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6069760 Method of eliminating wiggle noise for a disk driving/recording apparatus  
A method of eliminating a wiggle noise generated by a data write current applied to a thin-film head during a data write operation in a disk drive storage apparatus having a storage medium on which...
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...
6067205 Positioning system for accurately positioning a read/write head over a track  
A head positioning system accurately positions a read/write head along a selected track of a rotating magnetic disk. In one aspect, servo information is embedded along the track with the centerline...
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...
6064541 Servo pattern writing method for magnetic disk drives, and magnetic disk drive adopting the method  
Disclosed are a servo pattern writing method for magnetic disk drives making it possible to write a high-density and easily controllable servo pattern with high producibility, and a magnetic disk...
6061197 Adaptive control of a write inhibit signal in a disk drive based on adaptive track pitch  
A method for adaptively controlling the write inhibit signal in a disk drive apparatus. The disk drive apparatus include magnetic disks manipulated such that the total space that is to be allocated...
6061200 In-drive correction of servo pattern errors  
Embedded servo sectors within a data track of a hard disk drive including a rotating data storage disk and a closed loop rotary actuator structure for positioning a data transducer head relative to...
6058084 Disk-shaped recording medium using segment ID and disk unit using the disk-shaped recording medium  
The present invention relates to a disk unit or the like capable of improving the reliability of a sector ID-less system and performing rapid frame synchronization. A disk 101 has a plurality of...
6052250 Disk drive with separately determined servo and data track pitch  
In a disk drive having a disk and a sampled track positioning servo system with a plurality of servo tracks spaced apart by a servo track pitch, a method and apparatus for separately determining...
6049438 Method and apparatus for encoding digital servo information in a servo burst  
A method and apparatus for writing binary servo data into the servo bursts contained on the storage medium of a storage device. The binary servo information may include track identifying...
6049440 Self written read/write track servo parameter for spindle RRO compensation  
A method and apparatus is disclosed for compensating for spindle Repetitive Runout (RRO) by writing a servo parameter information field for both read and write tracks. Servo burst patterns may be...
6049441 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...
6049437 Apparatus for providing new servo information on a disk without entirely erasing old servo information  
The present invention is a method and apparatus for rewriting servo information on a disk of a hard disk drive. The old servo data is erased after the new servo data has been written, using a...
6049442 Multiply-written servo burst patterns for minimizing position error in servo disk drives  
A servo pattern for use on a data storage surface that includes at least one track to minimize position error during positioning of a transducer over the data storage surface. The servo pattern...
6046879 Weighted linearization of a position error signal in a disc drive  
Apparatus and method for providing a linearized position error signal in a disc drive. A first servo position error signal is generated by the disc drive as a selected combination of servo burst...
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...
6043951 Method, apparatus, and magnetic disk for optimizing off-track position of a magnetoresistive head  
An off-track optimizing apparatus, disk, and method for raising track density of a hard disk drive using a magnetoresistive head. An optimal off-track amount is detected in an initial test process...
6034835 Multiple servo track types using multiple frequency servo patterns  
A magnetic disk storage system uses multiple-frequency position error sensing (PES) patterns and produces track identification information from the PES signal by detecting changes in relative servo...
6034830 Information recording medium having divided cylinder address storage  
The present invention relates to an information recording medium for a disk drive having improved recording efficiency. The information recording medium is provided with discrete servo and data...
6034836 Method for compensating for track shift during servo control of a magneto resistive head  
A servo burst recording and servo control method for a magnetic storage device having a magneto resistive (MR) head comprises the steps of recording an additional burst signal having a magnitude as...
6031672 Method and apparatus for servo data pattern detection  
Methods and apparatus are provided for detecting servo information in a direct access storage device. A plurality of data symbols are read from a disk to produce a readback signal. Each data symbol...
6031674 Servo pattern forming method for floppy disk  
A method of writing servo patterns to a floppy disk with use of a magnetic head having a head gap wider than the track pitch of the floppy disk, which method comprises writing a servo pattern to...
6031683 Method for optimization of seek and settle performance in hard disk drives  
A method and apparatus for optimizing the seek/settle performance of a storage device. The present invention measures the seek/settle performance for each individual head and selects the heads with...
6025971 Magnetic disk drive using a nonvolatile solid state memory to store defect information  
A magnetic head drive of the present invention comprises a composite magnetic head structured by integrally combining a write head into a record head and a magnetic disk having a servo area where...
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...
6021028 Method of writing servo data and magnetic recording medium on which the servo data is written by the method  
A method of writing servo data onto a high density flexible magnetic disk (7) using a servo writer is disclosed. This method comprises the steps of providing surface rippling prevention means on...
