Patent ID: 8514512

Claim:
A disk storage device, comprising: a disk on which a servo pattern is recorded, the servo pattern comprising, for each track, a recording area, a plurality of position signals for detecting an offset position from a center of the respective track being recorded in the recording area; a head configured to read data recorded on the disk as the disk is being rotated; a driver configured to drive the head in a radial direction of the disk; a signal generator configured to generate a first timing signal indicating a timing for reading the position signals from the read data; a demodulator configured to demodulate a position of the head based on the position signals read in accordance with the generated first timing signal; and a controller configured to control the driver based on the demodulated position of the head, wherein, when the controller performs positional control along a virtual circular orbit of the disk, the signal generator is configured to generate a second timing signal, a period of the second timing signal for reading the position signals being shorter than that of the first timing signal, a center time of the period of the second timing signal being shifted closer than that of the first timing signal to a demodulation center time corresponding to a center of the recording area, and wherein, the second timing signal is obtained by bringing close one of a rising timing and a falling timing of the first timing signal to other one of the rising timing and the falling timing for each of the position signals, the other one of the rising timing and the falling timing being closer than the one of the rising timing and the falling timing to the demodulation center time.