Tue, 29 Sep 2015 08:00:00 EDTAn exemplary object is to provide a library apparatus, a magazine insertion detection method, and a program that are capable of detecting whether or not a magazine is inserted for all the magazine insertion positions without using sensors for detecting insertion of magazines. A library apparatus includes: a mark reading unit which is provided in an accessor unit which transfers a plurality of media that can be read and written by a computer, and reads a predetermined mark for all insertion positions of a plurality of magazines which can be inserted into the library apparatus and can accommodate the media, the mark being stuck to each of cells accommodating the media; and a control unit which, if the mark can be read, determines that a magazine is inserted at an insertion position which includes a read position for which a reading result that the mark can be read has been obtained, and, if the mark cannot be read, determines that no magazine is inserted at an insertion position which includes a read position for which a reading result that the mark cannot be read has been obtained.
Tue, 26 May 2015 08:00:00 EDTA data processing device includes a memory, an arithmetic circuit that accesses the memory by outputting an access control signal CTRL that controls access to the memory, a first data storage unit that stores first data used when a self-diagnosis is performed, a read-modify-write circuit that generates second data by replacing a part of the first data stored in the first data storage unit with modify data outputted from the arithmetic circuit, and a determination unit that diagnoses a failure of the read-modify-write circuit by comparing the second data with an expected value.
Tue, 26 May 2015 08:00:00 EDTA disk drive is disclosed comprising a disk, and a slider comprising a head, where the head comprises a write component electrically insulated from the slider. A bias voltage is applied to the write component, and a current flowing between the write component and the disk is measured, wherein the current is indicative of a fly height of the head.
Tue, 26 May 2015 08:00:00 EDTControlling a laser diode involves activating a first current source in preparation for writing to a magnetic recording medium. The first current source applies a threshold current to a laser diode that brings the laser diode close to an operating point. Responsive to a write signal, a second current source is activated that applies a write current to the laser diode. A combination of the write current and the threshold current fully energizes the laser diode and is less than a target recording current. Coincident with the activation of the second current source, a photodiode is activated that is optically coupled to the laser diode. The activated photodiode causes a feedback current to be applied to the laser diode.
Tue, 26 May 2015 08:00:00 EDTA magnetic read sensor having an antiferromagnetic located embedded within a magnetic shield of the sensor so that the antiferromagnetic layer can pin the magnetization of the pinned layer without contributing to read gap thickness. The sensor is configured with a pinned layer having a free layer structure located within an active area of the sensor and a pinned layer that extends beyond the free layer and active area of the sensor. The antiferromagnetic layer can be located outside of the active and exchange coupled with the extended portion of the pinned layer.
Tue, 26 May 2015 08:00:00 EDTA data reader may be configured at least with a magnetic stack positioned on an air bearing surface (ABS) and contacting a spin depolarizing layer that is a minority spin current carrier. The spin depolarizing layer can have a thickness and spin diffusion length corresponding to a net zero spin polarization at an interface of the magnetic stack and spin depolarizing layer.
Tue, 26 May 2015 08:00:00 EDTIn one embodiment, a magnetic head includes a lower shield, a magnetoresistive (MR) film positioned above the lower shield, the MR film including a pinned layer, an intermediate layer positioned above the pinned layer, and a free layer positioned above the intermediate layer, the free layer being configured for sensing data on a magnetic medium, wherein a track width of the MR film is defined by a width of the free layer in a cross-track direction, a bias layer positioned on both sides of the MR film in the cross-track direction, a track insulating film positioned on both sides of the MR film in the cross-track direction and between the MR film and the bias layer, and an upper shield positioned above the bias layer and the MR film, wherein a length of the free layer in an element height direction perpendicular to an air bearing surface of the magnetic head is less than a length of the pinned layer in the element height direction.
Tue, 26 May 2015 08:00:00 EDTA two-dimensional magnetic recording (TDMR) read head has upper and lower read sensors wherein the lower read sensor has its magnetization biased by side shields of soft magnetic material. The center shield between the lower and upper sensors may be an antiparallel structure (APS) with two ferromagnetic layers separated by an antiparallel coupling (APC) layer. The center shield has a central region and two side regions, but there is no antiferromagnetic (AF) layer in the central region. Instead the two side regions of the upper ferromagnetic layer in the APS are pinned by AF tab layers that are electrically isolated from the upper sensor. The upper ferromagnetic layer and the APC layer in the APS may also be located only in the side regions. The thickness of the center shield can thus be made thinner, which reduces the free layer to free layer spacing.
