Abstract: Embodiments of the present invention help to improve the capacity and the performance of a disk drive device. According to one embodiment, a data track pitch is set to each recording surface. The recording surfaces are divided into bands. A hard disk drive (HDD) sequentially moves a head to an adjacent data track in a band and performs a head switch at the band end in its data accessing. On a recording surface, the number of data tracks in each band is variable; and each band is constituted by different number of data tracks as necessary. The number of data tracks in each band is set so that the radial position of the band end comes close to the radial position of the corresponding band end on another recording surface. Accordingly, even if the recording surfaces have different variation rates of the data track pitch in the radial direction, increase in process time due to head switches can be suppressed.

Abstract: An exemplary embodiment of the invention includes methods of configuring a memory block including: providing a memory block, the memory block having a set of addressable memory locations; configuring the memory block to include a plurality of pages corresponding to the set of addressable memory locations, the plurality of pages each having a page size; and allocating at least one of the plurality of pages for storing at least one per-page data structure, the at least one per-page data structure co-located with the memory block. In some embodiments, methods further include: defining the set of addressable memory locations; and computing a number of pages needed to store the at least one per-page data structure. Advantages of the invention include flexible memory allocation. The invention supports a dynamic update of the memory per-page data structures so that the operating system can take full advantage of the available memory.

Abstract: A magnetic recording disk drive has a disk with a head positioning servo pattern of multiple circumferentially-spaced chevron patterns of discrete patterned servo islands. The disk drive has servo electronics that decodes the chevron patterns to determine the absolute radial position of the head without the need for separate track identification fields. The chevron pattern with the smallest radial period has a radial period P1 and each of the other chevron patterns has a period which is a unique multiple of P1. In one embodiment the first chevron pattern read by the head has period P1 and each successive chevron pattern read by the head has a period that is greater than the period of the chevron pattern immediately preceding it such that the period of each chevron pattern progressively increases.

Abstract: Provided is a magnetic recording apparatus including a magnetic recording medium having a magnetic recording position patterned of a magnetic substance and a read head reading information from the magnetic recording medium, wherein the magnetic recording medium includes: a data area having the magnetic recording position patterned including a plurality of data tracks; and a servo area including a servo burst for tracking the data tracks, wherein the servo burst includes a plurality of bursts deviating from one another in a downtrack direction, and a width of each of the bursts is equal to or greater than a width of the read head and narrower than twice the width of the read head. According to this structure, although data is reproduced using a read head having a greater width than a width of each of data tracks, a linear section in which an output voltage is reduced depending on a size of an off-track is formed. As a result, a dead zone can be removed.

Abstract: A method of writing a servo pattern of a hard disk drive includes measuring the speed of a head of the hard disk drive by reading a basic servo pattern written to only select ones of the data tracks of the disk, realizing a feedforward current profile when the difference between the actual speed of the head and a target speed of the head is within a predetermined range, and writing a reference servo pattern using the realized feedforward current profile. A final servo pattern is then written using the reference servo pattern.

Abstract: A magnetic recording disk drive has a position-error-signal (PES) servo pattern divided into at least two circumferentially adjacent fields that extend radially across the data tracks and include PES blocks that are DC magnetized in one direction, with each PES block having a magnetization opposite to the magnetization of its radially adjacent neighboring PES blocks. Each PES field is contiguous with and shifted radially relative to its circumferentially adjacent neighbor PES fields. Each PES block has a single DC magnetization, and the length of the magnetization is substantially longer than the length of the magnetizations in the other fields of the servo pattern.

Abstract: According to one embodiment, a magnetic recording tape includes a plurality of servo tracks, each servo track comprising a series of magnetically defined bars having an average height of between about 80 microns and about 120 microns, wherein an average stripe angle of the bars is between about 10° and about 25°. A stripe angle is measured between a longitudinal axis of each respective bar and a line oriented perpendicular to a direction of tape travel and parallel to a plane of the tape, wherein an average stripe width of the bars is between about 1.0 micron and about 2.2 microns and an average servo frame length of groups of the bars comprising a servo frame is between about 120 microns and about 180 microns. In more embodiments, a servo format and a system including a servo format are disclosed, along with other embodiments of magnetic tapes.

