A magnetic disk device includes a casing having a box-like base that has a bottom wall and a cover that has a first surface facing the bottom wall, a magnetic disk provided in the casing, a head configured to write data to the magnetic disk and to read data from the magnetic disk, an actuator assembly that supports the head in the casing, a conductive container on the first surface of the cover, and a conductive body in contact with the conductive container and the cover.

An apparatus includes a plurality of storage media mounted on a rotatable spindle. The apparatus also includes an actuator with at least one actuator arm configured to translate among the plurality of storage media and at least two heads supported on the at least one actuator arm. Each of the at least two heads is configured to communicate with the plurality of storage media.

A data storage device is disclosed comprising a first head actuated over a first disk surface, and a second head actuated over a second disk surface. During a first revolution of the disk surfaces, a first set of servo sectors are written to the first disk surface and a second set of servo sectors are written to the second disk surface, wherein the first set of servo sectors are circumferentially offset from the second set of servo sectors. During a second revolution of the disk surfaces, at least one of the servo sectors in the first set is read from the first disk surface and at least one of the servo sectors in the second set is read from the second disk surface to control a position of the first head over the first disk surface.

According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, an actuator including a voice coil motor that moves the head over the disk, and a controller that increases a second current value applied to the voice coil motor during deceleration of the head in a seek according to a first current value that is maximum value capable of being applied to the voice coil motor during acceleration of the head in the seek on the disk.

A data storage device is disclosed comprising a first disk surface, a first actuator arm, a first head connected to a distal end of the first actuator arm, an actuator, and a first coupler configured to couple the first actuator arm to the actuator. The first coupler is actuated in order to couple the first actuator arm to the actuator during at least part of a seek interval, and while the first actuator arm is coupled to the actuator, the actuator is moved in order to seek the first head over the first disk surface.

A disk device includes a magnetic disk having a data non-recording region, and a data recording region inside the data non-recording region, a plurality of heads configured to read and write information from and onto the magnetic disk, and a plurality of arms supporting the heads, the arms being rotatable to move the heads from a parked position to a desired data recording position above or below the magnetic disk. Each of the arms comprises an overlapping region that overlaps the data recording region of the magnetic disk in a thickness direction of the magnetic disk when the heads are at the parked position.

A magnetic disk device includes a casing having a box-like base that has a bottom wall and a cover that has a first surface facing the bottom wall, a magnetic disk provided in the casing, a head configured to write data to the magnetic disk and to read data from the magnetic disk, an actuator assembly that supports the head in the casing, a conductive container on the first surface of the cover, and a conductive body in contact with the conductive container and the cover.

Disclosed here is a magnet comprising a magnet body. The magnet body comprises a plurality of coated magnetic granules. Each coated magnetic granule of the plurality of coated magnetic granules comprises a magnetic granule and a metallic layer coating the magnetic granule

HDDs including multiple heads driven by separate actuator spindles can read from or write to one or more platters simultaneously. Simultaneous active heads can be used to increase data rate or for other purposes. The multiple independently-actuated heads can access the same platter or different platters and may be moved across an associated platter surface in a number of different ways. However, multiple independently operating actuators may lead to mechanical coupling between the actuators. For example, as certain resonant frequencies, the movement of one actuator arm may cause unacceptable movement of another actuator arm within the HDD. This mechanical coupling can have detrimental effects on the HDD. The disclosed coupling observer and disable systems detect and mitigate detrimental effects of mechanical coupling between the independently operated actuators.

A data storage device is disclosed comprising a first actuator configured to actuate a head over a disk, a second actuator configured to rotate the disk, a first control circuit configured to generate a servo command, and a second control circuit configured to receive the servo command from the first control circuit, control the first actuator or the second actuator using the servo command, and override the servo command to avoid an overcurrent condition.