Method and apparatus for loading head onto disk medium from ramp in disk drive
OwnerTatsuharu Kusumotoinventor
Life of this patent
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Abstract
A CPU performs head load control to load a head above a disk from a ramp by speed feedback control when a nonoperating state of a disk drive is released. The CPU uses a value corresponding to an amount of VCM current necessary for moving the head from a parking area on the ramp during a predetermined period of time until the first sampling time of the speed feedback control as an initial value of a control variable (initial control variable) used for the speed feedback control.
Claims16
A method of loading a head of a disk drive above a disk medium from a ramp of the disk drive located outside an outer circumference of the disk medium, the head being used to read information from the disk medium, the method comprising:
- performing head load control to load the head above the disk medium from the ramp by speed feedback control, the performing including generating a control variable to perform the speed feedback control every sampling time of the speed feedback control in accordance with a difference between a speed of the head and a target speed and supplying a current corresponding to the generated control variable to a voice coil motor, the voice coil motor serving as a driving source of an actuator which supports the head movably in a radial direction of the disk medium;
- and
- supplying a current corresponding to an initial control variable to perform the speed feedback control to the voice coil motor at a start of the speed feedback control, the initial control variable corresponding to an amount of current to be supplied to the voice coil motor to move the head from a parking area on the ramp during a predetermined period of time from the start of the speed feedback control until first sampling time of the speed feedback control.
A disk drive which reads information from a disk medium using a head, comprising:
- an actuator which supports the head movably in a radial direction of the disk medium using a voice coil motor as a driving source;
- a driver which drives the voice coil motor by supplying a current corresponding to a set control variable to the voice coil motor;
- a ramp provided outside an outer circumference of the disk medium, the head being parked on the ramp in a nonoperating state of the disk drive;
- means for when the nonoperating state of the disk drive is released, performing head load control to load the head above the disk medium from the ramp by speed feedback control based on a difference between a speed of the head and a target speed, the performing means including first setting means for setting a control variable corresponding to the difference between the speed of the head and the target speed every sampling time of the speed feedback control;
- and
- second setting means for setting an initial control variable used for the speed feedback control to the driver at a start of the speed feedback control by the performing means, the initial control variable corresponding to an amount of current to be supplied to the voice coil motor to move the head from a parking area on the ramp during a predetermined period of time from the start of the speed feedback control until first sampling time of the speed feedback control.
Dependencies are inferred from the claim text.