Patents by Inventor David Wachenschwanz

David Wachenschwanz 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: 7471484
    Abstract: A magnetic recording system includes a patterned medium comprised of land areas and trough areas, a write element which writes the data to the patterned medium, and a read element which reads the data from the patterned medium and servo information from the troughs. The land areas store data and the trough areas inhibit storage of data. The read element is wider than the write element.
    Type: Grant
    Filed: June 7, 2004
    Date of Patent: December 30, 2008
    Assignee: WD Media, Inc.
    Inventors: David Wachenschwanz, Michael McNeil, John Vicars
  • Publication number: 20070041306
    Abstract: A method of forming a discrete track recording pattern on a soft magnetic underlayer of a perpendicular magnetic recording disk. In one embodiment, the soft magnetic underlayer is continuous throughout the discrete track recording pattern.
    Type: Application
    Filed: October 27, 2006
    Publication date: February 22, 2007
    Inventors: David Wachenschwanz, Gerardo Bertero, David Treves, Andrew Homola, James Chao, Christopher Bajorek
  • Publication number: 20070039922
    Abstract: A method of forming a discrete track recording pattern on a soft magnetic underlayer of a perpendicular magnetic recording disk. In one embodiment, the soft magnetic underlayer is continuous throughout the discrete track recording pattern.
    Type: Application
    Filed: October 27, 2006
    Publication date: February 22, 2007
    Inventors: David Wachenschwanz, Gerardo Bertero, David Treves, Andrew Homola, James Chao, Christopher Bajorek
  • Patent number: 7161753
    Abstract: A discrete-track-recording (DTR) disk (also called “patterned” disk) has a sectored servo formed by modulation of its sidewalls in a predetermined manner, whereas sidewalls of data sectors are not modulated in this manner. Each servo sector has two side walls that are each respectively modulated in two different ways. Hence, a readback signal from a given servo sector contains components of each of the two different modulations, even in case of “DC” erase initiation. Therefore, the just-described modulated servo sectors eliminate servowriting. Moreover, data signals are read without filtering the modulation, because data sector sidewalls are not modulated.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: January 9, 2007
    Assignee: Komag, Inc.
    Inventors: David Wachenschwanz, David Treves
  • Publication number: 20060171051
    Abstract: A discrete-track-recording (DTR) disk (also called “patterned” disk) has a sectored servo formed by modulation of its sidewalls in a predetermined manner, whereas sidewalls of data sectors are not modulated in this manner. Each servo sector has two side walls that are each respectively modulated in two different ways. Hence, a readback signal from a given servo sector contains components of each of the two different modulations, even in case of “DC” erase initiation. Therefore, the just-described modulated servo sectors eliminate servowriting. Moreover, data signals are read without filtering the modulation, because data sector sidewalls are not modulated.
    Type: Application
    Filed: January 28, 2005
    Publication date: August 3, 2006
    Inventors: David Wachenschwanz, David Treves
  • Patent number: 7070870
    Abstract: A magnetic recording medium includes a substrate, an underlayer, a lower magnetic layer formed on the underlayer, an intermediate layer, and an upper magnetic layer formed on the intermediate layer. The intermediate layer is typically Ru, and promotes anti ferromagnetic coupling between the upper and lower magnetic layers. The upper and lower magnetic layers are typically Co alloys. The lower magnetic layer has a high saturation magnetization Ms to promote high exchange coupling between the upper and lower magnetic layers. The dynamic coercivity of the lower magnetic layer is lower than the exchange field to ensure rapid switching of the lower magnetic layer.
    Type: Grant
    Filed: February 1, 2005
    Date of Patent: July 4, 2006
    Assignee: Komag, Inc.
    Inventors: Gerardo Bertero, Sudhir Malhotra, David Wachenschwanz, Zhengsheng Shan, Donald Stafford
  • Publication number: 20060139814
    Abstract: A magnetic recording system includes a patterned medium comprised of land areas and trough areas, a write element which writes the data to the patterned medium, and a read element which reads the data from the patterned medium and servo information from the troughs. The land areas store data and the trough areas inhibit storage of data. The read element is wider than the write element.
    Type: Application
    Filed: June 7, 2004
    Publication date: June 29, 2006
    Inventors: David Wachenschwanz, Michael McNeil, John Vicars
  • Patent number: 7019924
    Abstract: A magnetic recording system includes a patterned medium comprised of land areas and trough areas, a write element which writes the data to the patterned medium, and a read element which reads the data from the patterned medium and servo information from the troughs. The land areas store data and the trough areas inhibit storage of data. The read element is wider than the write element.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: March 28, 2006
    Assignees: Komag, Incorporated, Maxtor Corporation
    Inventors: Michael McNeil, John Vicars, David Wachenschwanz
  • Publication number: 20050129984
    Abstract: A magnetic recording medium includes a substrate, an underlayer, a lower magnetic layer formed on the underlayer, an intermediate layer, and an upper magnetic layer formed on the intermediate layer. The intermediate layer is typically Ru, and promotes anti ferromagnetic coupling between the upper and lower magnetic layers. The upper and lower magnetic layers are typically Co alloys. The lower magnetic layer has a high saturation magnetization Ms to promote high exchange coupling between the upper and lower magnetic layers. The dynamic coercivity of the lower magnetic layer is lower than the exchange field to ensure rapid switching of the lower magnetic layer.
