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6118615 Apparatus for positioning head of magnetic storage device  
An enhancement of the precision of the positioning of the head in a magnetic recording device having a magnetoresistive head is provided. The burst pattern stored in a storage medium is read by the...
6097559 System and method for detecting head-to-disk contact in-situ a direct access storage device using a position error signal  
An apparatus and method for detecting low flying read/write heads provides for the detection of contact between an air bearing slider/transducer assembly and a surface feature developed on a...
6079043 Magnetic disk apparatus  
The present invention is a magnetic disk apparatus which is provided with means for dividing a large amount of data such as video data into segments with error correction code added thereto and...
6067206 Method and apparatus to compensate for servo wedge rotational offset after a head switch  
A disk drive controller having a microprocessor and a sampled signal head positioning system measures and stores the relative rotational offsets between heads arranged in a stacked relationship and...
6067204 Disc drive servo pattern insensitive to read head  
In a disc drive, a position error signal (PES) can be generated that is insensitive to the read element's magnetic and physical geometry and micro-track profile, and that has a spatial domain...
6064542 Methods and apparatus for positioning read/write head in a computer disk drive  
A method for ascertaining a position of a read/write head relative to a reference position on a rotatable disk in a computer disk drive. The method includes reading amplitudes of a set of servo...
6046878 Object positioning using discrete sliding mode control with variable parameters  
Apparatus and method for improving vibration and mechanical shock response of a system through the use of discrete-time sliding mode control with variable parameters are disclosed. A servo circuit...
6043952 Method of positioning a head in a disk drive using groups of servo bursts  
A method of positioning a head in a disk drive is disclosed. The method includes reading a first group of servo bursts and detecting a first error value based upon the head position, reading a...
6028731 Method and system for providing servo signals to a magnetic head positioning system of disk drive  
A method and system for developing continuous position control signals for continuously repositioning a data head relative to an addressed data track on a rotating magnetic disk. The method...
6025970 Digital demodulation of a complementary two-frequency servo PES pattern  
A servo pattern has bursts that are constructed from two frequencies in a complementary arrangement so that the servo pattern frequencies alternate in adjacent servo tracks. The servo pattern is...
6025966 Defect management for automatic track processing without ID field  
A defect management system for use in a data storage system. The defect management system generates a track defect list comprising a sector defect record for each of a set of defective sectors in a...
6014283 Non-quadrature servo burst pattern for micro-jogging a magnetoresistive head in a magnetic disk drive  
A magnetic storage disk drive having a servo burst pattern which asymmetrically increases the linear region in which a read head may be micro-jogged from a burst pair center line to align the read...
6005740 Method and apparatus for developing position error curves for magneto-resistive heads  
A disk having a servo burst pattern used for generating PES curves for MR heads is disclosed. The disk has a plurality of tracks and each of the tracks has a track width. The servo burst pattern...
6005739 Technique for controlling the position error signal of a disk drive  
A technique for controlling the position error signal of a disk drive using a disk recording a servo burst signal for controlling an on-track position of a head includes: checking whether the...
6002542 Magnetic disc read head positioning device and method  
A servo-demodulator for a pair of alternating signals generated by a magnetic disc read head and indicative of the position of the read head in relation to the center of a recorded track. The...
6002541 Method and apparatus for providing a linear position error sensing (PES) signal  
In accordance with the present invention a storage device servo control system that positions a head relative to multiple tracks of a storage medium includes a servo signal filter that receives a...
5999360 Disc drive servo system employing thermal signals  
A magnetic disc drive has a magnetoresistive element (26) for reading user data from concentric tracks of a rotatable magnetic recording disc (32). The magnetoresistive element has a resistance...
5999351 Multi-track density direct access storage device  
A multi-track density direct access storage device is disclosed. In accordance with a preferred embodiment of the present invention, a direct access storage device for data storage within a data...
5998994 MR head offset correction method and magnetic disk certifier  
A test data is written in an arbitrary point p on a non-linear characteristics portion of a hysteresis characteristics of a piezo actuator by a write head and the written test data is read out by...
5995317 Method and apparatus for real-time filtering of a position error signal for a disk drive servo system  
A method and apparatus for real-time filtering of a position error signal in a servo system of a disk drive. Pre-calculated periodic components of the position error signal (PES) are used as future...
5995305 Disk drive using off-track margin to obtain optimal performance parameters  
Adaptive channel optimization in a disk drive is achieved by selecting a track of the recording medium and then writing a first data pattern to opposite sides of the selected track. The first data...
5953178 Magnetic disk apparatus  
A magnetic disk apparatus includes a dual head equipped with an MR head for reading data and an inductive head for writing the data. One ID portion and one servo pattern are disposed in one sector...
5949603 Self servo writing file using the widest head  
A self servo writing file and method for writing servo patterns in a direct access storage device are provided. First servo information is written on a data storage media at a first crash stop. The...
5940240 Constant velocity servo linearity calibration method for MR head  
The invention is a method of calibrating a position error signal (PES) to overcome the problem of a measured displacement or PES that varies as a non-linear function of real displacement when the...
5940239 Velocity/position estimator of magnetic head in magnetic disk driving apparatus  
A magnetic disk drive apparatus includes a velocity/position estimator of a magnetic head, in which a gain can automatically be adjusted in accordance with a moving velocity of the magnetic head....
5930066 Information recording apparatus  
An apparatus records information on a hard disk with a magnetic head arm provided in a hard disk drive. The apparatus comprises an interference measuring system, containing an outgoing portion for...
