Abstract: The present invention includes a liquid lens; a voltage control circuit, and a switching unit, wherein the liquid lens includes a first plate comprising a cavity in which a conductive liquid and a non-conductive liquid are disposed; a second plate disposed above the first plate; and a third plate disposed below the first plate, wherein the voltage control circuit includes a first voltage generator configured to output a first voltage; and a DC bias terminal disposed between an output terminal of the first voltage generator and a ground voltage, and wherein the switching unit includes a plurality of first switches configured to transmit one selected from among the first voltage and the ground voltage to the plurality of individual electrodes; and a second switch configured to transmit one selected from among the first voltage and the ground voltage to the common electrode.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head, a command queue, a command residence time calculation unit calculating a residence time of each of commands in the command queue, a command information calculation unit calculating the number of the commands and a ratio, a limit time determination unit obtaining a latency limit time corresponding to the number of commands and the ratio, from a latency limit time determination table, and a command selection processing unit selecting a command to be executed, by considering the latency limit time.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to one or more disk surfaces of the one or more disks; and one or more processing devices, comprising an actuator mechanism control system configured for controlling the actuator mechanism. The one or more processing devices are configured to: output a multi-rate excitation to at least one multi-rate notch filter of the actuator mechanism control system; detect a frequency response of the actuator mechanism in response to the multi-rate excitation; and calibrate the at least one multi-rate notch filter of the actuator mechanism control system, based at least in part on the detected frequency response of the actuator mechanism.

Abstract: A servo direct-current feeder system can reduce an oscillating voltage across a power feeding path. The servo direct-current feeder system includes a direct-current power supply, a plurality of motor controllers that each control a servomotor, and a power feeding path that distributes power from the direct-current power supply to the plurality of motor controllers. Each of the plurality of motor controllers includes a current control loop unit that controls a current flowing through the servomotor. The current loop unit includes a current control loop including a notch filter having a center frequency corresponding to a frequency to occur from an oscillating voltage across the power feeding path.

Abstract: An apparatus and a method for generating a voice coil actuator (VCA) signal is described. A drive signal is generated to drive the VCA and a resulting current signal from the VCA detected. The frequency of the drive signal is adapted in response to detecting an asymmetry in the current signal.

Abstract: The present disclosure provides a feedback control system and method for a bidirectional VCM. The system employs an analog core that is common to both the PWM and linear modes of operation. The analog core includes a feedback mechanism that determines the error in the current flowing through the motor. The feedback mechanism produces an error voltage that corresponds to the current error, and applies the voltage to a control driver. The control driver then controls the motor, based on the error voltage, in either a PWM or linear mode. By sharing a common core, the switching time between modes is improved. Furthermore, the output current error between modes is reduced.

Abstract: A method and device for increasing an accuracy of a phase measurement, wherein the method includes: receiving a measurement signal; performing a frequency-domain transformation to the measurement signal to obtain a frequency-domain measurement sequence; determining phases that correspond to frequency-domain measurement signals, and determining a phase difference between the frequency-domain measurement signals that correspond to two neighboring specified frequency points; according to the phases, the phase difference and a window function, performing a sliding-window-type phase fitting to the frequency-domain measurement sequence, to obtain phase-fitting data that correspond to sliding windows; and according to the phase-fitting data of the sliding windows, determining phase-calibration data that correspond to the sliding windows, and, by using the phase-calibration data of the sliding windows, forming phase-calibration data within a specified frequency band.

Abstract: The technology described herein enables data storage across storage volumes having fewer features than the storage volumes otherwise would. In one example, a method includes, in a data access system, identifying first data for storage on physical storage volumes. Each of the physical storage volumes corresponds to respective ones of data channels and control channels. The method further includes segmenting the first data into data segments corresponding to respective ones of the data channels and transferring the data segments as respective bit streams over the respective ones of the data channels to the respective ones of the physical storage volumes. The method also includes providing real-time write control to the physical storage volumes over respective ones of the control channels. The real-time write control directs a process for how the physical storage volumes write the data segments.

Abstract: An apparatus comprises a mass storage unit and a plurality of circuit modules including a machine learning module, a programmable state machine module, and input/output interfaces. Switching circuitry is configured to selectively couple the circuit modules. Configuration circuitry is configured to access configuration data from the mass storage unit and to operate the switching circuitry to connect the circuit modules according to the configuration data.

Abstract: Provided is a technology of enabling notification, to a user, that the state of a machine system has changed prior to occurrence of machine resonance, irrespective of the direction of a resonance frequency change.

