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6751045 Compensation for repeatable run-out error  
A method and apparatus for compensating for repeatable run-out errors in a disc drive is disclosed. The compensation is created by determining transfer function values for a servo loop in the drive...
6747835 Method and apparatus for simultaneously measuring and calculating servo-related data  
A method and apparatus for simultaneously measuring and calculating servo-related data is disclosed. The method involves measuring the servo related data for a first track of a disc drive and then...
6728061 Head position control method, control device for disk device and disk device  
The present invention relates to a head positioning method and device for positioning a head to read information from disk media at prescribed positions using a rotary actuator, in which...
6721247 Disk apparatus and track following control method  
A disk apparatus has a head, a positional signal detection section that detects a track of a medium, a feedback control section which computes a control signal for moving the head from the location...
6721120 Prediction and cancellation of cage frequency in a disc drive  
A method for writing servo information to a disc rotatably mounted to a spindle motor. A measured cage frequency is obtained from a written reference track, from which an actual cage frequency is...
6714719 Video recording system using magnetic disk drive  
A video recording/reproduction system is equipped with a magnetic disk drive, which records and reproduces video data on a magnetic disk by driving a magnetic head. Herein, the magnetic disk drive...
6714372 Method of manufacturing a disk drive by measuring the read width in the servo-writer to set the write unsafe limit  
A method of manufacturing a disk drive where the width of the read element is measured at servo-writing time in order to establish a write unsafe (WUS) limit corresponding to a maximum distance...
6710953 Method and disk drive for improving data storage capacity of data tracks using push-down wedges  
A disk drive implements a technique for improving data storage capacity of data tracks having a servo wedge defect. A servo-fault position threshold is established for aborting a write operation if...
6710957 Servo mark detection device and servo mark detection method  
Servo marks on a storage medium such as a magnetic disk can be detected without fail by correcting misalignments or dislocations of servo gates due to an eccentricity of the storage medium,...
6707635 Method and apparatus for RRO learning on alternate tracks before and after shipping to cancel RRO in a disk drive  
The present invention may be embodied in a method, and related apparatus, for determining a repeatable runout (RRO) compensation value sets for a plurality of tracks on a disk in a disk drive,...
6700731 In-situ linearization of magnetic read/write head transducer position error signal  
A method, apparatus, and computer program product for linearizing a position error signal of a transducer in a hard disk drive. In one embodiment, a disk including a first plurality of tracks each...
6700730 Method of using an integral parameter for correct placement of a read/write head  
To provide a disk drive, a manufacturing method thereof, and a disk-drive controller which are capable of improving yield without increasing costs so significantly. When track-following control is...
6687078 Disk drive for writing micro-jog values along the centerline of a reserved track and for writing user data offset from the centerline of a data track  
The present invention may be regarded as a disk drive comprising a disk having a plurality of data tracks and at least one reserved track. At least one of the data tracks for recording user data...
6683744 Magnetic disk evaluation apparatus and method  
A magnetic-disk evaluation apparatus includes a magnetic head positioned relative to a magnetic disk including temporary servo signals. Fluctuation of a magnetic head in a seek direction is...
6680679 Method and apparatus for electrical conversion of non-return to zero encoded signal to return to zero encoded signal  
A method and apparatus for electrically converting a NRZ signal into a RZ signal. A NRZ signal is summed with a phase-aligned clock signal. The resultant summed signal is then passed through a...
6678108 Method and apparatus for identifying spindle imbalance in a hard disk drive  
A method and apparatus are provided for identifying spindle imbalance in a hard disk drive. Position error signal (PES) samples are received from a plurality of sectors of a predefined cylinder for...
6667840 Method for screening oscillatory PES with 1.7 kHz harmonic resonance  
The present invention provides a method to screen tracks on a magnetic disc in a disc drive for harmonic resonance. There are several algorithms in the method performing different functions at...
6661599 Enhanced adaptive feedforward control to cancel once-per-revolution disturbance by shaping the internal mode  
A method of producing a modified control signal to an actuator arm assembly of a disc drive to reduce RRO includes the step of generating a correction signal corresponding to a position error...
6657810 Disk drive employing separate read and write repeatable runout estimated values for a head having a read element offset from a write element  
A disk drive is disclosed comprising a disk having a plurality of tracks, each track comprising a plurality of data sectors for storing user data and a plurality of embedded servo sectors for...
6653965 Digital servo control method, digital Servo controller, storage device and head position control method  
A digital servo controller generates a control signal from an analog observation signal using an output equation, state equation or a transfer function, and performs high precision servo-control...
6654198 Repeatable run-out error compensation method for a disc drive  
Steps for isolating and correcting total written-in repeatable run-out error written into servo sectors of a disc drive include, determining a total repeatable run-out error value for each servo...
6654197 Disc drive dynamics identification using synchronous excitation signal  
A method and system for identifying the resonance characteristics of a disc drive. A repetitive excitation signal is applied to the actuator assembly. The repetitive excitation signal has a period...
6643236 Method of elimination of interference created by CDR/W run-out motor on sledge servers  
A method of elimination of interference created on CDR/W run-out motors on sledge servers, especially for the elimination of interference created by the run-out of the combination of CDR/W spindle...
6633521 Storage apparatus and servo recovery method of it  
The present invention relates to a storage device and a servo recovery method for the storage device, which restores the head to a track when the head goes off from the track of a storage medium,...
6631048 Magnetic reproducing apparatus with MR heads  
A magnetic reproducing apparatus has an MR head for each recording surface of a recording medium. The apparatus is capable of supplying a proper sense current to each MR head even if a control...
6628472 Method and apparatus for feedforward cancellation using a phase lock loop  
A method and apparatus are provided for generating a feedforward cancellation signal for a next sector of a disc in a disc drive. To form the cancellation signal, the method and apparatus generate...
