231results about "Digital recording" patented technology

According to one embodiment, a magnetic disk device includes a disk, a write head, an adjustment unit, and a write processing unit. The adjustment unit adjusts each of a first adjustment value, a second adjustment value, and a third adjustment value. The write processing unit can select shingled magnetic recording and perform write processing based on the first to third adjustment values. When the number of the plurality of tracks of the band is t+1 and the number of unused sectors among the plurality of sectors of the band is e. The adjustment unit adjusts the first to third adjustment values to establish ext.

According to one embodiment, a magnetic disk device includes a disk, a write head, and a write processing unit. The write processing unit executes first write processing of writing data to a first segment of a first data sector in a first data track. The write processing unit then executes second write processing of writing data to a first segment of a second data sector in the first data track. The write processing unit then executes third write processing of writing data to a second segment of the first data sector in a second data track.

According to the embodiment, an HDC receives a plurality of data segments from a host, and executes generation and addition of a first code and output of a data segment to which the first code is added to each data segment. An HDC calculates exclusive OR with respect to the first codes, and outputs obtained first information. The RWC performs data conversion and calculation of exclusive OR on the plurality of data segments to which the first code is added, and outputs the plurality of data segments after the data conversion and a track parity obtained by the calculation of the exclusive OR. The RWC acquires the first code from the plurality of data segments. The RWC calculates exclusive OR with respect to a group of the second codes which are the acquired first codes to acquire second information. The RWC compares the first information with the second information.

A plurality of servo patterns are recorded in a magnetic tape along a longitudinal direction. The servo pattern is at least one linear magnetization region pair. The linear magnetization region pair includes a first linear magnetization region, which is linearly magnetized, and a second linear magnetization region, which is linearly magnetized. The first linear magnetization region and the second linear magnetization region are inclined in opposite directions with respect to a first imaginary straight line along a width direction of the magnetic tape. The first linear magnetization region has a steeper inclined angle with respect to the first imaginary straight line than the second linear magnetization region.

The present invention comprises: a ferromagnetic body 10 that exhibits an anomalous Hall effect; a first current terminal and a second current terminal (I+, I-) that supply an electrical current to the ferromagnetic body 10; a first voltage terminal and a second voltage terminal (V+, V-) that detect a voltage generated in the ferromagnetic body 10; and a resistance adjustment layer that lies either at an interface between the first current terminal / second current terminal and the ferromagnetic body, or between the first voltage terminal / second voltage terminal and the ferromagnetic body. The resistance adjustment layer includes a high-resistance region and a low-resistance region. The low-resistance region electrically conducts between the first current terminal / second current terminal and the ferromagnetic body, or between the first voltage terminal / second voltage terminal and the ferromagnetic body.

To provide a magnetic disk device and a writing method for bypassing without using free bands.SOLUTION: A magnetic disk device according to an embodiment is a magnetic disk device that records data by shingled recording, in which data to be written to a track to be written and data to be located on one track ahead of the track to be written are received in a volatile memory and then written to the track to be written, when performing sequential writes to a shingled recording area on a magnetic disk and data not to be written to the shingled recording area among the data received in the volatile memory is stored in the volatile memory when an unexpected power failure occurs.SELECTED DRAWING: Figure 7

A servo pattern recording head includes: a plurality of head cores that are magnetically separated from each other; and a plurality of gap patterns that are formed on a front surface of each of the plurality of head cores and that are used for recording a plurality of servo patterns in a width direction of a magnetic tape by applying a magnetic field to the magnetic tape in response to a pulse current, in which the plurality of gap patterns are formed on the front surface along a direction corresponding to the width direction, and the plurality of gap patterns deviate from each other at a predetermined interval in a direction corresponding to a longitudinal direction of the magnetic tape between the gap patterns adjacent to each other along the direction corresponding to the width direction.

According to one embodiment, a magnetic disk device includes a disk, a write head, an adjustment unit, and a write processing unit. The adjustment unit adjusts each of a first adjustment value, a second adjustment value, and a third adjustment value. The write processing unit can select shingled magnetic recording and perform write processing based on the first to third adjustment values. When the number of the plurality of tracks of the band is t+1 and the number of unused sectors among the plurality of sectors of the band is e. The adjustment unit adjusts the first to third adjustment values to establish ext.

Described are systems, devices and methods for staggered bits magnetic recording. A staggered bits track pattern is recorded on granular magnetic recording media, thereby mapping a data bit sequence onto adjacent tracks so that the bits in one track are staggered relative to the bits in the adjacent track. A read head having an effective cross-track width extending across the tracks is aligned to read a sequence of combined bit signals as the read head is advanced in the down-track direction. Each combined bit signal combines one bit from each adjacent track. A data channel coupled to the read head is used to disambiguate the sequence of combined bit signals, thereby reproducing the data bit sequence.