Abstract: For improving data placement optimization in a computing storage environment, an application layer and/or a user are allowed to attach anticipated usage metadata and directive metadata to a file. The anticipated usage metadata contains a plurality of attributes describing characteristics of the file and the directive metadata contains directives comprising storage instructions for the file. Additionally, a set of metadata is added to the file at a time of creation. The core metadata includes characteristics such as an importance factor as to how essential the anticipated usage metadata and directive metadata should be followed when determining file placement with the computing storage environment.

Abstract: ECC is used to for controlling errors in blocks of data by including a measure of redundancy within the data for recovering one or more unreadable portions of the data. A codeword includes at least a message and one or more additional ECC blocks. In the event of an unreadable sector, the ECC is decoded and used to recover the erroneous or missing portion(s) of the message. With disc access parallelism, ECCs can now be distributed across data storage surfaces and/or multiple storage platters. Distribution of ECCs increases the likelihood of recovering data from a head failure or from burst errors on a data storage surface and adds the option to decode parity after only 1/n revolutions.

Abstract: The present technology includes a memory system and a method of operating the memory system. The memory system includes a memory device including an interface circuit and a semiconductor memory, and a controller configured to generate a command for controlling the memory device and output the command to the memory device. The interface circuit receives the command, transmits the received command to the semiconductor memory when the received command corresponds to the semiconductor memory, and performs a training operation of the interface circuit when the received command corresponds to the interface circuit and the received command is a specific command.

Abstract: A machine learning device performs machine learning related to optimization of a compensation value of a compensation generation unit with respect to a servo control device that includes a compensation generation unit configured to generate a compensation value to be added to a control command for controlling a servo motor and a limiting unit configured to limit the compensation value or the control command to which the compensation value is added so as to fall within a setting range. During a machine learning operation, when the compensation value or the control command is outside the setting range and the limiting unit limits the compensation value or the control command so as to fall within the setting range, the machine learning device applies the compensation value to the learning and continues with a new search to optimize the compensation value generated by the compensation generation unit.

Abstract: This disclosure describes, among other things, embodiments of devices, systems, and methods for using 3-dimensional (3D) magnetic sensors to detect the position of a magnetic target. By using 3D magnetic sensors, a two dimensional array of such magnetic sensors can be used to determine a 3D position of a magnetic target.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head including a write head configured to write data on the disk, a first read head, and a second read head each configured to read data from the disk, and a controller configured to detect a first error of each track pitch corresponding to each track of the disk on the basis of a first gap in a radial direction between the first read head and the second read head at each position in the radial direction of the disk, write a servo pattern on the disk on the basis of a first correction value used to correct the first error, and position the head on the basis of the servo pattern.

Abstract: Example alignment members are provided herein. In one example, the alignment member includes a frame member, a stiffener member, a bracket member, and a spring member. The frame member includes a set of roller bushings. The stiffener member includes a set of cam members. The bracket member to receive the stiffener member. The spring member is connected to the stiffener member. The spring member to expand and contract based on the position of the set of roller bushings.

Abstract: Example alignment members are provided herein. In one example, the alignment member includes a frame member, a stiffener member, a bracket member, and a spring member. The frame member includes a set of roller bushings. The stiffener member includes a set of cam members. The bracket member to receive the stiffener member. The spring member is connected to the stiffener member. The spring member to expand and contract based on the position of the set of roller bushings.

Abstract: Apparatus and method for managing data transfers in a data storage device with rotational media that can be rotated at different speeds. In some embodiments, a non-volatile main memory is formed on a rotatable medium accessed by a moveable data transducer. A media cache provides a non-volatile data storage area. A control circuit directs writes to the main memory as the medium is rotated at a first speed and directs reads from the main memory as the medium is rotated at a higher, second speed. Writes during the rotation of the medium at the second speed are directed to the media cache instead of to the main memory so that no data are written to the main memory at the second speed. The media cache may also be located on the medium or may be formed from solid-state semiconductor memory.

Abstract: According to an embodiment, a magnetic disk, a magnetic head, an actuator and a processing unit are provided. The processing unit acquires a feature amount from a position error between a demodulated position and an estimated position of the magnetic head based on a frequency resonance characteristic of the actuator or a frequency characteristic of vibration caused by disturbance of the actuator and, based on the feature amount, sets an on-track determination number used for confirming an on-track state of the magnetic head after seeking.

Abstract: Various techniques for speech coding and decoding are disclosed. For example, speech data generated from a speech signal may be decoded by receiving the speech data in a format that has at least one main pulse in a subframe of the speech data, and generating a first predicted pulse that has a lower gain than the main pulse. A second predicted pulse may also be generated as a mirror image of the first predicted pulse on a reverse time scale, on the other side of the main pulse in the subframe of the speech data. The the speech signal may be reconstructed using the first predicted pulse and the second predicted pulse.

