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公开(公告)号:MY124046A
公开(公告)日:2006-06-30
申请号:MYPI20002027
申请日:2000-05-10
Applicant: IBM
Inventor: NHAN XUAN BUI , GLEN ALAN JAQUETTE , KAZUHIRO TSURUTA , JOHN ALEXANDER KOSKI
IPC: G11B27/28 , G11B27/32 , G11B15/087 , G11B27/10 , G11B27/36
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 (102) COUPLED TO THE SERVO SYSTEM CONTINUOUSLY READS LINEAR POSITION REGISTRATION DATA MODULATED INTO THE PRERECORDED SERVO PATTERN. AN INTERPOLATOR (106) INTERPOLATES THE PRERECORDED REGISTRATION DATA TO PROVIDE PRECISION REGISTRATION INFORMATION FOR THE DATA SETS. UPON THE DRIVE (12) 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 (150) 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 (54) COUPLED TO THE COMPARATOR, RESPONSIVE TO THE COMPARISION MATCH INDICATION, SYNCHRONIZES THE READING AND/OR WRITING OF DATA SETS ON THE RECORDING MEDIA.(FIG 10)
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公开(公告)号:SG91275A1
公开(公告)日:2002-09-17
申请号:SG200002521
申请日:2000-05-09
Applicant: IBM
Inventor: NHAN XUAN BUI , JUNICHI FUKUDA , GLEN ALAN JAQUETTE , JOHN ALEXANDER KOSKI , KAZUHIRO TSURUTA
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:MY126603A
公开(公告)日:2006-10-31
申请号:MYPI20003412
申请日:2000-07-26
Applicant: IBM
Inventor: NHAN XUAN BUI , GLEN ALAN JAQUETTE , JUNICHI FUKUDA , KAZUHIRO TSURUTA , JOHN ALEXANDER KOSKI
Abstract: A DETECTOR AND METHOD FOR DETECTING DATA MODULATED INTO A TIMING BASED SERVO PATTERN PRERECORDED ON A MEDIA, COMPRISING SHIFTS OF PAIRS OF NON-PARALLEL TRANSITION STRIPES ARRANGED IN A FRAME TWO BURSTS. TIMING INTERVALS BETWEEN SEQUENTIAL TRANSITION STRIPES ARE DETECTED. INTERVAL COMPARISON LOGIC COMPARES SELECTED TIMING INTERVALS AND INDICATES WHETHER THE COMPARED INTERVALS REPRESENT A "0" OR A "1". FIRST AND SECOND COUNTERS RESPECTIVELY INCREMENT THE NUMBER OF THE COMPARED INTERVAL REPRESENTING A "0" AND REPRESENTING A "1" IN EACH FRAME. BIT COMPARISONLOGIC COMPARES, FOR EACH FRAME, THE INCREMENTED NUMBERS REPRESENTING A "0" AND A "1" TO A PREDETERMINED CRITERIA AND, UPON ONE OF THE NUMBER MEETING THE CRITERIA, IDENTIFIES THE CORRESPONDING "0" OR "1" AS THE BIT VALUE FOR THE FRAME. THE BITS ARE DATA COMPRISING LONGTUDINAL POSITION WORDS ARRANGED IN A LINEAR SEQUENCE. SEQUENCE LOGIC CALCULATES THE NEXT SEQUENTIAL POSITION WORD FROM AN IMMEDIATELY PRECEDING WORD AND DETERMINES WHETHER THE DETECTED WORD IS IN THE LINEAR SEQUENCE AS A VALIDITY CHECK, AND PROVIDED THE CALCULATED WORD AS THE OUTPUT.THUS, THE CORRECT POSITION WORD IS PROVIDED AT THE OUTPUT EVEN IF THE DETECTED WORD IS INVALID.FIGURE 6
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公开(公告)号:SG100716A1
公开(公告)日:2003-12-26
申请号:SG200103267
申请日:2001-06-01
Applicant: IBM
Inventor: NHAN XUAN BUI , JOHN ALEXANDER KOSKI , AKIMITSU SASAKI , KAZUHIRO TSURUTA
Abstract: A servo system and method position a head laterally with respect to defined servo tracks, employing fine and coarse actuators. A servo control integrates the position error between the head and a desired position in accordance with a predetermined function, and operates the coarse actuator to translate the fine actuator and the head in accordance with the integrated position error. A position error signal loop is coupled to a servo sensor for determining position error for operating the fine actuator to translate the head in a manner to reduce the position error. The position error signal loop may have a compensator function with both integration and other functions. A coarse servo control comprises a connection coupled to the compensator function for providing an integration control representing the integration function of the position error signal loop; and a driver coupled to the connection, operating the coarse actuator to translate the fine actuator and the head in accordance with the integration signal.
