Abstract: A magnetic tape device. The angle ? formed by the axis of the element array of the magnetic head with respect to a width direction of the magnetic tape is changed during running of the magnetic tape in the magnetic tape device. The magnetic tape satisfies Equation 1: TDSage+TDSenv?TC?0.10 ?m. In Equation 1, the TDSage is a maximum value of an absolute value of a difference between a servo band spacing obtained before storage for 24 hours in a predetermined environment and a servo band spacing obtained after the storage. TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value of servo band spacings obtained in each of five predetermined environments by ½, and TC is a value calculated by TC=L{cos (?initial???)?cos (?initial+??)}.

Abstract: A computer-implemented method, according to one embodiment, includes: receiving a first timestamp in response to a first servo reader detecting a stripe of a first servo burst on the magnetic tape, and receiving a second timestamp in response to a second servo reader detecting a stripe of a second servo burst on the magnetic tape. A third timestamp is received in response to the first servo reader detecting a stripe of a third servo burst on the magnetic tape, while a fourth timestamp is received in response to the second servo reader detecting a stripe of a fourth servo burst on the magnetic tape. The first, second, third, and fourth timestamps are used to determine the skew of the magnetic tape. Further still, the first and third servo bursts are in a same first servo sub-frame, while the second and fourth servo bursts are in a same second servo sub-frame.

Abstract: An actuator controller that is capable of drivingly controlling an actuator, such as a motor, with a sufficient accuracy in spite of a simple configuration while preventing an incorrect detection of switching of a magnetic pole. The actuator controller drivingly controls an actuator having a driving element and a stator. A driver supplies an electric current to a coil provided in the stator so as to drive the driving element. A sensor detects a magnetic field of the driving element so as to detect a position of the driving element. A processor exclusively controls a timing at which the sensor detects the magnetic field and a timing at which the driver supplies the electric current to the coil.

Abstract: A magnetic recording medium is provided and including an average thickness tT satisfies tT?5.5 [?m], and a dimensional change amount ?w in a width direction of the magnetic recording medium with respect to a tension change in a longitudinal direction of the magnetic recording medium satisfies 700 [ppm/N]??w.

Abstract: Technical solutions are described for tuning a building control system, such as a variable air volume system, which includes intervened control loops. In one aspect, a method includes receiving a performance objective of the system. The method also includes generating a collection of values for parameters of the control loops based on stored information that includes a stored velocity and a stored position. The method also includes evaluating the collection of values for the parameters by comparing a performance measure and the performance objective of the system. In response to a difference between the performance objective and the performance measure satisfying a predetermined threshold the collection of values are stored and the control loops are configured according to the stored information for the parameters. The present document further describes examples of other aspects such as systems, computer products.

Abstract: Methods and apparatus providing a smooth transition from a pulse width modulation mode to a linear mode to drive a voice coil motor are disclosed. An example apparatus includes an H-bridge; a pulse generator to generate a pulse when the voice coil motor driver transitions from pulse width modulation mode to linear mode; a first boost circuit to, when the pulse is generated, increase a first current being applied to a first gate of a first transistor in the H-bridge, the increase in the first current enabling the first transistor; and a second boost circuit to, when the pulse is generated, provide an additional path to ground from a node coupled to a second gate of a second transistor of the H bridge, the path to ground corresponding to a voltage drop that disables the second transistor.

Abstract: A control device includes at least one processor which functions as an advance angle detection unit, a storage unit configured to store information indicating a plurality of loci each indicating a relationship between the advance angle and a rotation speed of a rotor at each driving voltage, a target advance angle calculation unit configured to calculate a target advance angle based on the information, an advance angle control unit, a voltage control unit, and a switching unit configured to switch between a first control state for setting a target rotation speed by controlling the advance angle along one locus among the plurality of loci and a second control state for setting the target rotation speed by controlling the voltage in a state where the advance angle is fixed, according to the locus, the target advance angle, and the driving voltage.

Abstract: A method of digitizing an audio track carried on an elongate recording medium, such as a movie film, includes transporting the recording medium containing the audio track past a reader to enable sequential reading of the audio track. The reading of the audio track generates an analog output signal. The method also includes sensing a rate of transportation of the recording medium, and sampling the analog output signal at a sampling rate determined on the basis of the sensed rate of transportation to digitize the analog output signal. A system for digitizing audio is also disclosed.

Abstract: An EM pose tracking system controls a power mode by adjusting a transmit power of the EM transmitter based on a metric correlated with jitter in the EM readings. Such a metric includes metrics such as estimated noise computed from received EM data, a computed distance between the transmitter and the receiver, a measured signal power between the transmitter and the receiver, and the like. By adjusting the transmit power based on the jitter metric, the EM tracking system can reduce overall power consumption at a device that employs the EM tracking system, thus allowing the system to be used in a wider variety of devices and improving the user experience with those devices.