To provide an information processor, a magnetic recording and playback device, and a magnetic recording and playback system capable of improving processing accuracy.SOLUTION: According to an embodiment, an information processor includes an acquisition part and a processing part. The acquisition part is capable of acquiring a playback signal based on a signal obtained from a magnetic recording medium. The playback signal includes first input data, second input data, and third input data. The processing part is capable of carrying out first processing and second processing. In the first processing, the processing part derives a first derived characteristic amount from a first inner product of a first characteristic amount based on the first input data and a second characteristic amount based on the second input data. In the second processing, the processing part derives a second derived characteristic amount from a second inner product of a third characteristic amount based on the third input data and the first derived characteristic amount.SELECTED DRAWING: Figure 1

To provide a magnetic recording head including a read head with high signal output for use in a magnetic recording device.SOLUTION: A read head 500 includes a sensor 540 disposed on a media facing surface (MFS) and a spin generator 550 disposed away from the sensor and recessed from the MFS. The sensor and the spin generator are disposed on a non-magnetic layer 406. The sensor includes a free layer, and the spin generator includes at least one spin-orbit-torque (SOT) layer 510. The SOT layer is configured from a topological material such as BiSb. The sensor detects a read signal by using a first voltage lead line V+ and a second voltage lead line V-. The spin generator is configured to inject a spin current into the sensor via the non-magnetic layer by using a first current lead line I+ and a second current lead line I-. The shape of the non-magnetic layer is triangular or trapezoidal to further concentrate the spin current.SELECTED DRAWING: Figure 5A-5B

According to one embodiment, a magnetic disk device includes a disk, a write head, an adjustment unit, and a write processing unit. The adjustment unit adjusts each of a first adjustment value, a second adjustment value, and a third adjustment value. The write processing unit can select shingled magnetic recording and perform write processing based on the first to third adjustment values. When the number of the plurality of tracks of the band is t+1 and the number of unused sectors among the plurality of sectors of the band is e. The adjustment unit adjusts the first to third adjustment values to establish e<t.

To provide a magnetic recording device capable of stable recording operation.SOLUTION: A magnetic recording device 150 includes a magnetic recording medium group 20 and a magnetic head group 30. The magnetic recording medium group includes a first magnetic recording medium 21; a plurality of second magnetic recording media 22; and a plurality of third magnetic recording media 23. The magnetic head group includes a first magnetic head 31; a plurality of second magnetic heads 32; and a plurality of third magnetic heads 33. The first magnetic head can record data in the first magnetic recording medium by a first method. The plurality of second magnetic heads can record data in the plurality of second magnetic recording media by a second method. The plurality of third magnetic heads can record data in the plurality of third magnetic recording media by the second method. The first magnetic recording medium is provided between the plurality of second magnetic recording media and the plurality of third magnetic recording media in a first direction D1. The other magnetic recording medium in which the data is recorded by the first method does not overlap with the magnetic recording medium group in the first direction.SELECTED DRAWING: Figure 1

To provide a magnetic disk device capable of predicting whether error correction to a data track of a disk reaches a limit or not.SOLUTION: A magnetic disk device 1 includes a first disk having a first data track and a second data track, a first write head, a write processing unit, an error correction unit, a correction limit prediction unit 65, and a determination unit. During the write period, the correction limit prediction unit 65 calculates the excess amount OVR, calculates the metric value Mer by multiplying the excess amount OVR by the first weighting factor, updates the cumulative metric value ME, and generates the first prediction information. The determination unit determines whether to cause the write processing unit to continue the write processing on the second data track based on the first prediction information.SELECTED DRAWING: Figure 18

To provide an information processor, a magnetic recording reproduction device, and a magnetic recording reproduction system that can improve efficiency.SOLUTION: According to an embodiment, an information processor includes an acquisition part and a processing part. The processing part is configured to carry out first operation. The first operation includes first decoding, first accuracy evaluation, second decoding, and first determination operation. The first decoding includes processing a portion targeted for reproduction signal decoding by a first processing configuration to derive a first decoding result. When first accuracy of the first decoding result does not satisfy a first criterion, the second decoding includes processing the portion targeted for decoding by a second processing configuration to derive a second decoding result. The second processing configuration is at least partially different from the first processing configuration.SELECTED DRAWING: Figure 1

Described are systems, methods, and media for magnetic recording assisted by the use of ultrafast pulses such as ultrafast laser pulses. A layered magnetic medium includes a thin, magnetically softer capping layer disposed over a magnetically harder data recording layer. The capping layer is configured to have fast magnetization dynamics, and to have faster magnetization dynamics than the data recording layer. Due to the fast magnetization dynamics of the capping layer, ultrafast pulses can be used to assist a magnetic write field in magnetizing the capping layer without inducing any significant heating in the bulk of the media. The magnetization of the capping layer nucleates magnetization in the data recording layer under the influence of the magnetic write field.

