Patent ID: 7626898

Claim:
A disk device comprising: a pickup head which reads out data upon a disk; a pickup head shift control unit which supplies power to shift said pickup head along the radial direction of said disk; and an inner circumference position detection unit which detects whether or not said pickup head has shifted to the inner circumferential edge of said disk; wherein said pickup head shift control unit executes the following operations in sequence: (ST 1 ): supplying power so that said pickup head shifts to the neighborhood of a position at which the detection/non-detection of said inner circumference position detection unit changes over, and stops; (ST 2 ): after the step ST 1 , supplying power so that said pickup head shifts in the direction towards said position at which the detection/non-detection by said inner circumference position detection unit changes over, and continuing to supply power over a time period T 4 which is determined in advance to be sufficient for said detection/non-detection to change over; (ST 3 ): directly after the step ST 2 , starting supply of power to shift said pickup head in the opposite direction to the shift direction in the step ST 2 , and, when the detection/non-detection by said inner circumference position detection unit changes over, along with stopping said supply of power, also measuring the time period T 5 from when this step ST 3 started to when said detection/non-detection changed over; and (ST 4 ): after the step ST 3 , starting supply of power to shift said pickup head in the direction of the disk outer circumference, and, after a time period T 7 which is determined based upon said time period T 5 has elapsed, stopping this supply of power.