Abstract: A first reader spans first and second tracks of a recording medium and provides a first signal responsive to a first total longitudinal field of the first and second tracks. A second read spans two other tracks, at least one of the two other tracks being different from the first and second tracks. The second reader provides a second signal responsive to a second total longitudinal field of the two other tracks. A third reader spans two or more of the tracks and provides a third signal responsive to a total perpendicular field of the two or more tracks. User data is decoded from the first, second, and third signals.

Abstract: A signal processing apparatus for effectively detecting an abrupt change in a signal, in particular, an abrupt change different from an ideal pulse includes a converter that converts an input signal into a phase component signal in a frequency domain, a first calculator that calculates a phase gradient for each of a plurality of frequencies of the phase component signal as a first phase gradient, a weighting unit that weights the first phase gradient with an amplitude or a power of the input signal, thereby calculating a weighted first phase gradient, a second calculator that calculates a second phase gradient based on the weighted first phase gradient, and a determiner that determines presence of an abrupt change in the input signal based on the first phase gradient and the second phase gradient.

Abstract: When a motor is started up, an initial position detection circuit detects the initial position of a rotor using an inductive sensing method. An automatic parameter generating circuit determines a parameter to be used by the initial position detection circuit. The automatic parameter generating circuit measures: (i) a first time period ?+ required for a coil current to reach a threshold after a first polarity voltage is applied across an electrode pair of the motor; and (ii) a second time period ?? required for the coil current to reach a threshold after a second polarity voltage is applied across the electrode pair, for each threshold value, while the threshold value used in the measurement is changed. The threshold that provides a maximum difference between the first time period ?+ and the second time period ?? is held as the parameter to be used by the initial position detection circuit.

Abstract: A write head including a bearing surface and a write pole having a front surface that forms a portion of the bearing surface. The front surface has a leading edge, a trailing edge and side edges connecting the leading and trailing edges. The write head also includes side shields proximate to the side edges of the write pole, and a trailing shield over the write pole and the side shields. A trailing shield-write pole gap is present between the trailing edge and the trailing shield, and a trailing shield-side shield gap is present between the trailing shield and the side shields. The trailing shield side shield gap is substantially less than the trailing shield-write pole gap.

Abstract: A method according to one embodiment includes instructing a drive to detect a written signal burst on a magnetic tape and stop movement of the tape in response to detecting the written signal burst. A search for a defect is conducted in a location proximate to the written signal burst. An apparatus according to one embodiment includes a plurality of detector structures positioned in an array. Each of the detector structures includes a pair of conductive layers separated by an insulating material. A write transducer is aligned with each of the detector structures. A controller is configured to cause one of the write transducers to write a signal burst in response to the associated detector structure encountering a defect.

Abstract: First and second signal patterns are used to write corresponding portions of first and second adjacent tracks to a magnetic storage medium. A characteristic of the first signal pattern is changed based on the second signal pattern, the changing of the characteristic reducing an adjacent track interference affecting the second track.

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

Abstract: A data storage device is disclosed comprising a head actuated over a disk, and a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings. A commutation controller is configured to commutate the windings based on a commutation sequence driven by an oscillator. A rotation phase of the spindle motor is measured, and a phase error is generated based on the measured rotation phase of the spindle motor and a phase of the commutation sequence, wherein a frequency of the oscillator is adjusted based on the phase error.

Abstract: An apparatus includes: a media motor; a media mounted on the media motor; a head, over the media, the motion of the head controlled by a head actuation motor; a motor driver, coupled to the media motor, configured to adjust a media speed; and control circuitry configured to: coast the media motor in preparation for accelerating the head, and activate the head actuation motor including accelerating the head in a first direction for repositioning the head over the media.

Abstract: A data processing system includes a number of analog to digital converters operable to sample analog signals obtained from a magnetic storage medium to yield digital signals, multiple sync mark detectors operable to search for a number of different sync marks in the digital signals, and a sync mark detector output comparator operable to compare an output of each of the sync mark detectors to identify detection errors.

Abstract: A disk drive is disclosed comprising a disk comprising a plurality of servo tracks, wherein each servo track comprises a plurality of servo sectors. A position of the head is measured based on the servo sectors, and a compensated position of the head is generated based on the measured position of the head and a fly height of the head. The head is actuated over the disk based on the compensated position of the head.

