Abstract: An apparatus according to one embodiment includes a plurality of modules configured to at least read data stored on a magnetic recording tape, each of the modules having an array of readers. One module is configured to read data on a magnetic recording tape which none of the other modules can read. An apparatus according to another embodiment includes a first module configured to at least read data stored on a magnetic recording tape in a first range of formats, and at least a second module configured to at least read data stored on a magnetic recording tape in at least a second range of formats. The first range of formats does not include a format that is in the second range of formats. All of the modules are aligned along a tape travel direction.

Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of servo sectors defining a plurality of servo tracks. The servo tracks form a plurality of servo zones, and at least one servo sector of a servo track comprises a partial track address. A read signal generated by the head is processed to detect a current servo zone for the head, and the read signal is processed to detect the partial track address in one of the servo sectors of the current servo zone. A full track address is generated based on the detected servo zone and the detected partial track address.

Abstract: In various embodiments, a method of writing servo information to a recording medium may be provided. The method include forming a first servo pattern (including a servo burst pattern) on a segment of a first track of a first layer of the recording medium, the first track having a track width. The method may further include forming a second servo pattern (including addressing information) on a segment of a second track of a second layer of the recording medium. The second track is arranged from the first track by half the track width.

Abstract: In one embodiment, a system for integrating data and header protection in tape recording includes a processor and logic adapted to: provide a data array organized in rows and columns, each row of the data array including four interleaved C1 codewords (CWI-4), add a header to each row of the data array, each header including a CWI-4 Designation (CWID) which indicates a location of the CWI-4 within the data array, calculate ECC parity for at least one C1 codeword in each of the headerized rows, and modify the headerized rows to include the ECC parity, wherein each modified row includes four interleaved codewords, at least one codeword being a C1? codeword which includes ECC parity for a data portion of a C1 codeword and a portion of a header, wherein none of the CWIDs are split across multiple C1? codewords in a single modified row.

Abstract: An object of the present invention is to further improve a recording density in a magnetic disk apparatus using a shingle write system. In a magnetic disk apparatus including a magnetic disk, a recording head that writes information on the magnetic disk, and a controller that controls a writing operation of the recording head to the magnetic disk, the controller controls the writing operation such that the recording head writes information on a region including a target track and a portion of track adjacent thereto in an overlapping manner while position-shifting in a radial direction of the magnetic disk and a first writing frequency to a track on which information is last written is higher than a second writing frequency to another track.

Abstract: A disk drive having at least one disk with a major disk surface that includes a first region including a plurality of tracks and a second region including a plurality of tracks. The first and second region are separated by a guard band. The track or tracks near the guard band have a track width that is greater than the track widths of the tracks more distant from the guard band, such as those in the middle of the first and second regions as this reduces the occurrence of far track interference.

Abstract: A data signal comprising an even component and an odd component with differing amplitudes is received at a main automatic gain controller (AGC). The even component is adjusted by a first interleaved AGC and the odd component is adjusted by a second interleaved AGC such that even and odd component amplitudes are substantially equal. Amplitude adjusted even and odd components are recombined to define a data signal with components having substantially equal amplitudes. The even and odd components can be generated by a read transducer moving relative to a magnetic storage medium comprising tracks defined by discrete and spaced-apart recording bits arranged in an interspersed pattern. A read channel separates the data signal into even and odd samples such that a gain can be independently adjusted for each of the even and odd samples to compensate for asymmetry between the even and odd samples.

Abstract: An apparatus includes a magnetic head having an array of transducers. The apparatus is configured to read and/or write to a magnetic recording tape according to a format. The format specifies a number of active channels and a contiguous spare area on the magnetic recording tape. The format also specifies compatibility with a second format. The second format specifies a different number of active channels than the number of active channels specified by the format. A product includes a magnetic recording tape and data stored on the product specifying the aforementioned format.

