US 12,456,489 B2
Magnetic disk device
Takuji Matsuzawa, Kashiwa Chiba (JP)
Assigned to Kabushiki Kaisha Toshiba, Kawasaki (JP); and Toshiba Electronic Devices & Storage Corporation, Kawasaki (JP)
Filed by Kabushiki Kaisha Toshiba, Tokyo (JP); and Toshiba Electronic Devices & Storage Corporation, Tokyo (JP)
Filed on Mar. 11, 2024, as Appl. No. 18/600,894.
Claims priority of application No. 2023-046871 (JP), filed on Mar. 23, 2023.
Prior Publication US 2024/0321304 A1, Sep. 26, 2024
Int. Cl. G11B 5/00 (2006.01); G11B 5/596 (2006.01); G11B 20/10 (2006.01)
CPC G11B 5/59688 (2013.01) [G11B 5/59622 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A magnetic disk device, comprising:
a loop shaping filter disposed in parallel to a controller, having a peak in a predetermined frequency, and through digital filter coefficients of which are determined by a sensitivity function and a controlled object, wherein filter coefficients of the digital filter are determined based on a change in a sampling period of servo information; and
a filter coefficient update controller configured to, based on at least a first sampling period, first angular frequency peak of which is a gain characteristic of a first digital filter, where first filter coefficients of the digital filter derived with respect to the first sampling period is applied to the first digital filter, second angular frequency which is different from the first angular frequency, and a first matching parameter used to derive the first filter coefficients,
derive second filter coefficients of the digital filter with respect to a second sampling period which is different from the first sampling period.