| 摘要 |
PROBLEM TO BE SOLVED: To perform excellent recording on a plurality of recording layers of a multilayer optical disk.SOLUTION: A controller 83 of a disk drive moves a focus position of light beam within a range passing at least a plurality of recording layers 113, estimates positions of the plurality of recording layers on the basis of waveform of a focus error signal generated by a focus error generation part 86 as this movement occurs, assigns temporary layer information to a plurality of estimated recording layer positions respectively, uses the temporary layer information to turn on a focus servo from a state in which an estimated position of a recording layer selected as a recording destination of user data, reads layer information from a read-in area of a recording layer to which the focus servo is drawn, compares the read-in layer information with temporary layer information used for selecting a recording layer as the recording destination of the user data, and when the two information match, determines a recording layer to which the focus servo is drawn as a recording layer selected as a recording destination of the user data. |
