Matches 101 - 150 out of 548 < 1 2 3 4 5 6 7 8 9 10 11 >
Match Document Document Title
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...
6922301 Positioner of a disk drive that positions a data transducer with reduced vibration  
A disk drive includes a head stack assembly having a storage disk, a data transducer, an actuator pivot center and a positioner. The positioner includes a magnet assembly, a primary coil array that...
6917483 Non-consecutive transitional mechanism for seek operations when transitioning from a seek control to a track following control  
A method and apparatus for improving the settle time and thus, the transition from seek control to track following control in a disc drive system are provided. With the apparatus and method, two...
6914743 Vibration cancellation in a disk drive by using an acceleration sensor and adaptively adjusting its gain to minimize external acceleration effects  
Disclosed is a disk drive using an accelerometer to sense linear vibration and cancel its effects with an adaptive algorithm during track following. The accelerometer is oriented to detect...
6906485 Spindle motor control using a current profile to taper current transitions  
Method and apparatus for operating a motor. During a commutation state current is applied to a motor while field effect transistors (FETs) are held in an enable or disable state to effect current...
6903897 Performance of a rotary actuator in a disk drive  
A method for improving the performance of a rotary actuator in a disk drive, the rotary actuator comprises a voice coil motor (VCM) characterized by a torque parameter, the disk drive comprises a...
6903896 Head positioning method, and disk apparatus using the same  
A disturbance compensation signal is produced by estimating the magnitude of disturbance acting upon an actuator based on a driving signal and a voltage signal generated when driving the actuator....
6903894 Magnetic disc storage apparatus  
A magnetic disc storage apparatus including a magnetic head for reading information from a storage track on a magnetic storage disc driven to spin, a voice coil motor for moving the magnetic head...
6900958 Method and disk drive for improving head position accuracy during track following through real-time identification of external vibration and monitoring of write-unsafe occurrences  
A method is disclosed for improving head position accuracy in a disk drive during track following of concentric data storage tracks through real-time identification of external vibration and...
6898046 Method and system for rotational velocity-based algorithm for vibration compensation in disk drives  
A disk drive (HDD) (and method) subject to linear and rotational vibration, includes an independent sensing unit for sensing a rotational velocity component of the rotational vibration in a...
6891694 Method for writing streaming audiovisual data to a disk drive  
A method for writing streaming audiovisual data to a disk drive is performed by organizing the data into clusters and commencing writing the clusters to the first physical sector encountered after...
6891692 Disk drive apparatus, head position control method, and hard disk drive  
A position control system for a magnetic head improves servo tracking characteristics in a low frequency range without impairing the stability of seek operations. The position control system is...
6888696 Magnetic disk apparatus and servo signal recording method  
The magnetic disk apparatus includes a magnetic disk for storing thereinto information; a head equipped with a recording conversion element for writing information into the magnetic disk and a...
6876511 Disk drive and method of detecting servo address mark in the same  
A detector detects, in read data, a servo address mark of a type indicated by a register. Every time a SAM is detected during a self servo process, a CPU carries out tracking control in accordance...
6868477 Method and apparatus for optimizing skip mask operations in a disc drive  
A skip mask mechanism is implemented in a disc drive in order to increase performance by minimizing the number of necessary disc rotations required while executing a set of pseudo-sequential...
6864656 Magnetic disk drive and voice coil motor drive circuit  
A magnetic disk drive that drives and positions an actuator using a voice coil motor, includes a current sensing resistor connected in series to a terminal on current input side of the voice coil...
6862155 Squeeze evaluations that account for low frequency components, in a controller usable in a data handling system  
Position error values are obtained from a transducer head while following a plurality of servo tracks with a servo loop that band-blocks a frequency range that includes F, a nominal rotation...
6856483 Device and method for generating synchronous numeric signals with phase-delay minimization in control systems with open-loop compensation  
A device for generating synchronous numeric signals, including a first signal generator which supplies a numeric reference signal having a first frequency and a first period; and a second signal...
6853512 Data storage device, head positioning apparatus and head positioning method  
A data storage device that can perform a track following process even when vibrations are produced by a wide range of frequencies.
6853511 Average position error measurement in a data storage device  
A number of data pairs, each data pair comprises a write-to-read track misregistration (WRTMR) value and an average position error margin (APE) value, are determined for a data storage device. Each...
6847504 Split VCM actuator  
A split actuator comprising two spring coupled actuators that share a common pivot bearing. The two reduced inertia actuators permit overlapping motions during a seek operation thereby reducing...
6836182 Nested transimpedance amplifier  
A nested transimpedance amplifier (TIA) circuit includes a zero-order TIA having an input and an output. A first operational amplifier (opamp) has an input that communicates with the output of the...
6826006 Method for recursively determining repeatable runout cancellation values in a magnetic disk drive  
A method is disclosed for recursively determining repeatable runout (RRO) cancellation values in a disk drive having a head disk assembly (HDA) and a sampled servo controller. The HDA includes a...
6819519 Head position control method for a disk device and the disk device  
This invention relates to a head position control method for a disk device that uses a disk medium whose tracks have been formatted externally, and a disk device that effectively uses the range of...
6813111 Implementation method of digital phase-locked loop  
A phase lock loop to control phase error including a first phase error detector to detect the phase error in a first mode, a first loop filter to filter a first phase error by using a first factor,...
6801377 Performance test method of head gimbal assembly with precise positioning actuator  
A method of testing a performance of an HGA including a step of obtaining a displacement performance of a precise positioning actuator by driving this actuator to displace and by executing a track...
