| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to stably execute tracking servo and track seeking even if a track pitch is narrowed by forming two grooves varying in depth in such a manner that these grooves are adjacent to each other and forming both grooves so as to satisfy respectively prescribed relations. SOLUTION: This optical recording medium is formed with the grooves in such a manner that the first grooves and second grooves varying in depth are adjacent to each other. The first grooves and the second grooves are so formed as to satisfy equation I and equation II or equation III and equation IV. The phase depth X of the first grooves is expressed by xXn/λ and the phase depth Y of the second grooves by y×n/λ when the refractive index of the medium from the light incident surface to the grooves is defined as (n), the depth of the first grooves as (x) and the depth of the second grooves as (y). In the equation I and equation II, N is an arbitrary integer and in the equation III and equation IV, M is an arbitrary integer. |
