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公开(公告)号：CA2765148C
公开(公告)日：2017-09-19
申请号：CA2765148
申请日：2010-06-02
Applicant: IBM
Inventor： JELITTO JENS , CHERUBINI GIOVANNI , HUTCHINS ROBERT ALLEN , SANDBERG MELANIE JEAN
IPC: G11B5/584
Abstract: A method for monitoring a plurality of servo channels, providing a finite state machine ("FSM") comprising a single servo channel mode and a combined servo channel mode, and moving a sequential information storage medium comprising a plurality of servo bands across a read/write head comprising a corresponding plurality of servo sensors. The method further asserts an acquisition flag by a servo channel if that servo channel is tracking a servo pattern, and asserts a bit flag by a servo channel if a new LPOS bit is decoded. If at least one acquisition flag is asserted, the method determines if a bit flag is asserted by a servo channel associated with said asserted acquisition flag, and if an acquisition flag and a bit flag are asserted by a servo channel, the method determines a relative positioning of each servo sensor with respect to an associated servo pattern.
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公开(公告)号：DE102012216591B4
公开(公告)日：2015-12-10
申请号：DE102012216591
申请日：2012-09-18
Applicant: IBM
Inventor： CHERUBINI GIOVANNI , JELITTO JENS , HUTCHINS ROBERT A
Abstract: Bandlaufwerksystem (400), aufweisend: einen Magnetkopf (320) mit wenigstens einem Servosensor (308) zum Erkennen wenigstens einer festgelegten Servospur eines Magnetbandes (108, 422), wobei der Servosensor (702) so konfiguriert ist, dass er eine Vielzahl von Servoimpulsen von einem oder mehreren Servobursts (304) der Servospur lesen kann, während sich das Magnetband an dem Magnetkopf vorbeibewegt, wobei der eine oder die mehreren Servobursts wenigstens ein codiertes Datensymbol darstellen; einen Analog-Digital-Umsetzer (704), der so konfiguriert ist, dass er eine Sequenz an Mustern des Readback-Servosignals bereitstellt; einen digitalen Korrelator (708), der so konfiguriert ist, dass er ein Korrelationssignal zwischen der Sequenz und einer Referenzwellenform berechnen kann; ein Taktungs-Referenzmodul (714), dass so konfiguriert ist, dass es dem digitalen Korrelator ein Referenz-Taktungsmodell bereitstellt, das einen oder mehrere Interpolationszeitpunkte aufweist, wobei das Korrelationssignal, das zu jedem Interpolationszeitpunkt bestimmt wird, eine Erfassungsmessgröße für ein Datensymbol liefert; ein Korrelations-Interpolator (710), der so konfiguriert ist, dass er das Korrelationssignal zu den Interpolationszeitpunkten interpoliert und eine Längspositions-(LPOS)Erfassungsmessgröße gemäß den interpolierten Korrelationssignalsamples berechnet; und einen LPOS-(Längspositions-)Detektor (712), der so konfiguriert ist, dass er das codierte Datensymbol des einen oder der mehreren Servobursts unter Verwendung der berechneten LPOS-Erfassungsmessgröße decodiert und eine Zuverlässigkeit des decodierten Datensymbols des einen oder mehreren Servobursts schätzt, dadurch gekennzeichnet, dass das Bandlaufwerksystem des Weiteren einen Servosignal-Interpolator (706) aufweist, der so konfiguriert ist, dass er eine Sequenz an interpolierten Samples von der Sequenz bereitstellt, wobei der digitale Korrelator so konfiguriert ist, dass er ein Korrelationssignal zwischen der Sequenz an interpolierten Samples und der Referenzwellenform berechnet.
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公开(公告)号：GB2518678A
公开(公告)日：2015-04-01
申请号：GB201317262
申请日：2013-09-30
Applicant: IBM
Inventor： CHERUBINI GIOVANNI , FURRER SIMEON , JELITTO JENS , LANTZ MARK ALFRED
Abstract: A tape storage system simultaneously receives readback signals from a set of data readers DRi reading from data tracks DT1-14 of a set of adjacent data tracks extending along a longitudinal extension x of a tape. Each data track has a width wDT and each data reader has a width wDR that exceeds the width of a data track. In the readback signal of one of the data readers a simultaneous presence of two waveforms is detected stemming from two different servo patterns SP1, SP2 arranged in servo sections of adjacent data tracks. Lateral position, velocity, gain or timing information is derived from a measure of the energy of the two waveforms detected in the readback signal of the one data reader and another of the data readers and is used in the operation of the tape storage system. The servo patterns can have at least two different servo patterns, the servo sections of adjacent data tracks being longitudinally offset and partly overlapping.
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公开(公告)号：GB2514555A
公开(公告)日：2014-12-03
申请号：GB201309484
申请日：2013-05-28
Applicant: IBM
Inventor： CIDECIYAN ROY DARON , JELITTO JENS , SARAFIJANOVIC SLAVISA , STANEK JAN
Abstract: Data objects, to be stored on a storage medium, are divided into data segments or chunks. A hash of each data segment is generated. The hash tag and the physical location at which the segment is to be stored on the medium are stored in an index. When a new data segment is processed, its hash is used to determine whether an identical segment is already stored on the medium. If so, the new data segment is not stored. Otherwise, the new data segment is stored in a location, which is physically close to other data segments in the same data object. Consecutive segments of a data object may be stored in a single extent on the medium. The data object may be a file. The storage medium may be a sequential access medium, such as a magnetic tape.