6628579 Storage apparatus  
A learning control unit is provided between a feedback calculating unit and a driving unit. When a period for one medium rotation period is assumed to be T L , an unknown drive current function...
6624963 Static track spacing error correction in a disc drive  
An apparatus and method for correcting static track spacing errors in a data storage device having a plurality of concentric servo tracks. The data storage device includes a disc having a plurality...
6618219 Method and apparatus for feedforward cancellation using a peak detector  
A method and apparatus are provided for generating a feedforward cancellation signal for a next sector of a disc in a disc drive. To form the cancellation signal, the method and apparatus estimate...
6614614 Method and apparatus for writing servo pattern  
The invention relates to a method for writing servo patterns on a data recording disk of a disk drive device. A read/write head is stopped at a reference position on the data recording disk, then...
6611396 Disk level servo write  
A method for assembling and operating a fixed media hard disk drive using a disk or a stack of disks on which servo information is pre-written off the drive spindle. The disks are subsequently...
6608477 APPARATUS AND METHOD FOR ALTERING TRACK SCAN DATA BASED ON HEAD WIDTH RELATIVE TO DATA TRACK WIDTH AND DETERMINING THE POSITION ERROR SIGNAL FROM THE ALTERED TRACK SCAN DATA TO QUALIFY THE HEAD IN A DATA STORAGE DEVICE  
A method and apparatus to qualify heads to be used in disc drives. The method and apparatus collect a set of track scan data by moving the head across transitions in a track on a medium. The track...
6606210 Intelligent sector recovery algorithm  
A disc drive includes a base and a disc rotatably attached to the base. The disc drive also includes an actuator assembly rotatably attached to said base and a device for moving the actuator...
6606215 Compensation for repeatable runout error  
A disc drive having a servo loop for positioning a head over a disc includes a servo controller which generates a servo control signal in response to a received position error signal. An actuator,...
6606214 System and method to minimize bearing pivot effect in disc drive actuator  
A disc drive is provided which incorporates a rotatable actuator which is mounted to a base of the disc drive through a pivot mechanism. The actuator positioning is controlled by a servo system and...
6603630 Method and apparatus for monitoring track misregistration  
A method and apparatus for monitoring track misregistration that is quicker and that is not limited to worst case assumptions. The present invention includes a first memory for accumulating...
6597530 Method and apparatus for disk drive seek control  
A disk drive seek control system device to reduce track pitch. When data is recorded, an offset value is added to the position of a read head element along the width of a track corresponding to an...
6594106 Adaptive servo estimator and compensator for coil and carriage deformation in voice coil motor driven hard disk drive  
A system and method for adaptively compensating for real-time variations in mechanical dynamics of a head-positioning assembly during track follow and seek operations. The head-positioning assembly...
6587302 09Method for controlling repeatable runout compensation algorithm  
In a method for controlling a repeatable runout (RRO) compensation algorithm in a hard disk drive, it is determined whether to enable or disable an RRO compensation algorithm in a corresponding...
6574067 Optimally designed parsimonious repetitive learning compensator for hard disc drives having high track density  
A repetitive learning compensator for a servo system of a disc drive includes a memory buffer having a length N/m where N is the number of servo sectors in a track, m is a parsing factor greater...
6563663 Repeatable runout compensation using iterative learning control in a disc storage system  
A disc storage system is provided which includes a servo control loop for compensating for repeatable runout. Repeatable runout is compensated using table entries of the form Comp Value(k+1)=Comp...
6564110 Position controlling apparatus capable of reducing the effect of disturbance  
A discrete Kalman filter 12 and a disturbance estimating unit 13 are added to a feedback loop for feeding back a detected value of position from a position detector 6. The Kalman filter...
6560059 Method and apparatus for suppressing seek-induced vibration in a disc drive  
Apparatus suppresses seek-induced vibration in a disc drive. The apparatus is responsive to a selected bang-bang command to provide an operating signal to the actuator, such as a voice coil motor,...
6556371 Generation of higher-order harmonic sine and cosine sequences by indexing a first-order sine/cosine table  
A method of generating a higher-order trigonometric sequence, by constructing a table having a first-order trigonometric sequence, indexing the table to yield a different sequence based on an order...
6556368 Disk apparatus and control method therefor  
A method for controlling a disk apparatus in which a head scans tracks on a disk to record or retrieve information. The method includes a position error detection procedure which detects a position...
6556367 Storage apparatus and position sensitivity setting method  
High-accuracy position signals are obtained by correcting nonlinear position sensitivities of two phase signals demodulated from two-phase servo information, into linear ones. A position...
6552867 Head positioning controller for information recording and/or reproducing apparatus with head tracking of nonsynchronous radial runout (NRRO) of the disk  
An apparatus is constructed to record and/or reproduce information through a head on or from a disk which is an information recording medium. The apparatus has a first driving motor for supporting...
6549351 Auxiliary data encoding in a disk drive system  
A disk drive system comprises control circuitry and a disk device. The disk device transfers a read signal representing user data, servo data, and auxiliary data to the control circuitry. The...
6549362 Method and apparatus for the enhancement of embedded runout correction in a disk drive  
A method and apparatus for the enhancement of embedded runout correction in a disk drive is provided. According to the present invention, embedded runout correction values are obtained by...
6545835 Method and apparatus for RRO learning before and after shipping to cancel RRO in a disk drive  
The present invention may be embodied in a method, and related apparatus, for determining a repeatable runout (RRO) compensation value set for a track on a disk in a disk drive, wherein the disk...
Matches 201 - 250 out of 511 < 1 2 3 4 5 6 7 8 9 10 11 >