Patents by Inventor Kaizhong Gao

Kaizhong Gao 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: 7436632
    Abstract: A magnetic sensor for reading information from a magnetic medium. The magnetic sensor includes a bottom electrode and a first sensor disposed above the bottom electrode. The magnetic sensor also includes a middle electrode disposed above the first sensor, a second sensor disposed above the middle electrode and a top electrode disposed above the second sensor. The bottom electrode, the middle electrode and the top electrode are utilized to electrically connect the first sensor and the second sensor in parallel.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: October 14, 2008
    Assignee: Seagate Technology LLC
    Inventors: Shaoping Li, Song Xue, Kaizhong Gao, Patrick Ryan
  • Publication number: 20080225426
    Abstract: A system includes a magnetic device for writing to and reading from a magnetic medium and a sensor disposed adjacent to the magnetic device and proximate to the magnetic medium. The sensor generates signals related to thermal variations in the sensor caused by changes in a distance between the magnetic device and the magnetic medium.
    Type: Application
    Filed: March 16, 2007
    Publication date: September 18, 2008
    Applicant: Seagate Technology LLC
    Inventors: Mallika Roy, Kaizhong Gao, Insik Jin, William Bruce Fitzpatrick, Housan S. Dakroub, Sining Mao, Song S. Xue, Jeffrey Howard Lake, Dadi Setiadi
  • Publication number: 20080225584
    Abstract: The present invention relates to a memory cell including a first reference layer having a first magnetization with a first magnetization direction and a second reference layer having a second magnetization with a second magnetization direction substantially perpendicular to the first magnetization direction. A storage layer is disposed between the first reference layer and second reference layer and has a third magnetization direction about 45° from the first magnetization direction and about 135° from the second magnetization direction when the memory cell is in a first data state, and a fourth magnetization direction opposite the third magnetization direction when the memory cell is in a second data state.
    Type: Application
    Filed: March 16, 2007
    Publication date: September 18, 2008
    Applicant: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi, Yiming Shi, Song S. Xue, Sining Mao
  • Patent number: 7423826
    Abstract: A readback system includes a magnetic sensor that receives a sensor current. The magnetic sensor senses magnetic bits at a bit frequency and generates a sensor output. The readback system includes a channel circuit that modulates the sensor current at a modulation frequency higher than the bit frequency. The channel circuit samples the sensor output and combines multiple samples of the sensor output per magnetic bit into a combined sample output.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: September 9, 2008
    Assignee: Seagate Technology LLC
    Inventors: Shaoping Li, Jin Insik, Kaizhong Gao, Song Xue, Mike Montemorra, Housan Dakroub, Jason C. Jury
  • Publication number: 20080186636
    Abstract: A transducing head has a main pole and at least one magnetic element (such as a return pole or a shield) which provides a potential return path for a magnetic field produced by the main pole. The magnetic element is spaced from the main pole. The magnetic element has a first edge closest to the main pole and a second edge furthest from the main pole. Permeability of the magnetic element increases from the first edge to the second edge.
    Type: Application
    Filed: April 10, 2008
    Publication date: August 7, 2008
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Nurul Amin, Yuming Zhou, Kaizhong Gao, Patrick J. Ryan, Steven Kalderon, Song S. Xue, Shaoping Li, Mark T. Kief
  • Patent number: 7397633
    Abstract: A recording head for use with a storage medium is provided. The recording head includes a substrate, a magnetic pole, a first magnetic bias structure positioned on a first side of the magnetic pole, and a second magnetic bias structure positioned on a second side of the magnetic pole, Spacer material is positioned between the magnetic pole and the first magnetic bias structure and between the magnetic pole and the second magnetic bias structure.
    Type: Grant
    Filed: March 1, 2005
    Date of Patent: July 8, 2008
    Assignee: Seagate Technology, LLC
    Inventors: Song Sheng Xue, Mark Thomas Kief, Johannes van Ek, Nural Amin, Olle Gunner Heinonen, Kaizhong Gao, Patrick Joseph Ryan
  • Publication number: 20080137224
    Abstract: A magnetic writer includes a write element and an oscillation device disposed adjacent to the write element. The first oscillation device includes a first magnetic layer, a second magnetic layer having a magnetization vector including a component perpendicular to a major plane of the first magnetic layer. The first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer. The first oscillation device generates a high-frequency oscillation field when a current is directed perpendicular to the major plane of the first magnetic layer.
