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7385780 Online identification of secondary actuator transfer function via system decoupling in multiple-stage actuator servo systems in disk drives  
A hard disk drive that includes a voice coil motor and a micro-actuator. The micro-actuator is controlled by a servo that utilizes a micro-actuator controller and a corresponding micro-actuator...
7342740 In-situ compensation method of microactuator stroke sensitivity subject to temperature variation  
A hard disk drive that includes a voice coil motor and a micro-actuator. The micro-actuator is controlled by a servo that utilizes a micro-actuator calibration parameter. To compensate for...
7312945 Techniques for adjusting for actuator non-linearities in a data storage system  
The invention provides techniques for adjusting for actuator non-linearities in a data storage system. The invention is particularly useful for piezoelectric actuators, such as actuators that...
7283321 Disk drives and methods allowing for dual stage actuator adaptive seek control and microactuator gain calibration  
A disk drive includes a disk, a head, a coarse actuator, a microactuator, and a servo controller. The microactuator positions the head relative to the disk. The coarse actuator positions the...
7265936 Algorithm for DSA/microactuator total loop gain calibration  
A hard disk drive that includes a voice coil motor and a micro-actuator. The disk drive includes a servo with a voice coil motor loop, a micro-actuator loop and an overall loop. The servo is...
7250738 Nonlinear hysteresis control system  
A nonlinear hysteresis control system for controlling an actuator with nonlinear hysteresis effect is disclosed. An improved extended hysteresis effect profile further stores the displacement when...
7173790 Magnetic disk apparatus with dual stage actuator  
In one embodiment, a magnetic disk apparatus comprises a magnetic disk for recording information; a magnetic head that reads information from, or writes information to, the magnetic disk; an...
7164552 Method for self-servo writing a disk drive with dual-stage actuator  
A technique for setting the initial servo track pitch for a servo system of a hard disk drive (HDD) is based on using a secondary actuator, such as a microactuator or a milliactuator. The actuator...
7154702 Head actuator  
Disclosed herein is a head actuator for a head provided so as to accessible to a disk-shaped recording medium rotating above a base. The head actuator includes a main actuator driven so as to...
7145745 Multi-stage actuator disk drives, methods, and computer program products that compensate for repeatable runout based on estimated secondary actuator position  
Methods of compensating for repeatable runout in a disk drive are provided. The disk drive includes a data storage disk, a transducer adjacent to the disk, a primary actuator for positioning the...
7136257 Apparatus and method for maintaining stability in a disc drive servo loop  
An apparatus and method of maintaining stability in a servo loop of a disc drive is provided. A dither signal (a single frequency sine wave or a multi-frequency signal) is injected into the servo...
7126785 Multi-stage actuator disk drives, methods, and computer program products for seeking and then maintaining a transducer on track  
Disk drives, methods, and computer program products are provided for controlling seeking of a transducer that is adjacent to a rotatable data storage disk in a disk drive. The disk drive includes a...
7126780 Method, system, and article of manufacture for self-servowriting a disk  
A compound actuator self-servo writes a hard disk. The compound actuator moves to track n+1. A first head on the compound actuator track follows on track n. The other heads servo write on track...
7116510 Servo self-write disk drive with dual-stage actuator  
A hard disk drive (HDD) uses a technique for setting the initial servo track pitch for a servo system by using a secondary actuator, such as a microactuator or a milliactuator. The actuator of the...
7106552 Method for secondary-actuator failure detection and recovery in a dual-stage actuator disk drive  
A method for secondary-actuator failure-detection and recovery in a dual-stage actuator disk drive includes running a calibration test by the servo control processor and measuring the position of...
7075748 Disk drive with a dual-stage actuator and failure detection and recovery system for the secondary actuator  
A dual-stage actuator disk drive has calibration tracks located in a nondata band, and uses a secondary-actuator failure detection and calibration test run by the servo control processor. The...
7038886 Positioner for precisely moving an E-block of a disk drive  
A positioner ( 20 ) for a disk drive ( 10 ) that includes a magnet assembly ( 52 ), a conductor assembly ( 54 ), and a control system ( 22 ) is provided herein. The magnet assembly ( 52 ) includes...
7038877 Head positioning apparatus  
A head positioning apparatus capable of positioning a head at high speed and with high accuracy is provided. The head positioning apparatus includes a magnetic head, a head supporting mechanism, a...
7038876 Control system for a data storage device with constraint  
A control system for a data storage device including a constraint or weight to control stroke utilization and/or closed loop response of the control system. In particular, in one embodiment...
7035041 Displacement resetting systems and methods for the second stage of a hard disk drive dual-stage actuator  
A control system and method for a disk drive comprising first and second actuator arms. The control system comprises first and second stages and a reset system. The first stage displaces the first...
7031099 Head positioner and information recording/replaying apparatus  
A head positioner has a configuration employing a dual-stage actuator method, wherein positioning control is performed for a write/read according to cooperative operations of a coarse actuator and...
7019938 Head positioning method, and disk apparatus using the same  
A first estimator 13 estimates the position of a head based on a VCM driving signal u 1 and a voltage signal Va output from a VCM 6 to output a first head position estimation signal x 1est ....
7012780 Disk drive and methods that calibrate micro actuator positioning before seek operations  
A disk drive includes a data storage disk, a transducer, a micro actuator, a coarse actuator, and a controller. The micro actuator is configured to position the transducer relative to the disk over...
7009804 Method and apparatus for micro-actuator stroke sensitivity calibration in a hard disk drive  
A sinusoidal signal is added to the notch filtered micro-actuator control signal stimulating the micro-actuator. The voice coil control signal is notch filtered to remove the frequency component of...