To provide a magnetic disk device capable of improving efficiency of data processing.SOLUTION: A magnetic disk device 1 includes a disk, a write head, and a write processing section. The write processing section executes: first write processing for writing data in a first segment of a first data sector in a first data track (ST1); second write processing for writing the data in a first segment of a second data sector in the first data track (ST2); and third write processing for writing the data in a second segment of a first data sector in a second data track (ST6).SELECTED DRAWING: Figure 12

To provide a magnetic head and a magnetic recording device capable of improving recording density.SOLUTION: According to the embodiment, a magnetic head includes: first and second magnetic poles; and a laminate which is provided between the first and second magnetic poles. The laminate includes: a first magnetic layer; a second magnetic layer which is provided between the first magnetic layer and the second magnetic pole; a first non-magnetic layer which is provided between the first magnetic layer and the second magnetic layer; a second non-magnetic layer which is provided between the second magnetic layer and the second magnetic pole; and a third non-magnetic layer which is provided between the first magnetic pole and the first magnetic layer. The first magnetic layer contains a first element containing at least any one of Fe, Co, and Ni. The second magnetic layer contains (Fe100-xCox)100-yEy (where 10 atm%≤x≤50 atm% and 10 atm%≤y≤90 atm%). A second element E contains at least one selected from a group consisting of Cr, V, Mn, Ti, and Sc. The first magnetic layer does not contain the second element. Alternatively, the concentration of the second element at the first magnetic layer is lower than the concentration of the second element at the second magnetic layer.SELECTED DRAWING: Figure 1

To provide a magnetic recording device that can improve productivity and a manufacturing method thereof.SOLUTION: According to the embodiment, a magnetic recording device includes a magnetic recording medium, a magnetic head, and a control unit. The magnetic head includes a coil, a first magnetic pole, and a light-emission unit. The control unit performs a first operation and a second operation. In the first operation, the control unit records first servo position information to a first area of the magnetic recording medium. In the second operation, the control unit executes a repair operation when a first condition is not fulfilled. The first condition includes that the recording condition of the first servo position information is within a first range. In the repair operation, the control unit performs an erase operation for irradiating light from the light-emission unit to the first area, and performs a re-record operation for recording the first servo position information to the first area after the erase operation again.SELECTED DRAWING: Figure 1

Data is written in tracks in a first sub-region of a region of a disk using Shingled Magnetic Recording (SMR). It is determined whether a predetermined data storage capacity for the region can be reached by adding a sub-region guard band and shingle writing throughout a remaining portion of the region using a lower limit of track overlap. The sub-region guard band does not store data and separates the first sub-region from a second sub-region in the region. In response to determining that the predetermined data storage capacity for the region can be reached by adding the sub-region guard band and shingle writing with the lower limit of track overlap throughout the remaining portion of the region, the sub-region guard band is added, and the second sub-region is shingle written with at least as much track overlap as the lower limit of track overlap.

An indicator indicating a non-linearity of a servo pattern is within 15% or less of a track pitch. The track pitch is a pitch between tracks. The indicator indicates a degree of variation in the plurality of distance differences from an average value of the plurality of distance differences. The distance difference is a difference between a distance between a pair of first positions corresponding to each other in the width direction in the pair of servo patterns and a distance between a pair of second positions deviated from the pair of first positions in the width direction by a first predetermined interval in the pair of servo patterns. The plurality of distance differences are obtained by measuring the distance difference for each second predetermined interval along the width direction in the pair of servo patterns. The first predetermined interval is larger than the second predetermined interval.

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.

The servo pattern recording method according to one aspect of the present technology involves recording a servo pattern in a plurality of servo bands that are arranged at intervals in the width direction of a magnetic layer in a magnetic tape, the method including: causing the magnetic tape to travel with a prescribed tension; and recording a servo pattern in the plurality of servo bands at a second pitch narrower than a first pitch, which is the positioning interval of two servo lead heads in a tape drive device that records data in the magnetic layer or that plays back data recorded in the magnetic layer.

