Abstract:
An apparatus for operating a tape storage device comprises a tape skew estimation unit 4 for estimating a value related to a skew of a tape storage medium arranged in the tape storage device relative to a head module of the tape storage device. A servo pattern decoder 3 is configured to decode information encoded in a servo pattern written to one or more servo bands of the tape storage medium. The decoding is based on read-back signals RB1, RB2 of at least two servo readers of the tape storage device arranged for reading the servo pattern from the one or more servo bands and based on the estimated skew related value. The information can include longitudinal position (LPOS). The skew related value may be in the form of a time offset and the servo pattern decoder may include delay units 311, 312 for delaying a read back signal determined to be ahead in time before combining the read back signals. The read back signals may be weighted by a signal quality index (SDR).
Abstract:
Ein veränderliches Zeitintervall wird von einem zeitabhängigen Servoband erfasst, um die seitliche Position eines Servolesekopfs zu ermitteln. Das Servoband ist in einer Folge von Blöcken mit nichtparallelen Servostreifen in sequenziell angrenzenden Unterrahmen eines linearen Magnetbands angeordnet. Die Zeitintervalle umfassen mindestens ein erstes Zeitintervall (A) zwischen einem ersten Paar nichtparalleler Servostreifen eines Unterrahmens; und ein veränderliches Zeitintervall (C) zwischen einem Paar nichtparalleler Servostreifen zwischen den ersten Zeitintervallen (A), wobei die Servostreifen des veränderlichen Intervalls der sequenziell angrenzenden Unterrahmen einen zweiten Servostreifen des ersten Paars und einen ersten Servostreifen eines sequenziell nachfolgenden ersten Paars umfassen. Bei Positionssignalen handelt es sich um Verhältnisse, an denen das erste und das zweite Zeitintervall beteiligt sind.
Abstract:
PROBLEM TO BE SOLVED: To provide a compensator for synchronous sampling time-based servo system. SOLUTION: This method operates a tape drive, which has a basic tape speed for moving a magnetic tape along with a tape head, and which generates a first tape head position signal from the tape head at a first sample frequency proportional to the basic tape speed. Further, the method comprises the steps of: processing the first tape head position signal synchronized with the first sample frequency and controlling the tape head position using a control system including a compensator having a maximum phase response in a first cross over frequency; giving an interrupt signal synchronized with the first sample frequency to a processing system; and the processing system giving an output value h (k) which generates the maximum phase response at the first cross over frequency responsive to the processing system receiving the interruption signal. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide selected and different superimpose data information to identify a separated servo band for addressablility in which the separated servo band is independent in a magnetic tape having a vertical direction servo band in which servo information provided with superimpose data information is separated. SOLUTION: Servo information has transition extended in the horizontal direction not parallel to indicate the positioning of a horizontal direction, The selected different superimpose data information can have a lack of a part of the servo band. When the superimpose data information is the position information of a vertical direction, The selected different superimpose data information can have position information in which one or a plurality of servo bands are different. The selected different superimpose data information can have a band identifier in the superimpose data information of one or the plurality of servo bands. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To effectively and precisely identify the serve gap by dividing a detected group timing gap by a specified divisor, feeding a timing interval gap detection threshold, and measuring the timing intervals between detected transition stripes. SOLUTION: A divider 170 divides a detected group B timing interval by a specified divisor to output a divided timing interval gap detection threshold. The divisor is selected by a divisor selector 174 to generate longer thresholds than the timing interval between transition stripes of burst one by one, and this involves values for generating shorter thresholds than the timing intervals of a min. interval gap at the edge of a servo pattern. A servo gap output value of a comparator 110 is fed back to an interval counter 120, and the count is fixed to latch the detection. When a pulse detector 122 detects the next stripe transition, the interval counter is reset to zero again.
Abstract:
An alternative time interval is taken of a timing based servo band to determine lateral position of a servo read head. The servo band is arranged in a sequence bursts with non- parallel servo stripes in sequentially adjacent sub-frames of a linear tape. The timing intervals comprise at least a first time interval (A) between a first pair of non-parallel servo stripes of a sub-frame; and an alternative time interval (C) between a pair of non-parallel servo stripes intermediate the first time intervals (A), the alternative interval servo stripes of sequentially adjacent sub-frames comprising a second servo stripe of the first pair, and a first servo stripe of a sequentially succeeding first pair. Position signals are ratios involving the first and second time intervals.
Abstract:
Where a tape is subject to lateral shift excursions from one side of a head to another, a coarse actuator is positioned laterally to enable a fine actuator to follow lateral motion of a longitudinal tape having at least one longitudinal defined servo track. A position error signal loop is configured to sense servo sensor(s) and to determine position error between the head and a desired position related to the defined servo track(s). A servo control senses the lateral shift excursion of the defined servo track(s); determines a maximum positive peak and a maximum negative peak of the lateral shift excursion; and positions the coarse actuator substantially at a midpoint of the maximum positive peak and the maximum negative peak of lateral shift excursion of the defined servo track(s). Thus, the fine actuator follows the lateral shift excursion, while the coarse actuator remains at the midpoint.
Abstract:
Servoerkennungssystem zum Erkennen von Servospuren eines Längsbands. In einem Lese-/Schreibkopf sind zwei Servoleseköpfe in einem seitlichen Abstand auf einem ersten Kopfmodul angeordnet, und ein Servolesekopf ist auf einem zweiten Kopfmodul in einem Längsabstand von dem ersten Modul angeordnet. Ein Verfahren umfasst anfangs das Erkennen einer Bandservospur mit einem Servolesekopf eines ersten Moduls und dem Servolesekopf des zweiten Moduls zum Ermitteln der Schräglauf-Fehlausrichtung der Servospur. Ein der Schräglauf-Fehlausrichtung entsprechender Nullbezugswert wird gespeichert. Das Erkennungssystem schaltet von dem einen Servolesekopf jedes Moduls auf die zwei Servoleseköpfe des ersten Moduls um und verwendet den gespeicherten Wert, um den Lese-/Schreibkopf in der Position mit Null-Schräglauf zu positionieren. Die zwei Servoleseköpfe werden dann verwendet, um zwei Servospuren zu lesen, um das Datenband zu identifizieren und den Schräglauf zu steuern.