Abstract: Various illustrative aspects are directed to a data storage device comprising one or more disks, an actuator arm assembly comprising one or more disk heads and a voice coil motor (VCM), the VCM configured to operate in a PWM mode and a linear mode, and one or more processing devices configured to: seek the VCM towards a target track in the PWM mode; transition the VCM from the PWM mode to the linear mode, wherein the transitioning comprises switching an offset compensation value from a first offset compensation value to a second compensation offset value to compensate for a transition offset induced while transitioning the VCM from the PWM to the linear mode, wherein the first and the second offset compensation values correspond to the PWM and linear modes, respectively, and seek the VCM towards the target track in the linear mode for a linear mode time.

Abstract: A VCM (voice coil motor) is disclosed, the VCM including: a rotor including a lens-accommodating, both ends opened cylindrical bobbin and a coil block including a coil wound on a periphery of the bobbin; a stator including a cylindrical yoke formed with a lens-exposing opening, a plurality of magnets disposed inside the yoke and opposite to the coil block, and a housing disposed inside the yoke to fix the plurality of magnets; and an elastic member elastically supporting the bobbin.

Abstract: A rotary reciprocating drive actuator which includes a base portion including a bottom portion, and a pair of wall portions erected from both ends of the bottom portion; a movable body including a shaft portion rotatably supported by the pair of the wall portions via a bearing in such a manner that a movable magnet disposed at an outer side surface of one wall portion of the pair of the wall portions; and a drive unit including a core body and a coil body, the drive unit being attached to the outer side surface of the one wall portion, wherein another wall portion of the pair of wall portions is configured to be detachable from or adjustable in position with respect to the bottom portion.

Abstract: A rotary reciprocating drive actuator reciprocally and rotationally driving the movable body about the shaft part in relation to the fixed body by the electromagnetic mutual effect of the coil and the movable magnet, wherein the movable magnet is magnetized in the radial direction of the shaft part, the two magnetic poles are disposed facing each other across an air gap in the radial direction of the movable magnet and the shaft part, and the fixed body has a rotation-angle-holding part disposed facing the movable magnet across the air gap, the rotation-angle-holding part holding the rotation angle position of the movable magnet by the magnetic attraction force generated with the movable magnet.

Abstract: A data storage device includes a disc, an actuator arm assembly, a servo clock, and a feedback and control system. The disc includes a top and bottom surfaces and a servo wedge. The servo wedge includes a top surface boundary and a bottom surface boundary. The actuator arm assembly supports a head pair configured for interaction with the top and bottom surfaces. The servo clock is configured to determine a top time at which the head pair encounters the top surface boundary and a bottom time at which the head pair encounters the bottom surface boundary during a disc read/write interaction. The feedback and control system is configured to determine an operation time difference; compare the operation time difference to a certification time difference correlating to a target vertical position of the actuator arm assembly relative to the disc; and move the actuator arm assembly to the target vertical position.

Abstract: A coil system, including: pairs of planar coils vertically stacked in a vertical direction, each pair of planar coils including a first planar coil including a first outer turn and a second planar coil including a second outer turn overlapping the first outer turn and laterally offset from the first outer turn; and pairs of vertically stacked thermal conductor tracks, each pair of thermal conductor tracks including a first track and a second track overlapping the first track, laterally offset from the first track, and overlapping the first outer turns of the pairs of planar coils. The pairs of thermal conductor tracks are DC isolated from pairs of planar coils. The first outer turns and the second outer turns of the pairs of planar coils form a first comb-like structure. The plurality of pairs of thermal conductor tracks form a second comb-like structure engaged with the first comb-like structure.

Abstract: Various embodiments of the present disclosure provide a read/write device for a hard-disk memory system. The read/write device includes a fixed structure; a membrane region including a first and a second membrane, which are constrained to the fixed structure, and a central portion, interposed between the first and second membranes; a first and a second piezoelectric actuator, mechanically coupled, respectively, to the first and second membranes; and a read/write head, which is fixed to the central portion of the membrane region. The first and second piezoelectric actuators can be controlled so as to cause corresponding deformations of the first and second membranes, said deformations of the first and second membranes causing corresponding movements of the read/write head with respect to the fixed structure.