Abstract: A spin valve element according to an embodiment includes: a nonmagnetic base layer; a first terminal including a first magnetic layer connecting to a portion near one of opposing end faces of the nonmagnetic base layer; a second terminal including a second magnetic layer disposed and connecting to the nonmagnetic base layer so as to be at a distance from the first terminal; a third terminal including a third magnetic layer disposed and connecting to the nonmagnetic base layer so as to be at distances from the first and second terminals, the second terminal and the third terminal connecting to a current source that passes a sense current, and the first terminal and one of the second terminal and the third terminal connecting to a voltage detection unit that detects a voltage.

Abstract: In one general embodiment, an apparatus includes a magnetic head. The magnetic head has a first array of data transducers, a second array of data transducers spaced from the first array, and a third array of data transducers positioned between the first and second arrays. The magnetic head is positionable between a first position and a second position, where the longitudinal axis of the third array is positively or negatively angled relative to a line oriented perpendicular to an intended direction of tape travel thereacross when positioned towards the respective positions. Outer data transducers of the third array are about aligned with outer data transducers of the second array when the magnetic head is positioned towards the first position. The outer data transducers of the third array are about aligned with outer data transducers of the first array when the magnetic head is positioned towards the second position.

Abstract: A system and method for data storage and retrieval include a rotational head carriage unit having a plurality of heads. A tape drive unit moves a tape media length-wise across the head carriage unit while the head carriage unit rotates. The tape drive unit is adapted to use a tape comprising multiple recordable layers. The heads are adapted to read data from or write data to one recordable layer while rotating toward one edge of the tape media, and read data from or write data to another recordable layer while rotating toward the other edge of the tape media.

Abstract: Systems, methods, and other embodiments associated with back-EMF detection for motor control are described. In an embodiment, an apparatus includes a drive circuit configured to apply excitation signals to respective inputs of a motor, a signal inhibit circuit configured to convey a signal to inhibit application of the excitation signals during an interval, and a measuring circuit configured to measure a back-electromotive force (EMF) signal crossing a reference signal during the interval.

Abstract: Methods and apparatus are provided for detecting a sync mark in a storage system, such as a hard disk drive. A sync mark is detected in a storage system by obtaining one or more branch metrics from a data detector in the storage system; generating one or more sync mark metrics using the one or more branch metrics from the data detector; and identifying the sync mark based on the sync mark metrics. An input data set is optionally compared with a plurality of portions of a sync mark pattern to yield corresponding comparison values and the comparison values can be summed to obtain at least one result. A sync mark found signal is asserted based upon the at least one result.

Abstract: A HDD including a temperature sensor for sensing ambient temperature in the HDD, a spindle motor comprising a fluid dynamic bearing; and a controller configured for adjusting a rotational speed of the spindle motor based on the measured ambient temperature while a rigidity of the fluid dynamic bearing is maintained, and reducing power consumption of the HDD based on the adjusting the rotational speed of the spindle motor.

Abstract: A magnetic head according to an embodiment includes a first magnetic shield and a second magnetic shield that are opposed to each other, and a magnetoresistive film arranged between the first magnetic shield and the second magnetic shield, and including a first magnetic layer including a first metal layer that contains 90 at. % or more of Fe and a first Heusler alloy layer, a second magnetic layer arranged on a side of the first Heusler alloy layer opposite from the first magnetic layer, and an intermediate layer arranged between the first Heusler alloy layer and the second magnetic layer.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of servo sectors defining a plurality of servo tracks, wherein the servo tracks form a plurality of servo zones, and a servo data rate of servo sectors in a first servo zone is different than a servo data rate of servo sectors in a second servo zone. A disk locked clock is synchronized to the data rate of the servo sectors in the first servo zone, wherein the disk locked clock for generating a timing window relative to the servo sectors. When the head crosses from the first servo zone to the second servo zone, at least one of the disk locked clock and the timing window is adjusted to compensate for a timing transient.

Abstract: A read channel is configured to receive at least part of a data fragment read from a storage media into a register, wherein the data fragment is configured to be formatted with a preamble, a sync mark (e.g., a syncMark), and user data, and wherein the data fragment is missing a sync mark. A position in the data fragment is selected, a sync mark is assumed at the selected position. The data is then processed assuming the sync mark is at the selected position of the data fragment to determine whether the data converges. When a determination is made that the data converges, the data is recovered.

Abstract: A method according to one embodiment includes setting a default friction value to a predetermined value, determining whether a primary velocity is valid, determining a velocity error, determining whether the velocity error is in a predetermined range, accumulating the velocity error when the velocity error is determined to be in the predetermined range, repeating, until a time period has elapsed, each of: the determining the velocity error, the determining whether the velocity error is in the predetermined range, and the accumulating the velocity error when the velocity error is determined to be in the predetermined range, and calculating a new friction value based on the accumulated velocity error.

