Abstract: Systems and methods for improving accuracy of head positioning using existing servo patterns are provided. In one embodiment, a method for improving read head positioning is provided that comprises: writing a series of tracks over a range of read offsets to be calibrated; measuring a set of raw track profiles from the series of tracks; sampling the set of raw track profiles at a series of signal amplitude levels; constructing a reference track profile from the set of sampled track profiles; calculating a set of read offset deltas from each sampled track profile; merging the sets of read offset deltas into a set of average read offset deltas; and converting the set of average read offset deltas into a read offset correction table. A similar method for improving disk write head positioning is also provided which utilizes such a read offset correction table to eventually create write offset correction table.

Abstract: A method and circuit to stop a spindle motor in the absence of the external supply voltage in which the spindle motor is structured to move a hard disk provided with at least one reading or writing head moved by a voice coil motor, the spindle motor provided with a plurality of coils. The method includes rectifying the backelectromotive force of the spindle motor to produce a braking current, driving the voice coil motor with at least a portion of the braking current until the speed of the spindle motor becomes lower than a predetermined stop speed, and, after the parking of the at least one reading or writing head of the voice coil motor, stopping the spindle motor by short-circuiting the coils of the spindle motor.

Abstract: A power supply circuit for powering first and second groups of hard disk drives in a cabinet, includes a connector and first to third connection units. When there is only one server in the cabinet, the first node is connected to the first power terminal of the connector, the first connection unit is turned on, and the second connection unit is turned off. When there are two servers in the cabinet, the first and second nodes are respectively connected to the first and second power terminals of the connector, the first connection unit is turned on, and the second and third connection units are turned off.

Abstract: A disk drive is disclosed comprising a head actuated over a disk including a plurality of contiguous servo tracks for defining a plurality of data tracks. A first write command comprising first write data is received, and a first density of first data tracks over a first plurality of the contiguous servo tracks is selected, wherein the first write data is written to the first data tracks. A second write command comprising second write data is received, and a second density of second data tracks over the first plurality of the contiguous servo tracks is selected, wherein the second density is different than the first density. The second write data is written to the second data tracks.

Abstract: A magnetic recording medium may include an orientation control layer, a lower recording layer, an intermediate layer, and an upper recording layer that are stacked. The lower recording layer may have a coercivity higher than that of the upper recording layer, and the intermediate layer may include a layer including a magnetic material and having a saturation magnetization of 50 emu/cc or higher. The upper recording layer may include columnar crystals continuous with crystal particles forming the intermediate layer in a direction in which the layers are stacked.

Abstract: The invention is a patterned-media disks for multi-track recording that are fabricated by nanoimprinting from a master template and that have data islands arranged in a pattern to compensate for head skew. The islands are arranged along lines canted relative to a disk radial line by an acute angle, as required for multi-track recording. However, this angle is not the same for all bands, but varies from band to band to compensate for head skew. The angle the lines in a band are canted is reduced by the amount of head skew. There are a plurality of bands between the disk inside-diameter (ID) and mid-diameter (MD) where the angle is in one direction from a radial line and a plurality of bands between the disk MD and outside-diameter (OD) where the angle is in the opposite direction from a radial line.

Abstract: A hard-disk drive. The hard-disk drive includes a head-slider configured to fly in proximity with a recording surface of a magnetic-recording disk, and a fly-height variation compensator configured to generate a signal for compensating variation in fly height of a write element of the head-slider. The head-slider further includes the write element configured to write data to the magnetic-recording disk, a fly-height-adjustment heating element configured to displace the write element towards the magnetic-recording disk, and a position-adjustment heating element configured to displace the write element in at least a direction perpendicular to a flying direction. The fly-height variation compensator is further configured to add the signal for compensating variation in fly height to a control signal for output to the fly-height-adjustment heating element.

