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6590728 Hard disk having extended data region  
A hard disk includes at least one recording surface. The recording surface bears a plurality of servo sectors with each one of the servo sectors including a servo field and a data sector. The servo...
6587291 Asynchronously sampling wide bi-phase codes  
Sampling data with wide bi-phase code symbols includes sampling a wide bi-phase code symbol in the data a number (N) of times to produce samples of data, selecting a subset of the samples,...
6583943 System and method for providing nonadjacent redundancy synchronization bytes  
The present invention provides a system, method and data format wherein a redundant sync byte or group of sync bytes is provided in a data sector at a distance sufficient to isolate the redundant...
6584516 High-speed servo data interface system  
The invention provides a high-speed interface that transfers servo position data from the read channel integrated circuit to the drive control integrated circuit or another integrated circuit. The...
6580573 DISK DRIVE HAVING A CHANNEL CIRCUIT WHICH RECEIVES A READ SIGNAL REPRESENTING DATA IN A DATA SECTOR AND DATA IN A SERVO SECTOR IN A FIRST ORDER AND DEMODULATES THE READ SIGNAL TO PROVIDE DATA SECTOR DATA AND SERVO-SECTOR DATA IN A SECOND ORDER  
A disk drive has a channel circuit for demodulating data sectors and servo sectors stored on a rotating medium to provide data-sector data and servo-sector data. The channel circuit transmits the...
6577463 Tangential misalignment precompensation in a direct access storage device  
A system and method for precompensating for tangential misalignment in a direct access storage device adjusts a SID timing window individually for every track or surface of the direct access...
6574068 Servo control using continuous position error signal with high order polynomial component  
An apparatus and method for improved servo control in a disc drive. A rotatable disc has first, second, third and fourth radially staggered servo burst patterns which define a plurality of...
6567233 4-D shock-sensing for hard-disk drives  
There is a need for low-cost and reliable shock-sensing methods in magnetic hard-disk drives to maintain data integrity when a drive is subjected to external shocks. The present invention uses a...
6563673 Method and apparatus for minimizing slider fly heights over patterned media  
A patterned magnetic storage medium has a plurality of data sectors separated by respective servo sectors with each servo sector having a pattern of pits representing servo data. Grooves in each...
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...
6560058 Positioning control device, changeable magnetic disc device, and head control method  
A positioning control device is provided which is capable of avoiding the limit cycle in which the head moves back and forth between two dead zones on both sizes of the center of the target track....
6560054 Generation of a fixed angular disk position index in a DASD using a sensorless spindle motor  
A method of indexing a rotatable disk in a direct access storage device (DASD) having a sensorless spindle motor, by monitoring spindle motor voltage to detect a pattern of commutation spikes...
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...
6556365 Storage media having a wide servo band and high data format efficiency and a storage using the same  
A servo control method for a storage media includes arranging a plurality of servo sectors along a circumferential direction of the disk-type storage medium without successively arranging the...
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...
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...
6545830 Disk drive storing test pattern in calibration sectors that are longer than user data sectors for zone parameter calibration  
A disk drive is disclosed comprising a disk having a plurality of tracks including a plurality of data tracks and a plurality of reserved tracks. A plurality of embedded servo sectors are dispersed...
6545836 Servo control apparatus and method using absolute value input signals  
A servo control apparatus and method controls systems at least partially on the basis of an observable variable that has an absolute value functional relationship with the controlled variable and...
6545831 Servo-sector arrangement over several data arcs for a rotational head data recording and retrieving system  
This invention discloses a plurality of substantially parallel data arcs disposed on a flat data storage medium. The data arcs include at least two linearly aligned servo-data fields disposed in an...
6538834 Servo controller and servo control method  
A servo controller for correcting a read position of a head when reading data recorded on a recording medium. In accordance with the amplitude ratio of data signals read from each segment of a...
6535348 Servo control method and information storage device  
A servo control method and an information storage device are provided. In the method and device, positional information is detected in accordance with servo information including a plurality of...
6529341 Magnetic recording/reproduction device using preformat information  
A magnetic disk for a magnetic recording/reproduction device includes a magnetic head, wherein a magnetization bit-pattern corresponding to a preformat information signal is recorded beforehand on...
6529344 Method and system for compensating a head positioning servo in a storage device  
A method and system for compensating head positioning servo in a storage device. In accordance with the method and apparatus of the present invention, an open-loop gain of a head positioning servo...
6522493 Position error signal linearization using an auxiliary discontinuity removal routine  
A method, apparatus, and article of manufacture for determining a transducer position in relation to a media surface is described. The method comprises sensing positioning information on the media,...
6522488 Servo information writing method and storage device  
In a magnetic disk apparatus in which heads integrally having write heads and read heads are arranged correspondingly to data surfaces of plural media, servo information including phase servo...
6519104 Computer system comprising a host connected to a disk drive employing read channel IC with common port for data and servo  
A computer system is disclosed comprising a host connected to a disk drive, the disk drive comprising a disk having a disk surface. The disk drive further includes a controller and a channel...