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公开(公告)号：GB2508387A
公开(公告)日：2014-06-04
申请号：GB201221553
申请日：2012-11-30
Applicant: IBM
Inventor： CHERUBINI GIOVANNI , ENGELEN JOHAN B C , FURRER SIMEON , JELITTO JENS , LANTZ MARK ALFRED , ROTHUIZEN HUGO E
Abstract: A write head is provided for writing a servo pattern to a magnetic tape storage medium. The write head comprises at least a first write gap A and a second write gap B, the gaps being separately energizable. The second write gap comprises at least a first section a and a second section b. Energization of the second write gap causes a magnetic flux across the first section insufficient for changing a magnetization of a track and the second section 10 is designed such that energization causes a magnetic flux across the second section sufficient for magnetizing a track of the magnetic tape storage medium TP. The gaps may be inclined or perpendicular to a motion direction of the tape. The head may have a third write gap separately energizable to the first and second gaps where the third gap also has first and second sections. A method of writing a servo band comprises moving a servo band across at least first and second write gaps.
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Patent Agency Ranking
公开(公告)号：CA2874225A1
公开(公告)日：2013-12-27
申请号：CA2874225
申请日：2013-06-18
Applicant: IBM
Inventor： PANTAZI ANGELIKI , BUI NHAN XUAN , JELITTO JENS
Abstract: A tape drive configured to accurately position a head actuator in the presence of physical disturbances is disclosed. The tape drive includes a track-follow controller to position a head actuator over data tracks on magnetic tape. The tape drive further includes a disturbance observer configured to estimate a vibration disturbance and output a compensation signal to assist the track- follow controller to accurately position the head actuator over the data tracks in the presence of vibration. When estimating the vibration disturbance, the disturbance observer takes into account vibration frequency characteristics, such as frequency characteristics derived from a vibration specification associated with the tape drive, or frequency characteristics derived from known vibration disturbances experienced by the tape drive. A corresponding method is also disclosed.
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公开(公告)号：CA2717616A1
公开(公告)日：2009-12-23
申请号：CA2717616
申请日：2009-06-09
Applicant: IBM
Inventor： CHERUBINI GIOVANNI , CIDECIYAN ROY D , ELEFTHERIOU EVANGELOS S , JELITTO JENS
IPC: G11B5/584
Abstract: Methods and apparatus are provided for detecting L-bit sync words occurring at N-bit intervals in PPM-encoded servo pattern read signals read from magnetic tape (3) in tape drives (1). A soft output detector (11) processes the PPM-encoded servo pattern read signal to produce a series of soft output samples corresponding to respective bits encoded in the servo pattern. A sync word detector (12) then produces block correlation values for respective positions of a sliding L-sample block in the soft output sample series. The block correlation values are produced by calculating, at each block position, bit correlation values indicating correlation between respective samples and corresponding bits of the sync word, and summing each bit correlation value minus a predetermined function of the corresponding sample value. The sync word detector (12) then detects a sync word at the block position with the maximum block correlation value in an (N+L-1)-sample sequence of the soft output sample series.
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公开(公告)号：CA2636848A1
公开(公告)日：2007-08-02
申请号：CA2636848
申请日：2007-01-10
Applicant: IBM
Inventor： HUTCHINS ROBERT , JELITTO JENS , CHERUBINI GIOVANNI , ELEFTHERIOU EVANGELOS
IPC: G11B5/584
Abstract: A fully synchronous longitudinal position (LPOS) detection system is provided for improving the reliability of servo channels in tape systems. The system is based on the interpolation of the servo channel output signal, which is sampled by an analog-to-digital converter (ADC) at a fixed sampling rate, using a clock at a nominal frequency, so that interpolated signal samples are obtained at a predetermined fixed rate, independent of tape velocity. This predetermined fixed rate is defined in terms of samples per unit of length, as opposed to samples per unit of time, which is the measure of the ADC sampling rate. The resolution with which the servo channel signal is obtained at the interpolator output is thus determined by the step interpolation distance.
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公开(公告)号：DE602004006537D1
公开(公告)日：2007-06-28
申请号：DE602004006537
申请日：2004-11-19
Applicant: IBM
Inventor： FURRER SIMEON , JELITTO JENS , SCHOTT WOLFGANG , WEISS BEAT
Abstract: The invention relates to a method for modulating sub-carrier symbols to an intermediate-frequency OFDM signal having even and odd samples, including following steps: transforming a number N of the sub-carrier symbols to pre-processed sub-carrier symbols; performing a complex inverse discrete Fourier transformation (IDFT) on the pre-processed sub-carrier symbols to generate complex output symbols; and transforming the complex output symbols to the intermediate-frequency OFDM signal, wherein the sub-carrier symbols are transformed so that the even and odd samples of the intermediate-frequency OFDM signal are given by real and imaginary parts of the complex output symbols.
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公开(公告)号：AT362683T
公开(公告)日：2007-06-15
申请号：AT04798923
申请日：2004-11-19
Applicant: IBM
Inventor： FURRER SIMEON , JELITTO JENS , SCHOTT WOLFGANG , WEISS BEAT
Abstract: The invention relates to a method for modulating sub-carrier symbols to an intermediate-frequency OFDM signal having even and odd samples, including following steps: transforming a number N of the sub-carrier symbols to pre-processed sub-carrier symbols; performing a complex inverse discrete Fourier transformation (IDFT) on the pre-processed sub-carrier symbols to generate complex output symbols; and transforming the complex output symbols to the intermediate-frequency OFDM signal, wherein the sub-carrier symbols are transformed so that the even and odd samples of the intermediate-frequency OFDM signal are given by real and imaginary parts of the complex output symbols.
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