Abstract: According to one embodiment, a magnetic disk device writes a plurality of simulated reference patterns to the magnetic disk on write conditions different from each other, detects a write state of each of the simulated reference patterns, selects one of the write conditions according to detection results, and writes a plurality of regular reference patterns which become criteria for predetermined processing to be executed on the magnetic disk to the magnetic disk on the selected write condition.

Abstract: The present invention relates to the field of controlling tape drive magnetic head spacing and the use of hard disk drive heads in a tape drive. The present invention is related to magnetic tape data storage and tape recorders that include components designed to minimize or eliminate head-to-tape contact to reduce or eliminate wear and contamination of the tape and the magnetic heads. Methods and apparatus of the present invention may control the head-to-media spacing by moving locations of magnetic heads relative to a tape. Such apparatus may include components designed to minimize magnetic spacing. This may be accomplished using actuators that move magnetic heads, or that move both magnetic heads and the tape of a tape drive. This may include supporting a back surface of the tape. The movement of the tape past the magnetic heads may be performed using mechanisms that contact and drive the back surface of the tape.

Abstract: Repositioning to a beginning of an area of a tape medium to which a reposition request is directed can be completed. Reading, as a part of an error recovery procedure (ERP), between a first dataset of the area and an mth dataset of the area, can be completed, where m is a number of datasets for which cut and paste multi segments are to be generated. Cut and paste segments for each of the datasets in a range from the first dataset and the mth dataset can be generated. A subset of datasets within the range of the first dataset to the mth dataset having readable dataset information table (DSIT) information can be determined. A determination can be made whether the target data position is included within the subset of datasets within the range of the first dataset to the mth dataset by reading the DSIT information.

Abstract: Disclosed are a semiconductor device and a semiconductor system. The semiconductor device includes a command processing circuit for generating a write enable signal and a read enable signal in response to a command, a data strobe signal processing circuit for generating a data strobe signal in response to a clock and the read enable signal or for receiving the data strobe signal in response to the write enable signal and outputting a write data strobe signal, and a data processing circuit for converting analog data into digital data in response to the write data strobe signal and the write enable signal and converting the digital data into the analog data in response to the read enable signal.

Abstract: According to one embodiment, a system includes a controller configured to determine whether a position error signal (PES) is invalid while reading data from a magnetic medium using at least one data channel. An invalid PES indicates off-track reading or a defect in the magnetic medium. The controller is also configured to determine whether a PES value is above a first predetermined threshold in response to a determination that the PES is valid. Moreover, the controller is configured to inject error bits into a data stream in place of corresponding bits of decoded data in response to a determination that the PES is invalid, a determination that the PES value is above the first predetermined threshold, or a determination that the PES is invalid and the PES value is above the first predetermined threshold. Other systems and methods are described in accordance with more embodiments.

Abstract: Host data to be written to a recording medium is categorized as one of sequential data or random data. The sequential data is written to a first track width on the recording medium. The random data is written to a second track width on the recording medium, the second track width being larger than the first track width.

Abstract: In the present disclosure, a recording medium and a method of preparing a recording medium is provided. In a recording medium, a first annular servo track can be provided on a first layer of the recording medium, and second annular servo track can be provided on the first layer of the recording medium. The second annular servo track can be adjacent to the first annular servo track. In the recording medium, the first annular servo track and the second annular servo track are magnetically polarized and are magnetically opposing in polarity. A corresponding method of preparing a recording medium is provided.

Abstract: A tape storage medium comprises at least one servo band (SB) along a longitudinal extension (x) of the tape storage medium (TP) for supporting to determine positional information. The servo band (SB) comprises a set of servo tracks (STx) extending along the longitudinal extension (x) of the tape storage medium (TP) and arranged next to each other. Each servo track (STx) of the set contains a servo pattern with magnetic transitions at a defined frequency (fx), wherein the frequencies (fx) of magnetic transitions of servo patterns of adjacent servo tracks (STx) are different from each other. The set of servo tracks (STx) contains at least three servo tracks (STx) with magnetic transitions of different frequencies (fx).

