Abstract: Various illustrative aspects are directed to a data storage device comprising one or more disks, an actuator assembly comprising one or more disk heads; and one or more processing devices, configured to detect a plurality of areas with a coercivity lower than a threshold on the one or more disks; map out one or more sectors in each of the plurality of lower coercivity areas on the one or more disks; write data to, or read data from, the one or more disks, based at least in part on mapping out the one or more sectors in each of the plurality of lower coercivity areas. In some embodiments, the writing or reading data comprises writing data to, or reading data from, one or more sectors of the one or more disks that are not mapped out.

Abstract: A heat-assisted magnetic recording (HAMR) head has a slider with a gas-bearing-surface (GBS). The slider supports a near-field transducer (NFT) and a main magnetic pole that has a step or recess in the NFT-facing surface near the GBS that contains plasmonic material. A thermal shunt is located between the NFT and the main pole to allow heat to be transferred away from the optical spot generated by the NFT. The NFT-facing surface of the main pole that is recessed from the step away from the GBS is in contact with the thermal shunt, and the thermal shunt is in contact with the plasmonic material in the step in the back region recessed from the GBS, so there is no increase in the spacing between the NFT and a large portion of the main pole.

Abstract: The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Abstract: A disk device includes a first controller configured to determine a first operation amount of a first actuator based on a difference between a current position and a target position of a head, a second controller configured to determine a second operation amount of a second actuator based on the difference, and a processor. The processor is configured to perform a first filtering to calculate a first filter value based on a vibration detected at multiple points in time and filter coefficients, perform a second filtering to generate a second filter value based on the vibration detected at each of the multiple points in time, and update the filter coefficients based on the second filter values and a difference between the target position and an updated position of the head.

Abstract: According to an embodiment, each of a plurality of controller chips included in a magnetic disk device includes a buffer control circuit and an arbitration circuit, and controls a corresponding one of a plurality of actuator systems. The first controller chip is connected to a buffer memory via the buffer control circuit included in the first controller chip, and is connected to the second controller chip. The second controller chip is connected to the first controller chip and the third controller chip. The arbitration circuit included in the second controller chip performs arbitration between data transfer between the third controller chip and the first controller chip and data transfer between the first controller chip and an actuator system controlled by the second controller chip among the plurality of actuator systems.

Abstract: A heat-assisted magnetic recording head includes a first feature, a second feature, and a bilayer adhesion structure. The first feature includes a first primary metal. The second feature includes an oxide region, and a mixed metal oxide adhesion layer that is adhered to the oxide region and provided on a surface of the second feature. The bilayer adhesion structure includes the mixed metal oxide adhesion layer of the second feature, and a metal adhesion layer. The metal adhesion layer is disposed between and adhered to the first feature and the mixed metal oxide adhesion layer of the second feature. The metal adhesion layer includes a second primary metal that is different than the first primary metal.

Abstract: According to one embodiment, a read and write (RW) parameter adjustment method includes changing conditions of RW parameters to determine a capacity and characteristics for each of various heads of a test device to measure the characteristics and creating, for each of the heads, a database in which the measured characteristics are registered, and changing the conditions of the RW parameters for each of heads of a device to be adjusted to measure characteristics, searching the database created for each of the heads for a database having similar characteristics, and setting the capacity and characteristics in an appropriate balance based on the similar characteristics of the database obtained by the searching.

Abstract: Aspects of the present disclosure generally relate to a magnetic recording head assembly that includes an external alternating current (AC) source. A magnetic recording head of the magnetic recording head assembly includes a conductive structure between a main pole and a trailing shield. The conductive structure includes a conductive layer, and the conductive layer is nonmagnetic. The magnetic recording head assembly also includes an external AC source to supply AC current that flows through the conductive structure. In one aspect, the conductive structure is between a coil structure and the trailing shield, and the external AC source is coupled to the coil structure. The conductive structure and the external AC source facilitate consistently providing an enhanced AC writing field to facilitate effective and reliable writing, high ADC, high SNR, and reduced jitter.

Abstract: Various illustrative aspects are directed to a data storage device comprising a disk; a read/write head having read and write portions configured to read data from and write data to the disk; read and write heaters configured to thermally adjust read and write spacings of the read and write portions from the disk surface; and a controller configured to control power applied to the read and write heaters based on a dual heater power ratio (DHR) of the respective power applied to each heater. The DHR is set based on a point during touchdown at which a reader shield and a writer shield have maximum contact with the surface of the disk (DHRmax).

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; at least one actuator mechanism configured to position at least a first head proximate to a first disk surface and a second head proximate to a second disk surface; and one or more processing devices. The one or more processing devices are configured to: assign logical tracks to physical tracks of the disk surfaces such that a respective logical track comprises: at least a portion of sectors of a primary physical track, the primary physical track being on the first disk surface; and at least a portion of sectors of a donor physical track, the donor physical track being on the second disk surface. The one or more processing devices are configured to perform, using the first head and the second head, a data access operation with at least one of the logical tracks.

