Abstract: An electronic device is provided, including: a first drive electrode; a second drive electrode that is spaced apart from the first drive electrode; and a topological insulator that contacts both of the first drive electrode and the second drive electrode and has magnetism, wherein the topological insulator includes a first region having a first coercivity and a second region having a second coercivity that is different from the first coercivity. A fabrication method of a topological insulator is also provided, including: preparing a topological insulator having magnetism and a first coercivity; and forming a second region having a second coercivity that is different from the first coercivity by irradiating a partial region of the topological insulator with ions.

Abstract: A storage device includes a multi-reader transducer head with a first reader and a second reader having an effective cross-track separation equal to a multiple of a defined track-pitch of a storage medium of the storage device. The effective cross-track separation may permit for a simultaneous data read of two non-adjacent data tracks.

Abstract: A solar device is provided. The solar device includes a solar module configured to absorb solar energy to convert the solar energy to electrical energy, a DC converter configured to detect an input voltage output from the solar module and outputs a DC voltage corresponding to a maximum power point through the detected input voltage, an interface unit configured to transmit data including the input voltage detected from the DC converter and the DC voltage corresponding to the maximum power point, a data combiner configured to combine and transmit data on the solar module with the data received from the interface unit, a data synthesizer configured to remove a DC voltage offset from the data received from the data combiner, and a data controller configured to track a maximum power point using data from which the DC voltage offset has been removed.

Abstract: A system for tracking a position error of a read/write head. The read/write head is configured to read data recorded to a data layer of a recording medium and read servo information recorded to a dedicated servo layer of the recording medium. To read the servo information, the read/write head is configured to read, from a first track, a first servo signal including first servo bursts of a predetermined frequency, and read, from a second track adjacent to the first track, a second servo signal including second servo bursts of the predetermined frequency. The first servo bursts are orthogonal to the second servo bursts. A position error signal determination circuit is configured to determine the position error using at least one of the first servo signal and the second servo signal.

Abstract: The disclosure is related to systems and methods for achieving improved servo Gray code error detection and correction. A device may include a circuit configured to read servo data that is encoded using a Gray code encoding scheme to produce servo Gray code, read one or more Check bits associated with the servo Gray code, determine whether a read or write head is positioned over a target data track based on the servo Gray code and the one or more Check bits, and execute a read or write operation when the read or write head is positioned over the target data track.

Abstract: Systems, methods, and other embodiments associated with a data detector that processes signals read from a storage device are described. According to one embodiment, a detector for detecting a data signal embedded in a read signal from a storage device includes a signal estimator configured to generate an estimate of the control signal from the read signal by sampling the read signal to determine characteristics of the control signal. The read signal includes the data signal and the control signal. The signal estimator uses the characteristics to calculate the estimate of the control signal. The detector also includes a cancellation unit configured to produce the data signal by cancelling the estimate of the control signal from the read signal.

Abstract: According to embodiments of the present invention, a method for demodulating a position error signal from a readback servo signal having a first frequency associated with a first servo track of a storage medium and a second frequency associated with a second servo track adjacent to the first servo track is provided. The method includes sampling the readback servo signal at successive time instants to provide a sequence of samples, computing a Discrete Fourier Transform based on the sequence of samples, and providing a measurement indicative of the position error signal based on the Discrete Fourier Transform. According to further embodiments of the present invention, a demodulator is also provided.

Abstract: A servo information recording method continuously records servo information in a radial direction of a magnetic disk on a plurality of concentric tracks or on a single spiral track of a first recording layer that forms a magnetic layer of the magnetic disk together with a second recording layer to which data are recorded and from which data are reproduced, wherein the first recording layer has a coercivity higher than that of the second recording layer, and partially overlaps two mutually adjacent tracks when continuously recording the servo information on an entire surface of the first recording layer.

Abstract: Provided is a process for making a magnetic recording medium having a magnetically partitioned magnetic recording patterns, which comprises the following three steps (1), (2) and (3), conducted in this order: (1) a step of forming a magnetic layer on a non-magnetic substrate; (2) a step of removing surface layer portions of regions for magnetically partitioning the magnetic layer; and (3) a step of exposing the thus-exposed regions of the magnetic layer, from which the surface layer portions have been removed, to a reactive plasma or a reactive ion, to modify the magnetic characteristics of the regions of magnetic layer, whereby a magnetic recording pattern is formed which are magnetically partitioned by the regions of magnetic layer having the modified characteristics. Thus, a magnetic recording medium having an enhanced recording density and minimizing letter bleeding at writing can be made with a high efficiency.