6515818 Track follow at quarter track with narrow heads using non-conventional ordering of quadrature fields  
A method and apparatus for performing track follow and seeking at quarter track positions that uses a non-conventional ordering of the servo fields at the quarter track positions, wherein C−A or...
6515813 Method for controlling servo information detection timing and rotational speed of disk, and disk drive  
A method to enable servo information to be detected surely and stably even when a time interval between servo sectors is changed due to disk shifting. A time interval TS(i) is calculated according...
6515812 Servo format for hard disks, preferably hard disks  
A new embedded-servo format is proposed for use in disk drives, preferably hard disk drives. It is based on biphase modulation (more generally, p-phase modulation, where p>1) and offers...
6510016 Head positioning control system for disk drive  
A positioning control system for a disk drive can reduce static friction of the sliding type actuator to be a cause of degradation of low order spindle rotation synchronization run-out. The...
6507450 Method of continuously recording servo bursts along one continuous, single helix spiral  
An efficient, time saving, cost-effective method of using a servo track writer (STW) for continuously recording servo information along one, continuous, single helix spiral path on the surface of a...
6504663 Disk apparatus and disk medium having a ramp loading mechanism  
A disk apparatus having a ramp loading mechanism. A disk medium on which second servo patterns have been written in a landing area on the medium at a finer interval than that of first servo...
6498695 Method of detecting position on disk, disk unit and disk  
A method of detecting a position on a disk is applied to a disk which is time-divisionally recorded with a data region and a servo region based on a signal read from the disk, where the servo...
6496322 Head position control for a disk drive which performs recording about the rotational center even if the recorded servo information is eccentric  
An object of the present invention is to implement head position control in a disk drive for the case in which a disk is assembled into the disk drive after a precise track is recorded onto it...
6496315 Disk drive with off-track write prevention  
A disk drive with the capability to prevent off-track writing with reduced false triggering is described. An improved method of predicting the position of a head is used to determine whether the...
6490110 Servo data detection with improved phase shift tolerance  
Servo circuitry is disclosed that is configured to operate with a magnetic disk drive system. The servo circuitry is comprised of a first servo detector system, a second servo detector system, and...
6487035 Method and apparatus for adaptive feedforward cancellation  
A method and apparatus are provided for generating an adaptive feedforward cancellation signal for a next sector of a disc in a disc drive. The cancellation signal includes at least one tap weight...
6476989 Radial self-propagation pattern generation for disk file servowriting  
An improved servowriting system and method whereby errors introduced into the written servo information are reduced or eliminated for greater servowriting accuracy. Accuracy is enhanced by one or...
6476997 Disk device, track positioning method and method for generating a position error signal  
A disk device, track positioning method, and method for generating a position error signal in which the occurrence of a wrong correction operation can be prevented by creating an appropriate PES...
6473254 Method and system for compensation of nonlinearity or fluctuation of head-position signal  
A plurality of patterns are formed so that each is deviated slightly from another in each sector in the track width direction. Then, the pattern is followed up, thereby obtaining both a full-track...
6469849 Field ratioing demodulation circuit for a null-type servo pattern  
A method of generating a position error estimate generates a phase field signal and a position error field signal. A set of operations is performed on the phase field signal and the same set of...
6469852 Disk on which servo pattern is recorded and arithmetic processing method for servo pattern read from the disk  
The A burst and B burst for tracking are recorded with the width of track pitch, the address signal is recorded as the same signal with the interval equal to two track pitches (2×Tp) and B1 bit is...
6466387 Data recording disk and disk drive device for reducing wasted space on a data recording disk  
The present invention solves a problem that useless or wasted space exists on a data recording disk between read/write heads of narrower head width than others in the case that an uniform track...
6466385 Method and apparatus of forming a magnetic disk with a servo sector and a data sector on a spiral track  
A magnetic disk apparatus has: a head ( 2 ) that performs data recording and playback while moving relative to a magnetic disk ( 26 ) rotating at the prescribed speed; an actuator ( 3 ) that...
6466394 Storage device and method of detecting a position of a head on a disk of the storage device  
The storage device comprises a magnetic disk having a servo region with a two lines of servo pattern for each track, a servo demodulator for detecting a position of a head on the disk according to...
6462898 Disk drive with information encoded in the position error signal fields  
There is disclosed an error correction and detection method and apparatus for retreiving predetermined data, e.g. servo data, from the position error signal (PES) fields of a disk in a data storage...
6449111 Data frame write and read processes  
Write and read processes for a disk drive handle data and overhead fields in a data frame that extends between two servo sectors on a disk. A write process fills a buffer with both data values and...
6441981 Disk drive including a recording surface employing servo zones recorded at a channel frequency different from data zones  
A disk drive includes a disk having a disk surface, the disk surface having a plurality of tracks arranged in an embedded servo format. The disk surface includes a plurality of radially-extending...
6433950 Disk drive with radially dispersed servo bursts  
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...
6429989 Method for self-servowriting timing propagation  
A method for writing timing marks on a rotatable storage medium, such as on a disk in a disk drive, includes the steps of: 1) during a rotation of the disk, detecting the passage of at least a...