摘要:
A magnetic disk drive having a reduction in repeatable runout (RRO) effects is disclosed. The disk drive has a head disk assembly (HDA) and a sampled servo controller. The HDA includes a rotating magnetic disk, an actuator, and a transducer head. The magnetic disk has a plurality of embedded servo sectors for storing servo information including repeatable runout (RRO) cancellation values and RRO cancellation value error correction code (ECC) data at a servo data rate. The RRO cancellation value ECC data is only for detecting and correcting errors in the RRO cancellation values. In between the embedded servo sectors are data sectors for storing user data at a user data rate that is different from the servo data rate. The actuator positions the transducer head in response to a control effort signal generated by the sampled servo controller based on the servo information.
摘要:
A disk drive includes a sampled servo controller for periodically adjusting a control effort signal during a track-following operation based on embedded distributed position information and repeatable runout (RRO) cancellation values for reducing effects of RRO in the distributed position information during track following. A magnetic disk in the disk drive stores RRO information relating to predetermined RRO cancellation values for a data storage track. The RRO information for the data storage track includes at least one first data structure having a first predetermined number of data bits for representing an initial RRO cancellation value, and includes at least one second data structure having a second predetermined number of data bits associated with a respective subsequent RRO cancellation value. The first predetermined number of data bits is greater than the second predetermined number of data bits.
摘要:
A disk drive is disclosed comprising a disk, a head actuated over the disk, and a spindle motor for rotating the disk. The spindle motor comprises a rotating component, a stationary component, and a first and second bearing assembly disposed between the rotating component and stationary component for rotating the rotating component about the stationary component, wherein the disk is attached to the rotating component. The bearing assemblies comprise a stationary component surface and a rotating component surface having a lubricant disposed there between. The first bearing assembly employs an anionic lubricant such that a first voltage forms between the stationary component surface and the rotating component surface when the rotating component rotates about the stationary component. The second bearing assembly employs a cationic lubricant such that a second voltage forms between the stationary component surface and the rotating component surface when the rotating component rotates about the stationary component. A polarity of the second voltage being opposite a polarity of the first voltage to thereby reduce the potential at the disk surface.
摘要:
A system and method for processing track identifier errors to mitigate head instability in data storage devices is disclosed. The system and method includes computing a track id differential between an expected track id and a received track id, encoding the expected track id and the received track id, initiating a first action if the track id differential exceeds a pre-determined threshold and the encoded expected track id varies from the encoded received track id by a pre-configured number of bits, and initiating a second action if the track id differential does not exceed the pre-determined threshold or the encoded expected track id does not vary from the encoded received track id by a pre-configured number of bits.
摘要:
A Head Gimbal Assembly (HGA) for use in a disk drive and further includes a head having a read element and a write element; and a Trace Gimbal Assembly (TGA) attached to the head. The TGA includes a conductor array having a first end connected to the read element and the write element and a distal end for connecting the read element and the write element to a signal processing circuit, a conductive substrate supporting the head and the conductor array and a dielectric layer disposed between the conductor array and the conductive substrate. The TGA further includes a shunt connected at the distal end for shunting the read element; and an anti-static coating, covering a substantial portion of the conductor array for neutralizing electrostatic charge accumulation on the conductor array.
摘要:
A method of servo writing a disk for use in a disk drive is disclosed by writing discontinuous spiral tracks on the disk to protect against overheating the head and/or preamp circuitry. A write clock is synchronized to the rotation of the disk, and a plurality of discontinuous spiral tracks are written on the disk. Each discontinuous spiral track is written at a predetermined circular location determined from the write clock, and each discontinuous spiral track comprises a plurality of segments separated by gaps. Each segment comprises a high frequency signal interrupted at a predetermined interval by a sync mark.
摘要:
According to an aspect of the present invention, there is provided a slider for a disk drive. The slider includes a slider body including a slider body outer surface. The slider further includes an inductive write head including main and return poles. The slider further includes a slider ground pad disposed at the slider body outer surface. The slider ground pad is disposed in electrical communication with the main and return poles for electrically grounding the main and return poles.
摘要:
A head stack assembly includes a flex cable assembly. The head stack assembly further includes an actuator arm and a load beam coupled to the actuator arm. The head stack assembly further includes a trace suspension assembly backing layer coupled to the load beam and including a gimbal. The head stack assembly further includes a dielectric layer disposed upon the trace suspension assembly backing layer. The head stack assembly further includes a slider supported by the gimbal. The head stack assembly further includes a ground trace disposed upon the dielectric layer with the dielectric layer between the ground trace and the trace suspension assembly backing layer. The ground trace extends along the actuator arm and is electrically connected to the slider and the flex cable assembly for grounding the slider to the flex cable assembly.
摘要:
The present invention may be embodied in a disk drive comprising a rotating magnetic media having tracks identified by binary codewords, and in a related method. Each track codeword for a particular track within a contiguous band of tracks differs from a track codeword for an adjacent track within the contiguous band of tracks by a defined number of bits, and differs from a track codeword for a nonadjacent track within the contiguous band of tracks by at least the defined number of bits. The defined number N of bits is greater than four such that at least two bit errors may be corrected when reading a track codeword.
摘要:
A system and method for processing track identification data in a disk drive having concentric tracks each having a track identification field (TIF) stored in embedded servo sectors, the TIF includes a band segment identifying a group of tracks, and an index segment identifying a single track of the group of tracks. The system and method include reading a servo sector to obtain the TIF, parsing the TIF to obtain the band segment, comparing the obtained band segment to an expected band segment to obtain a band segment differential (BSD), initiating an action if the BSD exceeds a pre-determined threshold and varies from the expected band segment by a predetermined number of bits, initiating another action if the BSD exceeds the predetermined threshold and does not vary from the expected band segment by the predetermined number of bits. The process is then applied to the index segments of the band segment.