Abstract: A media drive includes a head, a servo signal processing circuit, an actuator and a processor. The head is positioned near a data storage medium, and includes a servo element. The servo signal processing circuit is coupled to the servo element to output a position error signal. The actuator controls a position of the head relative to the data storage medium. The processor communicates with the actuator and the servo signal processing circuit. The processor provides a filtered position error signal to the actuator to compensate for a position displacement between the head and the data storage medium. The filtered position error signal includes a sum of outputs from a first compensation filter and a second compensation filter that is each applied to the position error signal output. The compensation filters attenuate disturbance frequencies that contribute to the position displacement. Each of the compensation filters has a sampling rate relating to the respective disturbance frequency.

Abstract: A device for reading data recorded on a recording medium having multiple tracks, the device including: a receiver that receives designations of a number of data elements to be read; and a determination unit that determines an order of reading the data elements so that, no matter on which track of the tracks each of the data elements is recorded, the data elements are read in an order of recorded locations of the data elements in a direction along the tracks on which the data elements are recorded.

Abstract: The present invention, in some embodiments, relates to magnetic heads having modules with arrays of transducers able to read and/or write while the arrays are positioned at different angles relative to a magnetic medium, thereby enabling reading and/or writing in more than one data storage format. An apparatus according to one embodiment includes at least two modules, each of the modules having an array of N+1 transducers. Axes of the arrays are oriented about parallel to each other. N of the N+1 transducers of a first array of a first of the modules are about aligned with N of the N+1 transducers of a second array of a second of the modules when the axes of the arrays are tilted at a first angle between about 0.1° and about 10°.

Abstract: According to one embodiment, an electronic device includes a housing, a sensor, a disk device, a first determination controller, a first changing controller. The sensor senses a vibration of the housing. The disk device stores operation data, the disk device including a head, wherein the head retracts to a safety position when the sensed vibration exceeds a sensitivity level, and the operation data includes an evaluated value for evaluating an operation state of the head, and a threshold corresponding to the evaluated value. The first determination controller determines whether the evaluated value exceeds the threshold. The first changing controller changes the sensitivity level based on the result of the first determination controller.

Abstract: A method of testing a head for contamination includes detecting a first touchdown power of the head, the head having a flying height actuator; calculating a back-off power for the head using an estimated relationship between back-off power and touchdown power; determining an operating power that is equal to the detected first touchdown power minus the calculated back-off power; passing the head over a magnetic media one or more times while applying the determined operating power to the flying height actuator; detecting a second touchdown power after passing the head over the magnetic media; and determining whether contamination on the head exceeds a threshold amount based on the detected second touchdown power.

Abstract: A disk drive is disclosed comprising a disk, and a voice coil motor (VCM) operable to rotate an actuator arm about a pivot to actuate a head radially over the disk. A voice coil voltage is measured across the voice coil, a velocity command of the VCM is set to substantially zero, an inductor compensation circuit is toggled at least once by enabling and disabling the inductor compensation circuit, the inductor compensation circuit is enabled, the velocity command of the VCM is adjusted, and a control signal is generated and applied to the voice coil in order to move the actuator arm, wherein the control signal is generated in response to the adjusted velocity command, the voice coil voltage, and the estimated inductance voltage.

Abstract: A hard disc drive (HDD) of a larger native capacity is clipped to emulate a smaller capacity drive by allocating storage space in tracks in at least both a radially innermost region and radially outermost region of the platter(s). During normal operation, when data is written to or read from the clipped HDD, the actuator arm will move through its entire, normal range of motion, as the read/write heads seek tracks in both the radially inner and outer regions of the platter(s). In some embodiments, storage space is also allocated from tracks in regions interposed between the inner and outer regions. In one embodiment, all tracks on the platter(s) are divided into regions of substantially equal data storage capacity, and the storage space is allocated for the clipped HDD is divided substantially evenly across all the regions.

Abstract: A control system for a tape drive that uses position error signals (PESs) generated by a tape head assembly of the tape drive during longitudinal movement of a tape through the drive to dynamically adjust a lateral and/or angular position of tape to enhance tape drive performance (e.g., the ability of a tape head assembly to precisely follow one or more data and/or servo tracks on the tape). In one arrangement, the PESs and/or PES metrics are used as feedback into the system to steer the tape by moving one or more tape path guides until subsequently generated PESs or PES metrics have been optimized or have at least moved back into an acceptable range or to acceptable levels. The disclosed control system facilitates achieving increased stringencies on PES minimization that come with increased tape drive magnetic track densities.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, a spindle motor operable to rotate the disk, and a ramp near an outer periphery of the disk. When an emergency condition is detected, the head is unloaded onto the ramp, and failure analysis data identifying a cause of the emergency condition is logged.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, and a dynamic fly height (DFH) actuator operable to control a fly height of the head over the disk. A DFH control signal is applied to the DFH actuator to decrease the fly height of the head, wherein the DFH control signal comprises a DC component and an AC component comprising an excitation frequency. A touchdown metric is measured over an interval, and the head contacting the disk is detected in response to a frequency component of the touchdown metric at the excitation frequency.

