Various embodiments concern a dual stage actuation flexure. The dual stage actuation flexure comprises a flexure having a gimbal. The gimbal comprising a pair of spring arms, a tongue between the spring arms, and a pair of linkages respectively connecting the pair of spring arms to the tongue. The dual stage actuation flexure further comprises a pair of motors mounted on the gimbal and a pair of stiffeners respectively mounted on the motors. The dual stage actuation flexure further comprises a slider mounting. Electrical activation of the motors bends the pair of linkages to move the slider mounting about a tracking axis while the stiffeners limit the degree of bending of the motors during the electrical activation.

Apparatus and method for magnetic recording media. A rotatable magnetic recording disc has an outermost annular sidewall that extends at nominally 97 millimeters, mm for a 3- inch form factor data storage device or at nominally 67 mm for a 2- inch form factor data storage device. The rotatable magnetic recording disc further has a disc shaped substrate of metal or glass, and a magnetic recording layer supported by the disc shaped substrate and configured to magnetically record data along concentric tracks.

A linear actuator for linearly positioning a recording head in a data storage mechanism. The disclosed linear actuator includes an electrically conductive coil having first and second parts that are both wound in the same rotary direction about an axis, and a magnet spaced from the electrically conductive coil by an air gap. Transmission of an electric current through the first part of the electrically conductive coil in a first current flow direction about the axis and through the second part of the electrically conductive coil in an opposite second current flow direction about the axis induces linear movement of one of the electrically conductive coil and magnet relative to the other of the electrically conductive coil and magnet.

Implementations disclosed herein include a method to synthesize the controller of a multi-stage servo control system with multiple actuators in a hard disk drive by dividing controller synthesis into multiple dual-stage steps. The method includes measuring a first output of a first plant corresponding to a first actuator, measuring a second output of a second plant corresponding to a second actuator, designing a first controller responsive to the first output, designing a second controller responsive to the second output, and combining the first output and the second output to obtain a first combined output in a first dual-stage. The method also includes designing a third controller responsive to the first combined output, measuring a third output from a third plant corresponding to a third actuator, designing a fourth controller responsive to the third output, and combining the first combined output and the third output to obtain a second combined output.

A disk device includes first and second recording surfaces, a first head for the first recording surface, including a first heater which generates heat via a first electric power, a second head for the second recording surface, including a second heater which generates heat via a second electric power, and a control circuit configured to execute a first preheating operation in which the first electric power is supplied to the first heater for a first time interval prior to starting a first writing process to write data on the first recording surface by the first head, and to execute a second preheating operation in which the second electric power is supplied to the second heater for a second time interval prior to starting a second writing process to write data on the second recording surface by the second head. The first time interval is different from the second time interval.

An apparatus and method for dynamic multiple actuator drive data access includes: partitioning a data package of a received data transfer request into a plurality of data segments; assigning actuator drivers and actuator controllers; initiating a data transfer to or from the data storage medium using one or more of the plurality of actuators corresponding to the one or more assigned actuator controllers; storing or retrieving an individual data package of the data transfer request to or from the data storage medium wherein the entire data package is wholly accessible to a single actuator, if the data transfer request is a random data mode request; and storing or retrieving an individual data segment of the data transfer request to or from the data storage medium wherein the data package is accessible to the plurality of actuators, if the request is a parallel data mode request.

A magnetic disk device includes a magnetic disk that includes a plurality of tracks, a magnetic head for reading data from the magnetic disk, and a controller. The controller begins controlling the magnetic head to move to a second track of the plurality of tracks from a first track of the plurality of tracks before decoding of a first track signal output from the magnetic head is completed, wherein the first track signal is output from the magnetic head while the magnetic head is positioned over the first track.

According to one embodiment, a disk device includes a magnetic disk, a magnetic head, a suspension, a ramp mechanism, a housing, and a screw. The suspension holds the magnetic head and moves between a load position and an unload position. The ramp mechanism includes a ramp member that holds the suspension at the unload position, and a cylindrical member with a through hole, being fixed to the ramp member. The housing includes a first support surface with a screw hole supporting the cylindrical member. The screw includes a screw head and a screw shaft fitted into the screw hole through the through hole. The screw holds the cylindrical member between the screw head and the first support surface. A contact area between the cylindrical member and the housing is set to larger than a contact area between the cylindrical member and the screw head.

A magnetic disk device includes a disk, a head, and a control circuit. When writing data to a target range of a target track, the control circuit calculates an off-track amount based on the use information indicating use states of each of the first adjacent track and the second adjacent track, positions the head according to the calculated off-track amount, and writes data in the target range with the head positioned according to the calculated off-track amount.

According to one embodiment, a magnetic disk device includes a disk, a head configured to write data to the disk and read the data from the disk, and a controller configured to control write processing based on a first determination value corresponding to a first shift amount defined for the excessive number of times at which the first shift amount of the head in a radial direction of the disk exceeds a first threshold value causing a read error in a second track adjacent to a first track in the radial direction at a time of the write processing of the first track of the disk, and a second threshold value changing the write processing.