Matches 351 - 400 out of 762 < 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 >
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6215608 Hardware inhibit for a disk drive digital servo control system  
A direct access storage device that (DASD) includes a sector servo control system that controls disk write operations by receiving a servo pattern readback signal in a sector, determining track...
6204980 High speed gain stage with DC offset cancellation for servo demodulator circuit  
An integrated circuit servo system demodulator that incorporates a high speed gain stage with DC offset cancellation. The gain stage receives a differential voltage signal representing a servo...
6204991 Head position signal demodulator and head positioning unit using the demodulator  
A head position signal demodulator that demodulates a position signal indicating the position of the magnetic head in the disk radius direction based on a servo pattern recorded on the magnetic...
6198584 Disk drive with staggered calibration bursts that are disposably located in data regions and method of using the same for calibrating a read head  
A disk drive with a disk having a servo pattern including a special "calibration track" wherein a plurality of staggered calibration burst pairs define null points that are radially shifted from a...
6195220 Method and apparatus utilizing field ratioing demodulation techniques 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...
6191904 Data sector timing compensation technique based upon drive eccentricity  
A technique for reading data from a magnetic disk includes the steps of providing the magnetic disk including a cylinder having a plurality servo sectors, a plurality of data sectors, and a zone...
6188539 Extended position error signal linearization and normalization  
A method of producing a position error signal includes storing a normal position error value generated from a normal servo field and a quadrature position error value generated from a quadrature...
6188533 Data reading method, recording medium used in the method and storage apparatus using the method  
Desired data recorded in a recording medium is read as a result of a head scanning a desired track, track tracking information for detecting the amount of displacement of said head with respect to...
6185059 Method of controlling a disk drive for eliminating blanking intervals formed on a storage disk positioned within the drive  
A method of controlling a disk drive that reduces the space on the data storage surface of a storage disk otherwise effectively required to be taken up by embedded servo sectors. In disk drives...
6181505 Synchronous digital demodulator with integrated read and servo channels  
A synchronous digital demodulator and method for demodulating a read signal including a user data waveform and a servo waveform which are generated by a read head as the read head passes over a...
6181504 Method for measuring track pitches of a hard disk drive  
A hard disk drive (HDD) magnetically reading and writing digital data, and measuring the track pitch of a hard disk drive to detect more accurately the position error signal on each disk. The track...
6178059 Method for writing servo information on a magnetic recording disk  
A method for writing circular track position information on a magnetic recording disk comprising the steps of (i) rotating the magnetic recording disk, and (ii) aerodynamically floating in a helium...
6175458 Control of servo timing mark detection windows  
A disk drive processing system controls a Servo Timing Mark (STM) detection window in disk drive during a head switch operation. In response to the head switch operation, the system disables a...
6175465 Head positioning control system for use in a disk storage drive  
A servo system uses a disk on which two pairs of burst data items A and B and burst data items C and D are prerecorded, and the servo system performs positioning control for positioning a head...
6175472 Method for generating a position error signal calibration curve in a hard disk drive  
A method and apparatus for generating a position error signal (PES) voltage v. track distance curve for the head of a hard disk drive. The disk has a dedicated track which contains a plurality of...
6172839 Technique for measuring the position error signal of a disk drive  
A technique for measuring a position error signal of a disk drive, includes measuring the width of a track by sequentially following two adjacent tracks upon turning on power, and updating a...
6172828 Signal processing apparatus and a disk control apparatus, with head positioning control based on digitized servo data  
A signal processing device having a feature of analog-to-digital converting a burst signal has a feature of selecting a data bus to notify a disk control device of a conversion result via an NRZ...
6172836 Method and apparatus for writing the servo pattern for detecting fine defects in the servo burst signals of a hard disk drive  
A method of providing the servo pattern for detecting fine defects in the servo burst signals of a hard disk drive (HDD) comprises the steps of writing a preamble portion for providing a servo sync...
6167461 Programmable high performance disk formatter for headerless disk drive controller executing a series of low level instructions generated by a high level processing engine  
A programmable disk formatter for a disk controller in a headerless hard disk drive (HDD) system is disclosed. The disk formatter includes a high level processing engine that generates on the fly...
6166871 Method for decoding head position signal including on-the-fly compensation for misread track number  
A method for generating a reliable head position signal including track number validation. A head position signal is generated using two triangular signals PosN and PosQ having a phase difference...
6160674 Stable data writing method by tracking head speed in hard disk drive  
A hard disk drive traces a head speed to write data stably on a track of a magnetic disk. The hard disk drive seeks the track to position a head on the track sought, if a few consecutive head...
6157511 Disk drive with variable-phase servo burst patterns  
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...
6154330 Disk provided with servo patterns and method of recording servo patterns  
Each of servo patterns comprises servo information, an A burst signal and a B burst signal. The servo patterns are recorded at a smaller track pitch Tp in a data zone of a disk, and are recorded in...
6154331 Disk formatter write gate look-ahead device  
A device to turn on a disk formatter's write gate and NRZ line drivers with minimal delay from a sector pulse. The device utilizes a look-ahead scheme to asynchronously qualify a sector pulse to...
6151181 Magnetic disk device with dummy write function  
A magnetic disk device of embedded-servo type is capable of performing dummy operation for suppressing waveform degradation of signal reproduced by magnetic heads at a high speed with high...
