Abstract: A data storage device can have one or more data bits that are stored on a data storage medium and accessed with a transducing head. The data bits may be organized on the data storage medium to provide a surface data capacity. A performance degradation can be predicted for the transducing head by a controller connected to the transducing head. In response to the predicted performance degradation, the surface data capacity of the data storage medium is decreased.

Abstract: A tracking control device includes a signal detector that detects a tracking error signal, and a crossing direction, a crossing period and a crossing velocity of an objective lens from a detection signal of an optical detector, a tracking drive signal generator that generates a tracking drive signal on the basis of the tracking error signal, a velocity-reduction drive signal generator that generates a velocity reduction drive signal for converging the crossing velocity into a vicinity of zero on the basis of the crossing direction and the crossing period, a loop switch, and a system controller that causes to executes velocity reduction driving for driving the objective lens actuator on the basis of the velocity reduction drive signal and that controls each of the members so as to switch from the velocity reduction driving to driving for driving the objective lens actuator on the basis of the tracking drive signal.

Abstract: A magnetic recording hard disk drive (HDD) includes, in addition to conventional servo sectors with position error signal (PES) blocks, data position error signal (DPES) blocks that are written into the data sectors when data is written in the data sectors of the data tracks. During readback the PES blocks from the servo sectors are decoded into PES values to allow the head to follow the servo track, while the DPES blocks are decoded to obtain DPES values that are used in the servo control loop to modify the head position so the head follows the center of the data track. In a shingled magnetic recording HDD, wherein the write head is at least two shingled data tracks wide, a DPES block is written in two radially adjacent data tracks when data is written into the data sectors of the shingled data tracks.

Abstract: A method including determining a first frequency for (i) a first track in a servo layer of a storage medium, or (ii) a first sector in the servo layer. The servo layer is dedicated to storing servo information. The method further includes: obtaining first address information addressing the first track or the first sector; modulating the first address information according to the first frequency; and storing the modulated first address information in the servo layer. Subsequent to the storing of the modulated first address information, the servo information includes the modulated first address information.

Abstract: A method of detecting whether data in a tape drive used in a file system is tampered is described according to one embodiment. The method includes: (a) preparing a first tape cartridge including a tape on which multiple files and archival records of index information are stored in a WORM partition, and index information is stored in the R/W partition; (b) reading and comparing the index information of the R/W partition and the last index information of the WORM partition; and (c) when these two pieces of index information do not match, determining that the index information of the R/W partition is tampered when these two pieces of index information do not match.

Abstract: Two or more signals are read from two or more respective tracks of a disk drive recording medium using respective two or more read transducers co-located on a slider. The slider is aligned to the two or more tracks in response to the correlation between the two or more signals.

Abstract: Systems and method relating generally to data processing, and more particularly to systems and methods for utilizing multiple data streams for data recovery from a storage device.

Abstract: An apparatus for correcting crosstalk in an array reader magnetic recording system includes an array reader comprising a number of read heads operable to read data from a magnetic storage medium, a preamplifier configured to amplify the signals from the read heads, and a crosstalk correction circuit configured to reduce crosstalk between signals from the read heads.

Abstract: A technique implemented by a processor may include controlling a write head to write data to at least one partition of a data track of a magnetic data storage medium. The data track may include a plurality of partitions. The technique also may include determining, for each partition of the at least one partition, whether the partition has been previously written to by inspecting a partition overlap register associated with the data track. The partition overlap register stores a respective entry for each partition indicating whether the partition has been previously written to. The technique also may include, in response to determining that at least one respective partition of the at least one partition has been previously written to, incrementing a damage counter of at least one adjacent track and resetting each entry of the partition overlap register to indicate that each respective partition has not been previously written to.

Abstract: A disc device includes a plurality of magazines, each having a tray that stores a plurality of discs, a plurality of disc drives that performs recording or reproducing of information on or from the plurality of discs, a picker that draws out the tray from one of the plurality of magazines and that conveys the tray to a position near the plurality of disc drives, and a disc separating and supplying device that, at the position near the plurality of disc drives, holds the plurality of discs stored in the tray, separates at least one of the plurality of discs stored in the tray from a remainder of the plurality of the discs stored in the tray, and supplies the at least one of the plurality of discs stored in the tray to at least one of the plurality of disc drives.