7009799 Tiltable device, in particular hard disk actuator device, with roll and pitch angle active control  
In an actuator device for hard disks a suspension element carries a slider that is subject to undesired vibrations which give rise to rotations of the slider with respect to a nominal position. An...
6989949 Performance test method of head gimgal assembly with precise positioning actuator  
A method of testing a performance of the HGA has a step of writing information from the at least one thin-film magnetic head element onto a magnetic disk with driving the actuator for displacement...
6985327 Method and control scheme for compensating the coarse actuators undesired transients in dual stage control systems  
A compensation element ( 317 ) in a feedforward line in a dual stage control system for a data storage system compensates for the undesired transient motion of a first positioning element (i.e., a...
6977793 Magnetic recording disk drive with dual-stage actuator and control system with multiple controllers  
A disk drive with a dual-stage actuator has a servo control system with two controllers. One controller is a dual-stage controller that simultaneously generates a primary actuator control signal...
6975482 Settle control systems and methods for the second stage of a dual stage actuator  
An actuator control system and method for a hard disk drive comprising first and second actuators that support a head relative to a disk is disclosed. The actuator control system comprises a first...
6975481 Driver systems and methods for an actuator of a hard disk drive  
A displacement system for a hard disk drive comprising a driving circuit and first and second displacement elements. The driving circuit generates a driving signal from a source voltage level, a...
6975477 Micro actuator DC gain calibration scheme for HDD dual-stage actuator systems  
A servo system for displacing a head relative to a disk of a hard disk drive. The servo system comprises a dual-stage actuator, a calibration signal generator, and a calibration factor generator....
6972924 Disk drive attenuating excitation of arm vibration mode by simultaneously driving secondary actuator for non-active head  
A disk drive is disclosed employing a primary actuator for rotating an actuator arm about a pivot in coarse movements, and first and second secondary actuators coupled to the actuator arm for...
6934117 Technique to compensate for resonances and disturbances on primary actuator through use of a secondary actuator  
A control system for an actuator arm assembly of a hard disk drive reduces the Non-Repeatable Run-out (NRRO) caused from external sources exciting higher-frequency actuator arm assembly modes. The...
6922303 Reaction mass dual-stage actuator (DSA) and sensor  
A hard disk drive that has a reaction mass and a transducer that can be used to move and/or sense the acceleration of an actuator arm of the drive. The transducer is coupled to a disk controller...
6909571 Method and apparatus actively damping mechanical vibration and shock in head suspensions of a disk drive  
The invention includes a method of attenuating resonance frequency modes in head suspensions, which does not significantly increase the weight of the head suspension. The invention provides a way...
6888695 Information recording and reproducing apparatus having higher drive pulse frequency during seeking operation than during following operation  
An information recording and reproducing apparatus having a high track density, a high recording density in each of the tracks, and a short seeking time. In a seeking operation, a control circuit...
6883062 High-speed disk drive system  
A high-speed disk drive system that features significant performance improvements over previously available systems. By immediately fetching the data as soon as heads reach the destination...
6882494 Sensor system for disk device using floating head  
A sensor system for a disk device by using a floating head, comprising a head element that floats over a data recording area of a rotating disk so as to write data thereon or read data therefrom, a...
6873489 Method, system, and program for estimating coil resistance of a voice coil motor in a disk drive system  
Provided are a method, system, and program for estimating coil resistance of a voice coil motor for an actuator assembly in a disk drive system. An estimation is made of a calibration coil...
6833974 Head positioning device and disk drive using same  
Vibration detector receives as an input a relative displacement signal corresponding to a displacement distance of fine actuator, and extracts only a high frequency component. Fine actuator is...
6831807 Head positioner and disk drive using the same  
A head positioner comprises a degradation detecting unit for detecting degradation of a fine motion actuator based on current flowing through a piezo element constituting the fine motion actuator...
6829119 Disc drive microactuator with lateral position sensor  
A read/write head microactuator includes first and second insulating deposits that are flat, spaced apart by an air gap, and laterally movable responsive to a microactuator electrical drive...
6798610 Disk drive with self servo writing capability  
The present invention is directed to utilizing the capabilities of multi-stage actuators in disk drives to do self servo writing on the disk surfaces, thereby avoiding the use of a servo track...
6798609 Magnetic microactuator with capacitive position sensor  
A disc drive system includes a recording disc rotatable about an axis, a slider supporting a transducing head for transducing data with the disc, and a dual-stage actuation assembly supporting the...
6791786 Active damping of two-stage actuator system in a disc drive  
An actuator control system for a two-stage actuator system of a disc drive has a first, or primary, stage actuator consisting of a voice coil motor that positions the head relative to a disc and a...
6788490 Circuit for estimating the speed of an electromagnetic actuator  
A circuit estimates speed of an electromagnetic actuator associated with a reading head of a disk storage unit and a digital controller. The circuit includes first and second supply terminals and...
6785086 Transducer-level microactuator with dual-axis control  
A slider for carrying and finely adjusting both a radial position and a flying height of a transducing head with respect to a track of a rotatable disc includes a stator portion carried by a...
6778350 Feed forward control of voice coil motor induced microactuator disturbance  
A method is used for moving a transducing head between tracks of a disc in a dual-stage actuation assembly. The dual-stage actuation assembly has a main actuator for coarse positioning of the...
6765743 Micro-actuator transducer stack inertia cancellation control  
A micro-actuator of a head suspension either is wired in a reverse polarity to effect movement of the suspension arms in opposing directions relative to the magnetic disks or reversed in physical...
6751047 Stepped disc drive voice coil actuator acceleration for reducing resonance of head level micro-actuators  
A disc drive having a voice coil actuator with an attached suspension and head, the head including a micro-actuator. The micro-actuator having at least one natural frequency and at least one...
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