Abstract: Various illustrative aspects are directed to a data storage device comprising one or more disks, an actuator arm assembly comprising one or more disk heads and a voice coil motor (VCM), the VCM configured to operate in a PWM mode and a linear mode, and one or more processing devices configured to: seek the VCM towards a target track in the PWM mode; transition the VCM from the PWM mode to the linear mode, wherein the transitioning comprises switching an offset compensation value from a first offset compensation value to a second compensation offset value to compensate for a transition offset induced while transitioning the VCM from the PWM to the linear mode, wherein the first and the second offset compensation values correspond to the PWM and linear modes, respectively, and seek the VCM towards the target track in the linear mode for a linear mode time.

Abstract: A platform includes first and second actuation layers. The first actuation layer includes first and second frames and a plurality of actuators connected between the first frame and the second frame, wherein the plurality of actuators are adapted to move the first and second frames with respect to each other in a first direction. The second actuation layer includes third and fourth frames and a plurality of actuators connected between the third frame and the fourth frame, wherein the plurality of actuators are adapted to move the third frame and the fourth frame with respect to each other in a second direction, different from the first direction. Thereby, the fourth frame of the second actuation layer and the second frame of the first actuation layer are mechanically connected to each other, such that the second actuation layer experiences the movement in the first direction induced by the first actuation layer.

Abstract: In illustrative aspects, a system comprises an actuator; a control object, controlled by the actuator; and one or more processing devices. The one or more processing devices are configured to perform positioning control of the control object via the actuator, wherein performing the positioning control comprises: generating a feedforward polydyne positioning control input; and outputting the feedforward polydyne positioning control input to the actuator.

Abstract: A movable magnet is configured by alternately magnetizing an even number of magnetic poles forming an South pole and an North pole; a number of magnetic poles of a core body is equal to a number of magnetic poles of the movable magnet; an even number of magnetic poles of the core body is respectively arranged to face the movable magnet with an air gap therebetween on the outer peripheral side of a shaft portion; and a drive unit is provided with a magnet position holding portion to face the movable magnet and magnetically attracts the movable magnet to a reference position. A drive unit is attached to one wall portion of the pair of wall portions of a base portion, and an angle sensor portion for detecting a rotation angle of the shaft portion is attached to the other wall portion of the pair of wall portions.

Abstract: Various embodiments of the present disclosure provide a read/write device for a hard-disk memory system. The read/write device includes a fixed structure; a membrane region including a first and a second membrane, which are constrained to the fixed structure, and a central portion, interposed between the first and second membranes; a first and a second piezoelectric actuator, mechanically coupled, respectively, to the first and second membranes; and a read/write head, which is fixed to the central portion of the membrane region. The first and second piezoelectric actuators can be controlled so as to cause corresponding deformations of the first and second membranes, said deformations of the first and second membranes causing corresponding movements of the read/write head with respect to the fixed structure.

Abstract: An integrated circuit includes an H-bridge circuit having a first output node for coupling to a high-side terminal of an inductor and a second output node for coupling to a low-side terminal of the inductor. A current sense FET is coupled between a current source and the lower supply voltage to provide a reference current that includes a peak current limit at a sensing node. A current-sense comparator has a first input coupled to the sensing node, a second input coupled to the second output node and an output coupled to send an output signal towards a driver control circuit. A FET linear detection circuit is coupled to receive a gate voltage of an active low-side power FET and has an output coupled to enable the current-sense comparator when the active low-side power FET is operating in a linear region.

Abstract: A recording surface of a magnetic disk is divided into first and second zones. A first head of a first actuator arm assembly reads from and/or writes to the first zone exclusively. A second head of a second actuator arm assembly reads from and/or writes to the second zone exclusively. The first and second head are capable of simultaneously reading from and writing to the recording surface.

Abstract: A faulty tracking condition affecting a first head driven by a first actuator of a hard disk drive is determined. The faulty tracking condition is caused by a second actuator of the hard disk drive that is moving while the first actuator is performing a tracking operation. Responsive to the determination of the faulty tracking condition, seek forces of the second actuator that cause the faulty tracking condition affecting the first head are reduced. A controller verifies that similar faulty tracking conditions are reduced with the first head in response to the reduction in seek forces.