Abstract: A tape storage medium comprises at least one servo band (SB) along a longitudinal extension (x) of the tape storage medium (TP) for supporting to determine positional information. The servo band (SB) comprises a set of servo tracks (STx) extending along the longitudinal extension (x) of the tape storage medium (TP) and arranged next to each other. Each servo track (STx) of the set contains a servo pattern with a pseudo noise sequence (PN_x) of symbols, wherein the pseudo noise sequences (PN_x) of servo patterns of adjacent servo tracks (STx) are different from each other. The set of servo tracks (STx) contains at least three servo tracks (STx) with different pseudo noise sequences (PN_x).

Abstract: A disk drive is disclosed comprising a microactuator configured to actuate a head over a disk, and control circuitry comprising a first digital accumulator responsive to a first register. The first digital accumulator generates at least one of a velocity command and a position command for the microactuator, and the control circuitry configures the first register in order to limit at least one of a velocity and an acceleration of the microactuator.

Abstract: Provided are a computer program product, system, and method for determining a skew error signal (SES) offset used to determine an SES to adjust heads in a drive unit. A determination is made of a first difference in a first orientation with respect to a direction of movement of the recordable storage media based on first and second position information read by first and second servo read elements on a first head. A determination is made of a second difference in a second orientation with respect to the direction of movement of the recordable storage media based on third and fourth position information read by the first servo read element and a third servo read element on a second head. An offset, calculated based on the determined first and second difference, is used to generate an error signal to adjust the first and second heads.

Abstract: A data storage device is disclosed comprising a disk comprising a plurality of servo tracks defined by servo sectors, wherein each servo sector comprises a plurality of servo bursts. A head comprises a first read sensor and a second read sensor separated from the first read sensor by a cross-track spacing. A first servo channel processes a first read signal emanating from the first read sensor to generate a first position signal based on at least two servo bursts read using the first read sensor. A second servo channel processes a second read signal emanating from the second read sensor to generate a second position signal based on at least two servo bursts read using the second read sensor. A position error signal (PES) is generated based on the first position signal and the second position signal, and the head is servoed over the disk based on the PES.

Abstract: A method of correcting repeatable run out (RRO) errors for a HDD in which RRO data is instead stored in consolidated form within the reserved area of the disk, instead of storing RRO data in the servo patterns for each HDD track or sector. RRO data is preferably stored in the reserved area of a hard disk drive in compressed form. The compressed RRO data is subsequently read into DRAM in compressed form and then decompressed for use. Predictive techniques determine what compressed RRO data is needed for upcoming read/write operations.

Abstract: A data storage device with improved data storage densities, coupled with lower hard error and write-inhibit events is described. A feed-forward write inhibit (FFWI) method enables data tracks to be written more densely. Alternatively, the FFWI method may reduce the hard error and write inhibit events to improve data storage performance. A concept of virtual tracks enables the FFWI method to be applied to the writing of circular data tracks with non-circular servo tracks, or to the writing of non-circular data tracks with PES data from circular servo tracks—in both cases, improvements to performance and/or storage densities are enabled. The FFWI method may also be applied to the case of both non-circular servo and data tracks.

Abstract: A magnetic data recording system wherein the wherein adjacent track interference during writing is avoided by modulating the size of a write bubble on the magnetic media in response to a position error signal. If the position error signal indicates that the magnetic head is off-track, circuitry within the magnetic data recording system adjusts the size of the write bubble temporarily to prevent the write bubble from encroaching on a neighboring data track. This adjustment of the write bubble can be accomplished by adjusting power to the write head. Adjustment of the write bubble can also be achieved by adjusting power to a magnetic oscillator in a microwave assisted magnetic recording system (MAMR) or adjusting power to a heating element in a thermally assisted magnetic recording system.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising servo information. A position error signal is generated while executing a first plurality of seek operations to seek the head over a seek length, and first feed-forward compensation values are adapted for a first segment of the seek length using an iterative learning control algorithm based on the position error signal. During a second plurality of seeks, second feed-forward compensation values are adapted for a second segment of the seek length using the iterative learning control algorithm based on the position error signal. The servo control system is operable to execute the second plurality of seek operations using the first feed-forward compensation generated for the first segment of the seek length.