According to one embodiment, multiple first positions are set in a radial direction of a magnetic disk. The multiple first positions include multiple second positions and a third position different from the multiple second positions. A controller of a magnetic disk apparatus executes a first process in which an RRO correction value is measured at each of the multiple second positions and measurement of an RRO correction value at the third position is skipped. After the first process, the controller executes a second process of performing write or read access to multiple tracks. The second process includes acquiring a position error signal by a read head during the write or read access, and calculating an RRO correction value for the third position based on the position error signal.

The present invention provides a magnetic disk device that can efficiently record parity and has excellent error correction capabilities for user data on the disk. [Solution] The magnetic disk device comprises a disk DK, a write head WHD, a volatile buffer memory 80, a parity generation unit, a write processing unit 62, an error correction unit 64, a storage processing unit 65, and a normal correction limit prediction unit 66. The parity generation unit generates a first normal parity and a first strong parity based on first user data, and generates a second normal parity and a second strong parity based on second user data. The storage processing unit 65 overwrites the first recording area of ​​the buffer memory with the second strong parity if the first prediction information is normal information, and if the first prediction information changes to abnormal information, it leaves the first strong parity in the first recording area and stores the second strong parity in the second recording area of ​​the buffer memory.

This invention provides a disk device capable of improving performance and data reliability, and a method for setting refresh thresholds. The disk device of this embodiment includes: a disk having a first track; a head having a heater for writing data to the disk and reading data from the disk; and a controller for setting variations in parameters associated with write processing to the disk within one cycle of the first track, such that variations in evaluation metrics corresponding to write / read processing characteristics are suppressed within one cycle of the first track.

A data storage device comprises a magnetic medium and a head configured to be actuated over the magnetic medium. The head comprises a write element and a write driver configured to generate a write current to be applied to the write element. The write driver comprises a data switch section configured to switchably output low-level signals and high-level signals, and a stationary cascode section configured to receive the low-level signals and high-level signals from the data switch section and to generate a cascode pass through current. The data switch section comprises low voltage CMOS devices and the stationary cascode section comprises high voltage CMOS devices.

The invention relates to the technical field of magnetic tape units, in particular to a magnetic tape driver, a magnetic tape unit and a storage system.The magnetic tape driver comprises a read head, an analog equalization circuit and a digital processing chip; the read head is coupled with the analog equalization circuit, the analog equalization circuit is coupled with the digital processing chip, and the analog equalization circuit comprises an active filter; wherein the read head is used for reading an original analog signal from a magnetic tape of a magnetic tape unit and outputting the original analog signal to the analog equalization circuit; the analog equalization circuit is used for performing data equalization on the original analog signal through an active filter to obtain a first analog signal and outputting the first analog signal to the digital processing chip; the frequency response curve of the first analog signal is closer to the frequency response curve of a target signal type than the frequency response curve of the original analog signal, and the target signal type comprises partial response signals; and the digital processing chip is used for converting the analog signal into a digital signal and processing the digital signal. According to the embodiment of the invention, the order of the digital filter in the magnetic tape unit can be reduced.

The embodiment of the invention provides a magnetic disk device capable of appropriately executing a rewrite operation caused by ATI. A controller of a magnetic disk device according to the present embodiment adds a count value corresponding to a storage region in the vicinity of one of a plurality of storage regions in accordance with a write operation. The rewriting operation includes a seek operation, a stabilization operation waiting for attenuation of residual vibration of the magnetic head, and a rewriting of all data in the first storage area to the first storage area after the stabilization operation. The controller reduces a value of a count corresponding to the first storage area among the plurality of counts in accordance with the rewrite operation. The controller adds a value of a count corresponding to the second storage area among the plurality of counts in accordance with the rewrite operation. The stabilization operation includes an operation for determining whether or not the stabilization operation has been completed on the basis of whether or not a first condition is satisfied. The first condition varies depending on the opportunity of the execution of the retry operation.

To provide a magnetic disk device that can measure PPO correction values with high efficiency.SOLUTION: A plurality of first positions are set in a radial direction of a magnetic disk. The plurality of first positions includes a plurality of second positions and a third position different from the plurality of second positions. A controller of the magnetic disk device measures a RRO (Repeatable RunOut) correction value for each of the plurality of second positions, and executes a first step in which a RRO correction value is not measured for the third position. After the first step, the controller executes a second step in which write or read access is performed on a plurality of tracks. The second step includes acquiring a position error signal by a read head during access and calculating the RRO correction value for the third position based on the position error signal.SELECTED DRAWING: Figure 5