Abstract: An apparatus for detecting media flaws includes an envelope based media defect detector operable to identify a media defect based on an envelope of an input signal, a periodic pattern detector operable to determine whether the input signal comprises a data pattern, and a media flaw signal generation circuit operable to indicate a media defect when the envelope based media defect detector identifies the media defect and the periodic pattern detector determines that the input signal does not comprise the data pattern.

Abstract: Embodiments of the present invention utilize a hard disk drive buffer to minimize seek delays during background replication of a first volume and fulfillment of application input/output requests. According to one aspect of the present invention, a requested first sector of data is read along with one or more additional sectors of data. Upon determining that one or more of the read sectors of data should be replicated, the sectors are read from the disk buffer and written to a second volume.

Abstract: An emulation mitigation module is configured to mitigate emulation of legacy write requests on advanced disk devices using cached data stored in a cache memory of a storage system. A legacy write request may comprise write data blocks formatted in a legacy sector size while an advanced disk device may be formatted in an advanced sector size. The emulation mitigation module may execute a first method for modifying write requests using cached data, a second method for enforcing a minimum requested data size sent to the advanced disk device, and/or a third method for conditionally retrieving data from the advanced disk device and storing to cache. In some embodiments, the second and/or third method may be used with the first method to increase the effectiveness of the first method. The emulation mitigation module may improve performance and/or data integrity for of processing legacy write requests.

Abstract: Shingled magnetic recording (SMR) devices according to embodiments of the invention include unshingled cache regions that can be used for storage of data. The unshingled cache regions can be used in a variety of flexible ways including in an implementation of write-twice caching or for opportunistic temporary storage to improve performance. The cache regions can be offset between top and bottom surfaces of the disk and staggered between disks to provide shorter seek times to the nearest cache region. Embodiments of the invention are adapted for use with symmetric or asymmetric heads.

Abstract: A method for writing a servo track according to one embodiment comprises monitoring a lateral position of a magnetic tape passing over a servo writing head during a servo track writing operation; and writing servo marks to the magnetic tape, a timing of the writing of each mark being based on the monitored position of the magnetic tape. A system for writing a servo track according to one embodiment comprises a servo writing head for writing servo marks onto a magnetic tape; a device for optically monitoring a position of the magnetic tape during a servo track writing operation; and a controller for controlling a timing of the writing of the servo marks to the magnetic tape based on the monitored position of the magnetic tape. Additional systems and methods are also presented.

Abstract: An apparatus for detecting media flaws includes an envelope based media defect detector operable to identify a media defect based on an envelope of an input signal, a periodic pattern detector operable to determine whether the input signal comprises a data pattern, and a media flaw signal generation circuit operable to indicate a media defect when the envelope based media defect detector identifies the media defect and the periodic pattern detector determines that the input signal does not comprise the data pattern.

Abstract: Adaptively determining shingle guard band widths on at least one disk of a data storage device (DSD). The at least one disk includes a plurality of zones of shingle tracks for storing data. At least one of a magnetic erase width (MEW) and a magnetic read width (MRW) are measured and a shingle track pitch (STP) is determined. The shingle guard band width is determined based at least partly on the STP and at least one of the MEW or the MRW.

Abstract: Various approaches, methods, systems, circuits and devices for channel bit density estimation.

Abstract: A system, method, and apparatus for forming a high quality master pattern for patterned media, including features to support servo patterns, is disclosed. Block copolymer self-assembly is used to facilitate the formation of a track pattern with narrower tracks. E-beam lithography forms a chemical contrast pattern of concentric rings, where the spacing of the rings is equal to an integral multiple of the target track pitch. The rings include regions within each servo sector header where the rings are offset radially by a fraction of a track pitch. Self-assembly is performed to form a new ring pattern at the target track pitch on top of the chemical contrast pattern, including the radial offsets in the servo sector headers. When this pattern is transferred to disks via nanoimprinting and etching, it creates tracks separated by nonmagnetic grooves, with the grooves and tracks including the radial offset regions.