Abstract: According to an embodiment, a disk storage apparatus includes a disk with a servo pattern recorded thereon and a processor. The processor offsets a reader in a cross-track direction on the disk and performs a discrete Fourier transform (DFT) operation on an amplitude sequence of readback signals with respect to the cross-track direction. The processor calculates an optimal correction coefficient for a linearity correction function used for a linearity correction of a position error signal based on a result of the DFT operation.

Abstract: Various embodiments of the present invention provide systems and methods for recovering data from a storage medium. As an example, a data recovery circuit is disclosed that includes: a controller circuit, a data processing circuit, a selector circuit, and a combining circuit. The controller circuit is operable to position a sensor over a track of the storage medium at a first distance from the center of the track to yield a first data set, and to position the sensor over the track of the storage medium at a second distance from the center of the track to yield a second data set. The data processing circuit is operable to process a processing data set, and the selector circuit is operable to select between the first data set and a combined data set as the processing data set. The combining circuit is operable to combine the first data set with at least the second data set to yield the combined data set.

Abstract: Embodiments provide a method for a method comprising causing data to be written on a first track located on a disk; while writing the data on the first track, buffering, in a buffer module, the data; determining that while writing the data on at least a portion of the first track, a portion of a write head was offset with respect to the first track, such that at least the portion of the write head infringed on a second track; determining a direction of movement of the write head; and based on determining that the portion of the write head was offset and determining the direction of movement of the write head, selectively performing one of (i) using the data buffered in the buffer module to recover data of the second track, or (ii) discarding the data buffered in the buffer module.

Abstract: A hard disk drive (HDD) has a high track misregistration (TMR) mode of writing data. If the position error signal (PES) from the servo positioning information exceeds a first write inhibit threshold (WI-1), writing is not inhibited but a high TMR mode of operation is enabled. In high TMR mode, prior to writing data to the target track, the data on the adjacent tracks is read and stored in a buffer. The data to be written to the target track is also stored in the buffer, and is flagged to indicate that the data needs to be written. The data is then written to the target track. However, if during writing the PES exceeds a second threshold (WI-2), then the data from the adjacent encroached track in the buffer is flagged for writing and the process repeated with the encroached track set as the target track.

Abstract: Embodiments described herein provide for robust servo patterns that comply with planarization constraints and also allow use of a single master template for manufacture of both the front and back of a magnetic disk. Planarization constraints are met because only a portion of servo data is hard patterned on the magnetic disk and the hard patterned servo data areas comply with planarization constraints. The servo pattern has two symmetrical servo write assist patterns, one on each side of a central burst pattern. The servo sync, SAM, track-ID, sector-ID, and/or RRO values can be written magnetically by the write head onto these servo write assist patterns after the completion of the planarization process. The symmetric design of the servo pattern allows both a left-to-right and a right-to-left servo write and read back, thereby enabling use of a single master template in magnetic disk manufacture.

Abstract: A disk drive is disclosed comprising a disk having a plurality of servo tracks defined by servo sectors, and a head actuated over the disk. The disk drive further comprises control circuitry comprising a servo control system operable to position the head over the disk. A disturbance is induced in the servo control system, and while positioning the head over the disk, a data track is accessed. The disturbance induced in the servo control system causes the data track to be non-circular relative to a rotation axis of the disk such that the non-circular data track crosses multiple of the servo tracks over a revolution of the disk.

Abstract: According to one embodiment, there is provided an information recording device that records information on a magnetic disk using a magnetic head. The registering module registers position data of a temporary defective sector using a sector where an off-track has occurred as a temporary defective sector. The reading module reads data from a target track. The cancellation processing module performs inter-track interference component cancellation processing with respect to the data read by the reading module using data written to a track adjacent to the target track, in which when a sector adjacent to a processing target sector in a track width direction is a temporary defective sector registered in the registering module, inter-track interference component cancellation processing is performed using data written to a substitute sector corresponding to the registered temporary defective sector.

