Abstract: According to one embodiment, a magnetic disk device includes a disk, a head, a command queue, a command residence time calculation unit calculating a residence time of each of commands in the command queue, a command information calculation unit calculating the number of the commands and a ratio, a limit time determination unit obtaining a latency limit time corresponding to the number of commands and the ratio, from a latency limit time determination table, and a command selection processing unit selecting a command to be executed, by considering the latency limit time.

Abstract: According to one embodiment, an information processing device includes an acquisition part, and a processor. The acquisition part is configured to acquire a reproduction signal obtained from a recording part. The recording part includes a recording medium. The reproduction signal includes a first signal corresponding to information recorded in the recording medium. The processor is configured to derive a first output and a second output. The first output is obtained by first information being processed by a first processing model. The first information includes the first signal. The second output is obtained by the first information being processed by a second processing model. The processor is configured to output a result of processing the first information based on a third output. The third output is obtained based on the first output, the second output, and the first information.

Abstract: A method of reading servo wedge data from a rotating constant-density magnetic storage medium having a plurality of tracks, where each track is written at a track pattern frequency, the respective track pattern frequencies varying from a lowest frequency at an innermost one of the tracks to a highest frequency at an outermost one of the tracks, includes, for each respective track, determining, based on the pattern frequency of the respective track, a desired sampling position, sampling actual samples of servo wedge data based on a sampling clock used for all tracks, having a sampling frequency at least equal to the track pattern frequency of the outermost track, determining a phase relationship of the desired sampling position to the sampling clock, and, depending on the phase relationship between the sampling position and the sampling clock, interpolating a sample, or omitting interpolation of a sample and squelching the interpolation clock.

Abstract: According to one embodiment, a magnetic recording device includes a magnetic head and a controller. The magnetic head includes first and second magnetic poles, a magnetic element provided between the first magnetic pole and the second magnetic pole, first and second terminals electrically connected to one end and another end of the magnetic element, respectively, and a coil. The controller is electrically connected to the magnetic element and the coil, and performs a recording operation. In the recording operation, the controller supplies a recording current to the coil while applying an element voltage between the first and second terminals. When the applied voltage is changed while the recording current is supplied, a differential resistance of the magnetic element becomes a first differential resistance peak when the applied voltage is a first voltage, and becomes a second differential resistance peak when the applied voltage is a second voltage.

Abstract: A tape drive (226) for use in a tape library (10) that retains at least one tape cartridge (220) that retains magnetic tape (250) includes a drive housing (226A) and a media conditioner (255). The drive housing (226A) is configured to receive the tape cartridge (220). The media conditioner (255) is coupled to the drive housing (226A). The media conditioner (255) is configured to condition the magnetic tape (250) when the tape cartridge (220) is received within the drive housing (226A). The media conditioner (255) can be configured to remove at least one of abrasives, contaminants and lubricants that are on the magnetic tape (250) when the tape cartridge (220) is received within the drive housing (226A). The magnetic tape (250) is configured to move along a predefined path (251) within the drive housing (226A), which is defined by one or more rollers (254).

Abstract: In accordance with an embodiment, a circuit is configured to vary an intensity of a drive current of a resistive heater element based on the digital control signal. The circuit includes and output circuit configured to control a respective slew rate and an electric energy dissipated in the resistive heater element independently of a resistance value of the resistive heater element.

Abstract: A hard disk drive (HDD) includes a suspension connected to a stack arm. The suspension includes a mount plate, a hinge, a load beam, and a circuit. The mount plate includes a bottom surface facing a disk and an ear portion extending from a side edge of the mount plate. The bottom surface includes a planar region, a first indented region vertically recessed relative to the planar region, and a second indented region located at the ear portion and vertically recessed relative to the planar region. The load beam terminates in a load beam hinge is connected to the first indented region. The circuit extends along the first and second indented regions.

Abstract: The spindle motor includes; a shaft including a shaft portion and a flange portion, the shaft portion having a columnar shape extending in an axial direction, the shaft portion including a shaft end portion, the flange portion being provided at the shaft end portion and receiving a load in the axial direction; and a bearing sleeve rotatably supporting the shaft, the bearing sleeve having a tubular shape including a sleeve end portion having a large-diameter recess part formed in the axial direction. The shaft is a member formed of a copper alloy containing from 0.5 mass percent to 1.5 mass percent of silicon and from 0.5 mass percent to 3.0 mass percent of manganese, and the member includes the shaft portion and the flange portion integrated with one another.

Abstract: When writing data to a magnetic data storage medium, it is detected whether duration, before occurrence of a data transition, of data to be written exceeds a predetermined threshold. When the duration, before the transition, of the data to be written exceeds the predetermined threshold, the data is written by applying an initial pulse and then maintaining, until a shut-off pulse, a steady-state write current having an amplitude less than the initial pulse. A shut-off adjustment is determined based on a predetermined delay. The shut-off pulse is initiated at a time based on one bit period prior to the transition, adjusted by the shut-off adjustment. When the duration, before the transition, of the data to be written is at most equal to the predetermined threshold, the data is written by applying the initial pulse without applying a steady-state write current before the transition.

Abstract: According to an embodiment, there is provided a disk device including a disk, a head, a preamplifier and a controller. The head writes information to the disk according to a write current. The preamplifier causes the write current to flow through the head. The controller is capable of causing the preamplifier to perform current zero control for maintaining an amplitude of the write current at zero, and is capable of changing a time for maintaining the amplitude of the write current at zero according to a pattern of write data.

Abstract: A detection device includes a processing device and a storage medium. An ideal waveform signal indicating an ideal waveform of a servo pattern signal which is a result of reading a servo pattern recorded in a servo band of a magnetic tape by a servo reading element is stored in advance in the storage medium. The processing device acquires a servo band signal which is a result of reading the servo band by the servo reading element, and detects the servo pattern signal by comparing the servo band signal with the ideal waveform signal.

Abstract: A method for writing data to a magnetic data storage medium includes detecting whether the duration, before occurrence of a data transition, of data to be written exceeds a predetermined threshold, and, when the duration, before the occurrence of the data transition, of the data to be written exceeds the predetermined threshold, writing the data by applying an initial pulse and then maintaining a steady-state write current for a defined interval, and when the duration, before the occurrence of the data transition, of the data to be written is at most equal to the predetermined threshold, writing the data by applying the initial pulse without applying a steady-state write current before the data transition. The predetermined threshold may be determined by size of a magnetic bubble formed when writing a single bit to the magnetic data storage medium. A subsequent pulse may be applied following the defined interval.

Abstract: A system includes a plurality of optical identifiers and a reader for the optical identifiers. Each optical identifier has an optical substrate and a volume hologram (e.g., with unique data, such as a code page) in the optical substrate. The reader for the optical identifiers includes an illumination source (e.g., a laser), and a camera. The illumination source is configured to direct light into a selected one of the optical identifiers that has been placed into the reader to produce an image of the associated volume holograms at the camera. The camera is configured to capture the image. The captured image may be stored in a digital format by the system.

Abstract: According to one embodiment, a magnetic disk device comprising a magnetic disk, a magnetic head, and a controller that registers an address and a positioning error, determines whether or not a positioning error of a second sector that is two tracks ahead in a radial direction of a first sector to which a data is written is registered, and when the positioning error of the second sector is registered, sets a first threshold that allows a write operation for a positioning error of the first sector based on the positioning error of the second sector, and determines whether or not the positioning error of the first sector exceeds the first threshold, and stops the write operation when the positioning error of the first sector exceeds the first threshold.

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.