Abstract: In one embodiment, a system for integrating data and header protection in tape recording includes a processor and logic adapted to: provide a data array organized in rows and columns, each row of the data array including four interleaved C1 codewords (CWI-4), add a header to each row of the data array, each header including a CWI-4 Designation (CWID) which indicates a location of the CWI-4 within the data array, calculate ECC parity for at least one C1 codeword in each of the headerized rows, and modify the headerized rows to include the ECC parity, wherein each modified row includes four interleaved codewords, at least one codeword being a C1? codeword which includes ECC parity for a data portion of a C1 codeword and a portion of a header, wherein none of the CWIDs are split across multiple C1? codewords in a single modified row.

Abstract: A method, apparatus and a data storage device are provided for implementing track following and data recovery with readback of shingled data written in overlapping shingled data tracks on a recordable surface of a storage device. Positional information is identified with data readback of shingled data written in overlapping shingled data tracks. The identified positional information is used to selectively modify at least one predefined channel parameter, for example, to provide enhanced track following and enhanced data recovery.

Abstract: A method according to one embodiment includes reading and/or writing data to a magnetic recording tape using a head having at least two modules, each of the modules having an array of transducers, wherein an axis of each array is defined between opposite ends thereof, each of the axes of the head being tilted at an angle greater than 0° from a line oriented perpendicular to an intended direction of tape travel thereacross during the reading and/or writing. The method includes at least one of: introducing a timing offset to at least one servo channel to compensate for offset in servo readback signals introduced by the tilt of the head, introducing a timing offset to at least some read channels to compensate for offset in readback signals introduced by a tilt of the head, and introducing a timing offset to at least some write channels to enable writing of transitions that are readable by a non-tilted head.

Abstract: Systems and methods for writing a sequence of data to a disk drive using sorted data zones are provided. One embodiment includes a disk drive comprising one or more disks having a plurality of disk surfaces, wherein each disk surface comprises a plurality of data zones, each data zone having a data transfer rate; a plurality of heads, wherein each head is configured to write data to a respective one of the disk surfaces; and a controller configured to operate the plurality of heads to sequentially write a sequence of data blocks to the plurality of disk surfaces in accordance with an order of head-zone combinations ordered from highest data transfer rate to lowest data transfer rate, each head-zone combination corresponding to one of the heads and one of the data zones of the respective disk surface.

Abstract: In various embodiments, a recording medium having a servo layer configured to provide servo information and a data recording layer configured to record data, wherein the medium comprises a plurality of servo patterns and a plurality of data segment in one sector, each data segment corresponding to each of the plurality of servo patterns, wherein the plurality of servo patterns comprises a first servo pattern comprising an automatic gain control, a second servo pattern comprising a sector address mark, a third servo pattern comprising a GrayCode, and a fourth servo pattern comprising a plurality of servo bursts, wherein the data recording layer is configured to record the data on the data segments corresponding to the first, second, third and fourth servo patterns.

Abstract: According to one embodiment, a disk storage apparatus includes a storage device, a writing controller, and a controller. The storage device includes a nonvolatile cache area in which a part of consecutive data is temporarily stored. The writing controller is configured to write the consecutive data in a recording area on a disk by an SMR method, the recording area being different from the cache area. The controller is configured to write the part of the data to the cache area, to invalidate data corresponding to logical addresses of the part of the data and recorded in the recording area on the disk, and to set a recording area with the invalidated data recorded therein to be an update recording area in which new data is recordable.

Abstract: According to one embodiment, a disk storage apparatus includes an interrupt controller and a servo controller. The interrupt controller determines whether or not to carry out servo interrupt processing and holds a number of negative results of the determination. The servo controller includes an internal model configured to calculate an estimated current position of the head. The servo controller corrects a state of the internal model based on the number of negative results of the determination and performs head positioning control based on a result of a calculation of the internal model, if the result of the determination by the interrupt controller is affirmative.

