Abstract: A method for controlling a disk drive includes: detecting an amount of an impact applied to the disk drive, and determining whether the detected amount exceeds a critical value; reading position information of a cylinder, over which a head is positioned, when the detected amount exceeds the critical value, and suspending a command being implemented; determining whether the read cylinder number exceeds a reference cylinder number; and moving the head in an innermost peripheral direction of the disk when the read cylinder number exceeds the reference cylinder number, and moving the head in an outermost peripheral direction of the disk when the read cylinder number does not exceed the reference cylinder number.

Abstract: A disk drive is disclosed comprising a disk and a head actuated radially over the disk. An external servo writer is used to write reference servo bursts to the disk at a coarser radial resolution than product servo bursts. During a self servo writing operation, the reference servo bursts are processed to servo circularly to write a first set of product servo bursts to the disk. The reference servo bursts are also processed to servo spirally to write a second set of product servo bursts to the disk.

Abstract: A magnetic storage device, includes a head slider that floats having a designated height against a moving magnetic recording medium and has an element for recording, and a head suspension that supports the head slider and is provided at a head arm, wherein the floating height of the head slider can be adjusted, based on a recording frequency, by a deformation element.

Abstract: A hard disk drive utilizes hard disks that recover the historically unused read/write space or real estate located in the load/unload zone. Approximately one-half of the load/unload zone is recovered and available for reading and writing operations by forming a first or radially outermost read/write track beginning immediately adjacent to the inner radial edge of the load/unload zone and proceeding radially inward from there to the conventional location of first tracks in the prior art. In another version of the invention, almost the entire load/unload zone is recovered and available for reading and writing operations by aligning the first track with the center of the load/unload zone and proceeding radially inward from there as described above. Both of these versions make significant additional surface area on the disk available where, in the prior art, no data was stored, thereby increasing the efficiency and storage capacity of the hard disk drive.

Abstract: An apparatus and method of controlling an actuator of a data storage device detect and/or correct narrowband mechanical excitations such as due to spindle bearing defects through sensing and/or rejecting disturbance frequencies associated with such narrowband mechanical excitations in an actuator control signal generated by a data storage device controller. A narrowband filter may be used to reject, from an actuator control signal generated by a data storage device controller, a disturbance frequency associated with a spindle bearing defect in a data storage device, and disposed in proximity to a zero crossover frequency associated with the data storage device controller. In addition, a peak filter disposed in a control loop of a data storage device controller may be configured to detect a spindle bearing defect in a data storage device by detecting an amplitude of a control signal in the control loop in proximity to a disturbance frequency associated with the spindle bearing defect.

Abstract: A control system for an actuator arm assembly of a hard disk drive reduces the Non-Repeatable Run-out (NRRO) caused from external sources exciting higher-frequency actuator arm assembly modes. The actuator arm assembly includes a primary actuator and a secondary actuator. The control system includes a primary control loop controlling the primary actuator and a secondary control loop controlling the secondary actuator. The secondary control loop includes at least one peak filter at a frequency corresponding to at least one frequency that is greater in frequency than the primary mode of the actuator arm assembly. The primary actuator can be any type of primary actuator. Similarly, the secondary actuator can be any type of actuator that is located between the primary actuator and a read/write head.

Abstract: A servo track write method is disclosed in which, in a disk drive of a perpendicular magnetic recording system, servo data is written with the use of a single magnetic pole type head of the disk drive itself. In this method, the servo data is recorded on a disk in those servo areas with the use of the single magnetic hole type head mounted on the disk drive. A head mounted as the single magnetic pole type head is position-controlled relative to the servo area by a servo track writer. The servo data is recorded with perpendicular magnetization under a recording magnetic field from the single magnetic pole type head in accordance with the magnetic pole thickness of the single magnetic pole type head.

Abstract: A head positioner comprises a degradation detecting unit for detecting degradation of a fine motion actuator based on current flowing through a piezo element constituting the fine motion actuator and a performance recovering unit for repairing the degradation when the degradation is detected. A fine motion driver has a function of generating a fine motion driving signal, a function of generating a predetermined voltage used for detecting the degradation, and a function of outputting a high voltage signal used for repairing the degradation. Therefore, the present invention can provide a head positioner for realizing stable positioning control for a long time even when degradation of the positioning performance is generated by an electric short circuit or the like, and provide a disk drive.