Abstract: A magnetic disk device includes a disk including a plurality of areas divided in a radial direction, a head, and a controller configured to control the head to write data to a first area including a plurality of tracks that are separated from each other, and a second area including at least two adjacent tracks that partially overlap. A first distance between track centers of said two adjacent tracks in the radial direction is different from a second distance between track centers of another two adjacent tracks in the second area in the radial direction.

Abstract: A computer data storage system receives a plurality of data units from a host computer. The system stores the data units in a buffer memory. The system generates a plurality of data segments comprising a plurality of subsets of the plurality of data units. The system receives a plurality of dataset information tables (DSITs) corresponding to the plurality of data segments. The system appends the plurality of DSITs to the respectively corresponding plurality of data segments, to create a plurality of datasets stored in the buffer memory. The system determines a number of datasets stored in the buffer memory, exceeds a threshold value. And in response to determining the number of datasets, of the plurality of datasets stored in the buffer memory, exceeds the threshold value, the system stops the appending the plurality of DSITs to the respectively corresponding plurality of data segments.

Abstract: An apparatus includes a substrate and a reader deposited on the substrate. A laser is formed on a non-self supporting structure and bonded to the substrate. A plurality of heat sink layers are deposited between the reader and the laser and configured to provide thermal coupling between the substrate and the laser and sink heat away from the laser. A waveguide is deposited proximate the laser. The waveguide is configured to communicate light from the laser to a near-field transducer that directs energy resulting from plasmonic excitation to a recording medium.

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 data storage device is disclosed comprising a reel that is rotated for a first interval in order to expose a first frame of a magnetic tape to a head. The head is actuated in a first and second dimensions over the magnetic tape in order to access the first frame of the magnetic tape.

Abstract: A cartridge includes a tape-shaped magnetic recording medium and a cartridge memory. The cartridge memory includes a communication unit that communicates with a recording/reproducing device in a state where the cartridge is loaded on the recording/reproducing device; a storage unit; and a control unit that stores information received from the recording/reproducing device through the communication unit in the storage unit, reads the information from the storage unit according to a request from the recording/reproducing device, and transmits the information to the recording/reproducing device through the communication unit. The information includes manufacturing information of the cartridge and adjustment information for adjusting a tension applied to the magnetic recording medium in a longitudinal direction thereof, and the tape-shaped magnetic recording medium has a plurality of servo bands.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, a first actuator that moves the magnetic head to a predetermined position on the magnetic disk, a second actuator that is provided in the first actuator and adjusts a position of the magnetic head, a control unit that controls operations of the first actuator and the second actuator, and a storing unit that stores a coefficient of an approximation polynomial calculated based on an approximation formula for approximating voltage dependency of a gain of the second actuator. When controlling the operation of the second actuator, the control unit calculates the gain amplitude of the second actuator from the approximation polynomial in which the coefficient is used and amplitude of a voltage input to the second actuator.

Abstract: According to one embodiment, a magnetic disk device includes a disk including two first servo sectors and at least a second servo sector, a head, and a controller, wherein the first servo sector includes burst data and a first data pattern written before the circumferential direction of the burst data, the second servo sector includes the burst data, the first data pattern, and a second data pattern written after the circumferential direction of the burst data, a first frequency of the first data pattern is different from a second frequency of the second data pattern, and a first length of the first data pattern is different from a second length of the second data pattern.

Abstract: The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent, wherein the ferromagnetic powder is selected from the group consisting of hexagonal strontium ferrite powder and ?-iron oxide powder, and has an average particle size of 5 nm or more and 20 nm or less, wherein the magnetic layer has a servo pattern, and wherein an average area Sdc of magnetic clusters of the magnetic recording medium in a DC demagnetization state, measured by a magnetic force microscope is 0.2×104 nm2 or more and less than 5.0×104 nm2.

Abstract: An apparatus includes a substrate. A laser is formed on a non-self supporting structure and bonded to the substrate. A waveguide having a gap portion is deposited proximate the laser. The waveguide is configured to communicate light from the laser to a near-field transducer (NFT) that directs energy resulting from plasmonic excitation to a recording medium. An optical isolator is disposed over the gap portion.

Abstract: In an approach to HRTD recovery by writing the HRTD in a null data set, responsive to receiving a request to write a data set to a magnetic tape, a lead data set of a current wrap of a plurality of wraps of the magnetic tape is written, wherein the lead data set of the current wrap includes a current wrap HRTD that contains one or more directory records for each wrap of the plurality of wraps from a lead wrap of the plurality of wraps through a first prior wrap of the plurality of wraps, and further wherein the first prior wrap immediately precedes the current wrap.

