Abstract: Various illustrative aspects are directed to a system comprising: an actuator; a control object, controlled by the actuator; and one or more processing devices, configured to perform positioning control of the control object via the actuator, wherein performing the positioning control comprises: generating a trajectory control signal for a trajectory that comprises a polydyne acceleration ramp; and outputting the trajectory control signal to the actuator.

Abstract: Components are extracted from user data being read from a reader of a hard disk drive. The components collectively indicate both a magnitude and direction of a read offset of the reader over a track. The components are input to a machine-learning processor during operation of the hard disk drive, causing the machine-learning processor to produce an output. A read offset of the reader is estimated during the operation of the hard drive head based on the output of the machine learning processor. While reading the user data, a radial position of the reader over the track is adjusted via an actuator based on the estimated read offset.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a spindle motor, a magnetic head, a ramp load mechanism, a filter, and a control section. The control section rotates the spindle motor at a second rotating speed for a given period of time at startup of the device, and then loads the magnetic head from the ramp load mechanism to a prescribed position on the magnetic disk. The second rotating speed is higher than a first rotating speed at which the spindle motor is rotated at the magnetic head reads/writes data from/to the magnetic disk.

Abstract: A heat-assisted magnetic recording (HAMR) device is configured to write regions of neutral polarity on a magnetic media during a same pass of the recording head in which other regions are written of positive polarity and negative polarity. The various disclosed write techniques may facilitate creation of “zero state” (substantially net zero polarity) transition zones between each pair of data bits of opposite polarity and/or may facilitate the encoding of three different logical states (e.g., 1, 0, and ?1) on the media.

Abstract: An object of the present disclosure is to provide a magnetic recording medium excellent in electro-magnetic conversion characteristic and thermal stability. The present disclosure provides a tape-shaped magnetic recording medium including: a substrate; and a magnetic layer provided over the substrate and including a magnetic powder, in which the magnetic layer has an average thickness of equal to or less than 90 nm, the magnetic powder has an average aspect ratio of from 1.0 to 3.0, the magnetic powder has an average particle volume of equal to or less than 2,300 nm3, a coercive force Hc1 in a vertical direction of the magnetic recording medium is equal to or less than 4,500 Oe, a coercive force Hc2 in a longitudinal direction of the magnetic recording medium and the coercive force Hc1 satisfy a relation of Hc2/Hc1?0.8, and the ratio Hrp/Hc1 of a residual coercive force Hrp of the magnetic recording medium measured using a pulsed magnetic field and the coercive force Hc1 is equal to or less than 2.0.

Abstract: According to one embodiment, a magnetic head includes a protective layer. When an element unit is a magnetic recording element unit, the protective layer includes a first region on a magnetic recording element protrusion and a second region on a magnetic recording element shield, the first region and the second region being flush with each other, or the first region being recessed more than the second region. When the element unit is a magnetic reading element unit, the protective layer includes a third region on a magnetic reading element protrusion and a fourth region on a magnetic reading element shield, the third region and the fourth region being flush with each other, or the third region being recessed more than the fourth region.

Abstract: 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.

Abstract: System and methods for providing dynamic positional audio are disclosed. Methods can comprise determining availability of one or more devices to output audio and determining a location of the one or more available devices. Audio information can be received and at least a portion of the audio information can be configured to generate assigned audio information based on the determined location of the available devices. The assigned audio information can be transmitted to the available devices.

Abstract: A data storage device can have one or more rotating data media with data tracks that are radially disposed from a central spindle. The data tracks may be logically divided into multiple regions while a write strategy is generated with a region module to set a sequence of different regions for future data writes. Receipt of a data write request to the data storage media from a host can prompt the region module to classify the data write request as a sequential or random write in order to intelligently select a region to satisfy the data write request based on the write strategy to maximize data writing consistency for data associated with the data write request.

Abstract: A servo system for a magnetic tape storage system includes a magnetic tape (550) including a first servo band (573), and a first data band (575). An auxiliary servo pattern (575A) is embedded within the first data band (575). The auxiliary servo pattern (575A) is modified to generate an updated auxiliary servo pattern (688A) during a writing pass as data is being written to the first data band (575). The servo system can further include a magnetic tape drive (326) including a head assembly (456) having (i) a first write head (482) that writes data to the magnetic tape (550) as the magnetic tape (550) moves relative to the head assembly (456) in a first tape direction, (ii) a second write head (484) that writes data to the magnetic tape (550) as the magnetic tape (550) moves relative to the head assembly (456) in a second, opposite tape direction, and (iii) an auxiliary servo reader (487) positioned in a shadow of one of the first write head (482) and the second write head (484).