Abstract: A disk drive is disclosed having a first disk surface, and a head actuated over the first disk surface. The first disk surface comprises a plurality of servo tracks and a plurality of data tracks. The data tracks of the first disk surface are banded together into a plurality of data zones, including a first data zone and a second data zone. A first servo tracks per inch (STPI) to data tracks per inch (DTPI) ratio of the first data zone is substantially different from a second STPI to DTPI ratio of the second data zone.

Abstract: A burst included in a burst pattern of a magnetic recording medium is a rectangular region. The rectangular region is constituted by a first signal region formed across a plurality of data tracks and is of a shape in which the length in the down track direction gradually increases in the cross track direction, and a second signal region adjacent to the first signal region in the down track direction. The maximum length of the first signal region is an edge of the rectangular region.

Abstract: Systems and methods for detecting and designing enhanced disk sync marks using correlation detection are disclosed. The enhanced sync marks provide better noise immunity and higher detection rates over traditional Viterbi-based detection schemes even with a shorter sync mark length. The disk sync mark may provide optimal noise immunity for a particular target polynomial or a plurality of common target polynomials. The minimum Euclidean distance between a candidate sync mark and a plurality of right-shifted versions of the candidate sync mark is computed and compared with other candidate sync marks. The sync mark with the largest minimum Euclidean distance is then selected as the optimal mark. Systems and methods are also disclosed for detecting and designing a disk sync mark using correlation detection when the polarity of the disk is unknown or time-varying.

Abstract: A disk drive is disclosed comprising a disk comprising a plurality of tracks, and a head actuated over the disk. A plurality of refresh zones are defined, wherein each refresh zone corresponds to a plurality of the tracks. Data is written to a first refresh zone, and a first zone counter is updated for a second refresh zone at a first rate. Data is written to a third refresh zone, and the first zone counter is updated for the second refresh zone at a second rate different than the first rate.

Abstract: Injecting pad bits during a read operation to improve format efficiency is disclosed. In some embodiments, a pad sequence associated with error correction is not stored in a sector on a disk. Instead, the pad sequence is merged at a read channel with data stored in a sector that is accessed by the read channel.

Abstract: Techniques are described for providing media-referenced timing for operations on a data storage medium. In particular, Phase-Locked Loop (PLL) synchronization fields may be interspersed within data fields of the medium and may be read to obtain timing measurements. The PLL fields are illustratively pre-recorded at predetermined intervals on the medium and have a fixed number of dots of the bit patterned medium between the PLL fields. Phase and frequency of a write clock may be controlled based on the read PLL fields to translate the timing measurements from the PLL fields into phase and frequency corrections to synchronize the write clock to the data storage medium.

Abstract: A magnetic tape of the present invention includes a plurality of data bands in which a data signal can be recorded and servo pattern portions composed of a burst signal. The servo pattern portions are formed at a predetermined interval in a longitudinal direction of the magnetic tape in a plurality of data bands, and positions of the servo pattern portions formed in the respective data bands in the longitudinal direction of the magnetic tape vary. According to such a configuration, a magnetic tape can be provided, which is traced stably by the magnetic head even if the magnetic tape is deformed due to temperature and humidity.

Abstract: A wireless inductive coupling assembly for a heated glass panel assembly is provided that includes a metal oxide coated glass panel with a panel frame, an opening frame that cooperates with the coated glass panel frame to allow the panel to cover a panel opening, a receiving coil that is positioned in the panel frame and that is wired to the panel, and a sending coil that is positioned in the opening frame and that is wired to an electrical power source. When the electrical power source supplies electrical power to the sending coil, the sending coil wirelessly induces an electrical current in the receiving coil, which causes the dielectric panel to provide heat.

Abstract: A data storage apparatus includes a data storage medium, a write element, a non-volatile cache memory circuit, and a controller circuit. The controller circuit is configured to record data on the data storage medium in groups of overlapping tracks using the write element. The controller circuit is configured to store a shingle block of data from a subset of the overlapping tracks in the non-volatile cache memory circuit, while at least a portion of the data in the shingle block of data is updated.