Abstract: A magnetic head position control method is provided to control a magnetic head to follow the track on a DTM (discrete-track magnetic) disk by accurately detecting the eccentricity compensation amount through a simple process. An angle detection unit detects ?1 at which the relative displacement between the magnetic head and the tracks on the DTM (discrete-track magnetic) disk has a peak with no vibration data added. A vibration data calculation unit calculates first vibration data with first vibration amplitude, so that the displacement has a peak at ?2 displaced from ?1 by a predetermined value. The angle detection unit detects ?3 at which the relative displacement has a peak with the first vibration data added. A compensation data calculation unit calculates compensation data for the eccentricity of the tracks, from the detected angles ?1, ?3, the first vibration amplitude, and ?2. The position of the magnetic head is compensated according to the correction data.

Abstract: According to one embodiment, a disk drive includes a detection signal producing module configured to produce a detection signal by reading each of the spiral servo patterns, the spiral servo patterns being read by a head while the head scans a circumferential direction region on the disk media. A position error computation module is configured to produce servo burst signals A, B, C, and D using a plurality of frames obtained by dividing the detection signal at even time intervals, at least one burst signal of the servo burst signals being produced using at least two frames in the frames, and to compute a position error of the head based on amplitude values of the produced burst signals.

Abstract: A magnetic disk device has a magnetic recording medium in which one servo track and an array of at least one data track are formed alternately. A head portion includes a set of reading heads arranged in a radius direction of the magnetic recording medium for reading signals from the magnetic recording medium, and a controller controls a position of the head portion based on servo signals read from the servo tracks by the reading heads disposed at opposite ends of the set of reading heads.

Abstract: A synchronization system includes a signal generating module that generates a signal comprising modulated waveforms and a timing window generator that generates a timing window. A proportional integral controller (a) divides the timing window into a first half window and a second half window, (b) demodulates the digital signal in the first half window and the second half window, (c) compares an amplitude of demodulated signal in the first half window to an amplitude of demodulated signal in the second half window, (d) calculates a new location for the timing window, and (e) repeats (b), (c), and (d) until the amplitude in the first half window equals the amplitude in the second half window.

Abstract: Offtrack amounts corresponding to every servo in which data writing has been completed is stored in a storage unit. Offtrack amount corresponding to a next servo frame, which is a servo frame present next to a servo frame for which data has been written, is calculated from the offtrack amounts stored in the storage unit. Based on the offtrack amount of the next servo frame, it is decided whether data needs to be rewritten in a sector present before the next servo frame.

Abstract: Various embodiments of the present invention are generally directed to processing servo data on a storage surface by detecting a time difference between consecutive read signal envelopes from spiral servo information on the surface.

Abstract: Offtrack amounts corresponding to every servo in which data writing has been completed is stored in a storage unit. Offtrack amount corresponding to a next servo frame, which is a servo frame present next to a servo frame for which data has been written, is calculated from the offtrack amounts stored in the storage unit. Based on the offtrack amount of the next servo frame, it is decided whether data needs to be rewritten in a sector present before the next servo frame.

Abstract: A magnetic recording medium having a magnetic layer containing magnetic powder provided on a support is disclosed. The magnetic layer possesses a servo band in which a servo signal for controlling tracking of a magnetic head, and a data band on which a data is recorded. The servo signal is magnetized and recorded on the servo band, having been magnetized in one direction of the track direction thereof, in the direction other than the one direction. The thickness of the magnetic layer ranging from 10 to 180 ?m, and variation [standard deviation of Mrt] of the product [Mrt] of the residual magnetism by the thickness of the magnetic field being not more than 30%.

Abstract: The present invention is directed to a method and apparatus for dynamic placement of an integration window in a disk drive having a disk surface with spiral servo information written thereon. A read head is provided for reading the spiral servo information and generating a read signal envelope. A repetitive spiral position error, associated with one spiral of the spiral servo information, is measured. Placement of an integration window is dynamically adjusted based upon the measured repetitive spiral position error, so that a read signal envelope read by the read head appears more towards the center of the integration window than if the placement of the integration window was not dynamically adjusted. By adjusting the placement of the integration window, dynamic range is increased without increasing the size of the integration window.

