US Patent 7324413 Optical disc device

An optical disc device of the present invention has a carriage opposed to an optical disc medium and capable of moving in a radial direction of the optical disc medium; a first driving section for driving the carriage; an object lens mounted in the carriage for focusing laser light on the optical disc medium; a second driving section mounted in the carriage for displacing the object lens in the radial direction of the object lens; a lens-position detecting section fixed to the carriage for detecting positional information on the object lens; an eccentricity removing section for generating a position detecting signal by removing an eccentric component of the optical disc medium from the positional information on the object lens; and a displacement detecting section for determining, using the position detecting signal, whether or not the carriage should be driven and for providing an instruction to begin driving the carriage, to the first driving section, based on a result of the determination.