Abstract: A data storage device is disclosed comprising a first voice coil motor (VCM) comprising a first voice coil configured to actuate a first head over a first disk, and a second VCM comprising a second voice coil configured to actuate a second head over a second disk. The data storage device further comprises a spindle motor configured to rotate the first and second disk, wherein during a power failure the first and second disks rotating causes the spindle motor to generate a back electromotive force (BEMF) voltage. During the power failure, the BEMF voltage is applied to the first VCM and to the second VCM during a first interval. The BEMF voltage is monitored, and when the BEMF voltage falls below a first threshold, the BEMF voltage is disconnected from the first VCM and the second VCM during a second interval.

Abstract: A host for controlling a non-volatile memory card, a system including the same, and methods of operating the host and the system are provided. The method of operating the host connected with the non-volatile memory card through a clock bus, a command bus, and one or more data buses includes transmitting a first command to the non-volatile memory card through the command bus, transmitting first data corresponding to the first command to the non-volatile memory card through the one or more data buses or receiving the first data from the non-volatile memory card through the data buses, and transmitting a second command to the non-volatile memory card at least once through the command bus during or before transfer of the first data.

Abstract: A data storage device is disclosed comprising a first voice coil motor (VCM) configured to actuate a first head, and a second VCM configured to actuate a second head. A high priority is assigned to the first VCM and a low priority to the second VCM. A first access command is serviced using the first head by seeking the first VCM using a first high performance seek profile. When seeking the second VCM without seeking the first VCM, a second access command is serviced using the second head using a second high performance seek profile. When concurrently seeking the first VCM and the second VCM, the seeking of the second VCM is with a reduced performance seek profile, wherein the second high performance seek profile decreases a seek time of the second VCM compared to the reduced performance seek profile.

Abstract: A data storage device is disclosed comprising a first voice coil motor (VCM) comprising a first voice coil configured to actuate a first head over a first disk, a second VCM comprising a second voice coil configured to actuate a second head over a second disk, and a spindle motor configured to rotate the first and second disk, wherein during a power failure the first and second disks rotating causes the spindle motor to generate a back electromotive force (BEMF) voltage. During the power failure the first and second VCMs are unloaded, wherein during a first interval the first voice coil is connected to the BEMF voltage and the second voice coil is disconnected from the BEMF voltage, and during a second interval the second voice coil is connected to the BEMF voltage and the first voice coil is disconnected from the BEMF voltage.

Abstract: A data storage device is disclosed wherein multiple voice coil motors (VCMs) are unloaded using a back electromotive force (BEMF) voltage generated by a spindle motor. A velocity and position of each VCM is measured, and a priority assigned to each VCM based on the measured velocity and position. During a delay interval, the BEMF voltage is used to apply a first brake voltage to a high priority VCM and to apply a second brake voltage to a low priority VCM, wherein the second brake voltage is lower than the first brake voltage. After the delay interval, the BEMF voltage is used to apply the first brake voltage to the high priority VCM and to apply a third brake voltage to the low priority VCM, wherein the third brake voltage is higher than the second brake voltage.

Abstract: The disclosure is related to systems and methods of managing data storage in a memory device. In a particular embodiment, a method is disclosed that includes receiving, in a data storage device, at least one data packet that has a size that is different from an allocated storage capacity of at least one physical destination location on a data storage medium in the data storage device for the at least one data packet. The method also includes storing the at least one received data packet in a non-volatile cache memory prior to transferring the at least one received data packet to the at least one physical destination location.

Abstract: An apparatus includes a first controller, a second controller, and a coupling compensator. The first controller is configured to generate a first voice coil motor (VCM) control signal in response to a first position error signal. The second controller is configured to generate a second VCM control signal in response to a second position error signal. The coupling compensator is configured to generate a first feedforward correction signal in response to the first VCM control signal. The first feedforward correction signal modifies the second VCM control signal to generate a modified second VCM control signal.