Abstract: A magnetic disk device includes a magnetic disk including a track having a plurality of sectors, a motor configured to rotate the magnetic disk, a magnetic head, and a controller. The controller is configured to perform a first read operation of reading target sectors among the sectors of the track, with the magnetic head during a first revolution of the magnetic disk, detect an off-track state of the magnetic head during the first revolution of the magnetic disk, perform a first error correction with respect to data read from the target sectors during the first read operation, and perform a second read operation of selectively reading a part of the target sectors for which the off-track state has been detected or the first error correction is unsuccessful, with the magnetic head during a second revolution of the magnetic disk.

Abstract: According to one embodiment, a magnetic recording/reproducing device includes a plurality of magnetic recording medium each including a recording surface, a plurality of assisted magnetic recording heads each provided with the recording surface in order to perform assisted recording, and an assisting amount adjustment part connected to the assisted magnetic recording heads in order to adjust an assisting amount of each assisted magnetic recording head corresponding to a recording capacity of the recording surface.

Abstract: According to one embodiment, a magnetic disk device includes a disk that has a track including a first servo sector and a second servo sector that is different from the first servo sector, a head that writes data to the disk and reads data from the disk, and a controller that records first signal strength record data related to a signal strength at which first target servo data that is a target of the first servo sector is read, and standardizes first signal strength data related to a signal strength at which the first target servo data is read when the first target servo data is read.

Abstract: The present disclosure relates to heat-assisted magnetic recording (HAMR) write heads including a waveguide and a main pole having a main pole tip. One or more current paths are provided through the main pole tip. Terminals of the one or more current paths can be coupled to the main pole, a trailing shield, a leading shield, a heat sink layer, a touch pad, a pole diffusion barrier layer, a NTS sensor, or another suitable component of the HAMR write head.

Abstract: An apparatus includes a substrate. A laser is deposited above the substrate. The laser includes one or more non-self-supporting layers of crystalline material. The laser has a length along a light path in a range of about 40 um to about 350 um. An optical input coupler is configured to receive light from the laser. A waveguide is deposited proximate the optical input coupler. The waveguide is configured to communicate light from the laser via the optical input coupler to a near-field transducer that directs energy resulting from plasmonic excitation to a recording medium.

Abstract: A system includes a library compartment, a player and a gas generator. The library compartment houses a plurality of data storage disks. The player is external to the library compartment and comprises a head that is configured to interact with at least one of the plurality of data storage disks. The gas generator is fluidly connected to the player. An embodiment includes a partition between the library compartment and player, the partition including a selectively openable interlock. In an embodiment, the player has a negative fluid pressure relative to the library compartment. A method of controlling an environment in a disk player is also described. The method includes detecting a composition of a fluid environment in the disk player and detecting a pressure of the fluid environment in the disk player.

Abstract: An optical recording medium includes a plurality of information signal layers. The plurality of information signal layers include a recording layer having a first surface that faces a light irradiation surface and a second surface on the side opposite to the first surface, a first dielectric layer that is provided on the side of the first surface, and a second dielectric layer that is provided on the side of the second surface. The second dielectric layer provided in the information signal layer positioned on the innermost side when viewed from the light irradiation surface contains indium oxide and tin oxide.

Abstract: Described are heat assisted magnetic read-write heads that include a coupler, a waveguide, a transducer, and appurtenant structures, as well as related methods.

Abstract: Characterizing virgin tape cartridges in a characterization tape library and then sending the characterized tape cartridges to an end-user's library saves time and effort at the end-user's site. A characterized tape cartridge can be universally used in any compatible tape library if the virgin tape cartridge is characterized in a target calibration window that is within a specific range of heat and humidity. A calibration library can act as a ‘middleman’ receiving a virgin tape cartridge directly from an OEM. The virgin tape cartridge can be characterized followed by storing a record of the calibration in the tape cartridge's MAM while in the calibration library. The now post-characterized tape cartridge is then on to a user's tape library for use instead of just simply sending a virgin tape cartridge to the end user's library. The record in the MAM effectively changes the designation of the virgin tape cartridge to a post-calibrated tape cartridge.

Abstract: Various illustrative aspects are directed to a data storage device, comprising: one or more disks; an actuating mechanism comprising one or more heads, and configured to position the one or more heads proximate to disk surfaces of the one or more disks; and one or more processing devices. The one or more processing devices are configured to: determine a first burst value based on an averaged value of a first set of one or more bursts; determine a second burst value based on an averaged value of a second set of one or more bursts; generate a position error signal (PES) based on the determined first burst value and the determined second burst value; and control a position of at least one head among the one or more heads based on the PES.