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公开(公告)号：JP2001067847A
公开(公告)日：2001-03-16
申请号：JP2000215615
申请日：2000-07-17
Applicant: IBM
Inventor： BUI NHAN XUAN , FUKUDA JUNICHI , JAQUETTE GLEN ALAN , KOSKI JOHN ALEXANDER , TSURUTA KAZUHIRO
Abstract: PROBLEM TO BE SOLVED: To obtain a data detection method and a data detection apparatus for performing robust detection of data modulated into a servo pattern of a timing base. SOLUTION: First, a timing interval between sequential change stripes is detected, and then, an interval comparison logic circuit 112 determines whether '0' or '1' is represented. Thereafter, a first counter 106 increments the number of the compared intervals that represent '0', while a second counter 107 increments the number of the compared intervals that represent '1'. Then, a bit comparison logic circuit 123 compares the incremented number with a predefined reference value 122 for every frame. When either one is fitted to the reference value 122, the corresponding '0' or '1' is identified as a bit value for the frame.
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公开(公告)号：JP2001006140A
公开(公告)日：2001-01-12
申请号：JP2000139485
申请日：2000-05-12
Applicant: IBM
Inventor： BUI NHAN XUAN , FUKUDA JUNICHI , JAQUETTE GLEN ALAN , KOSKI JOHN ALEXANDER , TSURUTA KAZUHIRO
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.
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公开(公告)号：JP2002015532A
公开(公告)日：2002-01-18
申请号：JP2001170742
申请日：2001-06-06
Applicant: IBM
Inventor： NAAN KUSAN BUI , KOSKI JOHN ALEXANDER , SASAKI AKIMITSU , TSURUTA KAZUHIRO
Abstract: PROBLEM TO BE SOLVED: To remove a relative position sensor, while enabling tracking of a micromotion actuator by a coarse motion actuator. SOLUTION: The servo system and the method position a head in the lateral direction to a prescribed servo track, by using the micromotion actuator and the coarse motion actuator. A servo control integrates a position error between the head and a desired position according to a prescribed function, operates the coarse motion actuator to move the micromotion actuator and the head in translational motion according to position errors integrated. The position error is determined by combining a position error signal loop with a servo sensor, the micromotion actuator is operate, so that the position error is reduced, and then the translational motion of the head is performed. The position error signal loop has a compensator function, having an integration function and other functions. The coarse motion servo control is combined with the compensator function and includes connection which provides the integration control indicating the integration function of the position error signal loop, and a driver which is combined with the connection and operates the coarse motion actuator to move micromotion actuator and the head in translational motion in accordance with an integrated signal.
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公开(公告)号：JP2001178171A
公开(公告)日：2001-06-29
申请号：JP2000325546
申请日：2000-10-25
Applicant: IBM
Inventor： KOSKI JOHN ALEXANDER , BUI NHAN
Abstract: PROBLEM TO BE SOLVED: To provide a current-mode pulse-width modulation(PWM) technique for a brusless motor. SOLUTION: This brushless motor is controlled by increasing or decreasing the speed of the motor according to the polarity and the value of a pulse-width modulation control signal. With a motor current sensor, an actual motor current is detected. By using a current comparator, a desired reference current signal is compared with an actual current signal, and an error signal is generated. By using a pulse-width modulator, the error signal is converted into a pulse- width modulation error signal. By using an armature position sensor, the position of the armature of the motor is detected. On the basis of the pulse-width modulation error signal, a power switch is controlled, and the motor is controlled by a desired motor current corresponding to the desired reference current signal. When the error signal has a positive value, a negative value or a value of 0, a commutator drives the motor to either a positive position or a negative position or in the same way, so that the speed of the motor is increased, decreased or maintained.