    Type: Application
    Filed: December 6, 2006
    Publication date: June 12, 2008
    Applicant: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi, Yiming Shi, Sining Mao, Patrick J. Ryan, Song S. Xue, Shaoping Li
  • Patent number: 7382575
    Abstract: A transducing head has a main pole and at least one magnetic element (such as a return pole or a shield) which provides a potential return path for a magnetic field produced by the main pole. The magnetic element is spaced from the main pole. The magnetic element has a first edge closest to the main pole and a second edge furthest from the main pole. Permeability of the magnetic element increases from the first edge to the second edge.
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: June 3, 2008
    Assignee: Seagate Technology LLC
    Inventors: Nurul Amin, Yuming Zhou, Kaizhong Gao, Patrick J. Ryan, Steven Kalderon, Song S. Xue, Shaoping Li, Mark T. Kief
  • Patent number: 7359161
    Abstract: A magnetic sensor is provided. The magnetic sensor includes a magnetoresistive multi-layered portion that has a first resistance region and a second resistance region. At least two contacts are coupled to the magnetoresistive multi-layered portion. A sensing current flows from a first contact of the at least two contacts to a second contact of the at least two contacts via the first resistance region and the second resistance region of the magnetoresistive multi-layered portion. The first resistance region promotes a primary flow of the sensing current in a first direction substantially perpendicular to surface planes of the layers of the magnetoresistive multi-layered portion, and the second resistance region promotes the primary flow of the sensing current in a second direction substantially in parallel to surface planes of the layers of the magnetoresistive multi-layered portion.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: April 15, 2008
    Assignee: Seagate Technology LLC
    Inventors: Shaoping Li, Song Xue, Kaizhong Gao, Michael R. Montemorra, Patrick Ryan
  • Publication number: 20070297081
    Abstract: An apparatus includes a write element for writing to a medium. The apparatus is configured to effectuate an electrical potential difference between a portion of the apparatus and a portion of the medium such that a current flows between the apparatus and the medium to reduce a coercivity of the medium proximate to the write element.
    Type: Application
    Filed: June 27, 2006
    Publication date: December 27, 2007
    Applicant: Seagate Technology LLC
    Inventors: Alexey V. Nazarov, Olle G. Heinonen, Bharat B. Pant, Kaizhong Gao
  • Publication number: 20070217084
    Abstract: A device resets a biasing magnetization of a biasing element in a magnetic sensor. The device includes a magnetic structure that is magnetically coupled to the biasing element. A conductive element is disposed around at least a portion of the magnetic structure. When a current is passed through the conductive element, a magnetic field is produced that resets the biasing magnetization of the biasing element.
    Type: Application
    Filed: March 15, 2006
    Publication date: September 20, 2007
    Applicant: Seagate Technology LLC
    Inventors: Song Xue, Paul Anderson, Kaizhong Gao, Kristin Duxstad
  • Publication number: 20070211362
    Abstract: A readback system includes a magnetic sensor that receives a sensor current. The magnetic sensor senses magnetic bits at a bit frequency and generates a sensor output. The readback system includes a channel circuit that modulates the sensor current at a modulation frequency higher than the bit frequency. The channel circuit samples the sensor output and combines multiple samples of the sensor output per magnetic bit into a combined sample output.
    Type: Application
    Filed: March 10, 2006
    Publication date: September 13, 2007
    Applicant: Seagate Technology LLC
    Inventors: Shaoping Li, Insik Jin, Kaizhong Gao, Song Xue, Mike Montemorra, Housan Dakroub, Jason Jury
  • Patent number: 7201977
    Abstract: An anti-ferromagnetically coupled, granular-continuous (“AFC-GC”) magnetic recording medium having increased thermal stability, writability, and signal-to-medium noise ratio (“SMNR”), comprising a layer stack including, in sequence from a surface of a non-magnetic substrate: (a) a continuous ferromagnetic stabilizing layer; (b) a non-magnetic spacer layer; and (c) a granular ferromagnetic recording layer; wherein: (i) the continuous ferromagnetic stabilizing and granular ferromagnetic recording layers are anti-ferromagnetically coupled across the non-magnetic spacer layer, the amount of anti-ferromagnetic coupling preselected to ensure magnetic relaxation after writing; (ii) lateral interactions in the granular, ferromagnetic recording layer are substantially completely eliminated or suppressed; and (iii) the exchange coupling strength in the continuous, ferromagnetic stabilizing layer is preselected to be slightly larger than the strength of the anti-ferromagnetic coupling provided by the non-magnetic sp
    Type: Grant
    Filed: March 23, 2004
    Date of Patent: April 10, 2007
    Assignee: Seagate Technology LLC
    Inventors: Shaoping Li, Kaizhong Gao, Lei Wang, Wenzhong Zhu
  • Publication number: 20070072011
    Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic coercivity Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.