Abstract: A magnetic disk according to an embodiment includes: a plurality of data regions each including a plurality of tracks, each of the tracks being arranged to extend in a circumferential direction; a servo region provided between the data regions, the servo region extending in a radial direction, the servo region including: a plurality of guide patterns each extending in the radial direction; and at least one line of dots arranged by post patterns in the radial direction at least on a side of one of adjacent guide patterns, the post patterns being arranged in the radial direction between the adjacent guide patterns.

Abstract: A method and apparatus for data de-duplication is disclosed. Use de-duplication engine (DDE) divides data into regions. The DDE processes the regions in a serial fashion. The DDE clears its hash table before processing the first region. Each region is divided into a number of chunks. A hash is generated for each chunk in a region. When a hash for a chunk is not in a hash table, the hash is stored in the hash table and the chunk is stored on media. When the hash is a duplicate of a hash already in the table, the hash and chunk are discarded and a reference to the previously stored chunk is stored to the media. The DDE does not retain all the hashes from all the regions in the hash table at the same time. The DDE only retains the hashes for the current region being processed and N previous regions where N is a positive integer greater than zero.

Abstract: A seek control section is configured so that when a magnetic head is within a prescribed range from a zone boundary when there is a head change request, the magnetic head is driven to seek in a stable region, and then the magnetic head is changed from a current head to a target head. After the change from the current head to the target head, the target head is driven to seek the target position.

Abstract: Various embodiments provide a data storage device. The data storage device includes a recording medium having a dedicated servo layer for providing servo information. The dedicated servo layer may include a plurality of servo patterns, wherein each servo pattern includes a preamble providing information for synchronization of at least one of a read and a write operation of the data storage device.

Abstract: Described embodiments provide a method of cancelling inter-track interference (ITI) from one or more sectors read from a desired track of a storage medium. A road channel reads sectors in a desired track of the storage medium. A decoder of the read channel decodes the read sectors, and if the read sectors are incorrectly recovered from the storage medium, selected sectors of a first adjacent track and a second adjacent track are read. An ITI canceller of the read channel estimates ITI in the read sectors of the desired track corresponding to the selected sectors of each adjacent track and subtracts the estimated ITI of each adjacent track from the data for the sectors of the desired track, providing updated sector data. The ITI cancelled data is replayed to the decoder, which decodes the ITI cancelled data and provides the decoded ITI cancelled data as output of the read channel.

Abstract: Systems, methods, apparatus, and techniques are provided for controlling synchronization of a write clock. A frequency offset is estimated based, at least partially, on a location of the servo synchronization marker to produce the frequency offset estimate. A phase correction value and a frequency correction value associated with the write clock are obtained, and a data clock timing control signal is produced based on the frequency offset estimate, the phase correction value, and the frequency correction value. The data clock timing control signal is applied to a phase interpolator to modify a phase of the write clock.

Abstract: Storing data in a hard disk drive may include determining a percentage of storage usage (SU %) of the data tracks. If the SU % is less than a first threshold percentage (TP1), the method may include storing data to Nth data tracks. If the SU % is greater than or equal to TP1, but less than a second threshold percentage (TP2), the method may include storing data to about N/2 data tracks between said Nth data tracks. If the SU % is greater than or equal to TP2, the method may include storing data to data tracks between said N/2 data tracks and said Nth data tracks.

Abstract: Provided herein is an apparatus, including a servo pattern having magnetic features, wherein each magnetic feature of the magnetic features includes a single magnetic domain; a first population of the magnetic features; a second population of the magnetic features; and a selective magnetization means for selective magnetization of either one of the first population or the second population of magnetic features over the other.

Abstract: Systems, devices, apparatuses, and methods for segmented read-modify-write operations are disclosed. The examples provided can allow a system to perform a read-modify-write (RMW) operation for data stored in a main storage that has a larger data size than is capable of being stored in an available buffer. Examples of such a system include discs having bands of shingled tracks. In such example, each band can be split into segments containing one or more tracks and a read-modify-write-write (RMWW) operation can be performed for each segment. Further, a logical guard band can be implemented to protect the segments from overwriting a next track in a shingled band. Also, multiple scratchpads may be implemented.