Abstract: The present invention is directed to a method and apparatus for providing multi-point position demodulation of a read head when using spiral-written servo information. In one embodiment, a disk surface has spiral servo information written thereon. A read head generates a read signal envelope when reading the spiral servo information. A read signal envelope is detected within an integration window and integration values are accumulated over the integration window. The accumulated integration values are multiplied by a first number associated with a first integrator value and a second number associated with a second integrator value. A first position error signal associated with the first integrator value is determined, and a second position error signal associated with the second integrator value is also determined. A final position error signal is determined using the first position error signal and the second position error signal.

Abstract: A storage device in which file data is divided into multiple blocks for storage on a recording medium. The storage device includes an additional data storing section for storing additional data to be recorded on the recording medium in association with the data to be written, a position determining section for determining recording positions on the recording medium where the blocks should be respectively written, based on the additional data, and a block writing section for writing the respective blocks on the recording positions on the recording medium determined by the recording position determining section. The additional data thus defines a gap length between blocks of recorded data. During a read operation, if the gap length does not comport with the additional data, then an error is assumed.

Abstract: The present invention is directed to method and apparatus for determining a transducer's reference position in a disk drive having a disk surface with spiral servo information written thereon. The transducer comprises a read head for reading spiral servo information and a read signal envelope is generated when the read head reads the spiral servo information. An integration is performed over a first integration window, wherein the first integration window includes a read signal envelope. A reference position is determined for the read head using a second integration window (virtual integration window) that is included within, and smaller than, the first integration window. In one embodiment, the integration may be performed on a frame-by-frame basis. A determination may be made of the frame in the first integration window that includes a maximum sync amplitude. The second integration window may be centered using the frame that includes the maximum sync amplitude.

Abstract: A method for computing position error signal information of a transducer in a data storage system provides for different readback signals between adjacent tracks. The method involves a computation to obtain coarse position information from the servo bursts signals for track seeking and a computation to obtain a position indicator from the user data sector for more precise track following within the user data sector.

Abstract: A method and system for rewriting data on a tape when an error occurs during an initial write operation. When the initial write error occurs, the data is rewritten at a location that is a pre-defined block gap distance from the last valid write location on the tape. By measuring the length of the pre-defined block gap distance, the cause or causes of the write error or errors are known. Thus, the pre-defined block gap not only ensures that the data is not re-written in a no-write zone of the tape, due to the zone known to be error prone, but a historical record of past write errors is logged based on the length of the block gaps.

Abstract: A disk drive having a marker for identifying the transition between the first and last written servo wedges on a servo track. The marker indicates the likely position where closure error may occur during the operation of the hard disk drive. The marker is used by the control system of a hard disk drive to provide appropriate position control signals to the transducer assembly to maintain the proper positioning of the transducer about the disk surface. A method for forming the marker on a disk surface is further disclosed.

Abstract: A magnetic recording medium has a substrate, and a servo signal recording magnetic layer whose magnetization is oriented in a direction perpendicular to a surface thereof, a non-magnetic layer and a data recording magnetic layer, which are stacked on the substrate in the order mentioned. The servo signal recording magnetic layer has a coercivity higher than that of the data recording magnetic layer. The servo signal recording magnetic layer has servo tracks formed with a track pitch Tps, the servo tracks adjacent to each other in a track width direction being magnetized to opposite directions perpendicular to the film surface.

Abstract: The invention eliminates relative and absolute track shape errors by writing zero acceleration path (ZAP) correction factors into the servo sectors during track propagation. A servo track guide zone is written to the disc. ZAP correction factors are written to the guide zone and self-propagating servo writing commences. The ZAP correction factors are determined in only two disc revolutions per track. The read element follows track k, a previously written track, and the write element writes servo marks for track k+1 during a write revolution. The position signal is monitored and recorded in order to estimate the shape of track k+1 according to the inverse transformation method during a correction revolution.

Abstract: A servo-demodulator for a pair of alternating signals generated by a magnetic disc read head and indicative of the position of the read head in relation to the center of a recorded track. The servo-demodulator comprises a peak detector for successively and individually sampling the amplitude of each of a plurality of peaks of the pair of alternating signals, and a capacitor periodically connected to the output of the peak detector by a control logic for deriving a weighted average of the various successively sampled amplitudes. In this manner, the control logic obtains an averaged measure of amplitude with high immunity to noise.