Tue, 26 May 2015 08:00:00 EDTA method and system provide a magnetic transducer having an air-bearing surface (ABS). The method provides a first read sensor stack and defines a first read sensor in a stripe height direction from the first read sensor stack. The stripe height direction is perpendicular to the ABS. A shield is provided on the first read sensor stack and in a down track direction from the first read sensor stack. A second read sensor stack is provided. The shield is between the first read sensor and the second read sensor stack in the down track direction. Both the first read sensor and the second read sensor are defined from the first read sensor stack and from the second read sensor stack, respectively, in a cross-track direction. The cross-track direction is substantially perpendicular to the down track direction and substantially perpendicular to the stripe height direction.
Tue, 26 May 2015 08:00:00 EDTMethods for providing magnetic storage elements with high magneto-resistance using Heusler alloys are provided. One such method includes depositing a substrate including NiFe, depositing a seed layer on the substrate, depositing a buffer layer on the seed layer, and growing, epitaxially, an upper layer on the buffer layer, the upper layer including a Heusler alloy.
Tue, 26 May 2015 08:00:00 EDTA slider and microactuator elements are disposed on a gimbal portion of a flexure. A tongue of the gimbal portion has a first tongue portion, a second tongue portion, and a hinge portion. A leading-side portion of the slider is movably disposed on the first tongue portion. A trailing-side portion of the slider is secured to the second tongue portion. The hinge portion is formed between the first tongue portion and the second tongue portion. The gimbal portion is provided with a damper member includes a viscoelastic material layer and a constrained plate. The damper member comprises a first damper and a second damper. The hinge portion is exposed between the first damper and the second damper. A dimple on a load beam contacts the hinge portion at a point of contact.
Tue, 26 May 2015 08:00:00 EDTA tape guide roller, for use with a tape drive that is configured to receive a length of tape, includes a roller body having an outer surface with one or more grooved areas and one or more non-grooved areas. The one or more grooved areas make up seventy-five percent or less of the outer surface, and the one or more non-grooved areas make up at least twenty-five percent of the outer surface. Furthermore, the one or more grooved areas are configured to affect traction between the roller body and the tape as the tape passes over the roller body.
Tue, 26 May 2015 08:00:00 EDTVarious embodiments concern a dual stage actuation suspension that comprises a loadbeam having a load point projection. The suspension further comprises a gimbal assembly having a point of contact that is in contact with the load point projection such that the gimbal assembly can gimbal about the load point projection. The gimbal assembly is cantilevered from the loadbeam and has an axis of rotation aligned with the load point projection and the point of contact. The suspension further comprises a pair of motors mounted on the gimbal assembly and positioned proximal of the point of contact. The pair of motors is mounted between a tongue and a pair of spring arms to rotate the tongue about the point of contact and the load point projection. The loadbeam further comprises a void into which the pair of motors extends.
Tue, 26 May 2015 08:00:00 EDTA magnetic recording medium including a substrate, and at least one magnetic layer formed on the substrate. The magnetic layer is formed from an alloy containing Cobalt, and Platinum (Pt). The magnetic layer is also formed from grain boundary segregation materials comprising Manganese Oxide and at least one of Silicon Oxide, Chromium Oxide, and Cobalt Oxide (CoO).
Tue, 26 May 2015 08:00:00 EDTA method and system provide a magnetic transducer having an air-bearing surface (ABS). The magnetic transducer includes a main pole and at least one coil for energizing the main pole. The coil(s) have a number of turns. The magnetic transducer also includes at least one shunt coupled to at least one of the number of turns. At least one remaining turn of the number of turns carries a current. The shunt(s) carry a portion of the current from the shunted turn of the number of turns. Thus, the coil(s) have an effective number of turns is less than the number of turns.
Tue, 26 May 2015 08:00:00 EDTThe present disclosure provides for a magnetic writer pole for use in a hard drive. The magnetic writer pole comprises a first bevel formed by a non-magnetic layer, the first bevel formed at a first angle and extending to a first throat height. The magnetic writer pole further comprises a second bevel formed by the non-magnetic layer and extending distally from the first bevel at a second angle that is greater than the first angle and extending to a second throat height. The magnetic writer pole further comprises a third bevel formed by the non-magnetic layer and extending distally from the second bevel at a third angle that is greater than the second angle.
Tue, 26 May 2015 08:00:00 EDTA head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.