Abstract: A bit-patterned media (BPM) magnetic recording disk has two sizes of dots of magnetic material. The large and small dots are formed together in a hexagonal-close-packed (HCP) pattern. In the data regions none of the larger sized dots are adjacent one another; however in the servo regions some of the larger sized dots are adjacent one another. The adjacent larger sized dots form blocks that provide large amplitude “bursts” as the readback signal, as required for servo burst fields. The disk is made by imprint lithography using an imprint template, which can be made by directed self-assembly (DSA) of a block copolymer (BCP). The imprint template has two sizes of recesses, resulting in BPM disks with two sizes of dots. After the disks are imprinted they are exposed to a DC magnetic field, which magnetizes all the dots in the same direction.

Abstract: A storage medium for storing text-based subtitle data including style information, a reproducing apparatus and methods are provided for reproducing text-based subtitle data including style information separately recorded on the storage medium. The storage medium includes: multimedia image data; and text-based subtitle data for displaying subtitles on an image based on the multimedia image data, wherein the text-based subtitle data includes dialog information indicating subtitle contents to be displayed on the image, style information indicating an output style of the dialog information, and partial style information indicating an output style applied to a portion of the dialog information. Accordingly, subtitles can be provided in a plurality of languages without limited to the number of units of subtitle data. In addition, subtitle data can be easily produced and edited. Likewise, an output style of the subtitle data can be changed in a variety of ways.

Abstract: The present disclosure relates to a perpendicular pole head for creating a perpendicular magnetic moment in a concentrated pattern for writing the pattern on perpendicular magnetic media, such as BaFe based media. The pole head can have flux concentrators in the shape of the written pattern, which can be repeatedly applied to a moving magnetic medium to create a timing pattern on the media, e.g., a servo timing pattern.

Abstract: Data format that allows for format-efficient data storage, particularly on bit-patterned media. The data format allows for variations in the data storage device, such as reader-to-writer gap variations. A medium can also have at least a pair of a synchronization field and a quiet field with a length greater than a length of the synchronization field. These can be implemented in a bit patterned media system.

Abstract: A manufacturing method of a magnetic recording medium includes steps of forming a magnetic recording layer, a first mask layer, a second mask layer containing silicon as primary component, a strip layer, a third mask layer, and a resist layer, a step of patterning the resist layer to provide a pattern, steps of transferring the pattern to the third mask layer, to the strip layer, and to the second mask layer, a step of removing the strip layer by wet etching and of stripping the third mask layer and the resist layer above the magnetic recording layer, steps of transferring the pattern to the first mask layer and to the magnetic recording layer, and a step of stripping the first mask layer remaining on the magnetic recording layer.

Abstract: A data format that allows for format-efficient data storage, particularly on bit-patterned media. The data format uses an intersector gap that is dimensioned relative to a physical dimension of a transducer. Further described is a data storage medium comprising transducer overhead, such as an intersector gap, interleaved with fragment overhead. Also described is a storage medium comprising intersector gaps that each include a write splice and extra symbols.

Abstract: In one embodiment, a method includes spiral writing a DC pattern onto a magnetic disk medium using a writer of a magnetic head while moving the magnetic head in a direction about parallel to a radial direction of the magnetic disk medium while rotating the magnetic disk medium, reading the magnetic disk medium while moving the magnetic head in the direction about parallel to the radial direction of the magnetic disk medium while rotating the magnetic disk medium, and calculating a track pitch interval between data tracks of the magnetic disk medium based on the reading of the magnetic disk medium. In another embodiment, a magnetic disk medium includes a DC spiral pattern in a radial region further outward and/or a radial region further inward than a radial region where data is recorded.

Abstract: A method and apparatus for storing a disk drive media defect table or list. Defect table entries for a subject disk track are stored on the subject track and retrieved for determining defective sectors only when the subject track is accessed for a data read or write operation.