    Type: Application
    Filed: February 1, 2005
    Publication date: June 16, 2005
    Inventors: Gerardo Bertero, Sudhir Malhotra, David Wachenschwanz, Zhengsheng Shan, Donald Stafford
  • Publication number: 20050120545
    Abstract: A method of forming a discrete track recording pattern in a magnetic recording disk. In one embodiment, the discrete track recording pattern may be formed in a NiP layer continuous throughout the discrete track recording pattern. Alternatively, the discrete track recording pattern may be formed in a substrate.
    Type: Application
    Filed: January 21, 2005
    Publication date: June 9, 2005
    Inventors: David Wachenschwanz, Gerardo Bertero, David Treves, Andrew Homola, James Chao, Christopher Bajorek
  • Patent number: 6899959
    Abstract: A magnetic recording medium includes a substrate, an underlayer, a lower magnetic layer formed on the underlayer, an intermediate layer, and an upper magnetic layer formed on the intermediate layer. The intermediate layer is typically Ru, and promotes antiferromagnetic coupling between the upper and lower magnetic layers. The upper and lower magnetic layers are typically Co alloys. The lower magnetic layer has a high saturation magnetization Ms to promote high exchange coupling between the upper and lower magnetic layers. The dynamic coercivity of the lower magnetic layer is lower than the exchange field to ensure rapid switching of the lower magnetic layer.
    Type: Grant
    Filed: February 12, 2002
    Date of Patent: May 31, 2005
    Assignee: Komag, Inc.
    Inventors: Gerardo Bertero, Sudhir Malhotra, David Wachenschwanz, Zhengsheng Shan, Donald Stafford
  • Patent number: 6893748
    Abstract: A perpendicular magnetic recording disk having a soft magnetic film disposed between a substrate and a magnetic recording layer. The soft magnetic film includes a soft magnetic underlayer and one or more layer groups having a spacer layer and a soft magnetic layer disposed above the spacer layer in each layer group. The spacer layers induce anti-ferromagnetic coupling between the surrounding ferromagnetic layers. The spacer layers may be comprised of ruthenium. The soft magnetic layers may have a granular decoupled structured through the use of a segregate.
    Type: Grant
    Filed: May 20, 2003
    Date of Patent: May 17, 2005
    Assignee: Komag, Inc.
    Inventors: Gerardo Bertero, David Wachenschwanz, Sudhir Malhotra, Emur M. Velu
  • Publication number: 20050036223
    Abstract: A method of forming a discrete track recording pattern in a magnetic recording disk. In one embodiment, the discrete track recording pattern may be formed in a NiP layer continuous throughout the discrete track recording pattern. Alternatively, the discrete track recording pattern may be formed in a substrate.
    Type: Application
    Filed: November 27, 2002
    Publication date: February 17, 2005
    Inventors: David Wachenschwanz, Gerardo Bertero, David Treves, Andrew Homola, James Chao, Christopher Bajorek
  • Publication number: 20050008902
    Abstract: A perpendicular magnetic recording disk having a soft magnetic film disposed between a substrate and a magnetic recording layer. The soft magnetic film includes a soft magnetic underlayer and one or more layer groups having a spacer layer and a soft magnetic layer disposed above the spacer layer in each layer group. The spacer layers induce anti-ferromagnetic coupling between the surrounding ferromagnetic layers. The spacer layers may be comprised of ruthenium. The soft magnetic layers may have a granular decoupled structured through the use of a segregate.
    Type: Application
    Filed: May 20, 2003
    Publication date: January 13, 2005
    Inventors: Gerardo Bertero, David Wachenschwanz, Sudhir Malhotra, Emur Velu
  • Publication number: 20030179481
    Abstract: A magnetic recording system includes a patterned medium comprised of land areas and trough areas, a write element which writes the data to the patterned medium, and a read element which reads the data from the patterned medium and servo information from the troughs. The land areas store data and the trough areas inhibit storage of data. The read element is wider than the write element.
    Type: Application
    Filed: February 15, 2002
    Publication date: September 25, 2003
    Inventors: Michael McNeil, John Vicars, David Wachenschwanz
  • Publication number: 20030152805
    Abstract: A magnetic recording medium includes a substrate, an underlayer, a lower magnetic layer formed on the underlayer, an intermediate layer, and an upper magnetic layer formed on the intermediate layer. The intermediate layer is typically Ru, and promotes antiferromagnetic coupling between the upper and lower magnetic layers. The upper and lower magnetic layers are typically Co alloys. The lower magnetic layer has a high saturation magnetization Ms to promote high exchange coupling between the upper and lower magnetic layers. The dynamic coercivity of the lower magnetic layer is lower than the exchange field to ensure rapid switching of the lower magnetic layer.
    Type: Application
    Filed: February 12, 2002
    Publication date: August 14, 2003
    Applicant: Komag, Inc.
    Inventors: Gerardo Bertero, Sudhir Malhotra, David Wachenschwanz, Zhengsheng Shan, Donald Stafford
  • Publication number: 20030022024
    Abstract: A magnetic recording disk having a silica gel layer disposed between an aluminum substrate and a magnetic recording layer.
    Type: Application
    Filed: July 31, 2002
    Publication date: January 30, 2003
    Inventor: David Wachenschwanz