Patents by Inventor Christopher Dana Keener

Christopher Dana Keener 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).

  • Method and apparatus for performing spin valve combined pinned layer reset and hard bias initialization at the HGA level
    Patent number: 6728055
    Abstract: The present invention provides a method and apparatus for performing automated spin valve combined pinned layer reset and hard bias initialization at the head gimbal assembly level. The reset combines a current pulse with an assisting magnetic field. The pinned layer reset and hard bias initialization is automated and performed by a single tool at the head gimbal assembly level to increase manufacturing throughput.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: April 27, 2004
    Assignee: International Business Machines Corporation
    Inventors: Hardayal Singh Gill, Christopher Dana Keener, Gautam Ratilal Patel
  • Method of testing for response abnormalities in a magnetic sensor
    Patent number: 6661223
    Abstract: A method is disclosed for determining the presence of response abnormalities in magnetic sensors. The method includes placing the sensor in an applied magnetic field and collecting sensor resistance information as the magnitude and direction of the applied field is altered. The resistance values are then examined to determine the presence of response abnormalities.
    Type: Grant
    Filed: January 7, 2002
    Date of Patent: December 9, 2003
    Assignee: International Business Machines Corporation
    Inventors: Peter Cheng-I Fang, Christopher Dana Keener, Kenneth Donald Mackay, Frederick William Stukey, Jr.
  • Method of testing for response abnormalities in a magnetic sensor
    Publication number: 20030128025
    Abstract: A method is disclosed for determining the presence of response abnormalities in magnetic sensors. The method includes placing the sensor in an applied magnetic field and collecting sensor resistance information as the magnitude and direction of the applied field is altered. The resistance values are then examined to determine the presence of response abnormalities.
    Type: Application
    Filed: January 7, 2002
    Publication date: July 10, 2003
    Applicant: International Business Machines Corporation
    Inventors: Peter Cheng-I Fang, Christopher Dana Keener, Kenneth Donald Mackay, Frederick William Stukey
  • Screening test for transverse magnetic-field excited noise in giant magnetoresistive heads
    Patent number: 6538430
    Abstract: A method and system for the rapid automatic screening of GMR heads for Barkhausen noise during production. This system rapidly and repeatedly measures associated noise in a GMR head subjected to a smoothly-varying external transverse magnetic field. The repeated Transverse Magnetic-field Excited Noise (TMEN) measurements are automatically sorted into bins to form a histogram, which is then automatically evaluated to develop TMEN range and weighted sum measures, which are then compared with predetermined standards for automatic acceptance or rejection of the GMR head under test. The GMR sensor Barkhausen noise is quantified through the use of a bandpass filter to remove all direct sensor responses, leaving only the noise signals, which are then repeatedly sampled to develop valid statistical Barkhausen noise measures suitable for automated analysis.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: March 25, 2003
    Assignee: International Business Machines Corporation
    Inventors: Chris Carrington, Peter Cheng-I Fang, Don Horne, Christopher Dana Keener, Kenneth Donald Mackay, Antonio Perez, Jr., Frederick William Stukey, Jr.
  • SCREENING TEST FOR TRANSVERSE MAGNETIC-FIELD EXCITED NOISE IN GIANT MAGNETORESISTIVE HEADS
    Publication number: 20030038626
    Abstract: A method and system for the rapid automatic screening of GMR heads for Barkhausen noise during production. This system rapidly and repeatedly measures associated noise in a GMR head subjected to a smoothly-varying external transverse magnetic field. The repeated Transverse Magnetic-field Excited Noise (TMEN) measurements are automatically sorted into bins to form a histogram, which is then automatically evaluated to develop TMEN range and weighted sum measures, which are then compared with predetermined standards for automatic acceptance or rejection of the GMR head under test. The GMR sensor Barkhausen noise is quantified through the use of a bandpass filter to remove all direct sensor responses, leaving only the noise signals, which are then repeatedly sampled to develop valid statistical Barkhausen noise measures suitable for automated analysis.
    Type: Application
    Filed: August 23, 2001
    Publication date: February 27, 2003
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chris Carrington, Peter Cheng-I Fang, Don Horne, Christopher Dana Keener, Kenneth Donald Mackay, Antonio Perez,, Frederick William Stukey,