| 摘要 |
PROBLEM TO BE SOLVED: To precisely correct shift of a spot of first light for recording information on a bulk layer and second light to be used for positional control based on positional guide pieces, the shift being caused by skew or shift of the objective lens, in an optical drive device which applies the first light and the second light through a common objective lens to an optical disk recording medium having the bulk layer and a reference surface having the positional guide pieces spirally or coaxially.SOLUTION: A reference track TR-b1 is formed at a position in the bulk layer 5, which is the same radial position as that of the predetermined track on the reference surface Ref. In addition to this, while the spot positions of the first and second light are aligned in the direction of tracking, the correction amount of an optical axis by an optical axis adjustment part 14B is sampled using the reference track on the basis of each rotation angle. During recording, the sampled correction amount is transmitted to the optical axis adjustment part 14B at each rotation angle to correct the shift of the spot. |