Abstract: A method employing linear precoding and non-linear precoding for transmitting data between at least two transmitters and a plurality of receivers via a plurality of communication channels over a plurality of subcarrier frequencies, the method comprising the procedures of transmitting by either one of said at least two transmitters, at least two training signals to respective said receivers; receiving by respective said receivers, said at least two training signals; evaluating channel characteristics of at least part of said communication channels, according to said at least two training signals; determining a precoding scheme selection that defines for at least part of said communication channels, over which of said subcarrier frequencies, said data transmitted shall be precoded using either one of linear precoding and non-linear precoding, according to evaluated said channel characteristics; precoding said data according to determined said precoding scheme selection; and transmitting said data according said

Abstract: A hard disk device comprises a scanning mechanism that simultaneously scans a first recording medium surface with a first recording head and a second recording medium surface with a second recording head, a table storing band relative position information for a first band on the first recording medium surface and a second band on the second recording medium surface, and a processor. The processor calculates an inter-plane relative trajectory error between the first and second recording heads, determines a data access order performed by the first recording head on the first band and the second recording head on the second band, based on the band relative position information and the inter-plane relative trajectory error, and causes the first recording head to access a track and the second recording head to access a track in the data access order determined by the determining unit.

Abstract: A system is configured to use a de-randomizer and budget data structure to economize I/O operations for a shared storage device while still allowing access to the device to a number of different entities. Embodiments can identify a comparatively low cost next operation as compared to other I/O operations, including a cost for seek time, for a first entity to dispatch to the storage device when the first entity has sufficient budget to have the I/O operation performed on its behalf and to identify an I/O operation for a second entity to dispatch to the storage device when there is insufficient budget for the first entity.

Abstract: A method includes tracking access to files that are stored on a single disk, and identifying a file access sequence involving a first file and a second file stored on the disk, wherein the first file is accessed before the second file. The method further includes determining a time differential between a time that the first file is accessed and a time that the second file is accessed, and determining a direction and speed at which a drive head of the disk can move between sectors and tracks of the disk. Still further, the method includes migrating one or both of the first and second files to a new location on the disk so that, after the drive head of the disk has read the first file, the drive head is repositioned at a beginning of the second file in a period of time that is a function of the time differential.

Abstract: A data processing method includes acquiring to-be-stored data in a data table in a columnar database; dividing and/or combining the to-be-stored data according to space of an allocated disk cylinder; and storing same-row data of the to-be-stored data in a same disk cylinder, and in the disk cylinder, successively storing data in each section of columns. Correspondingly, the present disclosure further discloses a data writing method and a related apparatus and device. A technical problem in the prior art that a write speed is slow when a columnar database is running is resolved using the present disclosure, which greatly improves write efficiency of a columnar database. In addition, direct parallel reading or writing may also be implemented by means of hardware marking.

Abstract: A data compressing apparatus includes a polygonal line approximating circuit receiving first time series and outputs second time series by performing a polygonal line approximation process on the first time series. The polygonal line approximating circuit includes a first multiplier and a second multiplier performing multiplication having a first value calculated based on a difference between a time component of first data and a time component of second data in the time series data as input, and a third multiplier and a fourth multiplier performing multiplication having a second value calculated based on a difference between a sensor component of the first data and a sensor component of the second data as input.

Abstract: A feedback control system includes at least one servo unit controlling operation of a motor, wherein the at least one servo unit is configured to acquire operational data with respect to controlling the operation of the motor. The feedback control system also includes a programmable logic controller communicatively coupled to the at least one servo unit, wherein the programmable logic controller is configured to receive the operational data from the at least one servo unit and output real-time data corresponding to the operational data.

Abstract: An actuator control method and an actuator control device that incorporate an element of feedback control in time optimal control, including: a calculation step of calculating a switching time at which an acceleration output is switched to a deceleration output and an end time of the deceleration output expressed by time elapsed from a calculation time at which calculation for control is performed using a maximum acceleration and a maximum deceleration, which are measured in advance, at the time of the maximum output of control force of an actuator; a control output step of setting the control force of the actuator to a maximum acceleration output from the calculation time to the switching time, setting the control force of the actuator to a maximum deceleration output from the switching time to the end time, and ending the output of the control force at the end time, and an update step of calculating and updating the switching time and the end time by repeating the calculation step at each preset time.

