Patents by Inventor Drew M. Mader

Drew M. Mader 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).

  • Determining fly height using readback signal distortion
    Patent number: 11881239
    Abstract: A controller extracts a distortion component of a readback signal from a magnetic read head. The distortion component may be found using a finite length Volterra series, for example. The controller estimates a clearance between the read head and a recording medium based on the distortion component. This clearance measurement can be used for closed loop fly-height control of the read head.
    Type: Grant
    Filed: April 29, 2022
    Date of Patent: January 23, 2024
    Assignee: Seagate Technology LLC
    Inventors: Walter R. Eppler, Drew M. Mader
  • Laser temperature calibration in a HAMR device
    Patent number: 9236081
    Abstract: A method includes setting a heat assisted magnetic recording (HAMR) device located in a data storage system having a laser to an operating temperature. A threshold laser current is determined. An optimal laser current is determined. The threshold laser current and the optimal laser current are stored in memory. The steps of determining a threshold laser current, determining an optimal laser current and storing the threshold laser current and the optimal laser current into the calibration table are repeated until acceptable device performance is achieved at more than one operating temperature.
    Type: Grant
    Filed: March 31, 2015
    Date of Patent: January 12, 2016
    Assignee: Seagate Technology LLC
    Inventors: Alfredo S. Chu, Jason W. Riddering, Drew M. Mader, Huazhou Lou, Pu-Ling Lu