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公开(公告)号：CZ297495B6
公开(公告)日：2007-01-03
申请号：CZ20014146
申请日：2000-05-18
Applicant: IBM
Inventor： BUI NHAN XUAN , JAQUETTE GLEN ALAN , KOSKI JOHN ALEXANDER , TSURUTA KAZUBIRO
Abstract: Systém a způsob je určen pro přesnou registraci a synchronizaci datových skupin na záznamovémédium, které má předem zaznamenaný servo vzorek. Záznamové médium je podrobeno souvislémupohybu pro čtení a/nebo zápis datových skupin, přerušenému zastavením na konci zvolené datové sady a nově spuštěnému. Během souvislého pohybu záznamového média detektor připojenýk servo systému souvisle čte registrační datas lineární pozicí modulovaná do předem zaznamenaného servo vzorku. Interpolátor interpoluje předem zaznamenaná registrační data k zajištění přesných registračních informací pro datové skupiny. Poté co pohon zastaví záznamové médium, pak provede jednorázový posun zpět média a obnoví pohyb, jsou zajištěny zvolené přečtené a interpolované registrační informace.Detektor znovu přečte a interpoluje předem zaznamenaná registrační data a komparátor porovná znovu přečtené a interpolované registračníinformace se zajištěnými přečtenými a interpolovanými registračními informacemi a libovolný předem stanovený ofset, a indukuje shodu porovnání. Datový formátovač (54) připojený ke komparátoru (150), reagující na indikaci shody porovnání, synchronizuje čtení a/nebo zápis datových skupin na záznamové médium (70).
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Patent Agency Ranking
公开(公告)号：AT375029T
公开(公告)日：2007-10-15
申请号：AT00309568
申请日：2000-10-30
Applicant: IBM
Inventor： KOSKI JOHN ALEXANDER , BUI NHAN
Abstract: A current mode pulse width modulation (PWM) technique for brushless motors. The present system and method controls a brushless motor by increasing or decreasing motor speed respectively according to the polarity and value of a pulse width modulation (PWM) control signal. The PWM signal varies according to an error signal generated in proportion to the difference between a desired motor current and an actual motor current. A motor current sensor is used to sense an actual motor current being applied to the motor. A current comparator is used to compare the current desired reference signal and the actual current signal and to generate an error signal. A pulse width modulator is used to convert the error signal to a pulse-width modulated error signal. Armature position sensors are used for sensing armature positions of the motor. A commutator circuit receives the pulse-width modulated error signal and the armature positions of the motor. Power switches are coupled to outputs of the commutator and also coupled to the motor. The commutator controls activation and deactivation of the respective power switches based on the corresponding pulse-width modulated error signal to control the motor at a desired motor current that corresponds to the desired reference current signal. The commutator controls the respective power switches to drive the motor in either a more positive, a more negative direction, or in the same manner to respectively increase, decrease, or maintain the motor speed when the error signal correspondingly has a generally positive, negative, or zero value.
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公开(公告)号：AU6930201A
公开(公告)日：2002-02-25
申请号：AU6930201
申请日：2001-07-06
Applicant: IBM
Inventor： KOSKI JOHN ALEXANDER , SASAKI AKIMITSU , TSURUTA KAZUHIRO
IPC: G11B5/584
Abstract: A servo system and method position a head laterally with respect to magnetic tape longitudinal defined servo bands arranged in a longitudinally shifted pattern for identification, and separated by data tracks. A servo controller responds to a loss of lateral position, sensing an estimated longitudinal position of the magnetic tape. If the estimated longitudinal position is within a predetermined distance of an end of the tape, the servo controller operates a drive to continuously move the tape away from the sensed end. The servo controller senses a home lateral position sensor to determine whether a compound actuator is within a predetermined distance of the edge of the magnetic tape. If so, it operates the coarse actuator portion of the compound actuator to move laterally away from the edge of the magnetic tape; else, to move toward the edge. The servo controller senses a dual servo sensor to detect any two of the defined servo bands; and, upon sensing any two of the defined servo bands, detects the longitudinal shift to identify which ones of the two defined servo bands have been detected.
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公开(公告)号：AT516582T
公开(公告)日：2011-07-15
申请号：AT00303870
申请日：2000-05-09
Applicant: IBM
Inventor： BUI NHAN XUAN , FUKUDA JUNICHI , JAQUETTE GLEN ALAN , KOSKI JOHN ALEXANDER , TSURUTA KAZUHIRO
Abstract: Disclosed are a method and a detector for adaptively detecting servo gaps in a timing based servo pattern (50) prerecorded on a variable velocity media. The timing based servo pattern has groups of repeated pairs of non-parallel transition stripes arranged in bursts (52,54,55), the bursts separated by servo gaps whose (70-75) length is variable. A servo system sensor (26) senses the transition stripes in the longitudinal direction of the media. A group interval detector coupled to the sensor detects the timing interval between the same slope transition stripes of two sequential groups of bursts (BX,BY). A divider (170) divides the detected group timing interval by a predetermined divisor to provide a divided timing interval gap detection threshold (181). A sequential stripe interval detector coupled to the sensor measures the timing interval between stripes, and a comparator (110) compares the divided timing interval and the timing interval, identifying a servo gap upon the measured timing interval at least equaling the gap threshold. The detector responds to "valid" signals (BXOK,BYOK) which indicate the validity of the detected group timing interval, repeating operation of the divider to update the gap threshold, and repeating operation of the comparator with the updated gap threshold to continue to identify the servo gaps.