Abstract: A Data Storage Device (DSD) includes at least one disk surface and a plurality of actuators for accessing data stored on the at least one disk surface. A workload is determined for each actuator of the plurality of actuators, and a logical to physical mapping is modified based on at least one workload. The logical to physical mapping associates logical addresses of data with physical locations for storing the data on the at least one disk surface.

Abstract: A data storage device is disclosed comprising a first disk comprising first servo sectors A0-AN distributed around a circumference of the first disk, and a second disk comprising second servo sectors B0-BN distributed around a circumference of the second disk, wherein the second servo sectors B0-BN are offset circumferentially from the first servo sectors A0-AN. While the first and second disks are rotating second servo information is transmitted from a second servo channel to a first servo channel. One of the first servo sectors Ai is read to generate first servo information, and a first command value is generated based on the first servo information and the second servo information, wherein a first actuator is controlled based on the first command value.

Abstract: First and second controllers output respective first and second control signals for first and second plants that respectively correspond to the stages of an actuator. An inverse model of the first plant used to determine a decoupled output of the second plant from a combined output of the first and second plants. A disturbance estimate is subtracted from the second control signal to obtain a disturbance-corrected output. A loop-shaping filter is used between the disturbance corrected output and the second plant.

Abstract: A disk drive includes an actuator assembly and a controller. The actuator assembly generally includes an actuator having a velocity and a voice coil motor that has a detectable back electromotive force (BEMF). The actuator assembly is configured to position a read/write head. The controller is coupled to the actuator assembly and is configured to detect a catastrophic event occurring within the disk drive. In response to the detection of the catastrophic event, the controller activates a closed loop controlled slowing of the velocity using the detected BEMF as a control parameter.

Abstract: An apparatus includes a feedback controller receiving feedback from a position error signal of a hard drive read/write head. The feedback controller provides respective voice coil motor and microactuator control signals to a voice coil and microactuator that together position the hard drive read/write head in response to a position control signal. A rotational vibration feed-forward compensator receives vibration measurements via a sensor and providing a rotational vibration compensation signal in response thereto. A dynamic control allocator is coupled to the feedback controller and the rotational vibration feed-forward compensator. The dynamic control allocator is configured to combine a high frequency component of the rotational vibration compensation signal with the microactuator control signal; and to combine a low frequency component of the rotational vibration compensation signal with the voice coil motor control signal.

Abstract: In certain embodiments, an apparatus includes a first piezoelectric (PZT) element poled in the same direction as a second PZT element. The first and second PZT elements are configured to be driven while simultaneously sensing motion. The apparatus further includes a circuit configured to add outputs of the first and second PZT elements, extract the sensed motion, and detect off-track motion from the extracted sensed motion.

Abstract: A data storage device is disclosed comprising a disk, a head, and a microactuator configured to actuate the head over the disk. The data storage device further comprises control circuitry comprising a digital-to-analog converter (DAC) configured to generate a control signal applied to the microactuator. The control circuitry measures an operating temperature and then adjusts a range of the DAC based on the measured operating temperature.

Abstract: Apparatus and method for mitigating impedance changes in a microactuator conductive joint. In accordance with some embodiments, a microactuating element has a conductive input junction, the junction having dissimilar metals in contact with one another. The microactuating element is adapted to mechanically deform to displace a control object responsive to a micractuation control signal that is applied to the junction. A control circuit applies a bi-directional transition signal to the conductive input junction to reduce an increased impedance of the junction.

Abstract: Methods, systems, and computer program products for compensating unstable linear time-invariant due to input nonlinearities are described. In one implementation, compensating a controlled device may include controlling the controlled device using feedforward control. In another implementation, compensating the controlled device may include controlling the controlled device using feedback control.

Abstract: An apparatus comprising a magnetic media and a read/write unit. The magnetic media may be configured to store data. The magnetic media may also be rotated during access of the magnetic media. The read/write unit may comprise a plurality of transducers arranged in a linear array. Each of the transducers may be fabricated on a semiconductor substrate with fixed head positions with respect to the magnetic media. The read/write unit may also be positioned in close proximity to and across the surface of the magnetic media. Each transducer may be configured to read data from the magnetic media and write data to the magnetic media.