Tue, 26 May 2015 08:00:00 EDTIn accordance with one embodiment, a computer program product includes a computer readable storage medium having computer readable program code that is readable and/or executable by a processor to: receive a signal including precoded data read from a magnetic tape medium and pass the signal through a soft detector to calculator first soft information about each bit of the signal and to provide adaptive compensation for the precoded data, send the first soft information to a soft decoder, pass the signal through the soft decoder to calculate second soft information about each bit the signal, and send the second soft information to the soft detector, wherein the precoded data is passed through at least one precoder prior to being written to the magnetic tape medium via a precoder that applies 1/(1⊕D2) to bits of data, where D is delay corresponding to bit duration
Tue, 26 May 2015 08:00:00 EDTThe present disclosure generally relates to a HAMR head and a method for fabrication thereof. The HAMR head has a write head with a waveguide extending therethrough. A laser diode is coupled to a submount that is bonded to the write head using an adhesion layer, a solder structure, and a self-propagating multilayer alloying stack.
Tue, 26 May 2015 08:00:00 EDTApparatus and method for detecting and compensating for lubrication disturbance (lube disturb) events on a rotatable data recording medium. In some embodiments, a lube disturb event is detected responsive to displacement of a data transducer away from a first memory location on a rotating data recording medium during a write operation to write data thereto. The lube disturb event arises responsive to a transfer of accumulated contamination from a data transducer to a lubrication layer on the rotating data recording medium and a smearing of the transferred accumulated contamination along the first memory location. The write data are stored to a different, second memory location instead of to the first memory location responsive to the detected lube disturb event.
Tue, 26 May 2015 08:00:00 EDTA method according to one embodiment includes measuring a current position error signal, and calculating a statistical derivative using the current position error signal sample. A kurtosis value is calculated using a current position error signal sample or derivative thereof. A threshold value is adjusted using the kurtosis value. The statistical derivative is compared to the threshold value, and writing is enabled when the statistical derivative does not exceed the threshold value. A determination is made whether to enable or disable writing based on a stopwrite threshold when the statistical derivative exceeds the threshold value.
Tue, 26 May 2015 08:00:00 EDTA disk drive is disclosed including a disk having a plurality of sectors, and a head actuated over the disk. A defect threshold is initialized, and a first sector is read to generate a first read signal. The first read signal is processed to detect a defect in the first sector relative to the defect threshold. After detecting the defect, the defect threshold is adjusted and the first sector is reread to generate a second read signal. The second read signal is processed to detect the defect in the first sector relative to the adjusted defect threshold.
Tue, 26 May 2015 08:00:00 EDTA TMR sensor that includes a free layer having at least one B-containing (BC) layer made of CoFeB, CoFeBM, CoB, COBM, or CoBLM, and a plurality of non-B containing (NBC) layers made of CoFe, CoFeM, or CoFeLM is disclosed where L and M are one of Ni, Ta, Ti, W, Zr, Hf, Tb, or Nb. One embodiment is represented by (NBC/BC)n where n≧2. A second embodiment is represented by (NBC/BC)n/NBC where n≧1. In every embodiment, a NBC layer contacts the tunnel barrier and NBC layers each with a thickness from 2 to 8 Angstroms are formed in alternating fashion with one or more BC layers each 10 to 80 Angstroms thick. Total free layer thickness is
Tue, 19 May 2015 08:00:00 EDTA method for communication between computing devices includes identifying the parameters of a data transfer between a source computing device and a target computing device and identifying communication paths between a source computing device and target computing device, in which at least one of the communications paths is a physical network. A communication path is selected for the data transfer. When a data transfer over the physical network is selected as a communication path, a nonvolatile memory (NVM) unit is removed from the source computing device and placed in a cartridge and the cartridge is programmed with transfer information. The NVM unit and cartridge are transported through the physical network to the target computing device according to the transfer information and the NVM unit is electrically connected to the target computing device.
Tue, 19 May 2015 08:00:00 EDTA device for checking the running performance of a motor vehicle, which can have at least the following components: a system for measuring a distance of a motor vehicle which is integrated in a motor vehicle, a vehicle communication system for wireless data transmission, where the system is identifiable by a unique identification number of the motor vehicle, and data may be transmitted from the vehicle to a receiver, a stationary database system for storing and providing data, which is equipped with a receiver that allows communication with the in-vehicle communication system, and an interface which allows stationary and mobile communication terminal system.
Tue, 19 May 2015 08:00:00 EDTVarious embodiments may be generally directed to a magnetic sensor constructed with a decoupling layer that has a predetermined first morphology. A magnetic free layer can be deposited contactingly adjacent to the decoupling layer with the magnetic free layer configured to have at least a first sub-layer having a predetermined second morphology.