Abstract: Systems and methods are disclosed for positioning of a reader element in a data storage device employing shingled recording. In an embodiment, an apparatus may comprise a processor configured to receive a read command to retrieve data from a data storage medium having data stored in a shingled manner where at least one track is partially overlapped by an adjacent track, and retrieve the data by adjusting a position of a read element according to a track offset compensation value based on a measured parameter. In another embodiment, a method may comprise determining a track offset compensation value for a first area of a data storage medium based on a measured parameter for the area, adjusting a position of a read head based on the track offset compensation value, and reading data from the first area using the read head.

Abstract: Methods and apparatuses for generating and using servo correction data are disclosed. In one embodiment, an apparatus may comprise a data storage medium having a first track and a second track, servo correction data for the first track and the second track stored on the first track, and no servo correction data stored on the second track, and a controller configured to correct servo errors based on the servo correction data. In another embodiment a method may comprise receiving servo information related to a first data storage medium having a first track and a second track, generating one or more position error signals (PES) based on the servo information, generating servo correction data based on the one or more PES, and storing the servo correction data for the first track and the second track on the first track.

Abstract: A back electromotive force monitoring circuit has a speed detection voltage generator which biases a back electromotive force generated by a voice coil motor with a predetermined reference voltage to generate a speed detection voltage, and a calculator which generates a motor control signal in accordance with the speed detection voltage. The calculator includes a subtracter which subtracts the reference voltage from the speed detection voltage prior to generation of the motor control signal.

Abstract: Managing data stored in a Data Storage Device (DSD) including at least one disk for storing data. Data is written in a first region of the at least one disk with a first track density. A frequency of access is determined for the data written in the first region, and the frequency of access is compared to a threshold. Based on the comparison, a copy of the data written in the first region is written in a second region of the at least one disk with a second track density different than the first track density.

Abstract: A method and a device for efficient write operations are disclosed, which may be used in connection with shingled magnetic recording (SMR) in order to reduce write amplification (read-modify-write). The tracks on at least one data carrier surface are grouped into bands, and the address space of logical block addresses is divided into address subsets. Each of these address subsets is permanently assigned to a dedicated selection of tracks derived from all bands. Depending on the embodiment, the dedicated selection of tracks may be chosen in such a way that no write amplification occurs in a first phase and/or that recent data or newly added data can be altered without necessitating read-modify-write.

Abstract: An apparatus for observing turns and twists in magnetic phenomena including a nonferrous box, a stationary platform set in the middle of the box with a post to support a magnet, a right-hand and a left-hand screws united with coupling and having moving platforms at equal distance from the middle fixed platform with posts to support the specimen, the specimen poized by the magnetic field, and to hover the specimen move the platforms back and forth in continuous and intermittent motions, dc stepper motor to provide the motion, and controlled by power supply, push button switches, and limit switches.

Abstract: An apparatus comprises a controller configured to detect a seek failure of a read/write head. The controller is additionally configured to perform a seek recovery operation in accordance with a recovery sequence in response to the seek failure; the recovery sequence comprising a plurality of recovery procedures. Further, the controller is configured to determine if the seek recovery operation is successful and determine which of the recovery procedures provided the success. And, the controller is configured to dynamically calculate the success rate of each recovery procedure, modify the recovery sequence based on the success of the seek recovery operation and based on the success rate of recovery procedures providing the success.

Abstract: An apparatus includes: a media; a head over the media; and control circuitry configured to cause the head to: write a first precondition track with a preconditioning pattern on the media, and write a data track on the media at a first inter-track spacing with the head positioned in a first direction from the first precondition track.

Abstract: A disk drive is disclosed comprising a head actuated over 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 control circuitry including a read channel. The control circuitry configures a power mode of the read channel into a no-op mode, and when the head approaches a servo sector, configures the power mode into a servo mode. After configuring the power mode into the servo mode, the control circuitry waits for a pre-servo gate period, and after the pre-servo gate period, enables a servo gate to read the servo sector. After reading the servo sector, the control circuitry disables the servo gate and waits for a post-servo gate period. After the post-servo gate period, the control circuitry configure the power mode into the no-op mode.

Abstract: A hybrid drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, and a non-volatile semiconductor memory (NVSM). An access command is received from a host, the access command identifying at least one target logical block address (LBA). When the target LBA is mapped to a target data track on the disk, the head is positioned over the target data track and an accumulated access time is updated for the target LBA. The accumulated access time is compared to a first threshold, and the target LBA is migrated to the NVSM in response to the comparison.