6018430 Disk drive with multiple disk surfaces having improved allocation of servo sectors  
A servo sector allocation scheme for a disk based data storage system is disclosed that realizes an increased servo sampling rate without an associated increase in overhead. The scheme involves...
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...
6008962 Method and apparatus for providing read and write skew offset information for a magneto-resistive head  
The present invention is a method and apparatus for generating a skew or position offset signal for aligning the read element of an MR head with the centerline of written data, during a read...
6005727 Servo decoder for decoding an error correcting servo code recorded on a disc storage medium  
A servo decoder is disclosed for disc storage systems that operates according to a novel coding scheme capable of accurately decoding detected codewords representing servo track address during seek...
6005738 Methods and systems for self-servo-writing including writing positioning and timing bursts at different track pitches  
Methods and systems for self-servowriting a data storage medium are disclosed, including servoing to propagation bursts of a propagation pattern located in tracks other than an immediately...
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...
6005728 Disk recording medium for embodying high capacity hard disk drive  
A disk recording medium includes a servo track pattern where a gray code field has been deleted, capable of embodying a high capacity hard disk drive. The hard disk drive which uses as a recording...
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...
5995316 initialization method and apparatus for a runout cancellation method  
An initialization for runout cancellation for a hard disk drive such as a Small Computer System Interface (SCSI) hard disk drive. The hard disk drive at a servo sample rate updates a set of state...
5978168 MR head differential micro-jog  
A head positioning system accurately positions a read/write head along a selected track of a rotating magnetic disk. In one aspect, servo information is embedded along the track with the centerline...
5978170 Recording/reproducing apparatus and servo-information recording method  
An index determining unit determines that a current position in a disk medium corresponds to a true index when reaching a true index pattern of servo information recorded in the disk medium. The...
5966264 Two frequency servo PES pattern  
Servo pattern bursts are recorded with two frequencies that are detected using heterodyne detection with oscillators at the same frequency as the respective recorded frequencies. The two...
5966259 Magnetic recording medium formed in a plurality of tracks and magnetic recording-reproducing apparatus for the same  
The present invention relates to a magnetic recording medium and a magnetic recording/reproducing apparatus for the same. In the magnetic recording medium there are provided a read/write region...
5963386 Disk resident split data sector information management system on a headerless magnetic disk device  
A disk resident system for managing split data sector information in a headerless format magnetic disk device. The split data sector information is stored in a split data sector information field...
5959797 Magnetic recording apparatus having means for reading data associated with a non-readable servo sector  
A magnetic recording apparatus according to the present invention comprises a magnetic recording medium having a plurality of servo sectors and a plurality of data sectors on the tracks, first...
5956196 Disk drive employing dynamically reconfigured read channel to process a read signal at two different frequencies  
A disk drive having an embedded servo disk format preferably having a fixed-number of radial servo sample wedges per track, in which data blocks are located independently of the servo sample wedge...
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...
5936790 Servo sector allocation for high sampling rate  
A servo sector allocation scheme for a disk based data storage system is disclosed that realizes an increased servo sampling rate without an associated increase in overhead. The scheme involves...
5926333 Technique for generating sector pulses by comparing production clock values with stored sector length value  
A technique for generating sector pulses in a hard disk drive using hardware involves: receiving read reference clocks produced during a read operation of the hard disk drive and producing a byte...
5926336 Method and apparatus for rewriting servo information on a disk in a hard disk assembly  
The present invention is a method and apparatus for rewriting servo information on a disk of a hard disk drive. The new servo pattern is written on the tracks on the heads or sides of a disk pack...
5923491 Disk drive servo control system with selectable filtering for reduction of repeatable runout  
The present invention determines whether a filter is used for reading and writing on a disk to correct repeatable runout. The invention estimates the magnitude of repeatable runout for each disk by...
5923492 Variable-phase servo burst pattern used to minimize shield-related side readings  
A disk which incorporates a variable-phase servo burst pattern is disclosed. The disk has servo information thereon. The servo information includes a first servo burst pattern written on a first...
5920440 Gray code decoding circuit of a hard disk drive  
A gray code decoding circuit of a hard disk drive includes a servo pattern area, a data pick-up device, and a pattern detecting device. The servo pattern area has data recorded as a gray code. The...
5917670 Method for recovering data from disk with magneto-resistive head in presence of thermal asperities  
Momentary contact with a defect site of a data storage disk or free particle by a magnetoresistive read element of a flying head causes momentary heating and unwanted increase in element resistance...