G11B5/55

Vibration sensor feedforward control for magnetic storage device

A magnetic storage device that includes a housing, including a base, a cover, and an interior cavity. The magnetic storage device also includes an actuator controller, located in the interior cavity and configured to generate an actuator command signal. The magnetic storage device further includes an actuatable component, located in the interior cavity, and an actuator, located in the interior cavity and operable to actuate the actuatable component in response to the actuator command signal. The magnetic storage device also includes a vibration sensor, located in the interior cavity and configured to detect a vibration of the cover. The magnetic storage device further includes a sensor feedforward controller, located in the interior cavity and configured to generate a gain signal, based on the vibration of the cover detected by the vibration sensor, and to modify the actuator command signal proportional to the gain signal.

Magnetic disk device and rewrite processing method

According to one embodiment, a magnetic disk device includes a disk having a first region in which a plurality of tracks is written and a second region that is positioned with a gap in a first direction of the radial direction of the first region, and in which a plurality of tracks is overwritten in the first direction, a head, and a controller that offsets part of a plurality of tracks which is overwritten in the second region in a second direction opposite the first direction to perform rewriting.

SPLIT ACTUATOR DRIVE THAT LIMITS SLEW RATE OF AGGRESSOR VCM TO REDUCE VICTIM DISTURBANCES

A seek operation of a first actuator in a multi-actuator drive is modified, so that one or more disturbance-generating portions of the seek operation do not adversely affect operation of a second actuator in the drive. Radial motion of the aggressor actuator is controlled by limiting a slew rate of the first actuator during one or more portions of the seek operation to be less than or equal to a threshold value. Because slew rate of the first actuator is the rate of change of radial acceleration of the aggressor actuator with respect to time, limiting the slew rate of the first actuator prevents or reduces mechanical disturbances caused by jerk associated with motion of the first actuator.

Multi-sector read offset recovery

An integrated circuit includes a read/write channel and a servo controller. The read/write channel is configured to: determine, in connection with a first path, respective read errors associated with N number of the data sectors; estimate respective offset positions of the N number of the data sectors; and generate a second path based, at least in part, on the respective estimated offset positions. The servo controller is configured to cause adjustment of a position of a read transducer based on the second path.

STORAGE CONTROL APPARATUS AND STORAGE CONTROL METHOD
20230010385 · 2023-01-12 · ·

A storage control apparatus controls a tape apparatus including a plurality of tape drives. The storage control apparatus is configured to calculate, when causing the tape apparatus to execute write processing of dividing write data into a predetermined size and writing to a plurality of magnetic tapes, a write start position of the write data for each of the plurality of magnetic tapes where the write start position being different in each of the plurality of magnetic tapes and instruct the tape apparatus with the write start positions, and specify, when a reading range is designated, a read start position indicating a head of data in the reading range for each magnetic tape, and instruct the tape apparatus to read data in the reading range in an order from a magnetic tape of which the read start position is closer to an end of the magnetic tape.

Information processing apparatus and information processing method
11550274 · 2023-01-10 · ·

An information processing apparatus includes an n-th parameter adjuster and an (n+1)-th parameter adjuster. The n-th parameter adjuster adjusts an n-th parameter set so that an n-th evaluation value set based on the n-th parameter set approaches an n-th target value set. The (n+1)-th parameter adjuster adjusts an (n+1)-th parameter set so that an (n+1)-th evaluation value set based on the (n+1)-th parameter set approaches an (n+1)-th target value set. In addition, the n-th parameter adjuster acquires, based on initial value set or search value set of the n-th parameter set, an n-th actual measured value set or an n-th predicted value set, acquires an (n+1)-th target value set based on the initial value set or the search value set of the n-th parameter set, and searches for the n-th parameter set that optimizes the (n+1)-th target value set under a restriction that the n-th evaluation value set approaches the n-th target value set using the acquired n-th actual measured value set or the n-th predicted value set and the acquired (n+1)-th target value set.

Multi-layer PZT microactuator with active PZT constraining layers for a DSA suspension

A PZT microactuator such as for a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT is mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover most or all of the top of the PZT, with an electrical connection being made to the PZT where it is not covered by the restraining layer. The restraining layer reduces bending of the PZT as mounted and hence increases effective stroke length, or reverses the sign of the bending which increases the effective stroke length of the PZT even further. The restraining layer can be one or more active layers of PZT material that act in the opposite direction as the main PZT layer. The restraining layer(s) may be thinner than the main PZT layer.

DATA TAPE QUALITY ANALYSIS

Techniques for determining a data tape read quality value are disclosed. A data tape system generates a value representing a quality of a data tape based on attributes of the data tape. The system calculates the data quality value using an algorithm based on: (a) a particular data tape error correction value, (b) data tape length value representing a length of data tape traversed during data-processing operations, and (c) a scaling factor. The scaling factor is based on a relationship between the particular data tape error correction value and a rate of degradation of the data tape. The scaling factor may be generated by applying a trained machine learning model to attributes of a data tape. The model generates a scaling factor for a particular data tape based on the attributes of the particular data tape.

PARTITIONED DATA-BASED TDS COMPENSATION USING JOINT TEMPORARY ENCODING AND ENVIRONMENTAL CONTROLS
20220415357 · 2022-12-29 ·

A method for providing enhanced readability of data written to a magnetic tape, includes the steps of (i) writing data to a first tape partition using a tape drive, the data being written under a first dimensional stability condition; (ii) monitoring an ambient dimensional stability condition with a condition monitor to determine if the ambient dimensional stability condition has moved at least a predetermined threshold value from the first dimensional stability condition toward a preferred dimensional stability condition; and (iii) replicating the data to a second tape partition with a data replicator when it has been determined that the ambient dimensional stability condition has moved at least the predetermined threshold value from the first dimensional stability condition toward the preferred dimensional stability condition.

Two-dimensional magnetic recording (TDMR) for high areal density tape drive

The present disclosure is generally related to a tape drive including a tape head configured to read shingled data tracks on a tape. The tape head comprises a first module head assembly aligned with a second module head assembly. Both the first and second module head assemblies comprises one or more servo heads and a plurality of data heads. Each data head comprises a write head, a first read head aligned with the write head, and a second read head offset from the first read head in both a cross-track direction and a down-track direction. The first read heads and the second read heads are configured to read data from a shingled data track of the tape simultaneously. In some embodiments, the tape head is able to be dynamically tilted in order to tilt the first and second reads heads when reading curved portions of shingled data tracks.