Tue, 19 May 2015 08:00:00 EDTA heat-assisted magnetic recording (HAMR) air-bearing slider has an optically-transparent protective film over the near-field transducer (NFT) to protect the NFT from excessive heat caused by the accumulation of carbonaceous material on the slider's overcoat. The NFT is thus separated from the overcoat by the protective film. The protective film does not cover the write pole end, which is covered only by the overcoat, so there is no spacing loss between the write pole end and the recording layer on the disk. In one embodiment the protective film is coplanar with the recording-layer-facing surface of the slider and the overcoat covers both the protective film and the write pole end. In another embodiment the overcoat has a window that surrounds the protective film, with the protective film being substantially coplanar with the air-bearing surface (ABS) of the slider. In both embodiments the smooth topography of the slider's ABS is maintained.
Tue, 19 May 2015 08:00:00 EDTA flexible cable assembly (FCA) has a stiffener layer positioned in electrical contact with an electrical ground feature of the FCA, and a head stack assembly (HSA) may include a suspension tail electrically connected to the stiffener layer of the FCA, thus providing a robust ground path between the read/write head and the arm or E-block of the HSA. Additional efficient grounding techniques may include directly electrically connecting the suspension tail to the arm via a conductive adhesive, directly electrically connecting the FCA stiffener layer to the arm via a conductive screw, and/or directly electrically connecting the ground feature and the stiffener layer of the FCA to the arm using a ground post or screw.
Tue, 19 May 2015 08:00:00 EDTA multiple-segment transmission line in a hard disk drive enables a wider optimization range of the slope, duration and amplitude of the transmission line overshoot (TLO) wave shape. There is a first segment with two traces for connection to the write driver circuitry, an end segment with two traces for connection to the write head and at least two intermediate segments. The number of traces in a segment is different from the number of traces in the segments to which the segment is immediately connected. There is an even number of traces in each segment and the traces in each segment are interleaved. The number of segments and the number of traces in each segment can be selected to achieve the desired impedance levels for the different segments to achieve the desired wave shape for the TLO. All of the traces on the transmission line are preferably coplanar.
Tue, 19 May 2015 08:00:00 EDTA dual-stack read sensor is utilized in a storage device having an actuator arm that positions the read sensor over a rotating storage medium. The dual-stacked read sensor includes a primary read sensor having a first set of read sensor characteristics and a secondary read sensor having a second set of read sensor characteristics that differ from the first set of read sensor characteristics, wherein the secondary read sensor is positioned relative to the primary read sensor to be radially offset from the primary read sensor relative to a data track being read.
Tue, 19 May 2015 08:00:00 EDTA suspension includes a positive write trace and a negative write trace. The positive write trace is separated into at least two positive write trace sections located at two different layers respectively, and the negative write trace is separated into at least two negative write trace sections located at two different layers respectively. Each positive write trace section and each negative write trace section are alternately arranged along a longitudinal direction on two different layers, and the positive write trace sections at different layers are connected together via conductive crossovers, and the negative write trace sections are connected together via conductive crossovers. The present invention can obtain balanced propagation time in the stacked trace structure to reduce signal distortion, and obtain widened frequency bandwidth.
Tue, 19 May 2015 08:00:00 EDTVarious embodiments concern a DSA suspension of a disk drive. The DSA suspension comprises a support configured to attach to the disk drive, the support comprising a proximal portion, a distal portion, and a linkage portion therebetween. The DSA head suspension system further comprises at least one motor mounted on the support, each motor positioned between the proximal portion and the distal portion. The DSA suspension further comprises a damper attached to some or all of the proximal portion, the motor(s), the distal portion, and the linkage portion. The damper can be a single layer or multilayered. The damper can comprise viscoelastic material. The damper can be adhesive. The damper may only be attached to the support and the motors and not to other components of the DSA suspension.
Tue, 19 May 2015 08:00:00 EDTA slider includes a substrate having a trailing edge, a leading edge opposite the trailing edge, and an air bearing surface connecting the trailing edge with the leading edge; a read/write transducer formed at the trailing edge; and a coat layer attached on the trailing edge and covering on the read/write transducer. The slider further includes a protection layer for shielding the read/write transducer thereby preventing the read/write transducer from damaging during a laser soldering process. The present invention can prevent the read/write transducer from damaging during the laser bonding process and, in turn improve the reading and writing performance of the slider. The invention also discloses an HGA and a disk drive unit.
