Kabushiki Kaisha Toshiba

Toshiba Electronic Devices & Storage Corporation

Tatsurou Sasamoto

Akihiko Takeo

Takeyori Hara

Daisuke Sudo

Tatsuo Nitta

Kazuo Chokki

Hideki Hironaka

According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.

Magnetic disk device having two regions of different thicknesses

Magnetic head having difference skew angles at different regions on magnetic recording disk

According to one embodiment, a magnetic disk drive includes a detector and a servo controller. The detector detects, as actual timestamps, time intervals at which a head reads servo sync marks recorded on a disk at predetermined intervals. The servo controller controls a VCM actuator and a microactuator with feedback control in order to position the head at a target position. The servo controller comprises a feedforward controller configured to compensate for disturbance. The feedforward controller comprises a difference detector and an integrator. The difference detector detects a deviation of the actual timestamps from target timestamps as a timestamp difference. The integrator configured to convert the detected timestamp difference into displacement of the microactuator by integrating the detected timestamp difference. The feedforward controller provides a manipulating variable corresponding to the converted displacement, to a feedback control loop for the microactuator as a feedforward manipulating variable.

Magnetic disk drive and method for controlling microactuator in magnetic disk drive

Growing community of inventors

Tokyo, Japan

Tatsurou Sasamoto