Abstract: According to one embodiment, a magnetic storage medium, includes a magnetic recording layer that includes: a servo area including predetermined servo information; a user data area including predetermined user information; two preamble areas including a plurality of magnetic bodies made of magnetic particles, the magnetic bodies being arranged in a staggered pattern so that the staggered pattern is inverted with respect to an axis of symmetry at a track center; and a re-sync mark area positioned at a head of the preamble areas and indicates a start of the preamble areas.

Abstract: One embodiment includes a pulse duration control system for a magnetic disk-drive system. A rise delay system generates first control voltages in response to a write data input signal changing between a first state and a second state. A fall delay system generates second control voltages in response to the write data input signal changing between the first and second states. A comparator system generates a rising-edge overshoot signal and a falling-edge overshoot signal based on a comparison of the first and second control voltages. The rising-edge overshoot signal can set a duration of a positive overshoot current pulse for a write current at a transition of the write data input signal from the first state to the second state, and the falling-edge overshoot signal can set a duration of a negative overshoot current pulse for the write current at a transition from the second state to the first state.

Abstract: Disc drive data recovery methods and systems that utilize off center track information are provided. A disc drive data track is illustratively read at a first position along a width of the data track and at a second position along the width of the data track. The data read from the track is stored and tagged with indications of the first and the second positions. The tagged data is optionally used to calculate average waveforms for each of the first and the second positions and to identify the average waveform having the highest signal-to-noise ratio.

Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ? related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(?0t), and sin(?0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ?±?0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ?. The demodulator output signal is used for processing by data detection electronics.

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: A hard disk drive system includes a first channel module and a second channel module. The first channel module is configured to receive a first data from or transfer the first data to a first amplifier module of a hard disk assembly when reading from or writing to a first surface of a disk of the hard disk assembly. The second channel module is configured to receive a second data from or transfer the second data to a second amplifier module of the hard disk assembly when reading or writing to a second surface of the disk while the first channel module receives the first data from or transfers the first data to the first amplifier module.

Abstract: A hard disk drive with a read channel that averages data before the data is provided to a viterbi detector of the channel. Averaging the data reduces the zero mean noise in the data.

Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for detecting patterns in a data stream.

Abstract: A disk storage system having servo data stored thereon for accurate head position control over a magnetic or other storage medium. The servo data is seamless and untrimmed and consists of a primary servo burst set (AB burst) in which the difference defines the desired tract pitch for the surface. Multiple secondary servo burst sets (e.g., CD burst and EF burst) are written at the desired track pitch but radially offset from the primary burst set. In one embodiment, two secondary servo burst sets are used, but alternatively, any number of secondary servo burst sets could be used. In this exemplary embodiment having two secondary servo burst sets, the CD servo burst set is offset by ? of the track pitch from the primary servo burst set. Also in this embodiment, the EF servo burst set is offset by ? of the track pitch from the primary servo burst set. There are six bursts per set. The servo data is written in multiple servo sectors around the surface of the medium.

Abstract: A method for positioning a magnetic-recording head. The method includes correcting amplitude of each burst signal of a plurality of burst signals read out with the magnetic-recording head from each respective burst pattern of a plurality of burst patterns. In addition, the method includes computing a deviation of the magnetic-recording head from a track based on corrected amplitudes of the plurality of burst signals. Moreover, the method includes positioning the magnetic-recording head on the track based on the deviation of the magnetic-recording head.

Abstract: According to one embodiment, an information recording device includes: a recording controller configured to control recording of information on a magnetic recording medium having tracks by a recording method; a managing module configured to manage two or more counters corresponding to each of plural track groups that are adjacent to each other; an updating module configured to update a count of one of the two or more counters corresponding to a second track group that is adjacent to a first track group of the plural track groups when information has been recorded on the first track group; a determining module configured to determine an attribute of the second track group based on the updated count of the one counter; and a rewriting module configured to rewrite information recorded in the second track group based on the determined attribute.