Abstract: In one embodiment, a method includes detecting an error while writing data to a tape volume. The method further includes repositioning the tape volume for recovering from the error, and receiving, after the repositioning, at least a portion of the data for rewriting the at least a portion of the data to the tape volume. Further, the method includes determining, after the repositioning, a current position of the tape volume. Additionally, the method includes determining, based on the current position of the tape volume, whether the rewrite to the tape volume is allowed.

Abstract: A heat-assisted magnetic recording (HAMR) write apparatus includes a laser and has an air-bearing surface (ABS) that resides in proximity to a media during use. The HAMR write apparatus includes a write pole that writes to the media, coil(s) for energizing the write pole and a waveguide optically coupled with the laser. The waveguide includes an entrance distal from the ABS and a bottom proximate to the ABS. The waveguide also includes a mode converter, a mode stripper optically coupled with the mode converter and an inverse tapered section optically coupled with the mode stripper. The mode converter has sides converging from a first width proximate to the entrance to a second width distal from the entrance and less than the first width. The mode stripper is between the inverse tapered section and the mode converter. The inverse tapered section has an entrance and an exit wider than the entrance.

Abstract: Embodiments are related to systems and methods for data processing, and more particularly to systems and methods for data encoding and decoding.

Abstract: A thermally-assisted magnetic recording head includes a waveguide, a first plasmon generator, and a second plasmon generator. The waveguide includes a core and a cladding. The first plasmon generator is located on the leading side of the core. The second plasmon generator is located on the trailing side of the core. The cladding includes a first interposition section and a second interposition section, the first interposition section being interposed between the core and the first plasmon generator, the second interposition section being interposed between the core and the second plasmon generator.

Abstract: The disclosure is related to systems and methods of compensating for interference via a multi-reader system. A transducer or read/write head may include a write element and multiple read elements. A compensation circuit can be configured to process read signals from the multiple read elements to reduce noise within the read signals, such as caused by the writer being simultaneously active or for other reasons. The read signals may be combined to produce a compensated read signal that has less noise than the original read signals.

Abstract: A communication device includes a vibroscope or an accelerometer for detecting vibration or shock, a hard disk drive for storing data, and a wireless communication transceiver. In response to detecting vibration or shock, the communication device automatically broadcasts an alert message that identifies a physical location of the communication device at the time that the vibration or shock is sensed. In response to receiving an alert message from another communication device, the communication device automatically temporarily parks a read-write head of the hard disk drive to prevent damage from the vibration or shock.

Abstract: In one embodiment, a system includes logic configured to cause data, organized into a plurality of logical arrays including rows and columns of symbols, to be written to a first write section of a magnetic medium as a plurality of CWI-4 sets, each row of the logical arrays including four interleaved headerized C1? codewords (a headerized CWI-4), where each CWI-4 set includes M concurrently written rows of a logical array having M corresponding first headers, and cause some of the data to be written to a rewrite section of the magnetic medium as one or more rewritten CWI-4 sets, where a length of at least one rewritten row is greater than at least one of: a length of another rewritten row in the same rewritten CWI-4 set, and a length of at least one row in a CWI-4 set stored to the first write section of the magnetic medium.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes a magnetic recording medium, a recording unit, and a reproducing unit. The magnetic recording medium includes a first track including first and second sub-tracks extending in a first direction. The second sub-track is arranged with the first sub-track in a second direction intersecting the first direction. The recording unit records information in the first and second sub-tracks. The reproducing unit reproduces the information recorded in the first and second sub-tracks while opposing the first, second sub-tracks, and a boundary between the first and second sub-tracks. The first sub-track includes first magnetic recording components including first and second components. The second sub-track includes second magnetic recording components including third and fourth components. A first recording symbol is formed of the first and third components. A second recording symbol is formed of the second and fourth components.

Abstract: A data storage device is disclosed comprising a head actuated over a disk. A first control circuit comprises a pattern detector configured to detect at least one pattern in write data and generate a corresponding multi-state signal, and a transmitter configured to transmit a first differential signal representing the write data and a second differential signal representing the multi-state signal. A second control circuit comprises a receiver configured to receive the first differential signal and the second differential signal, and a write driver configured to generate a write current applied to the head based on the first differential signal and configured to adjust at least one property of the write current based on the second differential signal.

Abstract: A Data Storage Device (DSD) includes at least one disk surface for storing data and a memory for storing a bitmap buffer. A segment of a disk surface is identified that includes at least one defect region, and a segment bitmap is generated for the segment indicating the at least one defect region within the segment. The segment bitmap is stored in the bitmap buffer.