Abstract: A magnetic tape apparatus performs at least one of data reading processing and data writing processing on LTO wound around a reel. The magnetic tape apparatus causes the reel to rotate and move the LTO to a position at which the data writing processing or the data reading processing can be performed by a magnetic head. The magnetic tape apparatus is arranged along the width direction of the magnetic tape of LTO, which is driven, to detect medium abnormality that occurred in either a start-end or a stop-end in the width direction of the magnetic tape.

Abstract: Various embodiments of the present invention provide systems and methods for calculating and/or modifying fly height. For example, a circuit for calculating fly height is disclosed that includes: a first pattern detector circuit, a second pattern detector circuit, a first pattern fly height calculation circuit, a second pattern fly height calculation circuit, a first averaging circuit, a second averaging circuit, and a combining circuit.

Abstract: A method for determining a relationship between a hard disk drive throughput and a vibration source adapted in a computer device having a hard disk drive and the vibration source is disclosed. The method includes receiving a vibration sensing signal associated with the vibration source and a hard disk drive throughput rate associated with operations of the hard disk drive substantially at the same time, deriving a vibration sensing frequency function and a hard disk drive frequency function, determining whether a linear relationship exists between the vibration sensing frequency function and the hard disk drive frequency function, comparing the vibration sensing frequency function and the hard disk drive frequency function to derive a vibration information, and generating a counter vibration control signal according to the vibration information.

Abstract: A hard disk drive includes a magnetic head, at least one disk and a controller. A location signal is recorded on the at least one disk for determining a location of the magnetic head in relation to the at least one disk. The controller controls the location of the magnetic head based on the location signal decoded through the magnetic head. At least one of frequency and amplitude of the location signal is variable.

Abstract: An information recording and reproducing apparatus 1 having a high efficiency of information transfer includes one or more recording media forming a plurality of recording surfaces, a plurality of heads respectively disposed on the recording surfaces, a first actuator for supporting the heads and moving the heads uniformly, a plurality of second actuators provided one for an associated one of the heads, the second actuators moving the heads independently relative to the first actuator, recording processing circuits for simultaneously outputting recording signals, and reproducing processing circuits simultaneously supplied with reproduced signals read out by the heads to reproduce information from the reproduced signals.

Abstract: An improved microactuator suspension is provided for use with high density storage media. The number of microactuator elements is reduced to one and placed perpendicularly to the longitudinal axis of the suspension arm to maximize the windage and resonance performance and minimize the microactuator's contribution to bending stiffness and the off track bending component. An improved electrical connection eliminates the requirement for a jumper. These improvements reduce cost by reducing part count and assembly complexity.

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for controlling bi-directional drive current through an actuator. The method may include receiving a direction control signal, manipulating one or more devices to establish at least one switchable positive current path or at least one switchable negative current path through an actuator based at least in part on the direction control signal, providing feedback based at least on current associated with the actuator, and controlling the current based at least in part on the feedback. The method may include manipulating one or more devices to establish at least one positive current path and at least one negative current path through an actuator via pulse width modulation control.

Abstract: A method for detecting head-disc contact is disclosed. The method comprises locating a head including a head positioning microactuator and at least one of a read transducer and a write transducer adjacent to a disc such that the head is in communication with the disc, monitoring an output signal from the head positioning microactuator of the head, and evaluating the output signal to determine if the head contacts the disc.

Abstract: According to one embodiment, an actuator arm includes a joint, an extension, a pair of outer surfaces, and a linear protrusion. The joint is rotatably supported on a shaft. The extension extends from the joint and has a tip end connected to a head that performs at least reading or writing with respect to a rotating disk recording medium. The outer surfaces are in a front-and-rear relationship with each other. At least one of the outer surfaces faces the disk recording medium. The linear protrusion is arranged on and extends along an edge of at least one of the outer surfaces. The edge is located upstream on the outer surfaces in a flowing direction of an air flow generated by the rotation of the disk recording medium.