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公开(公告)号:MY134153A
公开(公告)日:2007-11-30
申请号:MYPI20013749
申请日:2001-08-09
Applicant: IBM
Inventor: KAZUHIRO TSURUTA , JOHN ALEXANDER KOSKI , AKIMITSU SASAKI , NAHN XUAN BUI
Abstract: A METHOD AND POSITION CONTROL FOR A SERVO SYSTEM FOR POSITIONING A HEAD LATERALLY WITH RESPECT TO DEFINED SERVO TRACKS. THE SERVO SYSTEM COMPRISES A SERVO SENSOR AND DETECTOR FOR SENSING LATERAL POSITION OF THE HEAD AND A COMPOUND ACTUATOR HAVING A FINE ACTUATOR PORTION AND A COARSE ACTUATOR PORTION. THE POSITION CONTROL PROVIDES POSITION INDICATIONS FOR THE COARSE ACTUATOR PORTION, WHICH MAY COMPRISE A TABLE RELATING PREDETERMINED NOMINAL LATERAL POSITION INDICATIONS TO THE DEFINED SERVO TRACKS. THE POSITION CONTROL POSITIONS THE COARSE ACTUATOR PORTION AT AN ESTIMATED POSITION WITH RESPECT TO THE DEFINED SERVO TRACKS, AND RESPONDS TO THE SERVO SENSOR TO DETERMINE WHICH SERVO TRACK IS CLOSEST TO THE ESTIMATED POSITION. THE POSITION CONTROL SETS THE COARSE ACTUATOR PORTION POSITION INDICATION TO THE PREDETERMINED NOMINAL LATERAL POSITION INDICATION OF THE CLOSEST DEFINED SERVO TRACK, E.G., BY LOOKING IT UP IN THE TABLE. THIS THEREBY CORRECTS THE INDICATION OF THE POSITION OF THE COARSE ACTUATOR PORTION.@@FIGURE 6 THE MOST ILLUSTRATIVE DRAWING.
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公开(公告)号:MY127261A
公开(公告)日:2006-11-30
申请号:MYPI20012652
申请日:2001-06-06
Applicant: IBM
Inventor: NHAN XUAN BUI , KAZUHIRO TSURUTA , JOHN ALEXANDER KOSKI , AKIMITSU SASAKI
Abstract: A SERVO SYSTEM (170) AND METHOD POSITION A HEAD LATERALLY WITH RESPECT TO DEFINED SERVO TRACKS, EMPLOYING FINE AND COARSE ACTUATORS (180, 182). A SERVO CONTROL INTEGRATES THE POSITION ERROR BETWEEN THE HEAD AND A DESIRED POSITION IN ACCORDANCE WITH A PREDETERMINED FUNCTION, AND OPERATES THE COARSE ACTUATOR TO TRANSLATE THE FINE ACTUATOR AND THE HEAD IN ACCORDANCE WITH THE INTEGRATED POSITION ERROR. A POSITION ERROR SIGNAL LOOP IS COUPLED TO A SERVO SENSOR (171) FOR DETERMINING POSITION ERROR FOR OPERATING THE FINE ACTUATOR TO TRANSLATE THE HEAD IN A MANNER TO REDUCE THE POSITION ERROR. THE POSITION ERROR SIGNAL LOOP MAY HAVE A COMPENSATOR FUNCTION (185) WITH BOTH INTEGRATION AND OTHER FUNCTIONS. A COARSE SERVO CONTROL COMPRISES A CONNECTION COUPLED TO THE COMPENSATOR FUNCTION FOR PROVIDING AN INTEGRATION CONTROL REPRESENTING THE INTEGRATION FUNCTION OF THE POSITION ERROR SIGNAL LOOP; AND A DRIVER (211) COUPLED TO THE CONNECTION, OPERATING THE COARSE ACTUATOR TO TRANSLATE THE FINE ACTUATOR AND THE HEAD IN ACCORDANCE WITH THE INTEGRATION SIGNAL. (FIG. 6)
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公开(公告)号:SG87184A1
公开(公告)日:2002-03-19
申请号:SG200005853
申请日:2000-10-12
Applicant: IBM
Inventor: JOHN ALEXANDER KOSKI , NHAN BUI
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:SG85717A1
公开(公告)日:2002-01-15
申请号:SG200004134
申请日:2000-07-24
Applicant: IBM
Inventor: NHAN XUAN BUI , JUNICHI FUKUDA , GLEN ALAN JAQUETTE , JOHN ALEXANDER KOSKI , KAZUHIRO TSURUTA
Abstract: A detector and method for detecting data modulated into a timing based servo pattern prerecorded on a media, comprising shifts of pairs of non-parallel transition stripes arranged in a frame of two bursts. Timing intervals between sequential transition stripes are detected. Interval comparison logic compares selected timing intervals and indicates whether the compared intervals represent a "0", or a "1". First and second counters respectively increment the number of the compared intervals representing a "0" and representing a "1" in each frame. Bit comparison logic compares, for each frame, the incremented numbers representing a "0" and a "1" to a predetermined criteria and, upon one of the numbers meeting the criteria, identifies the corresponding "0" or "1" as the bit value for the frame. The bits are data comprising longitudinal position words arranged in a linear sequence. Sequence logic calculates the next sequential position word from an immediately preceding word and determines whether the detected word is in the linear sequence as a validity check, and provides the calculated word as the output. Thus, the correct position word is provided at the output even if the detected word is invalid.
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