Abstract: Controlling positions of storage media heads is disclosed. An example storage media head position controller includes a position error filter to filter a media head position error based on a target position for a storage media head relative to a storage medium and a present media head position to generate a position signal, and a media speed monitor to modify an integration factor in the position error filter based on a media speed to adjust a phase margin of the position control loop.

Abstract: An initial phase offset between a center track and a side track is determined. An initial side track pulse shape is determined using the initial phase offset and side track interference. The initial side track pulse shape minimizes a contribution of the side track interference to a center track bit. The contribution of the side track interference is removed from the center track bit using the initial side track pulse shape and the side track interference.

Abstract: According to one embodiment, an information recording device includes: a magnetic recording medium having tracks; and a recording controller configured to control recording of information on a track provided between a first track group and a second track group adjacent to the first track group, the first track group and the second track group being included in a plurality of track groups, each of which includes a plurality of adjacent tracks partially overlap each other.

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage. Methods and systems of tape technology disclose optical tape media including: configurations, formulations, markings, and structure; optical tape manufacturing methods, systems, and apparatus methods and systems including: curing processes, coating methods, embossing, drums, testing, tracking alignment stamper strip; optical tape methods and systems including: pick up head adapted for the disclosed optical tape; and optical tape uses including optical storage media devices for multimedia applications.

Abstract: A method for controlling a hard disk drive, includes a track seeking servo routine in which seek time is measured in a mode of the routine after the trajectory mode, the measured seek time is compared with a predetermined period of time, and an alarm mode is induced when the measured seek time exceeds the predetermined period of seek time.

Abstract: A system and method for positioning a sensor relative to a storage medium. A system includes a first sensor and a second sensor arranged so that a point of a storage medium traverses each sensor at a different time. A processor is coupled to the sensors. The processor varies the timing of a sample representing a noise signal received from the sensors in accordance with medium velocity. The processor adjusts the position of the sensors based on the sample.

Abstract: A patterned magnetic recording medium for use in heat assisted magnetic recording comprises an electrically conductive heat sink layer and a plurality of discrete magnetic recording elements positioned adjacent to a first surface of the heat sink layer. Disc drives that include the patterned medium and a method of magnetic recording using the patterned media are also included.

Abstract: According to one embodiment, a disk storage apparatus includes a write module and a controller. The write module is configured to move a write head over a disk, and to perform the shingled write method, recording data in the first track while erasing data from a part of the second, i.e., adjacent track. The controller is configured to acquire a first head positioning error with respect to the first track and a second head positioning error with respect to the second track. If the first head positioning error exceeds an off-track threshold value, indicating that the data may no longer be maintained in the first and second tracks, the controller inhibits the data writing.

Abstract: A system and method for erasure flagging for errors-and-erasures decoding in storage devices includes determining a deviation measure between a read/write head position relative to a track of symbols in storage media. A reliability value is determined for the symbols based on the deviation measure. Flagging the symbols with a reliability value below a threshold as erasures is performed. The symbols are decoded using errors-and-erasures decoding in an iterative procedure.

Abstract: A transducer head apparatus (140) is disclosed for concurrently transferring data relative to a plurality of tracks on a data carrier. The head apparatus comprises a body (310) extending longitudinally, the body supporting a plurality of longitudinally spaced transducer elements (240, 241, 242, 250, 251, 252, 260, 261, 255, 256, 257, 265, 266, 267), and adjuster apparatus (330) operable to adjust the relative longitudinal dispositions of at least some of the transducer elements.

Abstract: A method to adjust the positions of a write element and read element disposed on a read/write head comprising a first assembly independently moveable along a first axis and comprising a first servo element, a second servo element, and the write element disposed between the first servo element and the second servo element and a second assembly independently moveable along the first axis and comprising a third servo element, a fourth servo element, and the read element disposed between the third servo element and the fourth servo element. The method moves a sequential information storage medium adjacent to the read/write head along a second axis, wherein the second axis is substantially orthogonal to the first axis, and determines a dynamic skew for the sequential information storage medium with respect to the read/write head using the first servo element and the second servo element. The method then positions the first assembly with respect to the second assembly to correct for that dynamic skew angle.

