G11B5/5547

Method and apparatus that modifies seek parameter to remediate cross-actuator interference

A faulty tracking condition affecting a first head driven by a first actuator of a hard disk drive is determined. The faulty tracking condition is caused by a second actuator of the hard disk drive that is moving while the first actuator is performing a tracking operation. Responsive to the determination of the faulty tracking condition, seek forces of the second actuator that cause the faulty tracking condition affecting the first head are reduced. A controller verifies that similar faulty tracking conditions are reduced with the first head in response to the reduction in seek forces.

Data storage device transmitting delta servo control value over serial interface
10504553 · 2019-12-10 · ·

A data storage device is disclosed comprising a disk comprising servo data, and an actuator configured to actuate a head radially over the disk. The disk drive further comprises control circuitry comprising a servo controller and a driver circuit comprising an accumulator, wherein the servo controller is configured to generate digital control values based on the servo data and transmit the digital control values over a serial interface to the drive circuit. The accumulator is initialized based on a first digital control value received over the serial interface during a first servo interval, and then the accumulator is adjusted based on a second digital control value received over the serial interface during a second servo interval. An analog control signal is generated based on an output of the accumulator, and the analog control signal is applied to the actuator.

MAGNETIC DISK DEVICE AND ACTUATOR CONTROL METHOD
20190371359 · 2019-12-05 ·

According to one embodiment, a magnetic disk device includes a disk, a first head, a second head, an actuator configured to position the first head and the second head over the disk, and a controller configured to control the actuator based on a first value having a first waveform suppressing a disturbance component, wherein the controller is configured to invert, in the first waveform, a polarity of a third waveform succeeding a first timing with respect to a polarity of a second waveform preceding the first timing in a case where the first head is changed to the second head at the first timing.

Magnetic disk device and actuator control method

According to one embodiment, a magnetic disk device includes a disk, a first head, a second head, an actuator configured to position the first head and the second head over the disk, and a controller configured to control the actuator based on a first value having a first waveform suppressing a disturbance component, wherein the controller is configured to invert, in the first waveform, a polarity of a third waveform succeeding a first timing with respect to a polarity of a second waveform preceding the first timing in a case where the first head is changed to the second head at the first timing.

Disk device, controller circuit, and control method

A disk device includes a recording medium on which data is recorded, a decoding circuit configured to decode data read from the recording medium, and a control circuit. The control circuit is configured to cause first data associated with a target sector referenced in a read request to be read from a target track of the recording medium, second data associated with a non-target sector that is not referenced in the read request to be read from the recording medium after the first data is read from the recording medium, and decoding of the first data to be completed by the decoding circuit after the second data is read from the recording medium.

Magnetic head control capable of avoidance media bumps during seeking process

According to one embodiment, a magnetic disk drive selects in command evaluation in reordering processing, a command accessible in a shortest time. The device determines whether media bumps which influence a dynamic flying height (DFH) control exist in a seek section between completion of a previous command and start of a selected command or not, calculates a latency necessary for avoidance of the media bumps if it is determined by the determination that the media bumps which influence the DFH control exist, and selects the command accessible in the shortest time including the time obtained by summing the latency calculated by the calculation as the command to be next processed.

MAGNETIC DISK DEVICE AND ACTUATOR CONTROL METHOD
20190272850 · 2019-09-05 ·

According to one embodiment, a magnetic disk device includes a disk, a first head, a second head, an actuator configured to position the first head and the second head over the disk, and a controller configured to control the actuator based on a first value having a first waveform suppressing a disturbance component, wherein the controller is configured to invert, in the first waveform, a polarity of a third waveform succeeding a first timing with respect to a polarity of a second waveform preceding the first timing in a case where the first head is changed to the second head at the first timing..

Magnetic disk device and command reordering method thereof
10372375 · 2019-08-06 · ·

A magnetic disk device includes a magnetic disk, a magnetic head, a voice coil motor which drives movement of the magnetic head relative to the magnetic disk, a drive circuit which drives the voice coil motor, a memory in which a seek time for a seek operation is stored in association with a seek distance of the magnetic head, and a controller. The controller changes the seek time stored in the memory in association with the seek distance based on a temperature and a power supply voltage of the drive circuit.

DISK DEVICE, CONTROLLER CIRCUIT, AND CONTROL METHOD
20190214040 · 2019-07-11 ·

A disk device includes a recording medium on which data is recorded, a decoding circuit configured to decode data read from the recording medium, and a control circuit. The control circuit is configured to cause first data associated with a target sector referenced in a read request to be read from a target track of the recording medium, second data associated with a non-target sector that is not referenced in the read request to be read from the recording medium after the first data is read from the recording medium, and decoding of the first data to be completed by the decoding circuit after the second data is read from the recording medium.

Magnetic disk device

According to one embodiment, a disk device includes a rotatable magnetic disk, an actuator which supports and moves a head, a ramp which holds the head at an unloaded position, a motor which rotates the magnetic disk, and a controller which performs a load operation and a seek operation. When a radial travel speed of the head during the load operation is referred to as Vr1, a circumferential travel speed of the head is referred to as Vt1, a radial travel speed of the head during the seek operation is referred to as Vrs, and a circumferential travel speed is referred to as Vts, the controller controls at least one of the radial travel speed of the head and number of revolutions of the magnetic disk to satisfy a relationship (Vr1/Vt1)<(Vrs/Vts).