    Type: Application
    Filed: September 27, 2005
    Publication date: March 29, 2007
    Inventors: Shaoping Li, Kaizhong Gao, Lei Wang, Wenzhong Zhu, Xiaobin Wang
  • Publication number: 20060198047
    Abstract: The present invention relates to a recording head with a storage medium. The head includes an assist mechanism to assist operation of the head.
    Type: Application
    Filed: March 1, 2005
    Publication date: September 7, 2006
    Inventors: Song Xue, Mark Kief, Johannes Ek, Nurul Amin, Olle Heinonen, Kaizhong Gao, Patrick Ryan
  • Patent number: 7102854
    Abstract: A transducing head has a main pole and at least one magnetic element (such as a return pole or a shield) which provides a potential return path for a magnetic field produced by the main pole. The magnetic element is spaced from the main pole. The magnetic element is formed at least in part of a magnetic material having a material property that reduces side writing at the magnetic element.
    Type: Grant
    Filed: October 3, 2003
    Date of Patent: September 5, 2006
    Assignee: Seagate Technology LLC
    Inventors: Feng Wang, Shaoping Li, Kaizhong Gao, Song S. Xue, Nurul Amin, Rick P. Michel, Ibro M. Tabakovic, Yuming Zhou
  • Publication number: 20060002034
    Abstract: A magnetic sensor is provided. The magnetic sensor includes a magnetoresistive multi-layered portion that has a first resistance region and a second resistance region. At least two contacts are coupled to the magnetoresistive multi-layered portion. A sensing current flows from a first contact of the at least two contacts to a second contact of the at least two contacts via the first resistance region and the second resistance region of the magnetoresistive multi-layered portion. The first resistance region promotes a primary flow of the sensing current in a first direction substantially perpendicular to surface planes of the layers of the magnetoresistive multi-layered portion, and the second resistance region promotes the primary flow of the sensing current in a second direction substantially in parallel to surface planes of the layers of the magnetoresistive multi-layered portion.
    Type: Application
    Filed: June 30, 2004
    Publication date: January 5, 2006
    Applicant: Seagate Technology LLC
    Inventors: Shaoping Li, Song Xue, Kaizhong Gao, Michael Montemorra, Patrick Ryan
  • Publication number: 20060002032
    Abstract: A magnetic sensor for reading information from a magnetic medium. The magnetic sensor includes a bottom electrode and a first sensor disposed above the bottom electrode. The magnetic sensor also includes a middle electrode disposed above the first sensor, a second sensor disposed above the middle electrode and a top electrode disposed above the second sensor. The bottom electrode, the middle electrode and the top electrode are utilized to electrically connect the first sensor and the second sensor in parallel.
    Type: Application
    Filed: June 30, 2004
    Publication date: January 5, 2006
    Applicant: Seagate Technology LLC
    Inventors: Shaoping Li, Song Xue, Kaizhong Gao, Patrick Ryan
  • Publication number: 20060002035
    Abstract: A differentiated sensor includes a pair of magnetic layers having magnetization directions that are substantially antiparallel in a quiescent state. At least one of the magnetic layers is a free layer. A spacer layer is disposed between the pair of magnetic layers.
    Type: Application
    Filed: June 30, 2004
    Publication date: January 5, 2006
    Inventors: Kaizhong Gao, Jian Shen, Shaoping Li, Song Xue, Juan Fernandez-de-Castro
  • Publication number: 20050214585
    Abstract: An anti-ferromagnetically coupled, granular-continuous (“AFC-GC”) magnetic recording medium having increased thermal stability, writability, and signal-to-medium noise ratio (“SMNR”), comprising a layer stack including, in sequence from a surface of a non-magnetic substrate: (a) a continuous ferromagnetic stabilizing layer; (b) a non-magnetic spacer layer; and (c) a granular ferromagnetic recording layer; wherein: (i) the continuous ferromagnetic stabilizing and granular ferromagnetic recording layers are anti-ferromagnetically coupled across the non-magnetic spacer layer, the amount of anti-ferromagnetic coupling preselected to ensure magnetic relaxation after writing; (ii) lateral interactions in the granular, ferromagnetic recording layer are substantially completely eliminated or suppressed; and (iii) the exchange coupling strength in the continuous, ferromagnetic stabilizing layer is preselected to be slightly larger than the strength of the anti-ferromagnetic coupling provided by the non-magnetic spacer
    Type: Application
    Filed: March 23, 2004
    Publication date: September 29, 2005
    Inventors: Shaoping Li, Kaizhong Gao, Lei Wang, Wenzhong Zhu