Abstract: A method is disclosed of servo writing a disk drive comprising a first head actuated over a first disk surface, and a second head actuated over a second disk surface. A first repeatable runout (RRO) of the first disk surface is measured, and a seek is performed to seek the first head over the first disk surface in response to the measured first RRO while writing a first spiral track to the second disk surface using the second head. As a result, the first spiral track comprises a second RRO that substantially matches the first RRO of the first disk surface.

Abstract: A plurality of sensors are used to sense disturbances in a data storage system. An adaptive gain component is associated with each of the sensors and provides a gain for each of the sensor signals. The gain of each sensor signal is adapted, individually, based on a correlation of each given sensor signal to the position error signal. This adaptation produces a position correction signal. The position correction signal is applied to a position signal that is used to position the reading and writing components and the storage medium relative to one another. This compensates for both rotary and linear vibration disturbances at the same time.

Abstract: A magnetic disk control device according to an exemplary of the invention includes a write controller to control, in a magnetic disk having tracks, the track being a storage area made by concentrically dividing a magnetic recording layer formed onto a disk into a plurality of areas, the track being divided into a plurality of areas in a rotative direction as sectors, writing information into the each sector; and a substitution controller to make, by detecting the sector or the track written at a frequency higher than a writing frequency based on a number of times of writing by the write controller to the sector or the track and by moving information recorded in an adjacent track adjacent to a high-writing-frequency track including the detected high writing frequency sector or to a high-writing-frequency track which is detected as a high writing frequency track to a track of a substitution area.

Abstract: Embodiments described herein provide for patterned media concentric zones with an alternating series of concentric servo zones and overlap zones. The overlap zones facilitate the writing of servo data between servo zones of different servo frequency. The overlap zones may be dual frequency zones. The dual frequency zones have a first set of overlap patterns with the substantially identical pattern as the bordering lower frequency servo zone and a second set of overlap patterns with the substantially identical pattern as the bordering higher frequency servo zone. A bootstrap zone can be included near the inner diameter to assist initial servo writing. Alternatively the overlap zones are bootstrap zones. Such bootstrap zones have both bootstrap patterns and overlap patterns, the overlap patterns have the substantially identical pattern as a bordering servo zone. Bootstrap patterns only require DC magnetization for servo operability.

Abstract: Various embodiments of the present invention provide systems and methods for calculating and/or modifying fly height. For example, a circuit for calculating fly height is disclosed that includes: a first pattern detector circuit, a second pattern detector circuit, a first pattern fly height calculation circuit, a second pattern fly height calculation circuit, a first averaging circuit, a second averaging circuit, and a combining circuit.

Abstract: A system and method are described for rendering Compact Discs (CDs) and Digital Video Discs (DVDs) unreadable. Embodiments comprise a frame, a guide for constraining motion of the frame with respect to a disc, and at least one scraping element. Scraping elements may be positioned to damage the disc volume descriptor while the frame moves in a constrained manner relative to the disc. The guide may comprise a spindle which engages the center hole of a disc to hold the frame in a radially-fixed position. A scraping element on the frame damages the disc as the disc rotates relative to the frame. The guide may be integrated, such that the frame comprises a slot through which the disc passes. A scraping element inside the slot damages a disc as it passes through. Embodiments are hand operated, not motorized, and some have no moving parts. Embodiments also function with non-optical media.

Abstract: A drive control apparatus includes a management unit, a detection unit, and an information unit. The management unit identifies a data write position on a tape onto which data is written sequentially, and manages correspondences between first addresses including an address larger than an address which is managed by an upper apparatus connected to the drive control apparatus and second addresses for making the upper apparatus identify the data write position on the tape. The detection unit detects that a drive which writes the data onto the tape fails in writing the data. The information unit informs the upper apparatus of a second address of a position on the tape at which write fails on the basis of detection by the detection unit.