Abstract: A data storage method, apparatus and system that increase drive capacity, minimize latency, reduce write access time and improve drive lifetime is described in this invention. In one embodiment, the data storage device described here is a composite hard disk drive comprises a number of recording media platters labeled from 1 to n, where n is greater than or equal to 2; wherein there exist two positive integer n1 and n2, where n1 and n2 are between 1 and n; n1 is not equals to n2; wherein the data tracks for the media platters n1 and n2 are written based on one of the following: 1) different RTs; 2) different WAs; or 3) different RTs and different WAs.

Abstract: Various circuits, systems, methods, and apparatus are disclosed to provide dynamic direct current (DC) level shifting for use with a summing component of a quad channel detector (QCD) of a media scanning system configured to detect carbon voids or other defects on the surface of a magnetic recording medium. In an example, a summing circuit receives separate input signals from four optical sensors of the scanning system and generates a summed output signal with an alternating current (AC) component representative of a defect and a direct current (DC) component representative of a total power of an optical transmitter of the scanning system. A DC level shifting circuit receives a fixed DC offset signal and the same four variable input signals. The DC level shifting circuit provides dynamic level shifting of the DC component of the summed output signal based on the fixed DC offset and the four input signals.

Abstract: According to one embodiment, a disk device includes a housing including a base with a bottom wall, a drive motor including a pivot erected on the bottom wall and a hub rotatably supported around the pivot, ten or more magnetic disks attached to the hub and stacked on a flange of the hub, and spacer rings attached to the hub and each disposed between each respective adjacent pair of two magnetic disks. A number of the spacer rings is one less than the magnetic disks. At least one spacer ring has a thickness different from that of the other spacer rings, and a difference between a maximum thickness and a minimum thickness of the spacer rings is 0.01 mm or more and 0.09 mm or less.

Abstract: A method for writing servo information in a disk drive that includes a write head and one or more recording surfaces includes: writing a first portion of a first spiral with the write head on a first recording surface of the one or more recording surfaces while controlling a radial position of the write head with a controller that is configured with a first set of controller parameter values; after the read head crosses a second spiral formed on a second recording surface of the one or more recording surfaces, determining a radial position error for the write head based on information associated with the second spiral; and in response to the radial position error exceeding a disturbance threshold value, writing a second portion of the first spiral with the write head while controlling the radial position of the write head with the controller while the controller is configured with a second set of controller parameter values.

Abstract: 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.

Abstract: Disclosed herein are embodiments of a heat-assisted magnetic recording (HAMR) head that includes a near-field transducer (NFT) with a trailing bevel. Also disclosed are sliders and data storage devices comprising those HAMR heads, and methods of manufacturing HAMR heads with NFTs having trailing bevels. A HAMR head comprises a waveguide core, a main pole, and a NFT comprising a trailing beveled edge at an acute angle to an air-bearing surface (ABS) of the HAMR head. A method of fabricating a HAMR head comprises depositing material for a NFT, creating a trailing-side surface of the NFT, and creating a trailing beveled edge in the trailing-side surface of the NFT at the ABS, and forming a dielectric layer over the trailing beveled edge. The trailing beveled edge is at an acute angle to the ABS, and a remainder of the trailing-side surface of the NFT is substantially perpendicular to the ABS.

Abstract: According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.

Abstract: A method includes determining an error after attempting to read, via a first read transducer and a second read transducer, a data sector in a first data track. The method further includes calculating a weight ratio associated with the data sector and determining a read offset direction of the data sector based, at least in part, on the calculated weight ratio.

Abstract: A thermally assisted magnetic head includes a slider, the slider includes a slider substrate and a magnetic head part. The magnetic head part includes a recording head, a reading head, a near field transducer and a medium-opposing surface. The medium-opposing surface includes a recording area and a reading area. The magnetic head part includes a record/read separately protective structure which an enhanced protective film is formed on the recording area and a reading head protective film is formed on the reading area. The enhanced protective film includes a plurality of films for effectively protecting the recording head and the near field transducer. The reading head protective film includes a thickness which is thinner than the enhanced protective film.

Abstract: An apparatus includes a magnetic head having a first array of read transducers, an array of write transducers, and a second array of read transducers. A center-to-center pitch of the read transducers in the first array is less than a center-to-center pitch of the write transducers. A center-to-center pitch of the read transducers in the second array is greater than a center-to-center pitch of the write transducers. The read transducers in the first and second arrays are aligned with the write transducers along an intended direction of tape travel thereacross for enabling read-while-write operation.