US 12,322,423 B2
Disk device
Daisuke Sudo, Kawasaki Kanagawa (JP)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (JP); and Toshiba Electronic Devices & Storage Corporation, Tokyo (JP)
Filed by Kabushiki Kaisha Toshiba, Tokyo (JP); and Toshiba Electronic Devices & Storage Corporation, Tokyo (JP)
Filed on Dec. 28, 2023, as Appl. No. 18/398,554.
Claims priority of application No. 2023-121460 (JP), filed on Jul. 26, 2023.
Prior Publication US 2025/0036294 A1, Jan. 30, 2025
Int. Cl. G11B 5/55 (2006.01); G11B 19/28 (2006.01)
CPC G11B 5/5547 (2013.01) [G11B 19/28 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A disk device comprising:
a head;
a disk having a recording surface;
a motor that causes the head to seek along the recording surface; and
a controller that controls the motor, wherein
the controller, when a rotation waiting time is absent from when the head reaches a target track of the disk to when the head reaches a target sector, increases an absolute value of a motor current in a first section in a first period in which the head is accelerated or decelerated, changes the absolute value of the motor current at a first average change rate in a second section after the first section in the first period, and decreases the absolute value of the motor current at a second average change rate that is steeper than the first average change rate in a third section after the second section in the first period, and
the controller, when the rotation waiting time is present, increases the absolute value of the motor current in a fourth section in a second period in which the head is accelerated or decelerated, changes the absolute value of the motor current at a third average change rate in a fifth section after the fourth section in the second period, decreases the absolute value of the motor current at a fourth average change rate steeper than the third average change rate in a sixth section after the fifth section in the second period, and decreases the absolute value of the motor current at a fifth average change rate steeper than the fourth average change rate in a seventh section after the sixth section in the second period.