Laser light irradiation can be performed on a recordable surface in a
defocused state with a high-power laser beam with safety without
incurring data destruction due to erroneous data recording or overwrite
recording even in the recording on an eccentric disk or regardless of
occurrence of wobbling of the disk surface. Laser irradiation is
performed after moving an objective lens radially inwardly beyond a PCA
located at an inner peripheral portion of the disk (or radially outwardly
beyond the PCA located at an outer peripheral portion of the disk) by
using a tracking coil.