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7312946 Method and apparatus for servo control in a disk drive  
According to one embodiment, in a disk drive which performs positioning control of a head on the basis of a servo burst pattern recorded on a disk medium, a servo processor generates a...
7283320 Magnetic recording medium including servo and data bands in the magnetic layer  
A magnetic recording medium having a magnetic layer containing magnetic powder provided on a support is disclosed. The magnetic layer possesses a servo band in which a servo signal for controlling...
7268968 Vibration suppression for servo control  
Embodiments of the present invention provide a way to modify the controller of a HDD head actuator to increase the error rejection capability and suppress the wideband vibration that affects the...
7265933 Disk drive computing repeatable run out while actuator arm is pressed against crash stop  
A disk drive is disclosed comprising a voice coil motor (VCM) for rotating an actuator arm about a pivot in order to actuate a head over a disk. The disk is rotated by a spindle motor, and a...
7248429 Adaptive settling control method and apparatus in track seek mode of disc drive  
A settling control method and apparatus perform an improved settling control regardless of a seek distance when a disc drive track seek control operation is performed. An adaptive settling control...
7227708 System and method for determining long-range erasure of adjacent tracks in hard disk drive  
A method for identifying victim tracks distanced from an aggressor track in a hard disk drive that are deleteriously affected by long range fringe effects causing adjacent track interference (ATI)...
7209311 Data storage device and control method therefor to prevent off-track writing  
Embodiments of the invention provide control of a disk data storage device to prevent off-track writing. In one embodiment, the SA acquires the CYLIDs and ADC Values generated from the SERVO...
7203023 Magnetic recording unit and magnetic recording medium  
The present invention provides a magnetic recording unit, including: a magnetic head; a magnetic recording medium having a servo pattern for adjusting a position of the magnetic head; a frequency...
7158338 Servo track having periodic frames of tone field and embedded synchronization marks  
Methods and systems for sensing a position of a transducer head with respect to a storage medium. One method includes generating a read signal from a servo track stored on a magnetic storage...
7106549 Magnetic recording and reproducing apparatus and magnetic recording medium  
A magnetic recording and reproducing apparatus extracts a record signal from a sum signal (ADD) of signals detected via first and second magnetic detection regions (RH 1, RH 2 ) that are formed to...
7106022 Velocity controlled disk drive head retraction with offset removal  
A control apparatus controls retraction of a device carried on a moveable member actuated by an electric motor. The control apparatus includes a measuring circuit with an output during a measuring...
7088535 Off-track retry method in hard disk drive  
An off-track retry method for recovering data incorrectly read due to a read error caused by an off-track error in a disk drive. The off-track retry method includes extracting read gain...
7085094 Interleaved repeatable runout correction for data storage device  
A reduction in computational load associated with correction of repeatable runout is provided. Rather than performing DFT for each analyzed frequency at each interrupt, at least some frequencies...
7072137 Data read device, read method and circuit controlling read device  
An HDC asserts the read gate of an RDC when a read head is positioned in a sector located before a sector that a hot system instructs to read data when seen from the rotation direction of a storage...
7009805 Detection of track misregistration within user data channel  
A method for computing position error signal information of a transducer in a data storage system provides for different readback signals between adjacent tracks. The method involves a computation...
7005849 System and method for high-speed massive magnetic imaging on a spin-stand  
A system ( 10 ) and method for high-speed massive magnetic imaging on a spin-stand ( 12 ) is provided. The system ( 10 ) includes a spin-stand system ( 12 ) for driving a rotational spindle ( 20 )...
6989949 Performance test method of head gimgal assembly with precise positioning actuator  
A method of testing a performance of the HGA has a step of writing information from the at least one thin-film magnetic head element onto a magnetic disk with driving the actuator for displacement...
6950271 Disk drive and disk drive control method  
A position detector generates a position error signal corresponding to a current position of a head, a position controller generates a position control signal from the position error signal, a...
6940677 Writing distinct servo patterns on individual transducers according to transducer read/write head characteristics in a data storage device  
Distinct servo patterns are written on data storage media of a data storage device. Servo patterns of a first type are written for transducers of the data storage device having a first transducer...
6924960 Timing compensation in a self-servowriting system  
A method is disclosed for defining tracks on a rotating magnetic disk medium of a disk drive. Reference tracks are followed using a servo control loop while writing servo patterns defining a first...
6914743 Vibration cancellation in a disk drive by using an acceleration sensor and adaptively adjusting its gain to minimize external acceleration effects  
Disclosed is a disk drive using an accelerometer to sense linear vibration and cancel its effects with an adaptive algorithm during track following. The accelerometer is oriented to detect...
6906485 Spindle motor control using a current profile to taper current transitions  
Method and apparatus for operating a motor. During a commutation state current is applied to a motor while field effect transistors (FETs) are held in an enable or disable state to effect current...
6888695 Information recording and reproducing apparatus having higher drive pulse frequency during seeking operation than during following operation  
An information recording and reproducing apparatus having a high track density, a high recording density in each of the tracks, and a short seeking time. In a seeking operation, a control circuit...
