Patent ID: 8004940
Filing Date: 2011-08-23
Classification: G11B

Abstract:
1. An optical disk device, comprising: a rotational drive portion that rotates a recording medium, on an information recording surface of which a plurality of addresses are recorded; an optical pick-up that records an information signal onto and plays back the information signal from the information recording surface of the recording medium that is rotated by the rotational drive portion; and a control portion that controls the rotation of the recording medium through the rotational drive portion, wherein the control portion performs control based on a first reference signal that can be read off the recording medium, such that the recording medium is rotated at a speed that is based on a specified clock count, and the control portion includes a reference signal generation portion that generates a second reference signal based on the first reference signal, a measurement portion that, based on the second reference signal, measures a current clock count during one revolution of the recording medium, based on a specified reference address among the plurality of the addresses that serves as a reference for rotation control, a comparison portion that compares the current clock count that is measured by the measurement portion and a target clock count during one revolution of the recording medium, and a reference address control portion that changes the reference address based on a result of the comparison by the comparison portion.