Patents by Inventor Alan Biggar Johnston

Alan Biggar Johnston 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: 8194508
    Abstract: The presently disclosed technology teaches a transducer head with a read sensor, a write pole, and one or more waveform sensors attached to the transducer head. Further, a waveform propagates in the direction of a BPM and the waveform sensor is configured to detect the waveform after it is reflected from the BPM. Additionally, a spin-polarized current is influenced by the BPM and a spin angular momentum sensor detects changes in spin angular momentum of the current. Further, a processor relates at least one property of the reflected waveform and/or current with positions of patterned bits on the BPM. The processor may then modify a timing signal and/or transducer head position to ensure that data bits are accurately written to the BPM. The end result is the ability to more quickly and accurately detect the patterned bits and synchronize a position of the transducer head with the patterned bits.
    Type: Grant
    Filed: November 5, 2009
    Date of Patent: June 5, 2012
    Assignee: Seagate Technology LLC
    Inventors: Alan Biggar Johnston, Dieter Klaus Weller, Mark Anthony Gubbins
  • Publication number: 20110102930
    Abstract: The presently disclosed technology teaches a transducer head with a read sensor, a write pole, and one or more waveform sensors attached to the transducer head. Further, a waveform propagates in the direction of a BPM and the waveform sensor is configured to detect the waveform after it is reflected from the BPM. Additionally, a spin-polarized current is influenced by the BPM and a spin angular momentum sensor detects changes in spin angular momentum of the current. Further, a processor relates at least one property of the reflected waveform and/or current with positions of patterned bits on the BPM. The processor may then modify a timing signal and/or transducer head position to ensure that data bits are accurately written to the BPM. The end result is the ability to more quickly and accurately detect the patterned bits and synchronize a position of the transducer head with the patterned bits.
    Type: Application
    Filed: November 5, 2009
    Publication date: May 5, 2011
    Applicant: Seagate Technology LLC
    Inventors: Alan Biggar Johnston, Dieter Klaus Weller, Mark Anthony Gubbins
  • Patent number: 6807027
    Abstract: A perpendicular write head includes a main pole, a return pole, and conductive coils. The main pole includes a seedlayer and a magnetic layer that is plated upon the seedlayer. The seedlayer is nonmagnetic, electrically conductive, and corrosion-resistant. The return pole is separated from the main pole by a gap at an air bearing surface of the write head and is coupled to the main pole opposite the air bearing surface. The conductive coils are positioned at least in part between the main pole and the return pole.
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: October 19, 2004
    Assignee: Seagate Technology LLC
    Inventors: Peter Kevin Mark McGeehin, Alison Mary Bell, Alan Biggar Johnston
  • Publication number: 20040028947
    Abstract: The present invention is directed to a corrosion resistant ferromagnetic alloy suitable for use as write pole material in on a magnetic media recording head, as well as to magnetic media heads containing the corrosion resistant alloy. The corrosion resistant film generally includes a rhodium-containing alloy, most typically a cobalt iron rhodium alloy. The invention is further directed to methods of forming the alloy and applying it to substrates, such as magnetic media recording heads. The corrosion resistant alloy provides significant corrosion resistance while simultaneously maintaining a high magnetic moment (Bs), which facilitates high density read and write functions.
    Type: Application
    Filed: October 17, 2002
    Publication date: February 12, 2004
    Inventors: Peter Kevin Mark McGeehin, Alan Biggar Johnston
  • Publication number: 20030189786
    Abstract: A perpendicular write head includes a main pole, a return pole, and conductive coils. The main pole includes a seedlayer and a magnetic layer that is plated upon the seedlayer. The seedlayer is nonmagnetic, electrically conductive, and corrosion-resistant. The return pole is separated from the main pole by a gap at an air bearing surface of the write head and is coupled to the main pole opposite the air bearing surface. The conductive coils are positioned at least in part between the main pole and the return pole.
    Type: Application
    Filed: December 17, 2002
    Publication date: October 9, 2003
    Applicant: Seagate Technology LLC
    Inventors: Peter Kevin Mark McGeehin, Alison Mary Bell, Alan Biggar Johnston
  • Patent number: 6222702
    Abstract: A shield for a read element of a magnetic recording head is disclosed. The shield includes a first and a second triangular shaped closure magnetic domains positioned approximate a top surface of the shield such that a first surface of each of the first and second magnetic domains are formed by a portion of a first side of the shield and a second side of the shield, respectively. The shield also includes a third and a fourth triangular shaped closure magnetic domains positioned approximate the bottom surface of the shield. A first surface of the third and fourth magnetic domains are formed by a portion of the first side and the second side of the shield, respectively. A first magnetic domain wall is positioned between the first and second triangular shaped closure magnetic domains, while a second magnetic domain wall is positioned between the third and fourth triangular shaped closure magnetic domains.
    Type: Grant
    Filed: August 13, 1998
    Date of Patent: April 24, 2001
    Assignee: Seagate Technology, Inc.
    Inventors: Declan Macken, Alan Biggar Johnston, Gregory Stephen Mowry, Charles Henry Tolman