Abstract: A method of storing data includes receiving general purpose (GP) data and special Error Tolerant or Streaming (ETS) data, storing the GP data using a data storage method, and storing the ETS data using a different data storage method which affects the access rate, resilience to errors, data integrity, storage density, or storage capacity. The storage medium, which can include a disk drive, flash memory, or holographic memory, is utilized differently depending on the required Quality of Service in aspects including block size, storage of error correction codes, utilization of error correction codes, storage area density, physical format pattern, storage verification, or reaction to failed storage verification. For disk drives these differences include spacing between tracks; overlap between tracks; spiral track formatting; concentric track formatting, and size of blocks, and for flash memories these differences include levels per cell and number of cells.

Abstract: Methods and apparatus describe processing of data for recording to a storage device. An apparatus includes, in at least one aspect, a plurality of buffers and circuitry configured to encode data stored in one buffer of the plurality of buffers concurrently with storing data in another buffer of the plurality of buffers and to write the encoded data from the one buffer to a storage device concurrently with encoding the stored data in the other buffer.

Abstract: A servo control system configured to position a head in accordance with position error signals between servo data on a disk read by the head in a servo sampling cycle and a target position. The system includes a plurality of adaptive peak filters connected in parallel configured to filter the position error signals and configured to change filter coefficients adaptively, and an estimator configured to estimate head vibration caused by disturbances using the servo data read by the head. The system further includes a selector configured to select a portion of the plurality of adaptive peak filters at preset occasions, and a setter configured to update coefficient settings of the portion of the adaptive peak filters selected by the selector in accordance with an estimation by the estimator.

Abstract: A method includes activating a stress-effecting layer of a thin film structure, having the stress effecting layer adjacent to a magnetic layer, to induce a magneto-elastic anisotropy in the magnetic layer.

Abstract: A disk drive is disclosed wherein a plurality of access commands received from a host are stored in a command queue. An access cost for at least a first and second access command in the command queue is generated, wherein each access cost comprises a seek length and a rotation latency. A first access command is selected from the command queue having a first access cost, and a window is defined relative to the first access cost and a first risk based penalty (RBP) of the first access command, wherein the first RBP represents a probability of missing a first data sector of the first access command. A second access command is selected from the command queue comprising a second access cost within the window. A choice is made between the first and second access commands in response to a second RBP of the second access command.

Abstract: Techniques for processing tape storage include determining a current position of a read device to read a data block from a tape storage medium having a plurality of duplicate data areas, receiving a request to read a data block from the tape storage medium, and reading the requested data block from a duplicate data area from among the plurality of duplicate data areas that is nearest the current position of the read device.

Abstract: A disk drive is disclosed comprising a plurality of disk surfaces, and a plurality of heads actuated over the respective disk surfaces. In one embodiment, control circuitry generates a pulse duty cycle signal for one of the heads. In another embodiment, the control circuitry generates a first pulse width modulated signal for a first head, and a second pulse width modulated signal for a second head, wherein the second pulse width modulated signal comprises a phase offset from the first pulse width modulated signal.

Abstract: A shingled magnetic recording hard drive is presented to a resource manager of a host device as an emulated device such as one or more optical media, an array of sequential access media, and/or write-once, read-many device. Data targeted for the emulated device is written to the shingled magnetic recording hard drive.

Abstract: Disclosed herein are methods and apparatuses that provide for variable data density on a disc data storage medium, where the variable data density may have a circumferential definition and a radial definition. In some examples, devices and methods may include measuring a read or write performance attribute on a disc data storage medium and selectively setting a data density rate that may vary in a circumferential direction for the disc data storage medium based on the read or write performance attribute. In other examples, apparatuses can include a data storage device having a disc data storage medium and a controller configured to measure a performance attribute of the disc data storage medium and to selectively set different Bits Per Inch (BPI) for data storage within different areas of the disc.

