 12, 2003Applicant: Fort James CorporationInventors: Douglas W. Johnson, Dale T. Gracyalny