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6181498 Recording and reproducing apparatus, information signal recording and reproducing system and method of managing invalid area information  
If a BS (bad spot) occurs when data is written, then BST (bad spot table) is updated and registered in an EOD (end of data), thereby making it possible to carry out a recovery operation with ease...
6178054 Selecting write fault thresholds by head and disc location in a disc drive  
A method is disclosed for optimizing write performance of a disc drive through the selection of optimum write thresholds. The disc drive has a controllably positionable head adjacent tracks defined...
6178053 Storage apparatus for reducing a read error caused by a thermal asperity of a magneto-resistive head  
For a read demodulating unit for demodulating read data and servo data which is used for head positioning from a reproduction waveform signal of a magneto-resistive head, a thermal asperity fault...
6175459 Magnetic disk drive with a disk medium defect detector and read channel IC used in the drive  
A magnetic disk drive capable of specifying even the type of a medium defect with a small number of read/write operations is disclosed. A read signal is sampled. A defect detector 40 of a read...
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...
6172832 Data storage system with improved biasing techniques for magneto-resistive element  
A magnetic storage system capable of separating thermal signals from data signals is disclosed. The magnetic storage system includes a magnetic media and a head associated with the magnetic media....
6172829 Digital audio tape recording/reproducing apparatus for use with multiple formats  
A data recording and reproducing apparatus for recording and reproducing data on azimuth tracks of a magnetic tape in which the data may be audio data or computer data in any of several different...
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...
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...
6157507 Performance evaluation method of an MR head and a magnetic disk device wherein the method is applied  
A performance evaluation method of an MR head whereby resolution performance of an MR head can be estimated, an isolated repreoduction wave form V(t) of the MR head is approximated by an equation...
6154866 Reproducing apparatus, error correcting unit and error correcting method  
A first error corrector performs error detection and error correction using inner codes on data subjected to an error correction coding processing with multiplication codes and a second error...
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...
6151180 Method and apparatus for detecting defects on a disk in a hard disk drive  
A method and apparatus for determining a number of defects detected on a disk in a hard disk drive. The hard disk drive comprises an actuator arm mounted to a housing and a head mounted to the...
6147827 Method of correcting read errors in a data storage system using targeted ECC  
An apparatus for correcting read errors in a disk drive is disclosed. In one embodiment, the apparatus includes circuitry for determining that an undesired distortion exists in a data signal read...
6147826 Magnetic disk apparatus having duplicate sync byte patterns  
A writing unit writes a first sync byte pattern SB1 to the head of data and writes a second sync byte pattern SB2 to the end of the data (DATA+ECC). When the first sync byte pattern SB1 is not...
6141167 Compensating circuit, equalizer and magnetic recording/reproducing apparatus using the same  
A compensating circuit for compensating positive-negative asymmetry of an input signal having an amplitude exhibiting a positive-negative asymmetry with reference to a given level. Either one of...
6141164 Data recording/reproducing apparatus employing read-after-write system  
A recording apparatus provided on, for example, a digital audio tape recorder or on a data storage device for correctly and reliably recording data. An ECC unit 23 appends the parity for error...
6137645 Method and apparatus for encoding and decoding digital data blocks with improved error correction  
First data blocks are reproduced from a recording medium. The first data blocks contain respective identification information pieces for discriminating the first data blocks from each other. A...
6137646 Disk apparatus using coincidence detection to generate variable sector pulses  
A disk apparatus has a disk medium with sector areas that have a servo area and a data area along the same cylinder. The servo areas also have a sector mark indicative of the servo area, a code...
6134061 Digital signal recording and reproducing apparatus and digital signal recording and reproducing method collectively recording inspecton codes and forming a gap therebetween during post-scoring  
A digital signal recording and reproducing method and apparatus for digitally recording and reproducing first and second signals in tracks on a magnetic recording includes an encoder and a...
6134065 Method and device utilizing erasure information as a reliability indicator in an information medium  
A method and a device in which information is written on a medium and is read out, and which establishes whether the information read is sufficiently reliable, and in which so-called erasure...
6130794 Statistical monitoring of data channels for enhanced data recovery performance  
Reading data from a data channel. The data channel is received by an input, and at least one data path processes the data channel to read data from the data channel. The data path is characterized...
6130793 Thermal asperity detection method, thermal asperity compensation method, magnetic disk unit and retry method therefor  
A thermal asperity detection method includes the steps of (a) converting an analog signal reproduced from a magnetic recording medium into a digital signal using an analog-to-digital converter, (b)...
6128147 Recording/reproducing method and apparatus for storing data in a memory after detecting errors in reproduced data from a magnetic tape  
An apparatus for recording and/or reproducing digital signals, such as PCM signals, as plural slanted tracks on a magnetic tape, includes a memory, first and second heads, a detection unit and a...
6124997 Data reproducing apparatus equipped with adaptive processing circuit  
In a data reproducing apparatus compatibility among plural recording media can be improved. In the data reproducing apparatus, the latest tap coefficient is stored as a tap coefficient in a...