Abstract: A contact event between a sensing device and a storage medium is detected by receiving a signal indicating a physical proximity between the sensing device and the storage medium; generating a plurality of frequency bin outputs; comparing one or more frequency bin outputs to a corresponding first level threshold to yield a corresponding comparator output; summing the comparator output with at least one prior instance of the comparator output to yield an aggregated value; comparing the aggregated value to an aggregate threshold to yield an aggregate output; and generating a contact event output if one or more of a first group of the plurality of frequency bin outputs has an associated aggregate output set to a predefined binary value and a predefined minimum number of a second group of the plurality of frequency bin outputs has an associated aggregate output set to a predefined binary value.

Abstract: A magnetic recording system configured for recording to a bit patterned media using both hypertrack recording and shingled recording. The magnetic recording system includes a write pole with a notched trailing edge that results in a write bubble with a trailing edge that has two outer convex lobes separated by a centrally disposed concave region. By locating one of the lobes over first and second data tracks of a hypertrack, a proper alignment of the relative phase of the two tracks can be maintained. Further adjustment to the alignment can be achieved by adjusting the radial location of the write head.

Abstract: A method, apparatus, and system for implementing spin-torque oscillator (STO) sensing with an enhanced delay control feedback circuit for hard disk drives. A detector receives an input signal from a STO read sensor having an oscillation frequency related to the strength of the detected magnetic signal field. The received input signal is mixed with a time delayed input signal for providing a detector output signal. A low frequency component signal of the detector output signal is monitored and a delay control feedback is applied to an adjustable time delay to bias the DC signal of the detector output signal.

Abstract: A magneto-impedance sensor element is formed in a planar type structure in which an amorphous wire is incorporated in a substrate. The magneto-impedance sensor element includes a nonmagnetic substrate, an amorphous wire arranged in an aligning direction of a planar pattern that forms a detecting coil, a spiral detecting coil formed of a planar pattern and a cubic pattern on an outer periphery of the amorphous wire, a planar insulating portion that insulates the planar pattern from the amorphous wire, a wire fixing portion to fix the amorphous wire on an upper surface of the planar insulating portion, and a cubic insulating portion that insulates the cubic pattern from the amorphous wire.

Abstract: A magnetic disk controller includes an error check code generating unit that generates error check codes associated with the encoded pieces of writing data; a first buffer that stores a first encoded piece of writing data and a first error check code associated with the first encoded piece; a second buffer that stores a second encoded piece of writing data and a second error check code associated with the second encoded piece; and a buffer control unit that, in a first period, substantially concurrently with a writing of the first encoded piece and the first error check code from the first buffer into a first sector of the magnetic disk, stores the second encoded piece and the second error check code into the second buffer.

Abstract: A device may be provided. The device includes a media including a servo layer and a data recording layer, and a recording head including a dimension sized to produce a magnetic writing field to write servo information on the servo layer.

Abstract: According to one embodiment, an information storage apparatus, includes: a recording medium with a first servo pattern having absolute position information and a second servo pattern having relative position information; a record reproducing head; a standard position detector calculating a standard position of the second servo pattern where an absolute position on the recording medium is specified, from a positional relationship between the first servo pattern and the second servo pattern; a head position controller positioning the record reproducing head in a target position on the recording medium, using the absolute position information of the first servo pattern, the standard position, and the relative position information of the second servo pattern; and a record signal generator generating a record signal to record a third servo pattern having absolute position information on the recording medium in the target position by the record reproducing head.

Abstract: Provided are a computer program product, system, and method for a magnetic disk drive. The disk drive has at least one disk platter having at least one recordable disk surface having an areal density of at least 200 gigabits per square inch. Either a diameter of the at least one disk platter is greater than 3.5 inches or the at least one disk platter rotates at less than 5400 RPMs. A read/write head reads and writes tracks of data with respect to the at least one disk surface. Modified tracks from write requests to write to the at least one disk surface on the at least one disk platter are cached in a non-volatile storage device for caching modified tracks. Modified tracks are cached in the non-volatile storage device to later destage to the at least one disk surface.