Abstract: Writing data to magnetic tape is performed by receiving data from a host, establishing sub data sets, computing C1 and C2 ECC, forming Codeword Quad sets, writing a beginning Data Set Separator to a magnetic tape, writing a plurality of contiguous instances of the CQ Set to the magnetic tape and writing a closing DSS. The number of instances of each Codeword Pair is increased, thereby allowing the benefits of writing short tape records and improving reading reliability while reducing susceptibility to mis-tracking errors and large defects, and while reducing the negative impact on data reliability. Otherwise unused latency times are utilizing and therefore no performance penalty is incurred.

Abstract: Methods, logic, apparatus and computer program product write data, comprising less than a full Data Set, to magnetic tape. Data is received from a host, a do-not-interleave command is issued and C1 and C2 ECC are computed. Codeword Quad (CQ) sets are then formed. At least one CQ set of the Data Set is written to a magnetic tape in a non-interleaved manner and a Data Set Information Table (DSIT) is written to the magnetic tape immediately following the at least one written CQ set. An address transformation may be used to cancel interleaving. Writing a CQ set may include writing a plurality of contiguous instances of the CQ set to the magnetic tape to maintain the effectiveness of ECC capability.

Abstract: A patterned perpendicular magnetic recording disk has a pre-patterned disk substrate with pillars and trenches arranged in data regions and servo regions. In the data regions, the height of the data pillars is equal to or greater than the spacing between the data pillars, while in the servo regions the height of the servo pillars is less than the spacing between the servo pillars. A magnetic recording material with perpendicular magnetic anisotropy is deposited over the entire disk substrate, which results in magnetic material on the tops of the data pillars and servo pillars and in the servo trenches. The material in the data trenches is either nonmagnetic or discontinuous. After the application of a high DC magnetic field in one perpendicular direction and a low DC magnetic field in the opposite direction, the resulting disk has patterned servo sectors with servo pillars all magnetized in the same perpendicular direction and servo trenches magnetized in the opposite perpendicular direction.

Abstract: A method of operating a hard disk drive (HDD) on the basis of a predicted new defect in a disk associated with the HDD is disclosed. The method includes detecting defects in a magnetic surface of the disk, defining a plurality of clusters by grouping the detected defects using a hierarchical clustering algorithm, calculating a curve fit for each one of the plurality of clusters, predicting a new defect likely to occur in the magnetic surface of the disk on the basis of the calculated curve fit; and writing data to the disk on the basis of the new defect prediction.

Abstract: Provided is a bit patterned medium including bridges which induce exchange coupling between adjacent bits in order to reduce a switching field difference resulting from different magnetization directions of bits. The bridges and the bits are integrally formed with each other. The bits are locally connected by the bridges. A magnetostatic force for each bit is reduced due to an exchange coupling between adjacent bits, thereby reducing a switching field distribution of the bits.

Abstract: Servo patterns and associated methods of fabricating servo patterns are described. For patterned storage media, data sectors and servo sectors may be patterned using self-assembly. In one embodiment, self-assembly is used to form a first array of islands and a second array of islands in servo sectors that are track-wise offset. A servo writing process is then performed to write a desired servo pattern in the arrays, such as for burst fields, synchronization fields, etc.

Abstract: A recording control device includes a recording unit, and generates a conversion rule by determining the number of divisions into which the total number of sectors is to be divided, an area to which data is to be moved, and a start position of a sector, based on a key received from a connected information processing device. When a data read or write request is received from the information processing device, the recording control device converts the request into an instruction to convert a sector position assigned by a received request into a virtual sector position, executes the converted instruction, and discards the generated conversion rule after executing the instruction, based on a generated conversion rule.

Abstract: A hard disk drive that stores data on a disk. An overshoot duration is used to write data onto the disk. The value of the overshoot duration is a function of the data rate, which can vary for different areas of the disk. For example, the data rate can be higher at an outer diameter of the disk than at an inner disk diameter. The overshoot duration can therefore be different when writing data at the outer diameter than the duration used to write data at the inner diameter. The data rate can be determined by analyzing a preamble of the data written onto the disk.