Abstract: In a method for operating a tape storage device comprising a tape head for reading and/or writing data from/to a tape in the tape storage device, a first tape skew value concerning a skew of the tape is determined and the first tape skew value is converted into a first skew control signal by means of a skew feedback controller. A second tape skew value concerning the skew of the tape is determined, and the second tape skew value is converted into a second skew control signal by means of feed-forward controller. At least one compensation signal for the second skew control signal is determined, and at least one of a rotational orientation of the tape head and a tape motion direction of the tape is controlled dependent on the second skew control signal and the compensation signal in case the first skew control signal fails.

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: According to one embodiment, there is provided a magnetic disk device including an acceleration feedforward module, an eccentricity correction module, and a control module. The acceleration feedforward module includes a first amplification module, a second amplification module, and an addition module. The first amplification module amplify a first rotation correlation value according to a rotation component by a first gain. The second amplification module amplifies a second rotation correlation value according to a rotation synchronization component of the rotation component, by a second gain acquired by subtracting the first gain from 1. The addition module adds the first rotation correlation value amplified by the first amplification module and the second rotation correlation value amplified by the second amplification module to obtain the first correction amount.

Abstract: Disclosed is a semiconductor integrated circuit for generating a frequency division clock signal that approximates a desired clock signal without increasing a size thereof. The semiconductor integrated circuit masks, for each programmable cycle, a clock signal to be supplied to a transmission clock generation unit 100, thereby delaying a counting operation of a clock counter 101, and setting a timing for extending a transmission clock signal so as to cause a transmission rate of an average frequency of the transmission clock signal to approximate a predetermined transmission rate, wherein the transmission clock generation unit 100 divides a frequency of a clock source signal S301 that is a high-speed clock signal.

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: In one embodiment, a tape movement constraint comprises a tiltable tape roller bearing having a grooved surface adapted to contact and engage a surface of the tape as the roller barrel rotates. An actuator adapted to pivot the roller bearing surface controls the lateral position of a tape. In operation, in one embodiment, the roller barrel of the roller bearing is rotated by engaging a surface of the tape roller barrel with a longitudinally moving magnetic tape. At least a portion of any air bearing between the moving tape and the barrel surface is quenched using grooves formed in the barrel surface. The lateral position of the moving tape is sensed and the rotating roller barrel is tilted in response to the sensed lateral position of the moving tape to control the lateral position of the moving tape. Other embodiments are described and claimed.

Abstract: A magnetic disk device includes: a recording medium provided with a plurality of write tracks; a magnetic write head including a magnetic pole, side shields, and a leading shield, a distance from the magnetic pole to each of the side shields being maintained to be uniform with a gap layer therebetween, and a distance from the magnetic pole to the leading shield being maintained to be uniform with a gap layer therebetween; and a control section rotating the recording medium, and allowing magnetic information to be recorded on the recording medium while allowing the magnetic write head to travel in a direction from an inner write track toward an outer write track or in a direction from the outer write track toward the inner write track, across write tracks in the recording medium. With such a configuration, format efficiency may be improved, and a width of an erase band on a magnetic disk may be minimized.

Abstract: A method of operation of a servo writing system includes: initializing a disk and a head positioned over the disk for writing a servo pattern on the disk; calculating a target velocity profile for writing the servo pattern on the disk; setting a movement profile for operating the disk, the head, or a combination thereof to the target velocity profile; determining a back electromotive force from operating the disk, the head, or a combination thereof according to the movement profile; calculating an actual profile of the movement of the disk, the head, or a combination thereof from the back electromotive force; and adjusting the movement profile by the actual profile to match the actual profile to the target velocity profile for writing the servo pattern on the disk.

Abstract: Systems, methods, and apparatus, including computer program products, for audio editing are provided. In some implementations, a method is provided. The method includes receiving audio data having a first audio channel and a second audio channel. The audio data is separated, into a plurality of blocks. An amount of misalignment is determined between the first audio channel and the second audio channel for the portion of the audio data in each block using a phase difference between the first and second audio channels for each of a plurality of frequency bands. The first and second channels are aligned using the determined misalignment.

Abstract: A magnetic disk is provided which is excellent in durability of the magnetic disk or particularly in LUL durability and CFT characteristics and has high reliability under a decreased floating amount of the magnetic head accompanying the recent rapid increase in a recording density and extremely severe environmental resistance accompanying diversification of the applications. The magnetic disk of the present invention is a magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate, and the lubrication layer is a film formed by a lubricant that contains two types of compounds having a perfluoropolyether main chain in the structure, a molecular weight distribution of the two types in total being within a range of 1 to 1.