Abstract: A data storage device is disclosed wherein an elevator actuator is controlled to move a head along an axial dimension toward a first disk surface of a first disk while processing a proximity signal generated by a proximity sensor. A first actuator position is detected when the actuator arm is proximate the first disk surface of the first disk based on the proximity signal.

Abstract: A laser beam is directed through a transmissive axicon telescope or a reflective axicon telescope such as in a magneto-optic Kerr effect metrology system. With the transmissive axicon telescope, a Gaussian beam profile is directed through a first axicon lens and a second axicon lens. The first axicon lens and second axicon lens transfer the Gaussian beam profile of the laser beam to a hollowed laser ring. The laser beam with a hollowed laser ring can be directed through a Schwarzschild reflective objective. With the reflective axicon telescope, the laser beam is directed through two conical mirrors that are fully reflective. One of the conical mirrors defines a central hole that the laser beam passes through.

Abstract: Two or more different elapsed time values are determined between transitions of a data signal applied to a magnetic write transducer of a heat-assisted magnetic recording apparatus. Two or more different power values of the laser are respectively associated with the two or more different elapsed time values. The two or more different power levels are selected to reduce differences between track widths of recorded marks having the two or more different elapsed time values.

Abstract: A computer-implemented method, according to one embodiment, includes: receiving, from a tape drive, a first error location on a magnetic tape where a first error occurred, in addition to determining one or more areas on the magnetic tape to be examined based on the first error location. Independent of a read and/or write operation, the tape drive is instructed to induce relative motion between a tape head and the magnetic tape such that the tape head is positioned adjacent to each of the respective one or more areas in turn. Moreover, each of the one or more areas having a respective number of measured servo errors which exceeds a threshold value is identified as a damaged area of the magnetic tape.

Abstract: A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The program instructions are readable and/or executable by a processor to cause the processor to: determine, by the processor, a first error location on a magnetic tape where a first error occurred. One or more areas on the magnetic tape to be examined are also determined, by the processor, based on the first error location. Independent of a read and/or write operation, relative motion between a tape head and the magnetic tape is induced by the processor, such that the tape head is positioned adjacent to each of the one or more areas in turn. Moreover, each of the one or more areas having a respective number of measured servo errors which exceeds a threshold value are identified, by the processor, as a damaged area of the magnetic tape.

Abstract: A magnetic recording medium includes a substrate, an underlayer, and a magnetic layer that are arranged in this order. The magnetic layer has a granular structure including magnetic grains having a L10 crystal structure, and grain boundary parts having a volume fraction in a range of 25 volume % to 50 volume %. The magnetic grains have a c-axis orientation with respect to the substrate. The grain boundary parts include a material having a lattice constant in a range of 0.30 nm to 0.36 nm, or in a range of 0.60 nm to 0.72 nm.

Abstract: A magnetic tape reading apparatus comprises an acquisition unit that acquires information on linearity of a servo pattern to be recorded on a servo band of a magnetic tape, a reading element unit in which at least two reading elements each of which reads data from a specific track region included in the magnetic tape are disposed, a servo reading element that reads the servo pattern, a control unit that performs control of positioning the reading element unit, a derivation unit that derives a deviation amount, and an extraction unit that extracts data recorded on the reading target track by performing a waveform equalization process on each reading result for the reading elements in accordance with the deviation amount.

Abstract: An apparatus comprises a slider having an air bearing surface (ABS), a leading edge, and a trailing edge opposing the leading edge. A writer having a write pole is situated at or near the ABS. A near-field transducer (NFT) is situated at or near the ABS and between the write pole and the leading edge of the slider. An optical waveguide is configured to couple light from a laser source to the NFT. A contact sensor is situated between the write pole and the trailing edge. The contact sensor comprises a first ABS section situated at or near the ABS, a second ABS section situated at or near the ABS and spaced apart from the first ABS in a cross-track direction by a gap, and a distal section extending away from the ABS and connecting the first ABS section with the second ABS section.

Abstract: A data storage device can transition a functional data storage medium into a read only data surface. Data can be written to a data storage medium with a data writer of a transducing head prior to a security threat being identified. A write head of the transducing head is deactivated in response to the security threat by selecting a permanent deactivation mechanism.