Abstract: A disk drive is disclosed comprising a servo control system operable to actuate a head over a disk. A sensor signal is filtered with a first filter comprising a frequency response, and the filtered sensor signal is filtered to generate a compensated sensor signal. An error signal is filtered with a second filter comprising the frequency response, and an adaptation control signal is generated based on the compensated sensor signal and the filtered error signal. An adaptive filter is adapted in response to the adaptation control signal, wherein the adaptive filter filters the sensor signal to generate feed-forward compensation values. The feed-forward compensation values are applied to the servo control system to compensate for the disturbance. A disturbance signal that represents the disturbance is generated, and the frequency response of the first and second filters is optimized based on the sensor signal and the disturbance signal.

Abstract: A data storage system according to one embodiment includes a magnetic head, a drive mechanism for passing a magnetic medium over the magnetic head, and a controller electrically coupled to the magnetic head. The data storage system is configured to use at least two different track width formats, where which of the at least two different track width formats used by the system during reading and/or writing of data is selectable. A magnetic tape-based data storage system according to another embodiment includes a magnetic head; a drive mechanism for passing a magnetic recording tape over the magnetic head; and a controller electrically coupled to the magnetic head, wherein the system is configured to use at least two different track width formats, wherein which of the at least two different track width formats used by the system during reading and/or writing of data is selectable.

Abstract: A disk drive is disclosed comprising a disk comprising tracks defined by servo sectors, a head, and control circuitry comprising a servo control system operable to actuate the head over the disk in response to the servo sectors. The servo control system is configured into a first state, and a position error signal (PES) representing a difference between a target location for the head and a measured location for the head is generated. An actuator control signal is generated in response to the PES, a feed-forward control signal is adapted in response to the servo sectors, and the actuator control signal is adjusted using the feed-forward control signal. The servo control system is configured from the first state to a second state, and a phase of the adaptation of the feed-forward control signal is adjusted based on the second state.

Abstract: A portable computing device prevents a magnetic disk unit protecting function from impairing usability for a user when the processor is used as a tablet PC. The portable computing device includes a magnetic disk unit, a magnetic disk unit protecting section operable when predicting an occurrence of an impact to carry out a magnetic disk unit protecting function for retracting a head of the magnetic disk unit, and a detecting section that detects whether a user is holding the portable computing device or not, and responsive to detecting that the user is holding the portable computing device, temporarily deactivating the magnetic disk unit protecting function.

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: Systems and techniques relating to storage devices, such as storage devices that employ Shingled Magnetic Recording (SMR), can include a device, which includes: circuitry configured to write stored data and parity data to discrete portions of a Shingled Magnetic Recording (SMR) track in a SMR storage device; and circuitry configured to recover stored data for one of the discrete portions of the SMR track using the parity data and the stored data read from remaining ones of the discrete portions of the SMR track.

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 disk drive is disclosed comprising a disk and a head actuated over the disk. A burst metric is generated in response to a burst read signal. The burst metric comprises at least one of an alpha metric comprising a ratio of a first burst amplitude of a first phased based servo burst measured at a first radial offset to a second burst amplitude of a second phased based servo burst measured at a second radial offset, a harmonic metric comprising a ratio of a first harmonic of the burst read signal as the head is moved radially over the disk to a higher harmonic of the burst read signal as the head is moved radially over the disk, and a spiral track crossing metric comprising a first and second interval each representing a partial duration of the read element crossing a spiral track.

Abstract: According to one embodiment, a first slider of a disk storage apparatus includes a first head and flies over a first recording surface of a first disk. A heater element in the first head projects the first head toward the first recording surface of the first disk depending on heater power. A controller of the apparatus reduces a value for the heater power from a first value to a second value before performing a seek operation of moving the first head such that the first head moves across a concentric circular area including a protrusion on the first recording surface. The controller measures a wait time needed for a flying height of the first head to increase to a first flying height in response to the reduction and starts the seek operation after the wait time elapses.

Abstract: A method of operating a disk drive is disclosed wherein the disk drive comprises a disk comprising a plurality of tracks, a head, and a closed loop servo system comprising a seek servo loop and a settle servo loop for actuating the head over the disk. When the head approaches a target track during a seek operation, the settle servo loop is enabled wherein a feedback control signal is generated based on a measured state of the servo system. The feedback control signal is adjusted with a feed-forward compensation. A phase shift between the measured state of the servo system and a corresponding estimated state of the servo system is compensated. The head is settled on the target track in response to the feed-forward compensation.

Abstract: A data storage device is disclosed comprising a head actuated over a disk, a spindle motor configured to rotate the disk, and control circuitry configured to perform a power fail operation by boosting a power voltage generated based on the spindle motor to generate a boosted voltage, controlling an operation of the data storage device using the boosted voltage, and when the power voltage falls below a threshold, reducing the boosting so as to reduce the boosted voltage.