Abstract: A disk drive is disclosed comprising a servo control system configured to control an actuator for actuating a head over a disk. Servo sectors are sampled at a servo sample frequency fs to generate a position error signal PES(k) that is filtered with a compensator to generate a first control signal u1(k). A first discrete-time sinusoid comprising a sinusoid frequency of fs+?f is added to the first control signal u1(k) to generate a second control signal u2(k). The second control signal u2(k) is applied to the actuator, and a frequency response of the actuator is determined at the frequency |?f|. The frequency response of the actuator is determined at the frequency fs+?f based at least in part on the frequency response of the actuator at the frequency |?f| and a measured signal of the servo control system when applying the second control signal u2(k) to the actuator.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks. A plurality of consecutive data tracks are written, and after writing to the plurality of consecutive data tracks, a first number of the consecutive data tracks are read and a second number of the consecutive data tracks are skipped, wherein the second number of data tracks are interleaved with the first number of data tracks. Defects in the data tracks are detected in response to reading the first number of data tracks.

Abstract: A library device in which, even if the relation between the number of pulses of a stepping motor and an encoder count number changes, a movement distance of a medium transfer means can be verified by an encoder count number counted by an encoder sensor is provided. A control means (2) determines a proof factor used when calculating an assumed encoder count number assumed based on the number of pulses according to a movement distance of a medium transfer means (5). When a movement distance of the medium transfer means (5) is verified, an assumed encoder count number, which is assumed based on the above-mentioned determined proof factor and the number of pulses according to the movement distance of the medium transfer means (5), and an actual encoder count number, which is counted by an encoder sensor when a stepping motor is driven by the number of pulses according to the movement distance of medium transfer means (5), are compared.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of servo tracks, wherein each servo track comprises a plurality of servo sectors. A plurality of zones are defined, wherein each zone comprises a plurality of the servo tracks. A metric is generated for each zone, and when the metric for a first zone exceeds a first threshold, feedback compensation values for at least two servo tracks are generated, wherein the feedback compensation values compensate for a written-in error of the servo sectors of each servo track. When the metric for a second zone does not exceed the first threshold, generating feedback compensation values for the second zone is skipped.

Abstract: A disk storage apparatus according to one embodiment includes a head, a storage device, a write module and a controller. The head writes data on a disk. The storage device has a storage area for temporarily storing the data written by the head. The write module writes data to tracks on a disk, while partially overlapping the data with previously written data to adjacent track. The controller detects a drift-off write of the head while writing data, determines a drift-off write area in which the drift-off write is occurred, and protects the data written in the storage area, if the data is written in the drift-off write area.

Abstract: A contact detection system includes a comparator operable to compare a signal derived from a contact sensor with a threshold and to indicate contact when the signal is greater than the threshold, a parameter estimation circuit operable to estimate parameters of a probability density function based on the signal derived from the contact sensor, and a threshold calculator operable to calculate the threshold based at least in part on the parameters of the probability density function.

Abstract: A magnetic head is arranged between two reels around which a magnetic tape is wound and contacts one side of the magnetic tape spanned between the two reels. A driver moves the magnetic head. A controller causes the driver to generate a driving force for pressing the magnetic head against the one side of the magnetic tape while keeping the magnetic head in contact with the magnetic tape. It is possible to cause the magnetic head to stably contact the magnetic tape even when the running position of the magnetic tape varies in accordance with the winding state of the magnetic tape around the reel.

Abstract: A disk drive is disclosed comprising a disk, a head comprising a laser operable to heat the disk while writing data to the disk, and a fly height actuator (FHA) operable to actuate the head vertically over the disk. A laser power applied to the laser during a write operation is calibrated, and a FHA write setting is generated for the FHA as a function of the calibrated laser power.

Abstract: A disk drive is disclosed wherein N data wedges of write data are buffered in a buffer. After writing at least two of the data wedges to the disk including a first data wedge and a second data wedge, a first servo metric value is measured when reading a first servo sector, and a second servo metric value is predicted based on the first servo metric value, wherein the second servo metric value corresponds to a second servo sector following the first servo sector. When the first servo metric value indicates a safe write condition and the second servo metric value indicates an unsafe write condition, the first data wedge is released from the buffer, and when the first servo metric value indicates a safe write condition and the second servo metric value indicates a safe write condition, the first and second data wedges are released from the buffer.

Abstract: Systems and methods for reducing problems and disadvantages associated with protecting data during cold excursions are provided. A method for preventing unreliable data operations at cold temperatures may include determining whether a first internal temperature of a hard disk drive (HDD) is below a threshold temperature. The method may also include initiating an artificial seek operation if the first internal temperature is below the threshold temperature.