Optical disc apparatus

An optical disc apparatus for a rewritable optical disc having a power calibration area for optimum recording power calibration, the apparatus comprising:

• an optical pickup for recording or erasing information on or from the optical disc by use of an optimum recording power obtained using the power calibration area;
• a used area detection unit for detecting a radially innermost end of a used area in the power calibration area based on a reproduction signal of a laser beam which the optical pickup receives during a seek movement, at the time of the optimum recording power calibration, by moving the optical pickup to seek from a radially innermost end to radially outward of the power calibration area;
• a remaining usable area determination unit for determining, based on the innermost end of the used area detected by the used area detection unit, whether the power calibration area has a remaining usable area which is an unused area beginning from the innermost end of the power calibration area, and which is of a size for carrying out the optimum recording power calibration at least one time;
• an optimum recording power obtaining unit for obtaining an optimum recording power (i) by performing the optimum recording power calibration at the innermost end of the power calibration area by partial or entire overwriting if the remaining power calibration area is smaller than a size for carrying out one-time optimum recording power calibration, and (ii) by performing the optimum recording power calibration in a portion of the remaining usable area in the power calibration area, which portion is neighboring and inner from the innermost end of the used area if the remaining usable area is equal to or larger than a size for carrying out one-time optimum recording power calibration;
• and
• a DC erase unit for erasing the used area in the power calibration area by use of the optimum recording power obtained by the optimum recording power obtaining unit using the used area in the power calibration area by the partial or entire overwriting, if the remaining usable area detection unit determines that the remaining usable area in the power calibration area is smaller than a size for carrying out one-time optimum recording power calibration.