Tue, 19 May 2015 08:00:00 EDTA magnetic recording tape according to one embodiment includes at least about eight data bands, wherein each data band is defined between a pair of adjacent servo tracks, each pair of adjacent servo tracks defining only a single data band therebetween. One of the servo tracks has data encoded therein, the data including data for encryption. A magnetic recording tape according to another embodiment includes a plurality of servo tracks, each servo track comprising a series of magnetically defined bars. An average height of the bars is less than about 50 microns. About eight to about twenty six data bands are present on the tape. A tape supply cartridge according to various embodiments has a magnetic recording tape as described herein.
Tue, 19 May 2015 08:00:00 EDTApproaches to improving hard disk drive far track interference problems include utilizing a wrap-around shield having recessed high magnetic moment layer(s). Embodiments include tapering the high-moment portion away from the air bearing surface (ABS) in the cross-track direction away from the write pole, thereby reducing exposure of high moment layers at the ABS to reduce the risk of unwanted track erasure away from the main pole. Embodiments include positioning the high magnetic moment layers in their entirety away from the ABS, such as with a laminate structure of high magnetic moment and low magnetic moment materials laid down in a direction away from the pole tip trailing edge.
Tue, 19 May 2015 08:00:00 EDTRecording heads for data storage systems are provided. Recording heads illustratively include a write pole, a bumper, a dielectric layer, and a surface. In some embodiments, a portion of the surface includes portions of the write pole, bumper, and dielectric layer. The write pole, bumper, and dielectric layer are illustratively made from materials that have polishing rates. In some embodiments, the polishing rate for the write pole material is more similar to the polishing rate for the bumper material than it is to the polishing rate for the dielectric layer material.
Tue, 19 May 2015 08:00:00 EDTA magnetic head according to one embodiment includes a module, the module having first and second transducers of different transducer types positioned towards a media facing side of the module, wherein the different transducer types are selected from a group consisting of data reader transducers, servo reader transducers, write transducers, piggyback read-write transducers and merged read-write transducers; a first protection structure for protecting the first transducer; and wherein the second transducer has either no protection or is protected by a second protection structure that is different than the first protection structure.
Tue, 19 May 2015 08:00:00 EDTA system according to one embodiment includes at least two write transducers for writing to a magnetic medium; and a low reluctance path from a first pole of a first of the write transducers to a second pole of a second of the write transducers. In another embodiment, either 1) the first pole of the first write transducer and the second pole of the second write transducer are positioned close enough to each other that a low reluctance path is present from the first pole of the first write transducer to the second pole of the second write transducer, or 2) a magnetic strap extends between the first pole of the first write transducer and the second pole of the second write transducer thereby creating a low reluctance path therebetween.
Tue, 19 May 2015 08:00:00 EDTA novel information storage device is disclosed and claimed. The information storage device includes a device housing with a generally rectangular bay to accommodate a disk drive. The generally rectangular bay includes a base portion and a plurality of side portions. The information storage device further includes a damping insert sheet disposed between the disk drive and the base portion. The damping insert sheet has a plurality of elastomeric cushions, for example with a cushion thickness in the range 0.5 mm to 10 mm, and a spanning sheet, for example having a sheet thickness in the range 0.02 mm to 0.35 mm. Each of the plurality of elastomeric cushions is attached to the spanning sheet. Each of the plurality of elastomeric cushions contacts and is compressed between the generally rectangular bay and the disk drive.
Tue, 19 May 2015 08:00:00 EDTA hard disc assembly includes a box and a hard disc body slidably mounted to the box. The box comprises a driving unit and a pivoting pole. The hard disc body comprises a disc member and a magnetic arm. A magnetic head is located on the magnetic arm and contacts the disc member. The magnetic arm is connected to the pivoting pole of the driving unit. The driving unit is configured to move the magnetic arm on the disc member. The magnetic head is configured to access data in the disc member when the disc member rotates. The magnetic head remains in contact with the disc member when the disc member stops rotating.
Tue, 19 May 2015 08:00:00 EDTProvided herein is an apparatus, including a clamping means for clamping at least one disk onto a hub at a mounting point on the hub for the at least one disk, wherein the clamping means is configured to sit wholly above the at least one disk; a seat in an outer perimeter of the hub configured to receive the clamping means; and a locking means for locking the clamping means onto the hub.
