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7623317 Magnetic disk device and magnetic recording medium  
A magnetic disk device has a magnetic recording medium in which one servo track and an array of at least one data track are formed alternately. A head portion includes a set of reading heads...
7623316 Circuit and method for protecting emergency head-retract capacitor in a hard disk drive  
A charging system includes a current source, a voltage pump, and a comparator that compares a charging level of a capacitor to each of a first threshold and a second threshold. A controller turns...
7623315 Circuits, systems, and methods for capacitive fly height measurement  
Circuitry, systems, and methods for measuring the fly height of a read/write head in a magnetic data storage system. The circuitry generally includes a measurement circuit configured to determine...
7623314 Head control device, storage device, and contact detection method  
A head control device for controlling, through thermal expansion of a heater, a position of a head for reading and writing data from and to a storage medium, includes a heater control unit that...
7623313 Method and apparatus for performing a self-servo write operation in a disk drive  
The present invention is directed to a method and apparatus for performing a self-servo write operation in a disk drive. In one embodiment, the disk drive includes a disk surface having a read head...
7623312 Hard disk drive off track event method and device  
Methods and devices are shown that identify suitable second data operations after experiencing an off track event in a first data operation and perform the second data operations before correcting...
7620739 Dynamic system control method  
Techniques are provided herein for reducing vibrations in various modes of a dynamic system. One such technique comprises incorporating vibration limiting and sensitivity constraints into a partial...
7619848 Method of searching to find a servo pattern corresponding to a servo pattern copy process  
A method of searching to find a servo pattern corresponding to a servo pattern copy includes unparking a magnetic head and moving the magnetic head onto an intermediate area of a rotating disk,...
7619847 Head controller, storage device, and head controlling method  
A level peak-acquiring unit acquires a peak of a signal level during a calibration wherein a heater power is increased from zero to a predetermined power. A sample acquiring unit acquires in a...
7619846 Self-servo writing using staged patterning  
An apparatus and method for servo writing are disclosed. The method includes writing of first servo data to a medium, detecting a velocity integrated position of the first servo data, and writing...
7619845 Method and apparatus for controlling disc drive using counter-electromotive force  
A method and an apparatus to control a disc drive, and more particularly, a method and an apparatus to control a disc drive using an indirectly determined counter-electromotive force. The method of...
7619844 Disk drive comprising a mechanical position sensor to prevent a runaway condition  
A disk drive is disclosed including a disk having a plurality of servo sectors that define a plurality of servo tracks, an actuator arm, a head attached to a distal end of the actuator arm, a...
RE40975 Head suspension with resonance feedback transducer  
A head suspension assembly including a load beam having a rigid region, a mounting region on a proximal end of the load beam, and a flexure on a distal end of the load beam. The flexure has a...
7616398 Fly height adjustment device calibration  
A method for calibrating a fly height adjustment device comprises flying a magnetic transducer coupled with a head gimbal assembly at a fly height from a magnetic recording data track. The magnetic...
7616397 Disk drive and disk drive control method  
Embodiments in accordance with the present invention improve the head characteristic and avoid collisions between a head element section and a recording disk. A hard disk drive according to an...
7610164 System and method of constant power biasing circuit  
A system is provided to adjust a separation distance between a read/write sensing head and a data storage medium surface in a hard disk. The thermal expansion of the sensing head based on heat...
7609473 Dissipation of liquid droplets in a magnetic disk drive  
Magnetic disk drives and associated methods are described for an improved process for dissipating liquid droplets that may accumulate on a slider of the magnetic disk drive. For the droplet removal...
7609472 Power and thermal management for a hard drive  
According to certain embodiments of the present invention, a data storage device is provided. The exemplary data storage device includes actuation mechanism control circuitry configured to...
7605997 Head-gap calculating device, storage device, head-gap calculating method, and computer product  
A harmonic wave obtaining unit performs a fast Fourier transform (FFT) operation on repeatable run out (RRO) correction data in the time domain and transforms the RRO correction data into a higher...
7605996 Method and system for detecting a change in a rotational velocity of a magnetic disk or a spindle coupled to the magnetic disk  
A method according to one embodiment comprises detecting a change in a rotational velocity of a magnetic disk or a spindle coupled to the magnetic disk, the change being caused by head-disk...
7605995 Servo writer, signal output control method and manufacturing method of magnetic tape using the signal output control method  
A recording current to be supplied to a magnetic head is regulated by a signal output control unit. A peak value (either of positive-going peak value and a negative-going peak value) is detected in...
7602580 Commutational ramp loading apparatus and method  
An apparatus and method for loading and offloading a read/write head from a load ramp onto a disc are disclosed. The apparatus includes at least a basedeck supporting a spindle motor with an...
7602575 Disk drive adjusting estimated reader/writer offset to achieve target burst crossing signal amplitude when propagating servo sectors  
A disk drive is disclosed comprising control circuitry for self servo writing a disk. An estimated reader/writer offset is initialized, servo bursts in a first servo track are read, the head is...
7602574 Storage apparatus, storage medium, and control method and program of storage apparatus  
In a storage medium to which information is recorded by using a write head of an inductive type, in addition to a servo section in which servo information is recorded and a data section to which...
7602573 Device and method for adjusting distance between magnetic head and data storage medium  
A device and method for adjusting a distance between a magnetic head and a data storage medium are provided. In the device, a microprocessor outputs a control signal for adjusting the distance to a...