Abstract: A recording medium for storing start position information for each zone, a method of managing data using the information, and an apparatus for recording the information and controlling recording and reproduction of data based on the recorded information. In a disc having a plurality of zones which form a group, and a spare area which is allocated at the start portion or the end portion of the group for replacing defects, when start logical sector numbers of each zone are changed by slipping replacement during initialization or reinitialization, the information is stored in the defect management area to thereby increase the compatibility of the medium. In particular, by the method and apparatus of managing data using information stored in a defect management area, generation of errors is prevented in reading or writing due to the change of a physical position of a real-recorded file which are caused by wrong calculation of the start logical sector numbers for each zone.

Abstract: A method includes writing data to a bit-patterned media at times determined by a clock having a period that is offset from a bit island period by a fixed offset to create one insertion or one deletion approximately within a predetermined number of bit islands, reading the data, and correcting the read data using error correction. An apparatus that implements the method is also provided.

Abstract: According to one embodiment, a disk drive has a DTM type disk. The DTM type disk has a servo area on one recording surface. In the servo area, a servo pattern is recorded. The servo pattern is composed of a projection-depression pattern and an N- and P-pole magnetic pattern. The N- and P-pole magnetic pattern is recorded in an address-data region that contains a cylinder code.

Abstract: A disk drive is disclosed comprising a disk having a plurality of data sectors, and a head actuated over the disk. The disk drive further comprises control circuitry operable to execute a write operation for writing data to the disk. A first part of the data is written to a first data sector together with a first sector signature data (SSD) record comprising a first parameter of the write operation and a first id that identifies the first parameter. A second part of the data is written to a second data sector together with a second SSD record comprising a second parameter of the write operation and a second id that identifies the second parameter.

Abstract: A method for writing data to a tape at multiple rates for simultaneously creating data tracks having differing linear data densities, according to one embodiment, includes passing a tape over a head, the head having an array of writers thereon; receiving incoming data; mapping the data to a two dimensional array corresponding to the array of writers; clocking some of the mapped data to a first writer in the array of writers at a first rate; and clocking some of the mapped data to a second writer in the array of writers at a second rate different than the first rate.

Abstract: According to one embodiment, a magnetic recording apparatus includes: an information recording module configured to record a predetermined number of lines of information with a predetermined length in an information recording region of a magnetic recording medium, each of the lines of information having a same recording start position with respect to a relative movement direction of the magnetic recording medium and a recording element, the each of the lines of information being provided with an overlaying portion of adjacent lines of information. The information recording module is configured to record clock information in one or a plurality of the lines of information.

Abstract: A system for grading defective bit patterned magnetic media by disk sector in hard disk drives recovers a portion of any defective sectors at a lower areal density. The invention reduces the track pitch density for sectors containing amalgamated islands while leaving the remainder of the defect-free sectors in the zone optimized for linear bit density. This recovers a portion of the defective sector, approximately in proportion to the ratio of amalgamated islands over the original number of islands. A typical zone is first optimized for tracks per inch during formatting of the patterned media disk drive. The zone is then broken up into sectors that can each be optimized separately for linear bit density to ensure the maximum sustainable capacity for each sector.

Abstract: The present invention enhances the capability to specify a recorded position of designated data, even when a tape medium is run at high speed. A controller of a tape drive includes: a data set generator for generating a data set; a metadata generator for generating metadata including the number of records in the data set and the like; and a writing unit for writing the data set to the tape medium with a high recording density, and writing the metadata to the tape medium with a low recording density. The controller also includes: a movement controller for receiving a record number of a designated record; a reading unit for obtaining the number of records and the like included in the metadata read by running the tape medium at high speed; and a comparison unit for determining whether or not to read the data set by lowering the speed of the tape medium to R/W speed, in comparison with the record number received by the movement controller and the number of records and the like obtained by the reading unit.

Abstract: A method for dividing a data area on a disk into a plurality of concentric zones and determining a format for each zone so that data tracks in the zone have the same number of data sectors. The method includes dividing a data area into a plurality of zones with provisional boundaries. The method also includes determining a linear recording density for a selected zone. The method further includes selecting the number of data sectors per data track corresponding to the determined linear recording density from specified values. Moreover, the method includes resetting a boundary of the zone at a new boundary shifted from the provisional boundary according to a selected value.

Abstract: A control module for a rotating storage medium includes a data wedge format table (DWFT). The control module also includes a buffer control module that has a DWFT queue that includes X entries from the DWFT and one of X first servo information for each of the X entries. X is a positive integer. A disk formatter module that compares the one of X first servo information with second servo information that is based on a current position of a read/write device in relation to the rotating storage medium.