Abstract: A disk drive having a single drive motor and multiple platters that incorporates two discrete data paths, actuators and heads to the disk platters. Utilizing the economy of very large capacity disk platters, two or more disk drives can be created within a single physical enclosure. These two disks will be share many common parts such as the drive enclosure and spindle motor, but will have the performance and appearance to the system as two or more independent disks. Instead of having one actuator arm, the virtual disks will have two or more actuator arms and two or more sets of digital electronics. The storage on all the platters is divided up among the actuators so that no storage location is shared, but all the actuators will operate concurrently. Each actuator will have exclusive use of a subset of the data storage. Disks normally only have one actuator connected to multiple heads, at least one per surface, which only allow a single data seek and data transfer at a time.

Abstract: Apparatus and method for head-disc interface (HDI) modal response monitoring. A sensing element disposed on a rigid actuator arm is mechanically impedance matched to a head-disc interface (HDI) supported by the actuator arm to resonate at a predetermined frequency corresponding to at least one disturbance associated with the HDI.

Abstract: An actuator assembly is provided for positioning a transducer with a primary frame and a secondary frame mounted thereto for transverse translation. A coarse actuator is connected to the frames for translating the secondary frame incrementally. A carriage with a transducer is mounted to the secondary frame for transverse translation. A fine actuator is connected to the secondary frame and the carriage. The coarse actuator provides coarse adjustment and the fine actuator provides fine adjustment of the transducer for following tape. A method for positioning a transducer is provides a transducer connected to a coarse actuator and a fine actuator. Tape is conveyed across the transducer and lateral motion of the tape is monitored. The transducer is positioned by the fine actuator relative to a lateral tape position, and if the position exceeds a predetermined range, then the transducer is positioned by the actuation of the coarse actuator.

Abstract: A microactuator reference limit used to prevent over-accumulation of internal states may be set based on the microactuator's mechanical properties and is applied at the reference point to the microactuator servo subsystem. A microactuator variable input limit to prevent over-accumulation of internal states may be dynamically determined based on the difference between a signal corresponding to the maximum physical stroke of the microactuator and an estimated motion of the microactuator. Either configuration of servo system automatically ensures that all the internal states of the microactuator controller will not over-react and cause excessive overshoot, sluggish response, and/or saturation.

Abstract: A track accessing mechanism includes a track accessing arm actuable by a primary actuation device for accessing concentric data tracks on a storage medium and at least one slider attached to the track accessing arm. The at least one slider includes a servo head configured to read positional information from a plurality of continuous, concentric rings radially spaced apart from each other on a storage medium and a data head configured to read and write user data to the least one concentric data track. At least a portion of each ring includes servo information. The at least one data track is positioned between each continuous, concentric ring on the storage medium.

Abstract: A high-aspect ratio motion limiter of a microactuator and a method for fabrication are disclosed. In one embodiment, at least one low-aspect ratio gap is created in a substrate of a microactuator of a hard disk drive. The low-aspect ratio gap is then utilized to facilitate the creation of a high-aspect ratio motion limiter in the substrate of the microactuator.

Abstract: Apparatus and method for head-disc interface (HDI) modal response monitoring. A sensing element disposed on a rigid actuator arm is mechanically impedance matched to a head-disc interface (HDI) supported by the actuator arm to resonate at a predetermined frequency corresponding to at least one disturbance associated with the HDI.

Abstract: A disk drive is disclosed employing a VCM control loop comprising a voltage detector operable to detect a back EMF voltage across a voice coil of a voice coil motor, a current detector operable to detect a current flowing through the voice coil, and a control voltage generator, responsive to a command input and the detected back EMF voltage, operable to generate a control voltage applied to the voice coil. Control circuitry within the disk drive (a) initializes the control voltage; (b) injects a transient into the VCM control loop and detects a corresponding current flowing through the voice coil; (c) adjusts the control voltage in response to a polarity of the detected current; (d) repeats elements (b) and (c) at least once; and (e) stores an offset value in response to the adjusted control voltage.

Abstract: An implementation of a disk drive with improved efficiency where a read head supported by a first positioning component is provided and a write head supported by a second positioning component is also provided. By positioning the write head behind the read head at a predetermined angle, the disk drive can execute a “read-before-write” or “read-modify-by-XOR-write” operation by before the platter has rotated a full revolution.