Abstract: An information recording and reproducing apparatus 1 having a high efficiency of information transfer includes one or more recording media forming a plurality of recording surfaces, a plurality of heads respectively disposed on the recording surfaces, a first actuator for supporting the heads and moving the heads uniformly, a plurality of second actuators provided one for an associated one of the heads, the second actuators moving the heads independently relative to the first actuator, recording processing circuits for simultaneously outputting recording signals, and reproducing processing circuits simultaneously supplied with reproduced signals read out by the heads to reproduce information from the reproduced signals.

Abstract: A recording medium, method and apparatus for managing data are discussed. According to an embodiment, the present invention provides a method of reproducing main data and additional data. The method includes receiving the additional data associated with the main data, the additional data being divided into a plurality of segment units; and reproducing the additional data in a synchronous manner with the main data using time information if indication information indicates a presence of the time information. The time information indicates a presentation time of the additional data with respect to the main data. The main data and the additional data are reproduced according to management data, the management data including link information for linking the main data and the additional data.

Abstract: A recording medium, method and apparatus for managing data are discussed. According to an embodiment, the present invention provides a method of reproducing main data and additional data. The method includes receiving the additional data associated with the main data, the additional data being divided into a plurality of segment units; and reproducing the additional data in a synchronous manner with the main data using time information if indication information indicates a presence of the time information. The time information indicates a presentation time of the additional data with respect to the main data. The main data and the additional data are reproduced according to management data, the management data including link information for linking the main data and the additional data.

Abstract: A plurality of disk drives in a disk drive array are synchronized. A synchronization signal is generated at a master disk drive. The synchronization signal is encoded as a radio frequency signal for transmission over a radio frequency network in communication with the plurality of disk drives. The transmitted radio frequency signal is received at a slave disk drive and decoded to recover the synchronization signal. Rotation of a disk in the slave disk drive is synchronized with rotation of a disk in the master disk drive based on the recovered synchronization signal.

Abstract: A system and method are described for aligning a data axis of one or more circular data-bearing tracks on an annular surface region of a magnetic media-bearing disk, with a spin axis of a spindle of a spinstand or a disk drive. The data axis is perpendicular to the surface region of the disk and the data tracks are concentric with respect to a data axis.

Abstract: Information indicative of the placement of spindle motor components may be obtained and used to provide a correction to one or more BEMF-derived attributes used to control the spindle speed. In some implementations, first and second signals indicative of BEMF of different stator windings may be used to determine a speed-related characteristic. The speed related characteristic may be used to determine an error amount, which may be used to determine a correction factor to control the speed of the spindle motor.

Abstract: Disk drives are synchronized by a timing signal generated in a master disk drive. The timing signal is transmitted over a power distribution network common to the disk drives. A slave drive receives the timing signal and synchronizes at least one disk based on the timing signal.

Abstract: A system and method to avoid disk lube pooling is presented. A track access monitor tracks the number of times that a program accesses a particular track located on a hard drive. When the track access monitor determines that the number of track accesses to a particular track exceed a track access threshold, the track access monitor invokes a sequence of events to scan adjacent tracks in order to uniformly redistribute lubrication over the hard drive. In one embodiment, the track access monitor incrementally performs the adjacent track scanning during hard drive idle periods, such as when the system waits for a password from a user or when the operating system conserves power and idles the hard drive due to lack of activity.

Abstract: The invention is directed to methods and apparatus for repositioning a data storage disc on a spindle assembly, to reduce eccentricity of data on the disc. The eccentricity can be identified and be reduced automatically by determining the magnitude and direction of an eccentricity vector that representing a misalignment of a central point around which the data are arranged on a data storage disk with an axis of a spindle, and moving the disc so that the eccentricity vector is reduced. One technique for moving the disc is to push the edge of the disc so that the central point moves closer to the axis of the spindle.

Abstract: A disk drive controller includes a servo system operable to associate a time stamp with an arrival of a servo wedge, a firmware loop and core PLLs in the read channel. The firmware loop is operable to determine a period between the arrival of a pair of consecutive servo wedges and produce a desired frequency of when to read/write data to disk based on the period between the arrival of a pair of consecutive servo wedges. Processing circuitry is operable to adjust a clock signal, wherein the clock signal itself is not locked to the data and produce a fine control signal for the core PLLs in the read channel. These core PLLs are operable to determine a phase and/or frequency associated with when an analog signal is sampled and/or written to disk, wherein these core PLLs comprises Fractional N Sigma Delta PLLs.