6124995 Fixed bit-rate encoding method and apparatus therefor, and tracking method for high-speed search using the same  
In a fixed bit-rate encoding method, a unit block composed of a predetermined number of transform blocks is constructed by dividing input image data into transform blocks and a unit for fixing the...
6122119 Method of correcting output waveform of head and magnetic disk unit  
A method of correcting an output waveform of a head includes the steps of (a) obtaining a sample error value of a sample value when subjecting an analog signal output from a head to an...
6119261 Method for recovering data from disk with a dynamic erasure offset ECC data recovery protocol  
A method for precisely locating and correcting data errors on a magnetic storage disk with a recording head, e.g. an MR head, in the presence of thermal asperities, scratches, or other data signal...
6118608 Disk drive unit and error recovery method executing shorter error recovery procedure when write errors and reset instruction occur  
A disk drive unit and an error recovery method for the disk drive unit which can reduce processing time for ERP in resetting, thereby shortening response time to the reset is described. A normal...
6118614 Method and apparatus for optimizing write current during servo writing a magnetic disk recording device  
A servo writer optimizes a write current during servowriting a magnetic disk recording device by measuring the head performances at the inner, outer, and middle regions prior to writing the servo...
6118607 Method for and apparatus for eliminating wiggle noise in a disk drive storage device using a thin film head  
A method for eliminating wiggle noise in a disk drive storage device including a magnetic thin film head and a disk provided with an alternate servo sector and a data sector is characterized by the...
6118602 Preamplifier for a read/write head  
A multi-head, disc drive, of a data storage system having a preamplifier that is split into a mother chip and set of daughter chips, each daughter chip corresponding to a head in the disc drive....
6115198 PR4 sampled amplitude read channel for detecting user data and embedded servo data  
A partial response class-IV (PR4) sampled amplitude read channel is disclosed for detecting user data and embedded servo data. The detected servo data is encoded using a novel servo code capable of...
6115332 Apparatus for relocating, grouping and housing a plurality of recording media based on their recording medium-related information  
A reproducing apparatus for a recording medium on which information signals and information indicating the type of the information signals are recorded includes a housing section, a reproducing...
6111708 Apparatus and method for detecting read/write gap failure and switching to an alternative read/write gap  
A magnetic storage device for storing and retrieving data from a magnetic medium such as a magnetic tape. The magnetic storage device includes a first write gap, a first read gap and at least one...
6111707 Tape duplexing with unique identity and error recovery  
A method for creating a duplicate copy of a tape in which a first tape having a first data set name and a second tape having a second data set name are allocated. Data is written to the first and...
6108152 Redundant synchronization fields to improve disc drive read performance  
An apparatus and method are disclosed for reducing the effects of thermal asperities and other anomalous conditions on disc drive read operations. An improved data block format is provided having...
6104560 Method and apparatus for data reproducing in disk storage system  
In a data reproducing device using a read channel of a PRML system, during a period of a continuous reproducing operation mode for continuous reproduction processing of adjacent data sectors, a...
6101053 Write condition setting method and disk unit  
A write condition setting method includes a measuring step for measuring at least one of a track per inch margin, an offset margin and an on-track accuracy margin with respect to a head for each of...
6094317 Method for controlling data reading/writing on random data section containing defective sector  
A method for controlling a data read/write operation of a disk drive recording device provided with re-allocated reserve sectors as a substitute for defective sectors, includes the steps of:...
6091557 Offset free thermal asperity T/A detector  
A circuit for detecting a disturbance signal in an information signal for a read channel circuit includes a resistor connected to ground and a capacitor to form an RC circuit to detect the...
6084733 Storage device and error recovery method executing a plurality of error recovery routines based on error type  
A storage device is described which has a plurality of different error recovery routines which are are divided into groups. When an error occurs, specific routines are selected from the groups in...
6084734 Data recovery using targeted ECC correction  
An apparatus for correcting read errors in a disk drive is disclosed. In one embodiment, the apparatus includes circuitry for determining that an undesired distortion exists in a data signal read...
6084732 Method of selecting zone lay-out of a hard disk drive on basis of head/recording medium performance  
A method of selecting a zone lay-out of a hard disk drive on the basis of head/recording medium performance, which method includes (a) setting a reference position of each of the magnetic heads to...
6075664 Write current setting method, and recording and reproducing device  
A write current is set to be an optimum write current. The write current is supplied to a recording head when information is recorded on a recording medium. First margin characteristics are...
6075666 Tape servo pattern having an embedded position count field  
A servo stripe pattern for determining the longitudinal position of the tape with respect to the tape head. A data field on each frame of the servo pattern includes a digital one or a zero. An...
6072649 Constant density recording method and system for headless format in hard disc driver  
A method of and a system for efficiently using split information stored in an unnecessary data sector, thereby reducing unnecessary data. The system includes first registers respectively adapted to...
6069758 Technique for reducing read channel optimization time  
A hard disk drive with a reduced read channel optimization test time and a reduced test time difference determines whether or not the time limit for testing the hard disk drive has elapsed whenever...
6069856 Information recording/reproduction method and apparatus using EPRML connection processing system using concatenated demodulators  
An information recording/reproducing apparatus includes first and second data demodulators having different data discriminating capabilities. The first data demodulator has a lower data...
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...