6873488 Enhanced MR offset with dynamic tuning range  
A reader-to-writer offset for a head positioned over a track on a disc in a disc drive having a plurality of tracks is generated by using two iterations. A first iteration is used to determine a...
6853511 Average position error measurement in a data storage device  
A number of data pairs, each data pair comprises a write-to-read track misregistration (WRTMR) value and an average position error margin (APE) value, are determined for a data storage device. Each...
6839196 Magnetic track following servo algorithm using signal quality  
A read servo mechanism that uses levels of read data signal quality to maintain track centerline is presented. In a seek operation mode, a baseline signal quality value is sampled at a current...
6795266 Magnetic disc drive  
A disk-shaped magnetic recording medium having a reference track and a plurality of data tracks is rotated by a motor which generates an index signal at a predetermined position. A magnetic head is...
6785075 Self-writing servo and clock fields on a recording medium  
A disc drive with an information portion previously written on a rotatable disc surface, a servo write clock generator phase lock loop circuit controlling timing for writing a reference mark to the...
6771455 Control system and control method for positioning a head above a desired position on disk  
Disclosed herein is a control system designed to position a head provided in a magnetic disk drive. The system has a controller, a signal output section, two gain/phase control sections and an...
6678106 Determining data sector splits across servo bursts in a disc drive  
A method and system for determining data sector splits across servo bursts in a disc drive having a data disc with an embedded servo configuration. The disc drive includes a data transducer...
6657801 Disk drive with improved characterization segment pattern and method of recording the same  
A disk drive and related method, the disk drive including a rotating magnetic disk and read and write elements for reading and writing data from and to the rotating magnetic disk, comprising: a...
6611397 Servo burst pattern defect detection  
Apparatus and method for improving operational performance of a disc drive by detecting defective servo burst patterns. A rotatable disc is provided with servo data which include a plurality of...
6600622 System and method for detecting displacement of disk drive heads on micro actuators due to contact with disks  
A disk drive with a detector circuit is connected to the distal end of a two-stage actuator. The actuator has a micro actuator for fine track positioning of a read/write head relative to a disk....
6594103 Read channel generating absolute value servo signal  
A servo control system 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 does...
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...
6532130 Head for reading magnetically stored data  
A head ( 130 ) for a disk storage device having a plurality of tracks ( 117 ) divided into memory cells ( 234 ), including a magnetic circuit ( 205, 230 a, 230 b, 250 a, 250 b ) for reading the...
6525897 Apparatus for developing a dynamic servo signal from data in a magnetic disc drive and method  
Apparatus using information about the extent of errors in sensed data for performing as a control function at least one of adjusting the position of a magnetic head to improve alignment relative to...
6389384 Servo processor code evaluation using a virtual disc drive  
Method and apparatus for evaluating programming used by a programmable processor device in a disc drive to carry out servo control of a head with respect to a rotatable disc. The programming is...
6381088 Apparatus for developing a dynamic servo signal from data in a magnetic disc drive and method  
Apparatus using information about the extent of errors in sensed data for performing as a control function at least one of adjusting the position of a magnetic head to improve alignment relative to...
6268975 Tape drive utilizing encoded file markers to locate target positions  
The present invention provides methods and apparatus for locating target positions within an encoded data stream, where the encoded data stream incorporates special, reserved codewords to represent...
6266205 Parallel servo with ultra high bandwidth off-track detection  
A magnetic storage system having one or more rotating disks is disclosed. In a preferred embodiment, each rotating disk has two magnetic surfaces which each contain a number of tracks. Each track...
6249396 Magnetic media having partitioned and presaturated data tracks  
The present invention provides an apparatus and method of partitioning a recording medium data track into two longitudinal regions and erasing any preexisting signal on each region with a DC bias...
6204989 Controlling a media master writing machine to produce curvilinear servo sector patterns  
Curvilinear servo sector patterns are produced on a master media by determining a series of offsets between a radially aligned reference and the desired curvilinear servo sector and expressing each...
6157510 Magnetic storage device with multiple read elements which are offset laterally and longitudinally  
A magnetic storage device is disclosed. The magnetic storage device contains a magnetic media. Previously recorded information resides on tracks in the magnetic media. A transducer is used to read...
6144516 Head displacement measuring method and apparatus and data recording/reproducing method and apparatus  
In a head displacement measuring method, prior to actual data recording or data reproduction, either one of the recording head and the reproducing head is wobbled, and the test data is recorded in...
6081401 Step gap head tracking servo  
A read/write magnetic head includes a step offset formed in the gap of the head which accordingly generates recorded transitions in a recording medium which also contain a step offset in each...
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...
6061201 Method of measuring the read-to-write offset in a disc drive having separate read and write elements  
A method of measuring the read-to-write offset of a track in a disc drive system having separate read and write elements measures the amplitude of a test signal across the width if a track. A test...
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...
6025969 Method and apparatus for measuring head deviation and method and apparatus for recording/reproducing data  
A data for measuring deviation between a recording head and a playback head easily for correctly reproducing data despite such deviation. A playback signal amplitude detection circuit 23 detects...
Matches 1 - 50 out of 181 1 2 3 4 >