Abstract: Provided are a computer program product, system, and method for a magnetic disk drive. The disk drive has at least one disk platter having at least one recordable disk surface having an areal density of at least 200 gigabits per square inch. Either a diameter of the at least one disk platter is greater than 3.5 inches or the at least one disk platter rotates at less than 5400 RPMs. A read/write head reads and writes tracks of data with respect to the at least one disk surface. Modified tracks from write requests to write to the at least one disk surface on the at least one disk platter are cached in a non-volatile storage device for caching modified tracks. Modified tracks are cached in the non-volatile storage device to later destage to the at least one disk surface.

Abstract: A method and apparatus for manufacturing magnetic storage media is provided. A structural substrate is coated with a magnetically active material, and a magnetic pattern is formed in the magnetically active material by treating portions of the material with energy from a laser, e-beam, or focused ion beam. The beam may be divided into a packet of beamlets by passing the beam through a divider, which may be a diffraction grating for laser energy, a thin film single crystal for electrons, or a perforated plate for ions, or the beam may be generated by an array of emitters. The beamlets are then focused to a desired dimension and distribution by optics or electric fields. The resulting beam packet may be shaped further by passing through an aperture of any desired shape. The resulting beam may be applied sequentially to exposure zones to treat an entire substrate or plurality of substrates.

Abstract: A method to read information from an information storage medium using a read channel, where that read channel includes a data cache, where the method generates an analog waveform comprising the information, provides that analog waveform to a read channel generates a digital signal from that analog waveform using one or more first operating parameters, corrects that digital signal at an actual error correction rate, determines if the actual error correction rate is greater than an error correction rate threshold. If the actual error correction rate exceeds the error correction rate threshold, then the method captures the digital signal, stores that captured data in a data cache, reads that digital signal from the cache, generates one or more second operating parameters, provides those one or more second operating parameters to the read channel.

Abstract: According to one embodiment, a data write control apparatus includes a magnetic disk, a write controller, and a retry controller. The magnetic disk includes a track in which data is recorded in sector unit. The write controller is configured to execute control to write a sector data block to a predetermined sector in the track. The retry controller is configured to execute control to retry a write process to a predetermined number of sectors to which data has been written and which include a first sector, and to manage the number of retries performed on each sector.

Abstract: A portable media player device includes a built-in mobile virtual private network and housing. A touch screen is mounted on the housing. A memory unit within the housing stores local and remote movie, video, photo, music and game files. A processing unit within the housing is adapted to execute media file stored in the memory unit and stored in the remote home computer and display the files on the touch screen. A user using the portable media player device can utilize the local and remote files by touching specific keys on the touch screen.

Abstract: According to one embodiment, a magnetic medium includes at least one recording layer including a first magnetic layer, a second magnetic layer and a non-magnetic layer. The first magnetic layer is form of a first magnetic material having a first magnetic anisotropy. The second magnetic layer is made of a second magnetic material having a second magnetic anisotropy different from the first magnetic anisotropy. The non-magnetic layer is made of a non-magnetic material and between the first and second magnetic layers, the first magnetic layer and the second magnetic layer being coupled such that directions of magnetization of the first and second magnetic layers are opposed to each other.

Abstract: An apparatus includes a read/write head disposed on a slider, a control circuit disposed on the slider, and an adjustable delay line disposed on the slider. The adjustable delay line delays transmission of aligned write data to the read/write head by an adjustable delay. The adjustable delay is controlled by the control circuit a function of read synchronization data provided by the read/write head.

Abstract: A voltage adjustment circuit for a storage medium includes a storage medium interface, a storage medium control chip, and a switch module. When the storage medium is read or written to by the storage medium control chip, the storage medium control chip transmits a pair of differential signals to the storage medium interface so that the switch module can control a power supply to power the storage medium. And the switch module will control the power supply not to power the storage medium when the storage medium control chip does not operate to read or write the storage medium.