According to one embodiment, a magnetic disk device includes a first disk including a first data sector, a second disk including a second data sector, a first head including a first read head, a second head including a second read head, a first controller that stops write operations of both the first head and the second head based on first data sector position error information obtained by reading and demodulating the first data sector by using the first read head, and a second controller that stops the write operations of both the first head and the second head based on second data sector position error information obtained by reading and demodulating the second data sector by using the second read head.

The disk device according to one embodiment includes magnetic disks, a magnetic head, a ramp, and a suspension. The suspension includes a sliding portion provided on a load beam. The suspension rotates about a second rotation axis between a load position and an unload position. The ramp includes a wall and a protrusion. The wall has a first support surface that supports the sliding portion when the suspension is located in the unload position. The protrusion includes a second support surface and an intermediate portion. The second support surface faces the magnetic head when the suspension is located in the unload position. The intermediate portion is located between the wall and the second support surface. The intermediate portion includes a first portion and a second portion. The second portion is located between the first portion and the first support surface in the radial direction of the second rotation axis.

The disk device according to one embodiment includes magnetic disks, a magnetic head, a ramp, and a suspension. The suspension includes a sliding portion provided on a load beam. The suspension rotates about a second rotation axis between a load position and an unload position. The ramp includes a wall and a protrusion. The wall has a first support surface that supports the sliding portion when the suspension is located in the unload position. The protrusion includes a second support surface and an intermediate portion. The second support surface faces the magnetic head when the suspension is located in the unload position. The intermediate portion is located between the wall and the second support surface. The intermediate portion includes a first portion and a second portion. The second portion is located between the first portion and the first support surface in the radial direction of the second rotation axis.

A method for collecting position information in a disk drive having a read head and a disk with a set of spirals formed thereon includes: while the read head crosses a first spiral included in the set of spirals, opening a first frame integration window; while the first frame integration window is open, generating first signals with the read head as the read head crosses over a first set of magnetic transitions; closing the first frame integration window; after closing the first frame integration window, generating second signals with the read head as the read head crosses over a second set of magnetic transitions; and determining a radial position of the read head by integrating amplitudes of the first signals, wherein the first set includes magnetic transitions having a first polarity, and the second set includes two or more magnetic transitions having a second polarity.

According to one embodiment, a magnetic disk includes a disk, first and second heads which write data to the disk and read data from the disk, a first actuator includes the first head, a second actuator includes the second head, first and second controllers which control the first head, the second head, the first actuator and the second actuator, an auxiliary power supply which supplies power when power from a power supply is shut off, and a power supply detection unit which makes power supplied from the auxiliary power supply to the first controller higher than the power supplied from the auxiliary power supply to the second controller when shutoff of power from the power supply is detected.

A data storage device is disclosed comprising a head actuated over an energy assisted magnetic media comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors. A write operation to a first data sector is executed by applying a first current to a write coil of the head while the head is over a second data sector preceding the first data sector, wherein the first current comprises a first amplitude. A second current is applied to the write coil while the head is over the first data sector, wherein the second current comprises a second amplitude lower than the first amplitude.

According to one embodiment, a magnetic disk device includes a rotatable magnetic disk and a magnetic head including a recording head portion that records data on the magnetic disk. The recording head portion includes a main magnetic pole that applies a recording magnetic field to the magnetic disk, a first yoke provided on a first side of the main magnetic pole and a second yoke provided on a second side of the main magnetic pole, which is opposite to the first side. The magnetic head includes a first heater provided to oppose a side of the first yoke, opposite to the main magnetic pole and a second heater provided to oppose a side of the second yoke, opposite from the main magnetic pole.

According to one embodiment, a magnetic disk device includes a rotatable magnetic disk and a magnetic head including a recording head portion that records data on the magnetic disk. The recording head portion includes a main magnetic pole that applies a recording magnetic field to the magnetic disk, a first yoke provided on a first side of the main magnetic pole and a second yoke provided on a second side of the main magnetic pole, which is opposite to the first side. The magnetic head includes a first heater provided to oppose a side of the first yoke, opposite to the main magnetic pole and a second heater provided to oppose a side of the second yoke, opposite from the main magnetic pole.

According to one embodiment, a disk device includes a housing including a base with a bottom wall, a drive motor including a pivot erected on the bottom wall and a hub rotatably supported around the pivot, ten or more magnetic disks attached to the hub and stacked on a flange of the hub, and spacer rings attached to the hub and each disposed between each respective adjacent pair of two magnetic disks. A number of the spacer rings is one less than the magnetic disks. At least one spacer ring has a thickness different from that of the other spacer rings, and a difference between a maximum thickness and a minimum thickness of the spacer rings is 0.01 mm or more and 0.09 mm or less.

According to one embodiment, a disk device includes a housing including a base with a bottom wall, a drive motor including a pivot erected on the bottom wall and a hub rotatably supported around the pivot, ten or more magnetic disks attached to the hub and stacked on a flange of the hub, and spacer rings attached to the hub and each disposed between each respective adjacent pair of two magnetic disks. A number of the spacer rings is one less than the magnetic disks. At least one spacer ring has a thickness different from that of the other spacer rings, and a difference between a maximum thickness and a minimum thickness of the spacer rings is 0.01 mm or more and 0.09 mm or less.