Abstract: A method of writing servo data to a data storage medium includes reading a servo instruction from a memory, the servo instruction comprising a control portion and a data portion, processing the servo instruction in a controller to generate a servo data pattern from the data portion based on the control portion, and transferring the servo data pattern to the data storage medium. The processing may include transforming the data portion into the servo data pattern based on the control portion. The processing also may include following a command in the control portion to use the data portion as an index to retrieve a pre-programmed servo data pattern from a pattern store. The transferring may include storing the servo data pattern in a buffer, and writing the servo data pattern from the buffer to the data storage medium.

Abstract: Methods and apparatus are provided for improved detection of servo sector data in a magnetic recording system using single bit error correction. Servo sector data is processed by detecting the servo sector data; determining whether a single bit error occurred in the detected servo sector data; and flipping a bit value of an individual bit in the detected servo sector data having a lowest amplitude sample among the samples of the detected servo sector data when a single bit error is detected in the detected servo sector data. The servo sector data comprises, for example, a servo address mark, Gray data, an RRO address mark and/or RRO data. For example, the bit value can be flipped by changing a binary value of one to a binary value of zero and changing a binary value of zero to a binary value of one.

Abstract: An implementation of a system disclosed herein provides a method of deferring decoding of a data sector received at a read channel of a storage device, in response to determining that a data sector cannot be decoded by a first decoder and storing the data sector for further processing by a second decoder.

Abstract: According to one embodiment, a magnetic recording medium includes: a data area on which a plurality of first magnetic dots are arranged at predetermined positions to record information; a servo area on which a plurality of second magnetic dots for specifying the positions of said plurality of first magnetic dots are arranged at predetermined positions; and servo frames configured so that a frequency of said servo frames is 2N per circumference of said medium having a radius, that said servo frames are radially discontinuous, and that said servo frame and a space-area, on which no servo frames exist, are alternately radially arranged at a cycle W.

Abstract: A method and system for performing a shortened acquire cycle for at least one fragment of at least one data sector having coherently written fragments, the coherently written fragments being written during a single rotation of a storage medium. The method includes performing a full acquire cycle for a first fragment of a particular data sector of the at least one data sector. The method further includes reusing at least a portion of the acquisition information of the first fragment to perform a shortened acquire cycle for at least one subsequent coherently written fragment. The method also includes reusing at least a portion of the acquisition information of the first fragment to perform a shortened acquire cycle for at least one subsequent coherently written fragment. Additionally, the method includes performing the shortened acquire cycle for the at least one subsequent coherently written fragment.

Abstract: Apparatus and method for writing data to a data storage medium using shingled magnetic recording (SMR). In accordance with some embodiments, a transducer is positioned adjacent a recording medium. The transducer is used to write data to the medium in the form of partially overlapping tracks grouped together into bands so that a first track and a last track in a selected band are wider than remaining tracks in the selected band.

Abstract: A data format that allows for format-efficient data storage, particularly on bit-patterned media. The data format uses an intersector gap that is dimensioned relative to a physical dimension of a transducer. Further described is a data storage medium comprising transducer overhead, such as an intersector gap, interleaved with fragment overhead. Also described is a storage medium comprising intersector gaps that each include a write splice and extra symbols.

Abstract: Data blocks to be stored on a disk-based data storage device (e.g., a hard disk drive, etc.) are coded together to form a plurality of linearly independent network coded blocks. The network coded blocks are then stored on the data storage device. Coded seeking may then be used to retrieve the original data blocks from the data storage device in a time-efficient manner. A read request may be sent to the data storage device requesting an innovative coded packet associated with the original data blocks. In response to the read request, the data storage device may read an innovative coded packet from the disk that is closest to current position of a read element of the device.

Abstract: A hard disk drive uses a second, reference burst field in a preamble to estimate burst phase and burst magnitude. Such estimations are used for position error signal integration and repeatable runout correction. Gain error is also derived from such estimations. Information contained in a preamble field is used in conjunction with the reference burst phase estimation to synchronize servo address marks.