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, there is provided a disk apparatus including a first disk, a second disk, a main actuator, a first actuator, a second actuator, a third actuator, and a driver circuit. The driver circuit is configured to be able to switch between a first mode and a second mode. The first mode is a mode where a first actuator, a second actuator, and a third actuator are driven in a same direction. The second mode is a mode where the first actuator and the second actuator are driven in opposite directions and where the third actuator and the second actuator are driven in opposite directions.

A method for writing to tape by a tape drive is provided. The method includes, in response to identifying a write error during a write to a tape in a certain HRTD region, repositioning the tape to a next HRTD region. The method further includes continuing the write at the next HRTD region.

An enlarged substrate configuration for magnetic recording media. In some embodiments, an apparatus comprises a disc shaped member of metal or glass configured as a substrate for a magnetic data recording disc for a 2 inch form factor data storage device or a 3 inch form factor data storage device. The disc shaped member has a top planar surface, an opposing bottom planar surface, an outermost annular sidewall that extends between the top planar surface and the bottom planar surface at an outermost diameter of nominally 67 or 97 millimeters, respectively, and an inner annular sidewall that extends between the top planar surface and the bottom planar surface to define a central aperture.

A first data group in an access sequence is selected. A distance from a current position of the tape medium is set to be a logical distance value, determined by a calculation function, that is substituted for the physical distance value for the data groups that are located in the specified regions as compared with other data groups located in the alternative specified regions. A second data group in the access sequence is selected. The logical distance value is then determined by multiplying a coefficient based on a physical positioning of each of the data groups in the tape medium, and a percentage of those of the plurality of data groups that have already been selected as the first data group and the second data group.

An apparatus and associated method contemplating a head gimbal assembly (HGA) and a bridge circuit including first and second microactuators attached to the HGA. Computation logic is connected to the bridge circuit and configured to independently measure an electrical output of each microactuator and to sum the electrical outputs to derive a value related to a vertically dominant modulation mode of the HGA.

An enlarged substrate configuration for magnetic recording media. In some embodiments, an apparatus comprises a disc shaped member of metal or glass configured as a substrate for a magnetic data recording disc for a 2 inch form factor data storage device or a 3 inch form factor data storage device. The disc shaped member has a top planar surface, an opposing bottom planar surface, an outermost annular sidewall that extends between the top planar surface and the bottom planar surface at an outermost diameter of nominally 67 or 97 millimeters, respectively, and an inner annular sidewall that extends between the top planar surface and the bottom planar surface to define a central aperture.

Rotational latency is reduced in a standard conventional form factor HDD system by replacing, for example, the prior art rotary arm actuator of a conventional HDD, with one or more belts and pulleys and one or more read/write heads mounted on, or otherwise associated with the belts. Multiple scaled iterations facilitate energy savings and power optimized systems, without compromise to data access performance.

According to one embodiment, a magnetic disk device includes a disk including a first recording area, a head includes a write head configured to write data to the disk, and a read head configured to read data from the disk, and a controller configured to set particular areas in same circumferential positions on tracks of the first recording area, and to write, to the respective particular areas, parity data based on data read from areas other than the particular areas.

Embodiments of the invention provide a device for measuring pitch and roll torques. The device comprises a sensor plate having a horizontal cross member, a vertical cross member and a surrounding member connecting ends of the horizontal and vertical cross members, wherein the horizontal cross member and the vertical cross member intersect each other at a centre region of the sensor plate; a VCM coil attached to the sensor plate and configured to generate a pitch and a roll torque when an electrical current is applied to the VCM coil; a first strain gauge attached to a surface of the horizontal cross member and configured to detect a horizontal strain caused by the pitch and roll torques; and a second strain gauge attached to a surface of the vertical cross member and configured to detect a vertical strain caused by the pitch and roll torques.