6144513 Detecting servo data and servo bursts from discrete time samples of an analog read signal in a sampled amplitude read channel  
A discrete time servo demodulation technique incorporated within a sampled amplitude read channel to demodulate embedded servo field information stored on a magnetic medium. The servo field...
6141176 Data storage disk with information encoded in the position error signal fields  
There is disclosed a disk for use in a disk drive and a method for making the disk. The position error signal (PES) fields for each track on the disk are written with predetermined data, e.g. servo...
6130796 Adaptive track pitch control method and apparatus for disk drives  
A method and apparatus for manipulating a magnetic disk to provide adaptive track pitch. A manufacturing station measures the actual radial width of an annular surface of the disk, which may...
6130797 Magnetic recorder and magnetooptical recorder  
Virtual tracks are set so that the rotation center of a magnetic recording medium or the vicinity of the rotation center coincides with the track center of the data information, and positioning...
6128154 Servo control method for a high capacity hard disk drive  
A servo control method of a hard disk drive includes: providing a disk having a plurality of first servo track patterns, including a gray code field, for providing track information for each track,...
6122131 Adaptively-controlled disk drive assembly  
A disk drive assembly including circuitry for adaptively selecting performance characteristics of the assembly. The performance characteristics are adaptively selected responsive to a balancing of...
6122134 Combined longitudinal and transversal tracking  
An information storage medium has at least a longitudinal bundle comprising three servo tracks (3, 4, 5). The bundle is arranged in consecutive tracking units (T(N)) of a determined longitudinal...
6122121 Data sector/servo split generator for a disk drive  
A data sector/servo split generator is disclosed for a disk drive apparatus implementing a zone bit recording format and having an embedded sector servo system where servo sector fields split at...
6122133 Hybrid method of determining a fractional track position of a read transducer in a hard disk drive  
A method used to implement a sampled servo control system in a magnetic disk drive for generating a fractional track portion of a position error signal to correctably maintain the alignment of a...
6118604 Constant density servo information in a disc drive  
A disc drive is disclosed having servo information written to one or more discs of the disc drive at a frequency that varies for each of the tracks defined on the disc, the servo information read...
6118616 Digital servo control method for controlling a head driver for moving a head to a target track  
The present invention relates to a servo control apparatus of a disk recording system and particularly to a servo control apparatus and method which are capable of controlling position of a head...
6118603 Disk with fault-tolerant sample-data servo pattern  
A headerless, fault-tolerant sample-data servo pattern, comprising an alternating sequence of first and second servo sectors, with the first servo sectors each including a partial track address and...
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...
6108153 Servo demodulator and method for synchronous servo demodulation  
A servo demodulator (20) is provided for generating a track identification signal (148) and a position error signal (150) from a servo wedge signal, such as a filtered servo wedge signal (112), in...
6101064 Methods and apparatus for efficiently controlling a read/write head in a computer disk drive  
Methods and apparatus for ascertaining a position of a read/write head relative to a reference position on a rotatable disk in a computer disk drive are disclosed. In one aspect of the present...
6098177 Storage unit having reduced wait time of process with respect to command request  
A storage unit is provided with at least one head for reproducing servo information from a medium, a processing part for carrying out a servo process to position the head with respect to the...
6091566 Magnetoresistive head and hard drive system having offsets from center of the servo area to minimize microjogging  
A magnetoresistive (MR) reproduction element is positioned during data recording, data reproduction, and formatting so that its total range of movement is 3/2 times a range of movement...
6091567 Modeling position error nonlinearity to improve servo performance  
An apparatus and method are disclosed for improving servo performance of a disc drive. The disc drive includes a head adjacent a rotatable disc on which data are stored on a plurality of tracks. A...
6091564 Disk drive with calibration bursts that are recorded on a spiral and method of recording the same  
A disk drive with a disk having a servo pattern including a special "calibration track" wherein a plurality of calibration burst pairs are recorded on a spiral centerline to define null points that...
6084739 Write synchronization system on a headerless format magnetic disk device  
A write synchronization system in a headerless format magnetic disk device. The system transmits encoded synchronization signals containing disk administration information such as servo burst...
6081397 Method and apparatus for SID-to-SID period estimation  
A method and apparatus for locating more accurately the beginning of data cells stored on a medium with embedded servo sectors and improving the efficiency with which data can be stored on a medium...
6078452 Disk drive employing method of writing a data block to a data sector following a defective servo sector  
A disk drive employs a method for writing a block of data (or multiple blocks of data) to a data region following a defective servo sectors. The disk drive includes a sampled head positioning servo...
6078462 Device and method for processing servo signals in a parallel architecture PRML reading apparatus for hard disks  
The device is to be used with a parallel architecture partial response maximum likelihood (PRML) reading apparatus comprising a variable-gain input amplifier, a low-pass analog filter, a...
6078461 In situ offset correction for position error signal  
The present invention generally provides a method and system for correcting for offset in a position error signal. In accordance with one embodiment of the invention, the readback signals dependent...
6078445 Gain control for a dual burst, dual frequency PES servo pattern  
Real-time gain control calibration is provided for each frequency of a disk drive storage system using dual-frequency, dual-burst position error sensing (PES) signals. Automatic and independent...
Matches 351 - 400 out of 762 < 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 >