Abstract: Disclosed are hard disk drives (HDDs), and methods for use therewith, that utilize reduced overhead servo fields, thereby simplifying the servo system. Reduced overhead servo fields may be of particular use in HDDs that utilize multi-revolution storage techniques to store data at much higher densities than what is possible for conventional HDDs. The relaxed performance requirements of high-density, multi-revolution drives provides opportunities for reducing servo overhead, thereby potentially further increasing the areal density capability of the magnetic media. Servo overhead may also be reduced by placing certain servo data on flash or other memory off of the media disk rather than in the servo fields written to the media disk.

Abstract: Disclosed are hard disk drives (HDDs), and methods for use therewith, that utilize reduced overhead servo fields, thereby simplifying the servo system. Reduced overhead servo fields may be of particular use in HDDs that utilize multi-revolution storage techniques to store data at much higher densities than what is possible for conventional HDDs. The relaxed performance requirements of high-density, multi-revolution drives provides opportunities for reducing servo overhead, thereby potentially further increasing the areal density capability of the magnetic media. Servo overhead may also be reduced by placing certain servo data on flash or other memory off of the media disk rather than in the servo fields written to the media disk.

Abstract: A high bandwidth, large stroke spin-stand for testing components of a disc drive includes a coarse positioning stage and a rotary micropositioning stage. The spin-stand is capable of positioning a transducer head relative to the data storage disc based on one or both of: (1) an angular position of a rotary actuator arm in the rotary micropositioning stage; and (2) servo data read from the data storage disc. The angular position of the rotary actuator arm is detected by an encoder. In one embodiment, position adjustments are based on the detected angular position. In another embodiment, position adjustments are based on servo data read from the data storage disc, but are also conditional on angular position being consistent with the servo data. In yet another embodiment, both angular position and servo data from a track are linearized to generate PES adjustment parameters that are recorded on the data storage disc to redefine the track as more circular or to linearize the PES.

Abstract: A magnetic medium comprises a magnetic disc having a read surface that has a plurality of tracks, at least some having servo sectors. The servo sectors comprise a plurality of magnetic irregularities, such as pits or regions of reduced magnetic coercivity, arranged in a servo pattern along the servo sector at a servo frequency. A magnetic pattern is recorded in the disc along the servo sector at a high carrier frequency. A process for manufacturing the servo pattern and for recovering servo data from the servo pattern are also described.

Abstract: A high bandwidth, large stroke spin-stand for testing components of a disc drive includes a coarse positioning stage and a rotary micropositioning stage. The spin-stand is capable of positioning a transducer head relative to the data storage disc based on one or both of: (1) an angular position of a rotary actuator arm in the rotary micropositioning stage; and (2) servo data read from the data storage disc. The angular position of the rotary actuator arm is detected by an encoder. In one embodiment, position adjustments are based on the detected angular position. In another embodiment, position adjustments are based on servo data read from the data storage disc, but are also conditional on angular position being consistent with the servo data. In yet another embodiment, both angular position and servo data from a track are linearized to generate PES adjustment parameters that are recorded on the data storage disc to redefine the track as more circular or to linearize the PES.

Abstract: A magnetic medium comprises a magnetic disc having a read surface that has a plurality of tracks, at least some having servo sectors. The servo sectors comprise a plurality of magnetic irregularities, such as pits or regions of reduced magnetic coercivity, arranged in a servo pattern along the servo sector at a servo frequency. A magnetic pattern is recorded in the disc along the servo sector at a high carrier frequency. A process for manufacturing the servo pattern and for recovering servo data from the servo pattern are also described.