| 摘要 |
PURPOSE:To make it possible to stabilize tracking servo and to make servo circuits common even with the optical recording medium of a land-recording type and the optical recording medium of a bit recording type. CONSTITUTION:The depth dg of the guide grooves 11 of the optical recording medium 10 of a land-recording type on which land parts 12 is formed between guide grooves 11 as recording tracks, and in which data are recorded on these land parts 12, is set within a 0<dg<lambda/4n range (where (n) is the refractive index of the optical recording medium 10). The depth dp of pits 21 of the optical recording medium 20 of the pit recording type with which the data are recorded in the form of the pits 21, is set at lambda/4n<dp<2n. As a result, the respective poles for the direction on the medium with respect to the off-track component of the tracking error signal obtd. as a push-pull signal from a bisected photodetecting element and the offset component by the movement of the objective lens are made to coincide with each other. |
