Matches 301 - 350 out of 548 < 1 2 3 4 5 6 7 8 9 10 11 >
Match Document Document Title
5774299 Adaptive calibration of read/write elements in a disc drive  
The track follow gain control of an actuator controller is calibrated by injecting a sinusoidal signal into the position error signal during a servo burst interrupt. The injected signal is bandpass...
5760990 Servo position error signal calibration in a hard disc drive  
A method for calibrating the position error signal in a servo system of a disc drive. The disc drive comprises a disc and an actuator adjacent the disc, the actuator including a head which is...
5754354 Magnetic disk drive unit with complex magnetic head of variable reading width  
A magnetic disk drive unit includes a first read amplifier connected to an inductive head, a second read amplifier connected to a magneto-resistive head, a selective output unit for selecting...
5748400 Method of compensating for the misregistration of the radial track positions of a floppy diskette in a disk drive  
A method comprises receiving a diskette into a drive, determining the logical format type of the data written on the diskette, and targeting any recorded track on either surface of the diskette...
5731723 Half symbol delay calibration for phase window centering  
The present invention provides a method and apparatus for half symbol delay calibration for phase window centering. To perform calibration of phase window centering, a carefully designed input...
5717538 Asynchronous position error signal detector employing weighted accumulation for use in servo system  
A servo system accurately detects and processes signals from servo patterns encoded on magnetic storage disks using weighted accumulation, for use in precisely positioning read/write heads with...
5708581 Method for maximizing feedforward orthogonality for minimizing servo system nuller instability  
An n-around nuller in a disk drive track-follow loop servo system is optimized by maximizing its feedforward orthogonality (channel separation). Sine and cosine terms (signals) are injected into...
5663847 Rejection of disturbances on a disk drive by use of an accelerometer  
A disk recording and/or reproduction device subject to shock and vibration. The track following function of the transducer is augmented by an acceleration responsive sensor. The acceleration...
5625508 Method and apparatus for servo demodulation in a direct access storage device  
A method and apparatus are provided for servo demodulation in a direct access storage device. A readback signal is sensed from at least one disk surface and locations of positive and negative peaks...
5617267 Servo data writing apparatus for supporting the free end of a rotating shaft in a magnetic disk device and method of writing servo data  
An HDD, to which servo data is written, is fixed on a base. As an upper base moves, a both-end supporting mechanism provided on the upper base approaches a rotation shaft which supports a disk....
5610777 Method and apparatus for writing servo tracks of a magnetic disk unit which uses a probe to control the positioning of the head  
The present invention relates to a method and apparatus for writing servo tracks of a magnetic disk unit, and has an object of providing a servo track writing method and apparatus which can reduce...
5602693 Method and apparatus for sensing position in a disk drive  
A system for positioning a plurality of heads traversing multiple disks in a disk drive system is disclosed herein. The positioning system includes a servo pattern recorded on at least one of the...
5602692 Sampled position error signal demodulation system for banded data disk drives  
A servo signal demodulator for a banded data disk drive system includes a single data sampling clock for both the data channel sampling and the servo data sampling. The demodulator includes an...
5602691 Magnetic disk drive apparatus using contact start/stop mode and head load/unload mode  
A magnetic disk drive apparatus includes a data storage medium, a magnetic head, an arm assembly, and a magnetic head retracting mechanism. The arm assembly includes a voice coil motor for driving...
5570244 Method and apparatus for controlling assertion of a write inhibit signal using separate threshold values for each of a plurality of recording surfaces  
A method for controlling assertion of a write inhibit signal in a disk drive is described. The disk drive comprises at least one rotating disk having data recording surfaces, and a head for each...
5550447 Pulse generating system responding to instruction pulses for generating driving pulses for diving motor  
A pulse generating unit responds to a series of instruction pulses to generate a series of driving pulses which includes alternately occurring first driving pulses and second driving pulses. The...
5548454 Information recording disk, its production method and recording apparatus  
In the information recording disk, the positioning signal of the information convertor is provided permanently, as a change in shape or material, to the front and reverse surfaces of the disk...
5537282 Data storage disk having improved tracking capability  
In the present invention a magnetic data storage includes disk recesses formed in the magnetic layer. The recesses are located in pairs on opposite sides of the data tracks, and the disk is...
5521891 Speed detection apparatus, speed control motor, and track jump control circuit  
A track jump control circuit comprises: a head; a rotary motor which drives the head and is controlled in accordance with an input signal; a unit for detecting a speed of rotation corresponding to...
5517631 Miniature disk drive having embedded sector servo with split data fields and automatic on-the-fly data block sequencing  
A programmable data sequencer transfers fixed length data blocks between variable length storage segments of a magnetic storage disk and a buffer memory within a data storage device. The data...
5517371 Track sector detection system for rotating disk data storage apparatus  
A system for detecting the servo sectors of a rotating magnetic disk solely from read pulses representative of information read on the disk. Each servo sector has a first or intersector gap, an...
5483393 Disk drive having head positioning servo with improved servo read signal processing using median servo burst peak magnitudes  
A disk drive for use with an embedded head positioning servo system is disclosed. The disk drive includes a disk on the surface of which spaced-apart servo bursts are prerecorded in servo sectors....
5475544 Head positioning control device for a magnetic disk apparatus  
A head positioning control device for a magnetic disk apparatus has a head selection circuit for selecting one of a plurality of magnetic heads based on an external head address, a servo control...
5459624 Activator control method and apparatus for positioning a transducer using a phase plane trajectory trough function for a direct access storage device with estimated velocity and position states  
A phase plane trajectory trough method and apparatus for fast settling of a data transducer for positioning a transducer head over a selected track on a disk surface are provided for use in a disk...
