A multi-layer piezoelectric microactuator assembly has at least one poled and active piezoelectric layer and one poled but inactive piezoelectric layer. The poled but inactive layer acts as a constraining layer in resisting expansion or contract of the first piezoelectric layer thereby reducing or eliminating bending of the assembly as installed in an environment, thereby increasing the effective stroke length of the assembly. Poling only a single layer would induce stresses into the device; hence, polling both piezoelectric layers even though only one layer will be active in use reduces stresses in the device and therefore increases reliability.

According to one embodiment, a magnetic disk device includes a disk, a head including a main magnetic pole having a first end and a second end opposite to the first end in a radial direction of the disk, a write shield facing the main magnetic pole with a gap, and an assist element provided in the gap and at a position where a first distance between the first end and the assist element and a second distance between the second end and the assist element are different from each other, and a controller which controls a voltage applied to the assist element according to a shingled write direction in which a second track is overwritten on a first track.

A magnetic tape reading apparatus including: a reading head which includes a reading unit disposed at a position corresponding to a single track included in a magnetic tape; a controller which controls the reading unit to read data plural times from a specific range of the single track in a running direction of the magnetic tape by a linear scan method; and a synthesis unit which synthesizes a plurality of reproducing signal sequences obtained by reading data plural times from the specific range by the reading unit.

A victim feedforward signal is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator, where the victim feedforward signal is configured to compensate for disturbances to a victim head caused by assertion of the aggressor VCM control signal. Each aggressor VCM control signal is asserted at a specific time by the aggressor actuator, for example in response to the aggressor head passing over a first servo wedge. A feedforward signal that compensates for the effect of the aggressor VCM control signal is then determined based on the aggressor VCM control signal, stored, and asserted via the victim microactuator at a predetermined time relative to when the aggressor VCM control signal is asserted.

A magnetic tape device includes: a magnetic head; a head actuator that holds the magnetic head; and a tape lifting mechanism including a lifter arm. The lifter arm comes into contact with the magnetic tape to separate a magnetic tape from the magnetic head. The tape lifting mechanism moves the lifter arm in a push-out direction in conjunction with the head actuator moving in a first direction. The tape lifting mechanism moves the lifter arm in a retreating direction in conjunction with the head actuator moving in a second direction. The lifter arm pushes out the magnetic tape to separate the magnetic tape from the magnetic head, in response to the lifter arm moving in the push-out direction. The lifter arm separates from the magnetic tape to bring the magnetic tape into contact with the magnetic head, in response to the lifter arm moving in the retreating direction.

A self servo-write process in performed on two or more recording surfaces simultaneously. In a dual-stage servo system, a first fine positioning servo system that includes a first microactuator independently controls the position of a first read/write head over a first recording surface of a hard disk drive, while a second fine positioning servo system that includes a second microactuator independently controls the position of a second read/write head over a second recording surface of the hard disk drive.

A device includes a servo controller that includes or that is coupled to memory. The memory stores multiple distinct disturbance control schemes. The servo controller is configured to select and implement one of the disturbance control schemes in response to receiving a command from a host. The servo controller can be implemented on a system on a chip.

A brake crawler for an elevator-type hard disk drive generally includes a first and second set of clamp arms vertically arranged, each of the first and second sets of clamp arms being capable of exerting a clamping force on a shaft or slider via activation or deactivation of an actuator element associated with each set of clamp arms. The brake crawler further includes an actuator element disposed between the first and second set of clamp arms which allows for movement of the first set of clamp arms away from the second set of clamp arms upon a change in state of the actuator element. Via a specific sequence of activating and deactivating various of the actuator elements associated with the brake crawler, the brake crawler is capable of inch worm-type movement up and down the shaft.

A data storage device includes at least one data storage medium having a plurality of tracks. The data storage device also includes at least one actuator that supports at least one head that is configured to interact with different tracks of the plurality of tracks on the at least one data storage medium to service commands from a host. The data storage device further includes a seek control circuit communicatively coupled to the at least one actuator. The seek control circuit is configured to store the commands from the host in at least one queue for execution by the at least one actuator. The seek control module is also configured to adjust power provided to the at least one actuator for seek operations to the different tracks of the plurality of tracks based on command age-related measurements of the commands from the host.

An external servo writer configured to write a plurality of embedded servo sectors on a magnetic tape to define a plurality of data tracks is disclosed. A first part of the plurality of embedded servo sectors is written while controlling an actuator to first move a head vertically along a width of the magnetic tape. A second part of the plurality of embedded servo sectors is written while controlling the actuator to second move the head vertically along the width of the magnetic tape.