According to one embodiment, a magnetic disk device includes a disk including a zone servo boundary area including a first area of a first servo frequency, a second area of a second servo frequency, and a third area of the first servo frequency, in a servo area, a head, and a controller demodulating first servo data of the first area to derive a position of the head and demodulating first corrected data of the third area to correct the position of the head. The first area, the second area, and the third area are aligned in order in a traveling direction. The first area and the second area are adjacent to each other in a circumferential direction of the disk. The second area and the third area are adjacent to each other in the circumferential direction.

A hard disk drive flexible printed circuit (FPC) includes a plurality of fingers extending from a main portion, with each finger having a thermally-conductive stiffener, at least one wiring layer over the stiffener, and a cover film over the at least one wiring layer, where the centroid of the stiffener is offset from the centerline of the cover film. Thus, utilizing the heat-sink characteristics of the stiffener, temperature differences among the upper and lower electrical pads of the FPC resulting from a heat-based interconnection procedure can be reduced and the temperatures across the FPC finger made more uniform, damage to the FPC prevented, and soldering yields improved.

A data storage device is disclosed comprising a head actuated over a disk. A spiral track is written on the disk, and a disk locked clock (DLC) is synchronized to the spiral track. The spiral track is read to generate a spiral track crossing signal, and the spiral track crossing signal is processed to generate a position error signal (PES) representing a position of the head over the disk. When the DLC indicates a first part of the spiral track crossing signal is corrupt, the corruption is compensated in order to generate a compensated PES. While servoing the head over the disk based on the PES, a plurality of concentric servo sectors are written on the disk based on the DLC.

According to one embodiment, there is provided a hard disk drive including a first recording surface, a second recording surface, a first magnetic head, a first actuator and a second actuator that move the first magnetic head, a second magnetic head, a third actuator and a fourth actuator that move the second magnetic head, a fifth actuator that moves the second actuator and the fourth actuator, a drive circuit that implements at least one of a first mode in which the second actuator and the fourth actuator operate differently from each other or a second mode in which the first and third actuators operate differently from each other, and a controller that controls the drive circuit.

According to one embodiment, when adjusting a position of a magnetic head by a microactuator, in a case where a difference of an absolute value of a first voltage value obtained by correcting a voltage value applied to the microactuator based on hysteresis and an absolute value of a second voltage value obtained by not correcting the voltage value applied to the microactuator based on the hysteresis is positive, a control unit applies a third voltage value obtained based on the second voltage value to the microactuator, and adjusts shortage of the adjustment executed by the microactuator by controlling at least one of a voice coil motor and/or a microactuator other than a microactuator applying a third voltage value.

According to one embodiment, when adjusting a position of a magnetic head by a microactuator, in a case where a difference of an absolute value of a first voltage value obtained by correcting a voltage value applied to the microactuator based on hysteresis and an absolute value of a second voltage value obtained by not correcting the voltage value applied to the microactuator based on the hysteresis is positive, a control unit applies a third voltage value obtained based on the second voltage value to the microactuator, and adjusts shortage of the adjustment executed by the microactuator by controlling at least one of a voice coil motor and/or a microactuator other than a microactuator applying a third voltage value.

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 that is rotationally driven and controls movement of the head mounted on the disk, and a controller that estimates a fundamental frequency of a position error signal generated in positioning control of the head, the fundamental frequency corresponding to a disturbance having harmonics, determines the fundamental frequency, determines the number of delay samples based on the fundamental frequency, and suppresses a multiplied frequency that is a harmonic of the fundamental frequency according to the number of the delay samples.

Motion of a first actuator in a multi-actuator drive is prevented from affecting a second actuator in the drive or from being affected by the second actuator. A coupling coordinator generates a hold command for the second actuator based on an operation to be carried out using the first actuator, where the hold command is generated before commands to carry out the operation are issued. The hold command may cause an aggressor actuator in the drive to halt a disturbance-generating operation being performed by the aggressor actuator or delay initiation of such an operation that is to be performed by the aggressor actuator. The hold command may cause a victim actuator in the drive to pause the execution of a sensitive operation being performed by the victim actuator or delay initiation of such an operation that is to be performed by the victim actuator.

A method for writing servo information in a disk drive that includes a write head and one or more recording surfaces includes: writing a first portion of a first spiral with the write head on a first recording surface of the one or more recording surfaces while controlling a radial position of the write head with a controller that is configured with a first set of controller parameter values; after the read head crosses a second spiral formed on a second recording surface of the one or more recording surfaces, determining a radial position error for the write head based on information associated with the second spiral; and in response to the radial position error exceeding a disturbance threshold value, writing a second portion of the first spiral with the write head while controlling the radial position of the write head with the controller while the controller is configured with a second set of controller parameter values.

A magnetic disk device includes a plurality of magnetic heads, a storage unit that stores a table storing, for each of the magnetic heads, a track skew value obtained by adding a head shared value and a head unique value, and a control unit that reads out the track skew value corresponding to one of the magnetic heads to be operated from the table and performs seek control.