Head position control method and disk device
AssigneeFujitsu Limited
InventorKazuhiko Takaishi
Life of this patent
Estimating the term…
Abstract
A disk device that has displacement of servo signals in the circumference direction and radius direction between a plurality of disks, prevents a drop in performance due to the displacement when the heads are switched. To deal with the displacement in the circumference direction, the sector numbers on the disk are converted by a table for each head. Also the servo gate time is corrected by the table according to the eccentricity of the disk, so the servo signal detection accuracy improves. Also to deal with the displacement in the radius direction, the track numbers on the disk are converted by the table using the difference value based on the reference head.
Claims24
A head position control method for a disk device which has a plurality of heads for at least reading different faces of a disk where servo signals for detecting the position of a head are recorded, comprising:
- a step of switching one, a first head of said plurality of heads to another, second head;
- a step of extracting a signal indicating a position in the circumference direction of said disk included in said servo signals read by said second head;
- a step of extracting a sector number shift value of said second head from the sector number shift values set for each one of said plurality of heads;
- and
- a step of generating a sector number from said signal indicating the position and said extracted sector number shift value.
A head position control method for a disk device which has a plurality of heads for at least reading the different faces of a disk where servo signals for detecting the position of the head are recorded, comprising:
- a step of calculating the time difference value in the circumference direction of said servo signals between said heads from said sector position where said heads are switched when one, first head of said plurality of heads is switched to another, second head;
- and
- a step of correcting the time of servo gate signals for extracting said servo signals by the time difference value.
A head position control method for a disk device which has a plurality of disks where servo signals for detecting the position of the head are recorded, comprising:
- a step of extracting the displacement amount of another head in the radius direction from a table which stores the displacement amount in the radius direction of another, second head based on one, first head of a plurality of heads where the displacement in the radius direction of said disk between one head and another head increases in the positive direction of the track number increasing direction when one head is switched to said another head;
- a step of converting the track number given by said extracted displacement amount;
- and
- a step of controlling an actuator for driving said head by the converted track number.
A disk device which has a plurality of heads for at least reading different faces of a disk where servo signals for detecting the position of the head are recorded, comprising:
- a table for storing sector number shift values which are set for each one of said plurality of heads;
- and
- a sector number generation section for generating the sector number by extracting a sector number shift value of a second head, to which a first head is switched, from said table, and correcting the signals indicating the position of said disk in the circumference direction which are included in said servo signals read by said second head.
A disk device which has a plurality of heads for at least reading the different faces of a disk where servo signals for detecting the position of the head are recorded, comprising:
- a signal demodulation section for extracting said servo signals from read signals of the head by a servo gate;
- and
- a servo gate generation section for calculating the time difference value in the circumference direction of said servo signals between said heads from the sector position of one, first head when one, first head of said plurality of heads is switched to another, second head, and correcting the time of servo gate signals for extracting said servo signals by the time difference value.
A disk device which has a plurality of disks where servo signals for detecting the position of a head are recorded, comprising:
- a table for storing the displacement amount in the radius direction of a second head based on one, first head of a plurality of heads where the displacement in the radius direction of said disk between one, first head and second, another head increases in the positive direction of the track number increasing direction;
- a track number conversion section for extracting, when the heads are switched, the displacement amount in the radius direction of said disk from said table and converting the track number given by said extracted displacement amount;
- and
- control section for controlling an actuator for driving said head with the converted track number.
Dependencies are inferred from the claim text.