Patents by Inventor Nathan J. Santee

Nathan J. Santee 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: 9355667
    Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of tracks defined by servo sectors, wherein each servo sector comprises a plurality of servo bursts and the servo sectors define a plurality of servo wedges. A first write operation is executed to a first track and a first absolute position for the head is generated corresponding to a first servo wedge. A second write operation is executed to a second track and a second absolute position for the head is generated corresponding to the first servo wedge. An off-track write condition is detected when executing the second write operation based on the first absolute position and the second absolute position. The first absolute position comprises a track address of the first track and a position error measurement based on the servo bursts in the first servo wedge.
    Type: Grant
    Filed: November 11, 2014
    Date of Patent: May 31, 2016
    Assignee: Western Digital Technologies, Inc.
    Inventors: Nathan J. Santee, Yanan Huang, Wei Xi, Hien T. Chu, Orhan Beker
  • Patent number: 9142235
    Abstract: A disk drive is disclosed comprising a disk having a plurality of tracks, a head, and a voice coil motor (VCM) and a microactuator for actuating the head over the disk in response to a feed-forward compensation value. A sinusoidal disturbance is applied to the microactuator, and the resulting feed-forward compensation value is processed to characterize the microactuator.
    Type: Grant
    Filed: October 27, 2009
    Date of Patent: September 22, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Alexander Babinski, Lingfei Zhou, Nathan J. Santee, Chuanwen Ji, Duc T. Phan
  • Patent number: 8902538
    Abstract: A disk drive is disclosed comprising a disk media, a head stack assembly (HSA) having a head coupled to its distal end, a microactuator used to provide fine position of the head and a voice coil motor (VCM) configured to actuate the HSA over the disk media, and control circuitry. The control circuitry may be configured to move the HSA in an alternating manner across the disk media while actuating the microactuator. One or more performance characteristics of the microactuator may be measured before and after the actuation of the microactuator, and failure may be detected based on the absolute or relative change of the one or more performance characteristics.
    Type: Grant
    Filed: July 1, 2013
    Date of Patent: December 2, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Yanning Liu, Nathan J. Santee, Yi Lu, Yanan Huang, Toviah N. Hirschberg
  • Patent number: 8743502
    Abstract: A disk drive comprising a head actuated over a disk, and control circuitry operable to spin the disk at a first spin rate. The control circuitry is further operable to reduce the spin rate of the disk from the first spin rate to a second spin rate, wherein the second spin rate is based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate. For example, the spin-up parameter may comprise one or more of a spin-up time limit, power setting, and ambient temperature.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: June 3, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Carl E. Bonke, Daniel D. Reno, Nathan J. Santee
  • Patent number: 8335049
    Abstract: A disk drive is disclosed comprising a first disk surface, a first head coupled to a distal end of an actuator arm, and a voice coil motor (VCM) and a first microactuator operable to actuate the first head over the first disk surface. A servo loop for servoing the head in response to the servo sectors is disabled, and after disabling the servo loop, the first microactuator is excited with a control signal at a test frequency in order to accentuate a crack in the first microactuator. After exciting the first microactuator, the servo loop is enabled, and after enabling the servo loop, the first microactuator is evaluated to detect the crack in the first microactuator.
    Type: Grant
    Filed: June 7, 2010
    Date of Patent: December 18, 2012
    Assignee: Western Digital Technologies, Inc.
    Inventors: Yanning Liu, Chuanwen Ji, Nathan J. Santee