Abstract: A system and method are described for aligning a data axis of one or more circular data-bearing tracks on an annular surface region of a magnetic media-bearing disk, with a spin axis of a spindle of a spinstand or a disk drive. The data axis is perpendicular to the surface region of the disk and the data tracks are concentric with respect to a data axis.

Abstract: A magnetic storage system includes a disk, a head, an actuator, a read channel, and a main controller. The main controller causes the head to read a data block of a selected track of the disk at each of a plurality of fixed offsets from a center of the selected track. The main controller samples a gain in the read channel a plurality of times while the head is reading the data block at each of the plurality of fixed offsets to obtain a plurality of gain samples for each of the plurality of fixed offsets. If the data block was written off-track with a non-constant offset, the main controller determines an approximate starting position and an approximate rate of change of an off-track deviation of the data block based on the plurality of gain samples for the plurality of fixed offsets.

Abstract: Methods and structures for recovering from an off-track position error in a dynamically mapped storage device. In a dynamically mapped storage device data is dynamically mapped to a physical location on the recordable media. Thus, when a write fault occurs, such as an off-track position error, the data may be re-written and re-mapped at a different location on the recordable media. In a dynamically mapped storage device data may be reordered into a sequential stream of contiguous physical data blocks. Random host data blocks may be mapped into sequential physical data blocks on the recordable media. Further, the sequential reordering of the data blocks may ensure that no data is present in tracks or sectors directly ahead of the track of sector being written. Further, the system has the ability to store multiple revolutions of host supplied data within the disk drive memory buffer and maintain the information in memory while writing it to the recordable media.

Abstract: A hard disk drive control module has a feed-forward signal input port communicatively coupled with a reference model. The hard disk drive control module has a tracking error signal input port communicatively coupled with a magnetic transducer of the hard disk drive. The hard disk drive control module has an error calculator module configured for determining a difference between an estimated tracking error signal in response to a first feed-forward signal and an actual tracking error signal of the magnetic transducer in response to the first feed-forward signal. The hard disk drive control module has a feed-forward signal adjuster module configured for adjusting a gain and a phase for a second feed-forward signal based on the difference between the estimated tracking error signal in response to the first feed-forward signal and the actual tracking error signal of the magnetic transducer.

Abstract: Various embodiments of the present invention provide systems and methods for determining changes in fly-height. For example, various embodiments of the present invention provide storage devices that include a storage medium, an offset frequency, a read/write head assembly, and a harmonic fly-height change detection circuit. The storage medium includes a periodic data pattern that repeats at a data frequency. The read/write head assembly disposed in relation to the storage medium such that it senses the periodic data pattern and provides a sensed periodic data pattern. The harmonic fly-height change detection circuit samples the sensed periodic data pattern at an aggregate frequency to yield a first set of samples and a second set of samples. The aggregate frequency is the data frequency adjusted by the offset frequency. The harmonic fly-height change detection circuit calculates a first magnitude of the first set of samples and a second magnitude of the second set of samples.

Abstract: An embodiment of a data misalignment correction method for a mass storage controller system that couples drives having large internal block sizes to a computer operating system having input/output data block requests, including automatically determining an amount of misalignment between a request of the input/output data block to the storage controller and the controller's current data alignment configuration and using the amount of misalignment to realign the mass storage controller system configuration to match the operating system's input/output requests for optimizing input/output performance with the attached drives.

Abstract: An information storage device includes a magnetic structure having a buffer track and a plurality of storage tracks connected to the buffer track. A write/read unit is disposed on the magnetic structure, and a plurality of switching devices are respectively connected to the buffer track, the plurality of storage tracks, and the write/read unit. The switching devices that are respectively connected to the buffer track and the storage tracks. The information storage device further includes a circuit configured to supply current to at least one of the magnetic structure and the write/read unit.

Abstract: Provided are a method, storage controller, and tape drive for adjusting read heads based on misregistration calculated from servo patterns. A plurality of first read heads read a plurality of servo patterns on a storage medium. A determination is made from the read servo patterns a skew at which the first read heads are positioned with respect to the servo patterns written to the storage medium. A determination is made of an adjustment factor to eliminate the determined skew. A plurality of second read heads that read the storage medium are adjusted by the adjustment factor.