Tue, 19 May 2015 08:00:00 EDTIn one embodiment, a system includes a robotic accessor for transporting media between multiple storage slots and one or more data storage drives; a controller for controlling the robotic accessor; a memory in communication with and/or integrated with the controller for storing information about the media and the storage slots, the information including data corresponding to a physical distribution of the media in the storage slots; and logic integrated with and/or executable by the controller, the logic being adapted to: position the robotic accessor at a computed optimal position during an idle period of the robotic accessor, the computed optimal position being based at least in part on the physical distribution of the media in the storage slots.
Tue, 19 May 2015 08:00:00 EDTSystems and methods are provided that may be implemented to provide a mechanical indicator to correlate magnetic disk drive IOP performance with features of mechanical and/or acoustic vibrational frequencies that are generated and captured or sensed outside of the disk drive itself. In one example, disk drive PES data may be collected concurrently with the capture of mechanical and/or acoustic vibrational data at different and progressive locations of vibration source, vibration path and vibration receiver in a disk drive operating environment, e.g., such as for disk drives installed within a server and/or storage chassis enclosure. In such case, PES threshold may be utilized to correlate performance of Drive IOP or drive servo-mechanical performance as a function of measured characteristics of vibration source/s that impart vibration to a disk drive.
Tue, 19 May 2015 08:00:00 EDTA head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.
Tue, 19 May 2015 08:00:00 EDTA magnetic storage medium is formed of magnetic nanoparticles that are encapsulated within nanotubes (e.g., carbon nanotubes).
Tue, 19 May 2015 08:00:00 EDTA method for reading a track of data may include positioning a read head at an initial position relative to the track of data and obtaining initial track signals, filtering the initial track signals, positioning the read head at an initial subsequent position relative to the track of data and obtaining initial subsequent track signals, and filtering the initial subsequent track signals. In an initial equalization, the filtered initial track signals and the filtered initial subsequent track signals are equalized to obtain equalized track signals. The read head is positioned at a further subsequent position relative to the track of data and further subsequent track signals are obtained The further subsequent track signals are filtered. In a subsequent equalization, previously obtained equalized track signals and the filtered further subsequent track signals are equalized. A storage device operating according to the method may have an equalizer in hardware or firmware.
Tue, 19 May 2015 08:00:00 EDTIn one embodiment, a method includes passing a signal through a noise whitening filter, passing the signal through a soft detector to calculate first soft information, passing the signal through the soft decoder to calculate second soft information based on the first soft information, and sending the second soft information to the soft detector, wherein the noise whitening filter is configured to process the signal according to the following transfer polynomial: W(D)=1−(p1D+ . . . p1Dλ), where p1 . . . pλ are noise whitening coefficients, D is delay corresponding to bit duration, and a transfer polynomial of the tape channel is F(D)=1+f1D+ . . . +fLDL, wherein L represents a memory length of the tape channel, and wherein λ represents a memory length of the noise whitening filter. Other methods, systems, and computer program products are described in more embodiments.
Tue, 19 May 2015 08:00:00 EDTA device for reading data recorded on a recording medium having multiple tracks, the device including: a receiver that receives designations of a number of data elements to be read; and a determination unit that determines an order of reading the data elements so that, no matter on which track of the tracks each of the data elements is recorded, the data elements are read in an order of recorded locations of the data elements in a direction along the tracks on which the data elements are recorded.
Tue, 19 May 2015 08:00:00 EDTA position detection encoder includes a scale and a detection head and has position detection circuits which are capable of outputting respective pieces of position information on Xf, Xs two tracks. The displacement detection encoder includes: a speed detection circuit which is provided in the detection head and detects a relative speed Xf, Xs relative to the scale; and a delay generation circuit which provides a time difference between two output request signals, the time difference being provided on the basis of a fine adjustment time tadj based on the relative speed Xf, Xs and the respective pieces of position information Xf, Xs on the two tracks, the output request signals St1, St2 urging the first and second position detection circuits to output the pieces of position information on Xf, Xs the two tracks.
Tue, 19 May 2015 08:00:00 EDTSystems and methods are disclosed for isolated bands of fractional tracks in data storage devices, particularly devices employing shingled magnetic recording. In one embodiment, a device may comprise a data storage medium including a first data storage area including tracks overlapped in a shingled manner and having a first circumferential portion of a track to store data, a second data storage area, and a guard area disposed between the first data storage area and the second data storage area, the guard area including a second circumferential portion of the track as a partial guard track. In some embodiments, the guard area may include at least one sector in the first circumferential portion of the track, such that at least one sector of the guard area is interposed between data storage sectors of the first data storage area.