According to one embodiment, a magnetic disk device includes a magnetic disk and a magnetic head. The magnetic disk includes a data area on/from which data can be recorded/reproduced. The magnetic head records data on the data area and reproduces data from the data area. An outer edge of the data area includes first outer edge, second outer edge positioned on the further inner circumferential side of the magnetic disk relatively to the first outer edge, and third outer edges each connecting between the first outer edge and the second outer edge. The outer edge of the data area incudes concave parts made inwardly concave toward the inner circumferential side of the magnetic disk at not less than part thereof.

An actuator rotational limiter mechanism for a multiple disk-stack, shared actuator hard disk drive includes an actuator comb with a cam-lock feature and an actuator limiter with a rotatable cam-roller that is engagable with the cam-lock feature to temporarily hold in place the actuator comb. The cam-lock feature may be positioned at or near a middle location of a back arm of the actuator armature, where the actuator comb being held in place by the cam-roller corresponds to the head slider being positioned on a load/unload ramp between adjacent disk stacks.

An actuator rotational limiter mechanism for a multiple disk-stack, shared actuator hard disk drive includes an actuator comb with a cam-lock feature and an actuator limiter with a rotatable cam-roller that is engagable with the cam-lock feature to temporarily hold in place the actuator comb. The cam-lock feature may be positioned at or near a middle location of a back arm of the actuator armature, where the actuator comb being held in place by the cam-roller corresponds to the head slider being positioned on a load/unload ramp between adjacent disk stacks.

A tolerance ring includes: a base formed of a strip-like member substantially wound around into a shape; a plurality of projections provided along a winding direction of the base so as to protrude from an outer peripheral surface of the base in a radial direction of the base orthogonal to the outer peripheral surface; at least one extended portion extending from at least one of edge end portions in a width direction of the base, the width direction extending orthogonally to the winding direction and the radial direction. The extended portion extends from a region that includes at least one of a plurality of straight lines passing through respective contact points disposed between a section of the base and a circumscribed circle that circumscribes the section and extend in parallel with the width direction.

A tolerance ring includes: a base formed of a strip-like member substantially wound around into a shape; a plurality of projections provided along a winding direction of the base so as to protrude from an outer peripheral surface of the base in a radial direction of the base orthogonal to the outer peripheral surface; at least one extended portion extending from at least one of edge end portions in a width direction of the base, the width direction extending orthogonally to the winding direction and the radial direction. The extended portion extends from a region that includes at least one of a plurality of straight lines passing through respective contact points disposed between a section of the base and a circumscribed circle that circumscribes the section and extend in parallel with the width direction.

First and second controllers output respective first and second control signals for first and second plants that respectively correspond to the stages of an actuator. An inverse model of the first plant used to determine a decoupled output of the second plant from a combined output of the first and second plants. A disturbance estimate is subtracted from the second control signal to obtain a disturbance-corrected output. A loop-shaping filter is used between the disturbance corrected output and the second plant.

A method, in accordance with one aspect, includes writing, by a tape drive, data tracks to a data band of a magnetic tape having servo bands flanking the data band, the writing being performed using a magnetic head that is not designed for a format of the magnetic tape. The writing includes overwriting a portion of each of the servo bands with the data tracks. A method, in accordance with another aspect, includes writing data tracks to a data band using a magnetic head that is not designed for a format of the magnetic tape. An effective pitch of servo readers of the magnetic head used simultaneously during the writing matches a servo reader pitch specification of the format of the magnetic tape. An average effective pitch of write transducers of the magnetic head is greater than a data track pitch specification of the format of the magnetic tape.

An apparatus, in accordance with one aspect of the present invention, includes a magnetic head having an array of transducers, the transducers comprising data elements, at least two first servo readers positioned toward a first end of the array and at least two second servo readers positioned toward a second end of the array. The array is symmetrical about a centerpoint of the array, such that a distance between a center of an innermost one of the first servo readers and a center of the data element closest thereto is the same as a distance between a center of an innermost one of the second servo readers and a center of the data element closest thereto, and such that a distance between a center of an outermost one of the first servo readers and the center of the data element closest thereto is the same as a distance between a center of an outermost one of the second servo readers and the center of the data element closest thereto.

A data storage device executes access commands received from a host by a recording head actuated over a magnetic storage medium. A target command is selected from queued host access commands. A free command is selected that can be executed during a time required for a seek from the recording head location to a target command location. A seek energy difference between the energy required to seek from the recording head location to a free command location to the target command location, and to seek from the recording head location directly to the target command location is determined. The device seeks to and executes the free and target commands if the seek energy difference is less than a threshold, and seeks directly to the target command if the seek energy difference is greater than the threshold.

A flexure assembly is described. The flexure assembly includes a gimbal portion on configured to receive a slider. The gimbal portion includes a first surface and a second surface which is opposite to the first surface. The slider is mounted on the second surface. The flexure assembly also includes a pair of microactuator elements. The flexure assembly also includes a tongue of the gimbal portion on which the slider is mounted. The tongue includes a dimple point which represents the center of the tongue. The flexure assembly also includes a pair of first supporting portions and a pair of second supporting portions of the gimbal portion. A pair of end portions are individually secured to the tongue and the first supporting portions and the pair of second supporting portions. The flexure assembly also includes a conductive circuit portion unsupported between a first stationary part and the pair of end portions.