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.

A first tone is written at a first frequency to outer tracks that surround an inner track of a magnetic recording medium. A second tone is written at a second frequency different from the first frequency to the inner track. The first and second frequencies are both lower than a frequency of an AC erase signal. A crosstrack profile of the inner track is determined based on reading amplitude of the second frequency via the read/write head.

Systems and methods for compensating for hysteresis in a disc drive are described. In one embodiment, a method may use an inverse hysteresis model to linearize effects of hysteresis of a microactuator in the disc drive. The hysteresis model may be a Coleman-Hodgdon hysteresis model. The hysteresis of the microactuator may be characterized, and the inverse hysteresis model may be based at least in part on the characterization. The inverse hysteresis model may be used to implement a digital filter. The digital filter may be employed in series with the microactuator to linearize the effects of hysteresis.

A data storage device includes a ramp configured to support at least one head in the data storage device, and a movement mechanism coupled to the ramp and configured to move the ramp from a first position to a second position by at least one of expansion or contraction of at least a portion of the movement mechanism. The data storage device further includes a ramp motion control module operably coupled to the movement mechanism. The ramp motion control module is configured to provide the movement mechanism with a first control signal that causes the movement mechanism to move the ramp from the first position to the second position. The data storage device additionally includes a latch configured to hold the ramp.

A suspension for a disk device comprises a load beam, a flexure and a damper member. The flexure overlaps the load beam, and comprises a tongue on which a slider is mounted and an outrigger connected to the tongue. The damper member is attached to the load beam. The outrigger comprises an arm opposing the load beam, and a folded portion extending from the arm and folded back in a thickness direction of the arm. Further, the folded portion is attached to the damper member.

The present disclosure generally relates to a lock mechanism for a tape embedded drive. The tape embedded drive comprises an enclosure enclosing a first tape reel, a second tape reel, and a lock mechanism. The first tape reel comprises a first gear, the second tape reel comprises a second gear, and the lock mechanism is disposed between the first and second gears. The lock mechanism comprises a latch lock, one or more latch tips disposed at a first end of the latch lock, a magnet disposed at a second end of the latch lock, and an electromagnet disposed adjacent to the magnet. When the electromagnet is activated, the latch lock moves to an unlocked position. When the electromagnet is de-activated, the latch lock moves to a locked position where the one or more latch tips are in contact with the first and second gears.

According to one embodiment, a magnetic disk device includes a disk including a first sector arranged at a first radial position deviated from a target position in a radial direction by a first offset amount larger than a first threshold value, a head that writes data to the disk and reads data from the disk, and a controller that reads the first sector by arranging the head at a second radial position deviated from the target position by a second offset amount different from the first offset amount.

A data storage device can consist of a data storage medium that has a recording surface accessed by a first transducing head suspended by a first actuator and a second transducing head suspended by a second actuator. The first actuator may be configured to access a first region of the recording surface while the second actuator is configured to access a second region of the recording surface. The first and second regions can be separate and non-overlapping.

A PZT microactuator such as for a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT is mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover most or all of the top of the PZT, with an electrical connection being made to the PZT where it is not covered by the restraining layer. The restraining layer reduces bending of the PZT as mounted and hence increases effective stroke length, or reverses the sign of the bending which increases the effective stroke length of the PZT even further. The restraining layer can be one or more active layers of PZT material that act in the opposite direction as the main PZT layer. The restraining layer(s) may be thinner than the main PZT layer.

According to one embodiment, a monitoring unit of a magnetic disk device monitors a supply voltage supplied to a plurality of actuators by a first threshold value at which power supply by back electromotive force of a motor is started, and a second threshold value that is larger than the first threshold value. In a case where the supply voltage is lower than or equal to the second threshold value and is higher than the first threshold value, a controller interrupts execution of processing of reading/writing data to a magnetic disk in at least one of the actuators according to a predetermined condition based on execution status of the processing in the actuators.