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公开(公告)号：MY119237A
公开(公告)日：2005-04-30
申请号：MYPI20013743
申请日：2001-08-09
Applicant: IBM
Inventor： BUI NHAN XUAN , KOSKI JOHN ALEXANDER , SASAKI AKIMITSU , TSURUTA KAZUHIRO
IPC: G11B5/584
Abstract: A SERVO SYSTEM AND METHOD POSITION A HEAD LATERALLY WITH RESPECT TO MAGNETIC TAPE LONGITUDINAL DEFINED SERVO BANDS ARRANGED IN A LONGITUDINALLY SHIFTED FOR IDENTIFICATION, AND SEPARATED BY DATA TRACKS. A SERVO CONTROLLER RESPONDS TO A LOSS OF LATERAL POSITION, SENSING AN ESTIMATED LONGITUDINAL POSITION OF THE MAGNETIC TAPE. IF THE ESTIMATED LONGITUDINAL POSITION IS WITHIN A PREDETERMINED DISTANCE OF AN END OF THE TAPE, THE SERVO CONTROLLER OPERATES A DRIVE TO CONTINUOUSLY MOVE THE TAPE AWAY FROM THE SENSED END. THE SERVO CONTROLLER SENSES A HOME LATERAL POSITION SENSOR TO DETERMINE WHETHER A COMPOUND ACTUATOR IS WITHIN A PREDETERMINED DISTANCE OF THE EDGE OF THE MAGNETIC TAPE. IF SO, IT OPERATES THE COARSE ACTUATOR PORTION OF THE COMPOUND ACTUATOR TO MOVE LATERALLY AWAY FROM THE EDGE OF THE MAGNETIC TAPE; ELSE, TO MOVE TOWAED THE EDGE. THE SERVO CONTROLLER SENSES A DUAL SERVO SENSOR TO DETECT ANY TWO OF THE DEFINED SERVO BANDS; AND, UPON SENSING ANY TWO OF THE DEFINED SERVO BANDS, DETECTS THE LONGITUDINAL SHIFT TO IDENTIFY WHICH ONES OF THE TWO DEFINED SERVO BANDS, DETECT THE LONGITUDINAL SHIFT TO IDENTIFY WHICH ONES OF THE TWO DEFINED SERVO BANDS HAVE BEEN DETECTED. @FIG. 4
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公开(公告)号：AT245847T
公开(公告)日：2003-08-15
申请号：AT00927599
申请日：2000-05-18
Applicant: IBM
Inventor： BUI NHAN XUAN , JAQUETTE GLEN ALAN , KOSKI JOHN ALEXANDER , TSURUTA KAZUHIRO
IPC: G11B27/28 , G11B27/10 , G11B27/32 , G11B27/36 , G11B15/087
Abstract: A system and method for precisely registering and synchronizing data sets on a recording media having a prerecorded servo pattern. The recording media is subject to continuing movement for reading and/or writing the data sets, interrupted by stopping at the end of a selected data set and restarting. During the continuing movement of the recording media, a detector coupled to the servo system continuously reads linear position registration data modulated into the prerecorded servo pattern. An interpolator interpolates the prerecorded registration data to provide precision registration information for the data sets. Upon the drive stopping the recording media, then back hitching the media and the movement restarting, selected read and interpolated registration information is provided. The detector again reads and interpolates the prerecorded registration data, and a comparator compares the again read and interpolated registration information to the provided read and interpolated registration information and any predetermined offset, and indicates a comparison match. A data formatter coupled to the comparator, responsive to the comparison match indication, synchronizes the reading and/or writing of data sets on the recording media.
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