5455720 Offset and gain error discriminator  
Positive and negative peaks of the differential pulses produced by a differential head of a disk drive are detected. The respective peaks, which represent the positive and negative peaks of the...
5450249 Demodulator circuit  
A demodulator circuit receives an input signal read from a track of a magnetic medium and generates a control signal to maintain alignment of a read-write head with the track. The demodulator...
5442498 Asynchronous track code encodement and detection for disk drive servo control system  
A disk head position control system having a disk head controller that moves a disk head relative to a surface of a magnetic media disk encoded with a plurality of tracks of a quadrature burst...
5434725 Magnetic disc driving device for controlling the position of a magnetic head relative to the disc  
A magnetic disc driving device is operated in such a manner that frequency signals recorded in an in-phase relation in servo regions of a magnetic disc of a sector servo system aligned in the...
5432659 Magnetic disk unit having a plurality of magnetic heads  
In a magnetic disk unit, a magnetic head to be activated is switched from a first magnetic head to a second magnetic head in accordance with an instruction supplied from a host system in a state...
5424885 Method for following data tracks in a disc drive using an improved thermal calibration method  
A method for following data tracks on data surfaces of a disc drive by organizing the data tracks in concentric cylinders including servo tracks on a dedicated servo surface and following servo...
5416652 Apparatus for, and methods of, recording signals in tracks on a memory member without a reference index  
A head records a track (e.g. a servo track) in a memory member outside of a clean room without using reference indices. In each of a plurality of cyclical movements (e.g. revolutions), signals...
5412640 Method for measuring and regulating the radial and tangential angles of a light beam  
With an optical playback device, for example, with a compact disk player, care should be taken to see that the light beam scanning the data radiates as perpendicular as possible onto the disk....
5408367 Method of optimizing operation of disk drive  
A method for individually evaluating a head and disk combination to selectively optimize and calibrate the read and write systems thereof in a short time is achieved by deliberately positioning the...
5402280 Method and apparatus for runout correction due to disk slip or spindle imbalance  
In a disk storage device, a method and apparatus for correcting a "runout" error by adding to the servo control signal a sinusoidal signal of amplitude and phase derived to cancel the runout error.
5402278 Method for recording a positioning signal on a magnetic recording disk and apparatus for recording the same  
This invention relates to a method for recording a positioning signal on a disk having a projection pattern. The method includes rotating a magnetic disk having a magnetic layer on a non-magnetic...
5383070 Method and device for measuring disk drive alignment  
A test disk is used to measure disk drive alignment and other parameters without removing the drive from its computer system and without any need for special test equipment. It includes a pair of...
5371637 Disk apparatus  
In a disk apparatus of contact-start-stop system, a head slider carries out a contact-start-stop operation at a non-specified position taken in the radial direction of a disk-shaped recording...
5359504 Magnetic disk apparatus  
A magnetic disk apparatus is disclosed wherein the apparatus comprises a magnetic disk, magnetic heads for recording and reproducing information to and from the magnetic disk, a disk driving device...
5341351 Method and means for optimally accessing data residing on dual actuator DASDs  
A method and means for ensuring maximal occupancy of dual actuators movable over a cyclic multitracked DASD in transferring any percentage mix of short and long records over a set of queued...
5333084 Electronically alignable flexible disk drive  
A disk drive in which the radial alignment, track zero alignment, index to data timing, write current, asymmetry and threshold dropout can be electronically adjusted. A plurality of programs stored...
5329409 Correction of current feedback offset for disc drive servo systems  
A process is provided for compensating for offset in the actuator current of the servo system of a disc drive. A typical disc drive includes a power amplifier providing actuator current to the...
5315451 Rotating storage track format emulation  
A method of emulating an original record format for a new rotating storage device, including the steps of; (a) determining an original angular position (α) of a record according to a first...
5311379 Method and system for positioning head on target cylinder of disk  
A method of positioning a magnetic head on a target cylinder of a magnetic disk uses a position signal derived from a servo signal which is read from a magnetic disk using a magnetic head. The...
5305159 Magnetic disk apparatus  
A disk system has a disk as a recording medium, and a disk recording/reproducing apparatus for recording and reproducing data by a head radially movable provided on a disk by a head moving...
5305158 Positioning control apparatus  
A positioning control apparatus comprises a feedback compensatory system and a feedforward compensatory system. The feedforward compensatory system comprises a detector for detecting a position of...
5303105 Shape memory alloy for centering a transducer carried by a slider in a support arm over a track on a magnetic disk  
An apparatus positions a transducer, carried by a slider, over a track on a magnetic disk. An arm has a first end for attachment to an actuator for rotating the arm and a second end for attachment...
5299075 Apparatus and method for shock attenuation in a disk recording and/or reproduction system using variable gain acceleration sensor  
A disk recording and/or reproduction device subject to acceleration forces in which the transducer track following function is augmented by an acceleration responsive transducer positioning...
5296995 Method of magnetically recording and reading data, magnetic recording medium, its production method and magnetic recording apparatus  
The present invention uses a magnetic recording medium equipped with those magnetically readable recording servo pits which are preformed on a magnetic recording medium and have different magnetic...
5283702 Power saving system for rotating disk data storage apparatus  
A flexible magnetic disk drive is disclosed which has a stepper motor coupled to a data transducer via a steel belt motion translating mechanism for moving the transducer from track to track on the...
5274511 Servo signal recording method and apparatus  
An external position detector is mounted on a head arm that also carries a transducer for tracking a magnetic disk. When the head arm is moved at constant speed, the position detector produces an...
Matches 301 - 350 out of 548 < 1 2 3 4 5 6 7 8 9 10 11 >