Abstract: According to one embodiment, a disk has a set of tracks thereon. A controller performs refresh control for reading data by a head from a track on the disk to be refreshed and for writing the read data by the head to a spare track adjacent to the track from which the data has been read. The controller switches the track from which the data has been read to a new spare track after the writing.

Abstract: A system and method involving a read channel pipeline having a plurality of vector sequencers that may be used to control the processing blocks. In one embodiment, a read channel pipeline may include processing blocks that may be controlled a command word provided by vector sequencers. Incoming data may be delineated by identifying an early period, a steady-state period, and a trailing period. Instead of controlling these blocks with a static state machine controller, a plurality of vector sequencers are coupled to the plurality of processing blocks. Thus, a first vector sequencer may control the processing blocks during the early period and the steady state period, but then hand off control to a second vector sequencer for the trailing period. Using vector sequencers for implementing command words allows for greater programming flexibility once the device has been manufactured and deployed for use.

Abstract: According to one embodiment, disclosed herein is a disk drive that has a disk of discrete-track media (DTM) type. The DTM disk has servo regions. Each servo region has dividing grooves and non-servo data parts. Each dividing grooves extends along the centerline of any projecting region having a width larger than a prescribed value. Each non-servo data part suppresses reproduction noise. The disk drive has a read/write channel that includes a reproduced-signal processing unit. This unit reproduces servo data from each servo region.

Abstract: A patterned media type magnetic storage medium has separated magnetic dots formed a data area having a first magnetic dots and a servo area. The micro position detection portion in the servo area is constructed with first and second dot arrays having a different number of second magnetic dots in the circumference direction and face with the center line that the first magnetic dots of the data area in the magnetic storage medium are disposed, as the axis. The area of the magnetic dot constituting the micro position detection portion of the servo area is small, so the coercive force of the servo area increases. The frequency is changed depending on the number of magnetic dots, and the phase is changed depending on the position of the magnetic dot array in the radius direction with the center line as an axis.

Abstract: A magnetic storage medium such as a BPM includes a plurality of magnetic dots for writing and reproducing data disposed in a magnetically separated manner so as to be spaced a predetermined distance in a down-track direction and a plurality of tracks concentrically disposed so that the magnetic dots are disposed in a magnetically separated manner. In the BPM, a phase-adjusting track is disposed in an arbitrary track among the tracks. On the phase-adjusting track, phase detection dots disposed in a down-track direction to allow writing and reproduction of phase detection data and blank bits providing a predetermined phase difference in a down-track direction to next successive phase-detecting dots are alternately disposed in a successive manner.

Abstract: A method and apparatus for reducing noise in a communication signal is provided. The method includes converting raw channel data from the communication signal to a sequence of transition code symbols, each symbol having a plurality of bits, each bit having a position within the symbol. The method also includes sending the bits of each symbol to a plurality of bins, each bin corresponding to the position of each bit within the symbol. For each bin having a number of transitions greater than a number of non-transitions, the method also includes flipping every bit in the bin and setting a corresponding bit in a flip control word to a first value. The method still further includes binary adding the flip control word to each transition code symbol.

Abstract: A disk drive is disclosed comprising a disk including a plurality of servo tracks defined by a plurality of servo sectors, wherein each servo sector comprises a plurality of servo bursts, and each servo burst comprises at least one of four phases. A first two of the phases are orthogonal, and a second two of the phases are orthogonal. As a head is actuated over the disk a servo sector is read to generate a read signal. The read signal is processed to demodulate the servo bursts into a position error signal (PES) representing an offset of the head from a target radial location on the disk, and the read signal is also processed to decode at least two of the phases of the servo bursts into a binary sequence.

Abstract: A disk drive is disclosed comprising a disk having servo data defining a plurality of servo tracks. The servo data comprises a preamble comprising a varying length across a radius of the disk, and a plurality of slanted line servo bursts recorded at a tilt angle with respect to the preamble. The tilt angle varies across the radius of the disk commensurate with the varying length of the preamble. A position error signal (PES) is generated in response to a phase difference when reading the preamble and the slanted line servo bursts.