5909336 Position detection scheme for headerless disk controller  
The present invention provides a method and apparatus for providing position detection using a unique binary sequence encoded in indexing bits stored in servo wedges. The present invention...
5903408 Data recording/reproducing apparatus having track interference reduction mechanism  
The invention provides a data recording/reproducing apparatus for recording and reproducing data on and from a disklike recording medium while rotating the disklike recording medium by a spindle...
5898535 Method and apparatus for recording and reproducing data in and from a data sector even when thermal asperity occurs in the servo area  
A read/write circuit detects the occurrence of a thermal asperity in accordance with data read from a disk. Thermal asperity status register sets a flag corresponding to thermal asperity occurrence...
5894375 Magnetic disk apparatus and method that reverses sense current in magnetoresistive head  
Recording signals can be reproduced without needing a deviation of a recording magnetic pole and a magneto-resistive element in a track width direction and without causing an off-track in a whole...
5892635 Servo writer for magnetic disk drive and servo writing method  
A CPU instructs a VCM driver, a spindle motor driver and a servo data reading or writing circuit, to writing servo data for error detection at any of default rotation frequencies stored in a...
5880953 Control system and information recording and reproducing apparatus  
An actuator moves a signal reproducing element based on an applied control input. An error detector detects a difference in relative position between a desired track and the signal reproducing...
5877914 Amplifier output clamping scheme  
An amplifier in which a clamping circuit is an integral part of the output stage structure is used as a voice coil driver for positioning the heads of a memory disk drive. The output stage,...
5872669 Disk drive apparatus with power conservation capability  
A disk drive apparatus is disclosed for primary use with portable, laptop or other information storage systems. The disk drive apparatus includes one or more about 2.5 inch hard disks. The disk...
5870241 Method and apparatus for evasive maneuvering to keep DASD heads away from protruding surface defects  
Apparatus and a method are provided for mapping aperities or protruding disk defects in a data storage disk file. A protruding disk defect is identified and a head and disk interference value is...
5867341 Disc drive system using multiple pairs of embedded servo bursts  
A method and apparatus determining head position of a data transducer head relative to a selected one track of a multiplicity of concentric tracks within a magnetic/disc drive is provided. At least...
5859740 Information storage disc and information recording and reproducing apparatus  
An information recording and reproducing apparatus and an information storage disc for use therewith. The information storage disc has ID storage areas formed in predetermined locations in the...
5854715 Method for tracking a read head on a data area on a disk and disk apparatus using the method  
In a magnetic disk apparatus using a composite thin-film magnetic head, high-speed reading and writing operations are achieved without increasing a read error rate and without decreasing a...
5848438 Memory mapping defect management technique for automatic track processing without ID field  
Defect management for automatic track processing without an ID field, processes defect information for a track on a magnetic media within a disk drive system. A system which uses any method of...
5825582 Sliding mode control of a disk drive actuator for positioning a read/write head over a selected track during seeking and tracking operations  
A sliding mode controller is disclosed for controlling the motion of a read/write head actuated by a voice coil motor over a rotating magnetic disk storage medium. The magnetic disk comprises a...
5825580 Data recording/reproducing device and burst position conversion coefficient setting method in the same  
A data recording/reproducing device for performing positioning control of at least one head using a plurality pairs of burst data recorded on a disk, comprises burst position conversion coefficient...
5825579 Disk drive servo sensing gain normalization and linearization  
An apparatus, system and method are described for generating a continuous and linear position signal generated from stitched position error signal (PES) components, for use by a servo control...
5822147 Position control apparatus and method with a digital filter and a phase change filter section in a disk storage device  
A head position signal Y(N), which represents the size and direction of the deviation of the current position of a magnetic head to the target position in terms of a digital value, is input at...
5818651 Motor control device for information recording and reproducing apparatus  
A motor control device of an information recording and reproducing apparatus has a disturbance observer for outputting a compensating voltage signal. The compensating voltage signal compensates for...
5801896 Method and apparatus for servo pulse detection with high AC coupling and large pulse asymmetry  
Track information decoding circuitry of a data storage device servo control system decodes binary track information in a readback servo signal by detecting opposite polarity track information pulse...
5801311 Rotary drive accelerator  
A rotary shock testing system including a rotating table mounted to a bearing plate of a precision bearing assembly. The bearing plate to which the rotating table is attached preferably includes...
5796544 Disk drive system which uses a common DAC for digital positioning control and analog positioning control  
Provided is a disk drive with a disk and an actuator assembly on which a communication device is mounted for communication with the disk. Position information read from the disk is processed...
5796542 Servo-track writer system having a plurality of engaging pins co-axially rotated with head actuator pivot axes  
An apparatus and method useful in a servo-track writer (STW) system for simultaneous servowriting of tracks on disk surfaces in a plurality of disk drive head assemblies (HDAs). The STW system...
5781365 Sliding mode control of a magnetoresistive read head for magnetic recording  
A sliding mode controller is disclosed for controlling the motion of a magnetoresistive (MR) read head actuated by a voice coil motor over a rotating magnetic disk storage medium. The magnetic disk...
5781360 Method and apparatus for detecting data track misregistration  
Apparatus for detecting data track misregistration is described. The present invention involves the interaction of a microprocessor with a demodulator. Microcode within the microprocessor initiates...
Matches 251 - 300 out of 548 < 1 2 3 4 5 6 7 8 9 10 11 >