Abstract: Aspects include readers for magnetic storage media. Each reader is operable to read multiple tracks from the storage media simultaneously by using a plurality of active regions, each active region for reading a different track. The active regions may be disposed in rows of columns, and between rows, each active region in a row may be separated from other active regions in that row to prevent interference between those active regions. Active regions of different rows may be offset from each other such that no active region overlaps with another active region over the same data track. Active regions may share shielding and/or sense current conductors. Active regions may comprise AMR, CIP GMR, CPP GMR, including spin valve and tunneling varieties of flux sensors. Multiple active regions in a row may be defined from a single MR element by spaced apart voltage tabs. Readers may be integrally fabricated in layers.

Abstract: A head for a hard disk drive that includes a primary read element and a first sensor read element coupled to a head body. The first sensor read element is offset from the primary read element. The first sensor read element provides a read signal that can be analyzed to determine a pitch of the head. The head may also have a second sensor read element that is offset from the first sensor read element. The second sensor read element provides a read signal that can also be analyzed to determine a pitch of the head. Read signals of the first and second sensor read elements can be analyzed to determine a roll of the head.

Abstract: A method for reading data from a magnetic recording tape having multiple adjacent data tracks according to one embodiment includes simultaneously detecting signals from a plurality of read devices, at least some of the read devices being positioned over multiple data tracks while other of the adjacent read devices are positioned over single data tracks; determining which of the read devices is positioned over a single data track; and simultaneously reading data from the data tracks using only those read devices over the single data tracks. A method for reading and writing data to a magnetic recording tape according to another embodiment includes simultaneously writing data tracks to a magnetic medium; and simultaneously reading the data tracks on the magnetic medium using a plurality of adjacent read devices; wherein the number of the adjacent read devices is at least twice the number of the adjacent write devices.

Abstract: Embodiments of the present invention provide a recording disk capable of curtailing the amount of servo data to be stored thereon, and a disk drive. According to one embodiment, servo data area sets each of a first servo data area and plural second servo data areas arranged in that order in a read direction HR are arranged successively on each of tracks of a magnetic disk. Stored in a second sector data section included in the second servo data area is data representing a distance in the read direction HR from the position of the first servo data area to that of the same second servo data area. The amount of data stored in the second sector data section is less than that of data stored in a first sector data section included in the first servo data area.

Abstract: A magnetic head according to one embodiment includes an array of elements, the elements being selected from a group consisting of data readers, data writers, and combinations thereof; wherein a first subset of the elements is operable for reading or writing data in a first tape format, wherein a second subset of the elements is operable for reading or writing data in a second tape format, at least some of the elements being present in both subsets, wherein a number of servo bands supported in each of the formats is one more than a number of data bands on a medium written in the particular format.

Abstract: According to an aspect of an embodiment, an apparatus, includes: a medium having inner and outer edges and including first and second servo regions extending radially, and containing first and second servo information written thereon, respectively, the first servo region extending outwardly from the inner edge to cover tracks, the first and second servo region having positioned adjacently across a circular boundary; a head for reading out said first servo information and said second servo information; and a processor for executing a process comprising: reading out the first or second servo information; and when controlling the track position across the boundary, adjusting the relation of the first and second servo information across the boundary in control the track position.

Abstract: An information storage device includes a magnetic track and a pinning element for pinning the magnetic domain wall. The magnetic track includes a plurality of magnetic domains and a magnetic domain wall arranged between each pair of adjacent magnetic domains. The pinning element is configured to apply a magnetic field to pin the magnetic domain wall to the magnetic track. The magnetic field may have the same magnetization direction as the magnetic domain wall.

Abstract: A method is disclosed for determining position information of a transducer. At least a first code and a second code are chosen. The first code has different characteristics than the second code. User data written to a first sub-track is encoded with the first code and user data written to a second sub-track is encoded with the second code. The first code read from the first sub-track is obtained and the second code read from the second sub-track is obtained. Position information of the transducer is extracted from the obtained characteristics of the first code and the obtained characteristics of the second code.