Abstract: A servowriting method for a patterned-media magnetic recording disk uses a special position error signal (PES) alignment pattern located in each servo sector. A gross feedforward correction signal to compensate for gross eccentricity of the disk relative to the center of rotation of the servowriter spindle is applied to the actuator. With the gross feedforward correction applied to the actuator the read head generally follows a data track centerline and will detect signals from PES alignment fields as each servo sector passes the read head. This results in a readback signal at each servo sector that represents the fractional track-width radial offset of the read head in that servo sector from a data track centerline. The set of radial offsets for all of the servo sectors is used to modify or fine tune the gross feedforward correction signal that is applied during the servowrite process.

Abstract: A magnetic tape cartridge including magnetic tape with servo information is provided. The servo information comprises a plurality of parallel longitudinal servo bands that lie between a plurality of longitudinal data bands. The plurality of servo bands include odd servo bands and even servo bands, wherein each of the odd servo bands lie between each of the even servo bands. Each of the plurality servo bands include a plurality of frames, wherein each frame includes a plurality of bursts of transition stripes, and each burst having a first transition stripe. The first transition stripe of each burst of each the odd servo band is longitudinally shifted from the first transition stripe of each burst of each even servo band by a substantially equal distance, D, such that servo information of the odd servo bands is interleaved with the servo information from the even servo bands.

Abstract: A computer system, a disk storage device and a method of controlling the same reads data by a reading size from a disk storage unit in which the data is stored according to a request of an application for reading data. The data is divided from the reading size into a size allocated by the application and stored in a memory region which the application accesses.

Abstract: According to one embodiment, there is provided a magnetic recording medium having a data region in which a plurality of recording tracks, each including magnetic dots arrayed in a down-track direction with a pitch p, are formed in a cross-track direction, and a servo region including a preamble in which a plurality of lines of magnetic dots, which are arrayed in a cross-track direction with a pitch p, are formed at equal intervals in the down-track direction.

Abstract: A servo pattern magnetization method is provided, having full-amplitude servo signals, to eliminate the need for intensity modification and waveform shaping during servo signal reading, and to improve the precision of head positioning and enable an increase in track recording density. A servo pattern magnetization method for a perpendicular recording discrete track medium, having a plurality of recording areas and a plurality of servo areas separating the plurality of recording areas, has a process of recording magnetization perpendicular to the substrate and in opposite directions in each of the magnetic recording layers of the plurality of servo blocks, by means of the leakage magnetic field from the soft magnetic layers separated from other servo blocks when a magnetic field is applied.

Abstract: Data storage systems are provided. Data storage systems illustratively include a recording head having a writing element and a bit patterned medium having a plurality of media dots. In some embodiments, the plurality of media dots pass the recording head at a media dot frequency. In some embodiments, the writing element writes data to the bit patterned media at a writing frequency that is less than the media dot frequency.

Abstract: The invention is directed to a data storage medium that includes a plurality of servo bands distributed across the data storage medium and a plurality of data tracks positioned between each of the plurality of distributed servo bands. The data storage medium comprises a servo band pitch of less than 200 micrometers. The large number of servo bands distributed across the data storage medium with a relatively small servo band pitch reduces the influence of media dimensional instability. In this way, the invention may substantially increase data read head positioning accuracy, especially in the case of narrow track widths. A read head array arranged in a two-dimensional matrix that includes a first servo read head, a second servo read head, and a plurality of data read heads positioned between the first and second servo read heads may be applied to a data storage medium as described herein.

Abstract: Embodiments of the present invention provide a magnetic disk drive in which the error correction capability of ECC is improved without sacrificing the storage capacity. In one embodiment, a data track adopts a format structure in which no data-to-data gap area is formed in data sectors. When one of the data sectors is updated in a state in which the rotational speed of a magnetic disk does not satisfy specified conditions, a leading end area of a succeeding data sector or a trailing end area of a preceding data sector is overwritten by the data sector. If a read error occurs in the overwritten data sector, ERP steps are executed to perform read retry so that the read error is recovered by means of on-the-fly ECC or erasure correction. In the case of the erasure correction, an erasure pointer equivalent to the maximum number of overwritten bytes is set.