7602572 Stability margins and error recovery in servo control systems  
Adjusting a servo control system includes identifying a gain crossover frequency for the servo control system, generating a sensitivity function for the servo control system, measuring a...
7602571 Apparatus and method to control flying height of magnetic head in retry mode and disk drive using the same  
An apparatus and method to retry data read and write while changing a flying height of a magnetic head in a disk drive. The apparatus includes the magnetic head including a magnetic read element to...
7602568 Synchronous RRO write  
A hard disk drive system includes a control module that generates a phase offset signal for a repeatable run out (RRO) field of a servo wedge based on an RRO phase of the RRO field and a data phase...
7602131 Voice coil motor control system and method using pulse width modulation  
A system includes a current control module that supplies current to a voice coil motor during a first period to rotate an actuator arm in a first rotational direction, that discharges the current...
7599145 Storage medium device, deformation controller and head slider  
A storage medium device has at least one head which includes a read head element and a write head element. The device has a deformable element which changes a distance between the read head element...
7599143 Information recording/reproduction apparatus, head levitation height control method and head levitation control circuit  
There is provided an information recording/reproduction apparatus, a head levitation height control method, and a head levitation control circuit capable of adequately controlling a head levitation...
7599142 Apparatus and method for slider-disk contact indication by monitoring the spindle control signal in a hard disk drive  
A hard disk drive including an electrical property meter sensing a spindle control signal to create an electrical property reading. Spindle control signal stimulates spindle motor to rotate at...
7599139 Disk drive having a high performance access mode and a lower performance archive mode  
A disk drive is disclosed including a disk having a plurality of tracks, and a head actuated over the disk. A write frequency of write data received from a host is monitored. When the write...
7597792 Magnetic recording disk having DTR patterned CSS zone  
A method and apparatus is described for gradually transitioning a slider from operation over a patterned data zone to landing on a patterned CSS zone. The ratio of raised area width to recessed...
7595958 System including a hard disk drive and stray magnetic field sensor and associated method  
A system includes a host device and a disk drive interfaced with the host device are described as well as an associated method. The disk drive includes a magnetic media for storing information...
7595952 Magnetic head evaluation apparatus and method for manufacturing magnetic disk drive using the same  
Embodiments in accordance with the present invention provide a low-priced magnetic head evaluation apparatus capable of evaluating characteristics at high speed. According to one embodiment, a...
7593179 Control apparatus, storage apparatus, and writing control method  
A control apparatus detects positional information of a head performing writing processing every predetermined time interval, and computes next-sample projected positional information of the head...
7593178 Method of reducing abrasion of disk by using dithering process and disk drive using the same  
Embodiments of the invention reduce abrasion of a disk via a dithering process that spreads a friction area between a magnetic head and the disk when a magnetic head lifts from the surface of the...
7590799 OSD deterministic object fragmentation optimization in a disc drive  
An apparatus includes a storage medium, an arm for positioning a recording head adjacent to the storage medium, and a controller for receiving objects and for selecting blocks on the storage medium...
7589929 Servo pattern writing apparatus, servo pattern writing method, servo pattern reading apparatus, and servo pattern reading method  
There is provided a technique capable of eliminating the need to create data for compensating the displacement of a servo pattern occurring at the time of writing the servo pattern using an...
7589928 Magnetic recording device including a thermal proximity sensor  
A system includes a magnetic device for writing to and reading from a magnetic medium and a sensor disposed adjacent to the magnetic device and proximate to the magnetic medium. The sensor...
7589925 Method of accessing variable density data tracks in a disk drive  
A disk drive has multiple disk surfaces and corresponding heads, each disk surface includes multiple regions, and each head is for recording on and playback of information from a corresponding disk...
7586711 Magnetic performance of a magnetic transducer operating within a hard disk drive  
A method for improving the magnetic performance of at least one magnetic transducer operating within a hard disk drive. The method comprises flying the magnetic transducer at a distance of...
7586710 Control of transducer to tape spacing  
A tape drive apparatus for reading and writing data on a magnetic tape includes at least one transducer that interacts with the magnetic tape. A temperature control element is positioned to...
7586709 Read write offset error correction using geometric reference in self servo write process  
A hard disk drive having a self servo write offset error correction mechanism to improve self servo write process is disclosed. In accordance with certain aspects of the present invention, there is...
7583467 Hard disk drive apparatus, method to control flying on demand of hard disk drive apparatus using thermal asperity signal, and recording media for computer program thereof  
A method to control an FOD (flying on demand) voltage of a hard disk drive apparatus using a TA (thermal asperity) signal includes providing at least one protrusion having a predetermined height on...
7583466 Disk drive determining operating fly height by detecting head disk contact from disk rotation time  
A disk drive is disclosed including a disk having a plurality of tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors. The disk drive further comprises...
7583465 Disk drive adaptive resonance compensation method and apparatus  
A method used in a disk drive system for compensating a frequency component affecting servo control performance. The method includes detecting a frequency component affecting a servo control output...
7583462 Head amplifier with a heat controller  
Timely and proper flying height adjustment is achieved using a controller, which is designed for a magnetic recording and reproducing apparatus that does not use a magnetic head having a heating...
7580217 Disk drive with hybrid analog-digital acceleration feedforward control system and method for rejecting rotational vibration  
A disk drive uses a hybrid analog-digital acceleration feedforward control system and method for cancellation of rotational disturbances. A rotational vibration (RV) sensor is used with an analog...