6795265 Closed loop charge mode drive for piezo actuators using a DC restore amplifier  
A piezo actuator drive circuit ( 40 ) adapted to operate in both a charge mode and a voltage mode. A low frequency compensation loop ( 44 ) is formed from a piezo actuator output (OUT6XP) of a...
6795262 Method of modifying on-track declaration algorithm of a disk drive based upon detection of external vibration condition  
A method of expanding the on-track operational range of a disk drive based upon detection of an external vibration condition. The method involves detecting that a vibration state exists and, while...
6785083 Application of reduced bias levels to disc drive read elements during periods of inactivity  
Apparatus and method for enhancing disc drive reliability by applying reduced read bias levels to read elements of a disc drive during an idle mode of operation. A preamplifier driver circuit...
6775090 Adapting logical track addresses in relation to head offsets  
Method and apparatus for improving data transfer rate performance of a disc drive data handling system having a plurality of transducing heads adjacent a corresponding plurality of data recording...
6768614 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...
6768609 Reducing position error signal nonlinearity through iterative calibration of a compensation table  
Apparatus and method for reducing nonlinearities in a position error signal (PES) of a disc drive data handling system. The disc drive data handling system includes a disc recording surface having...
6768607 Adaptive dual-frequency notch filter  
A disk drive comprises an actuator servo control system including at least one disk, an actuator structure comprising at least transducer head for writing and/or reading data from the disk and...
6765749 Frequency attenuating filter apparatus and method for a data storage device  
An attenuating filter for the servo control processor of a disc drive data storage device. The filter is constructed by determining the peak resonance in the structure frequency response above a...
6762895 Magnetic disk drive and position error signal generation method  
A signal is read out from a two-layered perpendicular magnetic recording medium by a composite head formed from a single-pole perpendicular recording head and magnetoresistance effect type...
6762644 Apparatus and method for a nested transimpedance amplifier  
A nested transimpedance amplifier (TIA) circuit includes a zero-order TIA having an input and an output. A first operational amplifier (opamp) has an input that communicates with the output of the...
6757129 Magnetic disk storage apparatus  
In a magnetic disk storage apparatus, when a drive current of the voice coil motor is small, the head drive control circuit executes the linear drive mode under which the voice coil motor is driven...
6757127 Adaptive temperature compensated AC unlatch algorithm  
An information handling system, such as a disc drive, includes a base, a disc stack rotatably attached to the base, and an actuator assembly movably attached to the base. A region of the disc stack...
6757126 Magnetic recording medium having tracking control area formed adjacent data tracks  
A magnetic recording medium having a magnetic layer includes a plurality of tracks formed on the magnetic layer. The tracks have information magnetically recorded thereon. A magnetization change...
6754031 Method and apparatus for controlling an access mechanism within a disk drive  
A method and apparatus for controlling an access mechanism within a disk drive are disclosed. A servo apparatus comprises a first detection module for discretely detecting a displacement value of...
6754030 Optimal reader-to-writer offset measurement of a head in a disc drive for reduced track misregistration  
A method of and apparatus for generating a reader-to-writer offset for a head positioned over a track on a disc in a disc drive having a plurality of tracks is disclosed. A reader and a writer are...
6751043 Digital servo control system for a hard disc drive using a voice coil motor in voltage mode  
This invention comprises an architecture for voltage mode control of a voice coil motor in a hard disk drive. In contrast to conventional current mode control, coil current is not sensed or...
6751042 Track pitch correction method and apparatus  
Many parallel tracks on a storage surface of a data handling device are arranged in a longitudinal direction. Each track has a track center comprising reference points for fine lateral positioning....
6747837 Disk drive comprising an integrator for controlling a VCM actuator and transformer for controlling a piezoelectric actuator  
A disk drive is disclosed comprising a voice coil motor (VCM) actuator and a piezoelectric (PZT) actuator. The VCM actuator is driven by a control effort including an integrator, and the PZT...
6747836 Position control system and method for magnetic hard disk drive systems with dual stage actuation  
A head position control system for a dual stage actuation disk drive system. A feedback system is provided for modifying a primary and a secondary input command signal to produce primary and...
6747833 Magnetic disk drive with a head oscillation function and the control method thereof  
The position information of the magnetic head is generated also from the data area to improve the positioning accuracy. The magnetic disk drive has a function of oscillating the magnetic head in...
6744589 Single-sided unipolar device driver for a piezoelectric transducer in a disc drive  
A disc drive including a rotatable data track, a dual-stage actuator with a primary actuator motor supporting an actuator arm, a read/write head supported by the actuator arm and communicating with...
6738218 Disk storage device and head positioning method  
Settling response characteristics after change-over from a speed controller to a position controller is attained. Fluctuations in a time taken until change-over is made from the speed controller to...
6735033 Method for recovering from shock events occurring to a disk drive during data write operations to improve data reliability  
The invention relates to a method for recovering from shock event to a disk drive. Embedded servo wedges are read to generate position error signal (PES) values. The disk drive is transitioned to a...
6724563 Two-stage actuator with sensitivity function preventing disturbances at all frequencies  
By increasing the gain of a controller for coarse motion CFBV within a frequency band in which the gain of a sensitivity function SP=1/(1+PP·CFBP) of fine motion actuator DP and controller for...
Matches 101 - 150 out of 548 < 1 2 3 4 5 6 7 8 9 10 11 >